From 1c57036a799273d17b9db012498478643465a5ac Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Mon, 26 Aug 2019 15:00:01 -0700
Subject: [PATCH 01/17] android: move yaml configuration down to java layer

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../io/envoyproxy/envoymobile/engine/BUILD    |  1 -
 .../engine/EnvoyConfiguration.java            | 44 ++++++++++---
 .../engine/EnvoyConfigurationImpl.java        | 15 -----
 .../envoymobile/engine/EnvoyEngine.java       |  8 +--
 .../envoymobile/engine/EnvoyEngineImpl.java   | 17 +++---
 .../io/envoyproxy/envoymobile/engine/BUILD    | 13 ++++
 .../engine/EnvoyConfigurationTest.kt          | 61 +++++++++++++++++++
 .../src/io/envoyproxy/envoymobile/Envoy.kt    |  7 ++-
 .../io/envoyproxy/envoymobile/EnvoyBuilder.kt | 35 +----------
 .../envoymobile/EnvoyBuilderTest.kt           | 56 ++---------------
 .../io/envoyproxy/envoymobile/EnvoyTest.kt    | 22 ++++---
 11 files changed, 147 insertions(+), 132 deletions(-)
 delete mode 100644 library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfigurationImpl.java
 create mode 100644 library/java/test/io/envoyproxy/envoymobile/engine/BUILD
 create mode 100644 library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt

diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/BUILD b/library/java/src/io/envoyproxy/envoymobile/engine/BUILD
index 8685c5446a..63d6c651df 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/BUILD
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/BUILD
@@ -22,7 +22,6 @@ envoy_mobile_java_library(
     name = "envoy_base_engine_lib",
     srcs = [
         "EnvoyConfiguration.java",
-        "EnvoyConfigurationImpl.java",
         "EnvoyEngine.java",
         "EnvoyEngineImpl.java",
         "EnvoyHTTPStream.java",
diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
index 70d41c0536..a62d88f154 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
@@ -1,11 +1,39 @@
 package io.envoyproxy.envoymobile.engine;
 
-public interface EnvoyConfiguration {
-
-  /**
-   * Provides a default configuration template that may be used for starting Envoy.
-   *
-   * @return A template that may be used as a starting point for constructing configurations.
-   */
-  String templateString();
+public class EnvoyConfiguration {
+
+  public final String configYAML;
+  public final int connectTimeoutSeconds;
+  public final int dnsRefreshSeconds;
+  public final int statsFlushSeconds;
+
+  public EnvoyConfiguration(String configYAML, int connectTimeoutSeconds, int dnsRefreshSeconds, int statsFlushSeconds) {
+    this.configYAML = configYAML;
+    this.connectTimeoutSeconds = connectTimeoutSeconds;
+    this.dnsRefreshSeconds = dnsRefreshSeconds;
+    this.statsFlushSeconds = statsFlushSeconds;
+  }
+
+  public String resolve(String defaultConfigurationYAML) {
+    String resolvedYAML;
+    if (configYAML == null) {
+      resolvedYAML = defaultConfigurationYAML;
+    } else {
+      resolvedYAML = configYAML;
+    }
+    String resolvedConfiguration = resolvedYAML
+        .replace("{{ connect_timeout }}", String.valueOf(connectTimeoutSeconds))
+        .replace("{{ dns_refresh_rate }}", String.valueOf(dnsRefreshSeconds))
+        .replace("{{ stats_flush_interval }}", String.valueOf(statsFlushSeconds));
+    if (resolvedConfiguration.contains("{{")) {
+      throw new ConfigurationException();
+    }
+    return resolvedConfiguration;
+  }
+
+  static class ConfigurationException extends RuntimeException {
+    ConfigurationException() {
+      super("Unresolved Template Key");
+    }
+  }
 }
diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfigurationImpl.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfigurationImpl.java
deleted file mode 100644
index 0f9db4e706..0000000000
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfigurationImpl.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package io.envoyproxy.envoymobile.engine;
-
-public class EnvoyConfigurationImpl implements EnvoyConfiguration {
-
-  /**
-   * Provides a default configuration template that may be used for starting Envoy.
-   *
-   * @return A template that may be used as a starting point for constructing configurations.
-   */
-  @Override
-  public String templateString() {
-    JniLibrary.load();
-    return JniLibrary.templateString();
-  }
-}
diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngine.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngine.java
index 42e7b1a75e..aacb67b4b3 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngine.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngine.java
@@ -12,19 +12,19 @@ public interface EnvoyEngine {
   EnvoyHTTPStream startStream(EnvoyObserver observer);
 
   /**
-   * Run the Envoy engine with the provided config and log level.
+   * Run the Envoy engine with the provided envoyConfiguration and log level.
    *
    * @param config The configuration file with which to start Envoy.
    * @return A status indicating if the action was successful.
    */
-  int runWithConfig(String config);
+  int runWithConfig(EnvoyConfiguration envoyConfiguration);
 
   /**
-   * Run the Envoy engine with the provided config and log level.
+   * Run the Envoy engine with the provided envoyConfiguration and log level.
    *
    * @param config   The configuration file with which to start Envoy.
    * @param logLevel The log level to use when starting Envoy.
    * @return int A status indicating if the action was successful.
    */
-  int runWithConfig(String config, String logLevel);
+  int runWithConfig(EnvoyConfiguration envoyConfiguration, String logLevel);
 }
diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
index eb29328cf4..7435b55ee2 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
@@ -24,27 +24,28 @@ public EnvoyHTTPStream startStream(EnvoyObserver observer) {
   }
 
   /**
-   * Run the Envoy engine with the provided config and log level.
+   * Run the Envoy engine with the provided envoyConfiguration and log level.
    *
-   * @param config The configuration file with which to start Envoy.
+   * @param envoyConfiguration The configuration file with which to start Envoy.
    * @return A status indicating if the action was successful.
    */
   @Override
-  public int runWithConfig(String config) {
-    return runWithConfig(config, "info");
+  public int runWithConfig(EnvoyConfiguration envoyConfiguration) {
+    return runWithConfig(envoyConfiguration, "info");
   }
 
   /**
-   * Run the Envoy engine with the provided config and log level.
+   * Run the Envoy engine with the provided envoyConfiguration and log level.
    *
-   * @param config   The configuration file with which to start Envoy.
+   * @param envoyConfiguration   The configuration file with which to start Envoy.
    * @param logLevel The log level to use when starting Envoy.
    * @return int A status indicating if the action was successful.
    */
   @Override
-  public int runWithConfig(String config, String logLevel) {
+  public int runWithConfig(EnvoyConfiguration envoyConfiguration, String logLevel) {
     try {
-      return JniLibrary.runEngine(config, logLevel);
+      String resolvedConfig = envoyConfiguration.resolve(JniLibrary.templateString());
+      return JniLibrary.runEngine(resolvedConfig, logLevel);
     } catch (Throwable throwable) {
       // TODO: Need to have a way to log the exception somewhere
       return 1;
diff --git a/library/java/test/io/envoyproxy/envoymobile/engine/BUILD b/library/java/test/io/envoyproxy/envoymobile/engine/BUILD
new file mode 100644
index 0000000000..c24647aa5d
--- /dev/null
+++ b/library/java/test/io/envoyproxy/envoymobile/engine/BUILD
@@ -0,0 +1,13 @@
+licenses(["notice"])  # Apache 2
+
+load("//bazel:kotlin_test.bzl", "envoy_mobile_kt_test")
+
+envoy_mobile_kt_test(
+    name = "envoy_configuration_test",
+    srcs = [
+        "EnvoyConfigurationTest.kt",
+    ],
+    deps = [
+        "//library/kotlin/src/io/envoyproxy/envoymobile:envoy_interfaces_lib",
+    ],
+)
\ No newline at end of file
diff --git a/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt b/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
new file mode 100644
index 0000000000..dd960a8122
--- /dev/null
+++ b/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
@@ -0,0 +1,61 @@
+package io.envoyproxy.envoymobile.engine
+
+//private const val TEST_CONFIG = """
+//mock_template:
+//- name: mock
+//  connect_timeout: {{ connect_timeout }}
+//  dns_refresh_rate: {{ dns_refresh_rate }}
+//  stats_flush_interval: {{ stats_flush_interval }}
+//"""
+
+
+class EnvoyConfigurationTest {
+// TODO: Write these tests well
+
+//  @Test
+//  fun `specifying connection timeout overrides default`() {
+//    builder = EnvoyBuilder()
+//    builder.addConfigYAML(TEST_CONFIG)
+//    builder.addEngineType { engine }
+//
+//    builder.addConnectTimeoutSeconds(1234)
+//    val envoy = builder.build()
+//
+//    assertThat(envoy.envoyConfiguration).contains("connect_timeout: 1234s")
+//  }
+//
+//  @Test
+//  fun `specifying DNS refresh overrides default`() {
+//    builder = EnvoyBuilder()
+//    builder.addConfigYAML(TEST_CONFIG)
+//    builder.addEngineType { engine }
+//
+//    builder.addDNSRefreshSeconds(1234)
+//    val envoy = builder.build()
+//    assertThat(envoy.envoyConfiguration).contains("dns_refresh_rate: 1234s")
+//  }
+//
+//  @Test
+//  fun `specifying stats flush overrides default`() {
+//    builder = EnvoyBuilder()
+//    builder.addConfigYAML(TEST_CONFIG)
+//    builder.addEngineType { engine }
+//
+//    builder.addStatsFlushSeconds(1234)
+//    builder.build()
+//    val envoy = builder.build()
+//    assertThat(envoy.envoyConfiguration).contains("stats_flush_interval: 1234s")
+//
+//  }
+//
+//  @Test(expected = ConfigurationException::class)
+//  fun `specifying configs with invalid templates will throw on build`() {
+//    builder = EnvoyBuilder()
+//    builder.addConfigYAML(TEST_CONFIG)
+//    builder.addEngineType { engine }
+//
+//    builder.addConfigYAML("{{ missing }}")
+//    builder.build()
+//  }
+
+}
\ No newline at end of file
diff --git a/library/kotlin/src/io/envoyproxy/envoymobile/Envoy.kt b/library/kotlin/src/io/envoyproxy/envoymobile/Envoy.kt
index e35123d330..62ba780f40 100644
--- a/library/kotlin/src/io/envoyproxy/envoymobile/Envoy.kt
+++ b/library/kotlin/src/io/envoyproxy/envoymobile/Envoy.kt
@@ -1,5 +1,6 @@
 package io.envoyproxy.envoymobile
 
+import io.envoyproxy.envoymobile.engine.EnvoyConfiguration
 import io.envoyproxy.envoymobile.engine.EnvoyEngine
 import java.nio.ByteBuffer
 
@@ -21,15 +22,15 @@ enum class LogLevel(internal val level: String) {
  */
 class Envoy constructor(
     private val engine: EnvoyEngine,
-    internal val config: String,
+    internal val envoyConfiguration: EnvoyConfiguration,
     internal val logLevel: LogLevel = LogLevel.INFO
 ) : Client {
 
-  constructor(engine: EnvoyEngine, config: String) : this(engine, config, LogLevel.INFO)
+  constructor(engine: EnvoyEngine, envoyConfiguration: EnvoyConfiguration) : this(engine, envoyConfiguration, LogLevel.INFO)
 
   // Dedicated thread for running this instance of Envoy.
   private val runner: Thread = Thread(ThreadGroup("Envoy"), Runnable {
-    engine.runWithConfig(config.trim(), logLevel.level)
+    engine.runWithConfig(envoyConfiguration, logLevel.level)
   })
 
   /**
diff --git a/library/kotlin/src/io/envoyproxy/envoymobile/EnvoyBuilder.kt b/library/kotlin/src/io/envoyproxy/envoymobile/EnvoyBuilder.kt
index 02c5ee2542..9825782566 100644
--- a/library/kotlin/src/io/envoyproxy/envoymobile/EnvoyBuilder.kt
+++ b/library/kotlin/src/io/envoyproxy/envoymobile/EnvoyBuilder.kt
@@ -1,29 +1,20 @@
 package io.envoyproxy.envoymobile
 
 import io.envoyproxy.envoymobile.engine.EnvoyConfiguration
-import io.envoyproxy.envoymobile.engine.EnvoyConfigurationImpl
 import io.envoyproxy.envoymobile.engine.EnvoyEngine
 import io.envoyproxy.envoymobile.engine.EnvoyEngineImpl
 
-class ConfigurationException : Exception("Unresolved Template Key")
 
 open class EnvoyBuilder internal constructor(
-    private val envoyConfiguration: EnvoyConfiguration
 ) {
   private var logLevel = LogLevel.INFO
-  private var configYAML: String
+  private var configYAML: String? = null
   private var engineType: () -> EnvoyEngine = { EnvoyEngineImpl() }
 
   private var connectTimeoutSeconds = 30
   private var dnsRefreshSeconds = 60
   private var statsFlushSeconds = 60
 
-  constructor() : this(EnvoyConfigurationImpl())
-
-  init {
-    configYAML = envoyConfiguration.templateString()
-  }
-
   /**
    * Add a log level to use with Envoy.
    * @param logLevel the log level to use with Envoy.
@@ -40,7 +31,7 @@ open class EnvoyBuilder internal constructor(
    * @param configYAML the YAML file to use as a configuration.
    */
   fun addConfigYAML(configYAML: String?): EnvoyBuilder {
-    this.configYAML = configYAML ?: envoyConfiguration.templateString()
+    this.configYAML = configYAML
     return this
   }
 
@@ -80,7 +71,7 @@ open class EnvoyBuilder internal constructor(
    * @return A new instance of Envoy.
    */
   fun build(): Envoy {
-    return Envoy(engineType(), resolvedYAML(), logLevel)
+    return Envoy(engineType(), EnvoyConfiguration(configYAML, connectTimeoutSeconds, dnsRefreshSeconds, statsFlushSeconds), logLevel)
   }
 
   /**
@@ -92,24 +83,4 @@ open class EnvoyBuilder internal constructor(
     this.engineType = engineType
     return this
   }
-
-
-  /** Processes the YAML template provided, replacing keys with values from the configuration.
-   *
-   * @parameter template: The template YAML file to use.
-   * @returns: A resolved YAML file with all template keys replaced.
-   * @throws ConfigurationException when the yaml configuration replacement is incomplete
-   */
-  private fun resolvedYAML(): String {
-    val resolvedTemplate = configYAML
-        .replace("{{ connect_timeout }}", "${connectTimeoutSeconds}s")
-        .replace("{{ dns_refresh_rate }}", "${dnsRefreshSeconds}s")
-        .replace("{{ stats_flush_interval }}", "${statsFlushSeconds}s")
-
-    if (resolvedTemplate.contains("{{")) {
-      throw ConfigurationException()
-    }
-
-    return resolvedTemplate
-  }
 }
diff --git a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
index 13e5467ffb..0fe5816cbe 100644
--- a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
+++ b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
@@ -3,7 +3,6 @@ package io.envoyproxy.envoymobile.io.envoyproxy.envoymobile
 import io.envoyproxy.envoymobile.ConfigurationException
 import io.envoyproxy.envoymobile.EnvoyBuilder
 import io.envoyproxy.envoymobile.LogLevel
-import io.envoyproxy.envoymobile.engine.EnvoyConfiguration
 import io.envoyproxy.envoymobile.engine.EnvoyEngine
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.Test
@@ -22,24 +21,23 @@ class EnvoyBuilderTest {
 
   private lateinit var builder: EnvoyBuilder
 
-  private var envoyConfiguration: EnvoyConfiguration = mock(EnvoyConfiguration::class.java)
   private var engine: EnvoyEngine = mock(EnvoyEngine::class.java)
 
   @Test
   fun `adding custom config builder uses custom config for running Envoy`() {
-    `when`(envoyConfiguration.templateString()).thenReturn(TEST_CONFIG)
-    builder = EnvoyBuilder(envoyConfiguration)
+    builder = EnvoyBuilder()
+    builder.addConfigYAML(TEST_CONFIG)
     builder.addEngineType { engine }
 
     builder.addConfigYAML("mock_template:")
     val envoy = builder.build()
-    assertThat(envoy.config).isEqualTo("mock_template:")
+    assertThat(envoy.envoyConfiguration.configYAML).isEqualTo("mock_template:")
   }
 
   @Test
   fun `adding log level builder uses log level for running Envoy`() {
-    `when`(envoyConfiguration.templateString()).thenReturn(TEST_CONFIG)
-    builder = EnvoyBuilder(envoyConfiguration)
+    builder = EnvoyBuilder()
+    builder.addConfigYAML(TEST_CONFIG)
     builder.addEngineType { engine }
 
     builder.addLogLevel(LogLevel.DEBUG)
@@ -47,48 +45,4 @@ class EnvoyBuilderTest {
     assertThat(envoy.logLevel).isEqualTo(LogLevel.DEBUG)
   }
 
-  @Test
-  fun `specifying connection timeout overrides default`() {
-    `when`(envoyConfiguration.templateString()).thenReturn(TEST_CONFIG)
-    builder = EnvoyBuilder(envoyConfiguration)
-    builder.addEngineType { engine }
-
-    builder.addConnectTimeoutSeconds(1234)
-    val envoy = builder.build()
-    assertThat(envoy.config).contains("connect_timeout: 1234s")
-  }
-
-  @Test
-  fun `specifying DNS refresh overrides default`() {
-    `when`(envoyConfiguration.templateString()).thenReturn(TEST_CONFIG)
-    builder = EnvoyBuilder(envoyConfiguration)
-    builder.addEngineType { engine }
-
-    builder.addDNSRefreshSeconds(1234)
-    val envoy = builder.build()
-    assertThat(envoy.config).contains("dns_refresh_rate: 1234s")
-  }
-
-  @Test
-  fun `specifying stats flush overrides default`() {
-    `when`(envoyConfiguration.templateString()).thenReturn(TEST_CONFIG)
-    builder = EnvoyBuilder(envoyConfiguration)
-    builder.addEngineType { engine }
-
-    builder.addStatsFlushSeconds(1234)
-    builder.build()
-    val envoy = builder.build()
-    assertThat(envoy.config).contains("stats_flush_interval: 1234s")
-
-  }
-
-  @Test(expected = ConfigurationException::class)
-  fun `specifying configs with invalid templates will throw on build`() {
-    `when`(envoyConfiguration.templateString()).thenReturn(TEST_CONFIG)
-    builder = EnvoyBuilder(envoyConfiguration)
-    builder.addEngineType { engine }
-
-    builder.addConfigYAML("{{ missing }}")
-    builder.build()
-  }
 }
diff --git a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyTest.kt b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyTest.kt
index 7ab60aabc1..85fd3a412e 100644
--- a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyTest.kt
+++ b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyTest.kt
@@ -4,6 +4,7 @@ import io.envoyproxy.envoymobile.Envoy
 import io.envoyproxy.envoymobile.RequestBuilder
 import io.envoyproxy.envoymobile.RequestMethod
 import io.envoyproxy.envoymobile.ResponseHandler
+import io.envoyproxy.envoymobile.engine.EnvoyConfiguration
 import io.envoyproxy.envoymobile.engine.EnvoyEngine
 import io.envoyproxy.envoymobile.engine.EnvoyHTTPStream
 import org.junit.Test
@@ -18,11 +19,12 @@ class EnvoyTest {
 
   private val engine = mock(EnvoyEngine::class.java)
   private val stream = mock(EnvoyHTTPStream::class.java)
+  private val config = EnvoyConfiguration("", 0, 0, 0)
 
   @Test
   fun `starting a stream on envoy sends headers`() {
     `when`(engine.startStream(any())).thenReturn(stream)
-    val envoy = Envoy(engine, "")
+    val envoy = Envoy(engine, config)
 
     val expectedHeaders = mapOf(
       "key_1" to listOf("value_a"),
@@ -47,7 +49,7 @@ class EnvoyTest {
   @Test
   fun `sending data on stream stream forwards data to the underlying stream`() {
     `when`(engine.startStream(any())).thenReturn(stream)
-    val envoy = Envoy(engine, "")
+    val envoy = Envoy(engine, config)
 
     val emitter = envoy.send(
         RequestBuilder(
@@ -68,7 +70,7 @@ class EnvoyTest {
   @Test
   fun `sending metadata on stream forwards metadata to the underlying stream`() {
     `when`(engine.startStream(any())).thenReturn(stream)
-    val envoy = Envoy(engine, "")
+    val envoy = Envoy(engine, config)
 
     val metadata = mapOf("key_1" to listOf("value_a"))
     val emitter = envoy.send(
@@ -88,7 +90,7 @@ class EnvoyTest {
   @Test
   fun `closing stream sends empty trailers to the underlying stream`() {
     `when`(engine.startStream(any())).thenReturn(stream)
-    val envoy = Envoy(engine, "")
+    val envoy = Envoy(engine, config)
 
     val emitter = envoy.send(
         RequestBuilder(
@@ -107,7 +109,7 @@ class EnvoyTest {
   @Test
   fun `closing stream with trailers sends trailers to the underlying stream `() {
     `when`(engine.startStream(any())).thenReturn(stream)
-    val envoy = Envoy(engine, "")
+    val envoy = Envoy(engine, config)
 
     val trailers = mapOf("key_1" to listOf("value_a"))
     val emitter = envoy.send(
@@ -127,7 +129,7 @@ class EnvoyTest {
   @Test
   fun `sending request on envoy sends headers`() {
     `when`(engine.startStream(any())).thenReturn(stream)
-    val envoy = Envoy(engine, "")
+    val envoy = Envoy(engine, config)
 
     val expectedHeaders = mapOf(
       "key_1" to listOf("value_a"),
@@ -153,7 +155,7 @@ class EnvoyTest {
   @Test
   fun `sending request on envoy passes the body buffer`() {
     `when`(engine.startStream(any())).thenReturn(stream)
-    val envoy = Envoy(engine, "")
+    val envoy = Envoy(engine, config)
 
     val body = ByteBuffer.allocate(0)
     envoy.send(
@@ -172,7 +174,7 @@ class EnvoyTest {
   @Test
   fun `sending request on envoy without trailers sends empty trailers`() {
     `when`(engine.startStream(any())).thenReturn(stream)
-    val envoy = Envoy(engine, "")
+    val envoy = Envoy(engine, config)
 
     val body = ByteBuffer.allocate(0)
     envoy.send(
@@ -191,7 +193,7 @@ class EnvoyTest {
   @Test
   fun `sending request on envoy sends trailers`() {
     `when`(engine.startStream(any())).thenReturn(stream)
-    val envoy = Envoy(engine, "")
+    val envoy = Envoy(engine, config)
 
     val trailers = mapOf("key_1" to listOf("value_a"))
     envoy.send(
@@ -211,7 +213,7 @@ class EnvoyTest {
   @Test
   fun `cancelling stream cancels the underlying stream`() {
     `when`(engine.startStream(any())).thenReturn(stream)
-    val envoy = Envoy(engine, "")
+    val envoy = Envoy(engine, config)
 
     val trailers = mapOf("key_1" to listOf("value_a"))
     val emitter = envoy.send(

From 57606e96b4d3ab33ab9ee882582d1b2f2cd87793 Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Mon, 26 Aug 2019 15:03:05 -0700
Subject: [PATCH 02/17] clean up

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../envoymobile/engine/EnvoyConfiguration.java    | 15 +++++++--------
 .../test/io/envoyproxy/envoymobile/engine/BUILD   |  2 +-
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
index a62d88f154..97e9f5e3fa 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
@@ -7,7 +7,8 @@ public class EnvoyConfiguration {
   public final int dnsRefreshSeconds;
   public final int statsFlushSeconds;
 
-  public EnvoyConfiguration(String configYAML, int connectTimeoutSeconds, int dnsRefreshSeconds, int statsFlushSeconds) {
+  public EnvoyConfiguration(String configYAML, int connectTimeoutSeconds, int dnsRefreshSeconds,
+                            int statsFlushSeconds) {
     this.configYAML = configYAML;
     this.connectTimeoutSeconds = connectTimeoutSeconds;
     this.dnsRefreshSeconds = dnsRefreshSeconds;
@@ -21,10 +22,10 @@ public String resolve(String defaultConfigurationYAML) {
     } else {
       resolvedYAML = configYAML;
     }
-    String resolvedConfiguration = resolvedYAML
-        .replace("{{ connect_timeout }}", String.valueOf(connectTimeoutSeconds))
-        .replace("{{ dns_refresh_rate }}", String.valueOf(dnsRefreshSeconds))
-        .replace("{{ stats_flush_interval }}", String.valueOf(statsFlushSeconds));
+    String resolvedConfiguration =
+        resolvedYAML.replace("{{ connect_timeout }}", String.valueOf(connectTimeoutSeconds))
+            .replace("{{ dns_refresh_rate }}", String.valueOf(dnsRefreshSeconds))
+            .replace("{{ stats_flush_interval }}", String.valueOf(statsFlushSeconds));
     if (resolvedConfiguration.contains("{{")) {
       throw new ConfigurationException();
     }
@@ -32,8 +33,6 @@ public String resolve(String defaultConfigurationYAML) {
   }
 
   static class ConfigurationException extends RuntimeException {
-    ConfigurationException() {
-      super("Unresolved Template Key");
-    }
+    ConfigurationException() { super("Unresolved Template Key"); }
   }
 }
diff --git a/library/java/test/io/envoyproxy/envoymobile/engine/BUILD b/library/java/test/io/envoyproxy/envoymobile/engine/BUILD
index c24647aa5d..6e79dabacd 100644
--- a/library/java/test/io/envoyproxy/envoymobile/engine/BUILD
+++ b/library/java/test/io/envoyproxy/envoymobile/engine/BUILD
@@ -10,4 +10,4 @@ envoy_mobile_kt_test(
     deps = [
         "//library/kotlin/src/io/envoyproxy/envoymobile:envoy_interfaces_lib",
     ],
-)
\ No newline at end of file
+)

From ee7b4abc533588c503925b10572d23bc60db621d Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Mon, 26 Aug 2019 15:08:47 -0700
Subject: [PATCH 03/17] new line

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt b/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
index dd960a8122..29fa48b966 100644
--- a/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
+++ b/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
@@ -58,4 +58,4 @@ class EnvoyConfigurationTest {
 //    builder.build()
 //  }
 
-}
\ No newline at end of file
+}

From 50da5fba702378dfdee0d4407da9333ab7472a05 Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Mon, 26 Aug 2019 15:37:20 -0700
Subject: [PATCH 04/17] push

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt   | 2 --
 1 file changed, 2 deletions(-)

diff --git a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
index 0fe5816cbe..882a7edeab 100644
--- a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
+++ b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
@@ -1,12 +1,10 @@
 package io.envoyproxy.envoymobile.io.envoyproxy.envoymobile
 
-import io.envoyproxy.envoymobile.ConfigurationException
 import io.envoyproxy.envoymobile.EnvoyBuilder
 import io.envoyproxy.envoymobile.LogLevel
 import io.envoyproxy.envoymobile.engine.EnvoyEngine
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.Test
-import org.mockito.Mockito.`when`
 import org.mockito.Mockito.mock
 
 private const val TEST_CONFIG = """

From cfed93ae28755b4fc60f8fe3fa774b1cf0ce64ad Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Mon, 26 Aug 2019 18:18:47 -0700
Subject: [PATCH 05/17] fix

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../envoyproxy/envoymobile/engine/EnvoyConfiguration.java  | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
index 97e9f5e3fa..a472b3a0ea 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
@@ -23,9 +23,10 @@ public String resolve(String defaultConfigurationYAML) {
       resolvedYAML = configYAML;
     }
     String resolvedConfiguration =
-        resolvedYAML.replace("{{ connect_timeout }}", String.valueOf(connectTimeoutSeconds))
-            .replace("{{ dns_refresh_rate }}", String.valueOf(dnsRefreshSeconds))
-            .replace("{{ stats_flush_interval }}", String.valueOf(statsFlushSeconds));
+        resolvedYAML
+            .replace("{{ connect_timeout }}", String.format("%ss", connectTimeoutSeconds))
+            .replace("{{ dns_refresh_rate }}", String.format("%ss", dnsRefreshSeconds))
+            .replace("{{ stats_flush_interval }}", String.format("%ss", statsFlushSeconds));
     if (resolvedConfiguration.contains("{{")) {
       throw new ConfigurationException();
     }

From b008e8e5f055f522cbf0c175c18f4229f731a296 Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Tue, 27 Aug 2019 10:08:35 -0700
Subject: [PATCH 06/17] format

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java   | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
index a472b3a0ea..adb3edc153 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
@@ -23,8 +23,7 @@ public String resolve(String defaultConfigurationYAML) {
       resolvedYAML = configYAML;
     }
     String resolvedConfiguration =
-        resolvedYAML
-            .replace("{{ connect_timeout }}", String.format("%ss", connectTimeoutSeconds))
+        resolvedYAML.replace("{{ connect_timeout }}", String.format("%ss", connectTimeoutSeconds))
             .replace("{{ dns_refresh_rate }}", String.format("%ss", dnsRefreshSeconds))
             .replace("{{ stats_flush_interval }}", String.format("%ss", statsFlushSeconds));
     if (resolvedConfiguration.contains("{{")) {

From ecdf0fd0eeae7b65e421ea123884fe6bccc1c184 Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Tue, 3 Sep 2019 11:46:26 -0700
Subject: [PATCH 07/17] clena up and add tests

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../engine/EnvoyConfiguration.java            | 32 +++++---
 .../envoymobile/engine/EnvoyEngineImpl.java   |  5 +-
 .../engine/EnvoyConfigurationTest.kt          | 80 ++++++-------------
 .../io/envoyproxy/envoymobile/EnvoyBuilder.kt |  7 +-
 .../envoymobile/EnvoyBuilderTest.kt           | 34 ++++++++
 .../io/envoyproxy/envoymobile/EnvoyTest.kt    |  2 +-
 6 files changed, 90 insertions(+), 70 deletions(-)

diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
index adb3edc153..68a8658292 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
@@ -3,29 +3,33 @@
 public class EnvoyConfiguration {
 
   public final String configYAML;
-  public final int connectTimeoutSeconds;
-  public final int dnsRefreshSeconds;
-  public final int statsFlushSeconds;
+  public final Integer connectTimeoutSeconds;
+  public final Integer dnsRefreshSeconds;
+  public final Integer statsFlushSeconds;
 
-  public EnvoyConfiguration(String configYAML, int connectTimeoutSeconds, int dnsRefreshSeconds,
-                            int statsFlushSeconds) {
+  public EnvoyConfiguration(String configYAML) {
     this.configYAML = configYAML;
+    this.connectTimeoutSeconds = null;
+    this.dnsRefreshSeconds = null;
+    this.statsFlushSeconds = null;
+  }
+
+  public EnvoyConfiguration(int connectTimeoutSeconds, int dnsRefreshSeconds, int statsFlushSeconds) {
+    this.configYAML = null;
     this.connectTimeoutSeconds = connectTimeoutSeconds;
     this.dnsRefreshSeconds = dnsRefreshSeconds;
     this.statsFlushSeconds = statsFlushSeconds;
   }
 
+
+
   public String resolve(String defaultConfigurationYAML) {
-    String resolvedYAML;
-    if (configYAML == null) {
-      resolvedYAML = defaultConfigurationYAML;
-    } else {
-      resolvedYAML = configYAML;
-    }
     String resolvedConfiguration =
-        resolvedYAML.replace("{{ connect_timeout }}", String.format("%ss", connectTimeoutSeconds))
+        defaultConfigurationYAML
+            .replace("{{ connect_timeout }}", String.format("%ss", connectTimeoutSeconds))
             .replace("{{ dns_refresh_rate }}", String.format("%ss", dnsRefreshSeconds))
             .replace("{{ stats_flush_interval }}", String.format("%ss", statsFlushSeconds));
+
     if (resolvedConfiguration.contains("{{")) {
       throw new ConfigurationException();
     }
@@ -33,6 +37,8 @@ public String resolve(String defaultConfigurationYAML) {
   }
 
   static class ConfigurationException extends RuntimeException {
-    ConfigurationException() { super("Unresolved Template Key"); }
+    ConfigurationException() {
+      super("Unresolved Template Key");
+    }
   }
 }
diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
index 7435b55ee2..34ab997f29 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
@@ -44,7 +44,10 @@ public int runWithConfig(EnvoyConfiguration envoyConfiguration) {
   @Override
   public int runWithConfig(EnvoyConfiguration envoyConfiguration, String logLevel) {
     try {
-      String resolvedConfig = envoyConfiguration.resolve(JniLibrary.templateString());
+
+      String resolvedConfig = envoyConfiguration.configYAML == null
+              ? envoyConfiguration.resolve(JniLibrary.templateString())
+              : envoyConfiguration.configYAML;
       return JniLibrary.runEngine(resolvedConfig, logLevel);
     } catch (Throwable throwable) {
       // TODO: Need to have a way to log the exception somewhere
diff --git a/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt b/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
index 29fa48b966..d3b4437ad9 100644
--- a/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
+++ b/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
@@ -1,61 +1,33 @@
 package io.envoyproxy.envoymobile.engine
 
-//private const val TEST_CONFIG = """
-//mock_template:
-//- name: mock
-//  connect_timeout: {{ connect_timeout }}
-//  dns_refresh_rate: {{ dns_refresh_rate }}
-//  stats_flush_interval: {{ stats_flush_interval }}
-//"""
+import org.junit.Test
+
+private const val TEST_CONFIG = """
+mock_template:
+- name: mock
+  connect_timeout: {{ connect_timeout }}
+  dns_refresh_rate: {{ dns_refresh_rate }}
+  stats_flush_interval: {{ stats_flush_interval }}
+"""
 
 
 class EnvoyConfigurationTest {
-// TODO: Write these tests well
-
-//  @Test
-//  fun `specifying connection timeout overrides default`() {
-//    builder = EnvoyBuilder()
-//    builder.addConfigYAML(TEST_CONFIG)
-//    builder.addEngineType { engine }
-//
-//    builder.addConnectTimeoutSeconds(1234)
-//    val envoy = builder.build()
-//
-//    assertThat(envoy.envoyConfiguration).contains("connect_timeout: 1234s")
-//  }
-//
-//  @Test
-//  fun `specifying DNS refresh overrides default`() {
-//    builder = EnvoyBuilder()
-//    builder.addConfigYAML(TEST_CONFIG)
-//    builder.addEngineType { engine }
-//
-//    builder.addDNSRefreshSeconds(1234)
-//    val envoy = builder.build()
-//    assertThat(envoy.envoyConfiguration).contains("dns_refresh_rate: 1234s")
-//  }
-//
-//  @Test
-//  fun `specifying stats flush overrides default`() {
-//    builder = EnvoyBuilder()
-//    builder.addConfigYAML(TEST_CONFIG)
-//    builder.addEngineType { engine }
-//
-//    builder.addStatsFlushSeconds(1234)
-//    builder.build()
-//    val envoy = builder.build()
-//    assertThat(envoy.envoyConfiguration).contains("stats_flush_interval: 1234s")
-//
-//  }
-//
-//  @Test(expected = ConfigurationException::class)
-//  fun `specifying configs with invalid templates will throw on build`() {
-//    builder = EnvoyBuilder()
-//    builder.addConfigYAML(TEST_CONFIG)
-//    builder.addEngineType { engine }
-//
-//    builder.addConfigYAML("{{ missing }}")
-//    builder.build()
-//  }
 
+  @Test
+  fun `resolving with default configuraiton resolves with values`() {
+    val envoyConfiguration = EnvoyConfiguration(123, 234, 345)
+
+    val resolvedTemplate = envoyConfiguration.resolve(TEST_CONFIG)
+    assertThat(resolvedTemplate).contains("connect_timeout: 123s")
+    assertThat(resolvedTemplate).contains("dns_refresh_rate: 234s")
+    assertThat(resolvedTemplate).contains("stats_flush_interval: 345s")
+  }
+
+
+  @Test(expected = ConfigurationException::class)
+  fun `resolve templates with invalid templates will throw on build`() {
+    val envoyConfiguration = EnvoyConfiguration(123, 234, 345)
+
+    envoyConfiguration.resolve("{{ }}")
+  }
 }
diff --git a/library/kotlin/src/io/envoyproxy/envoymobile/EnvoyBuilder.kt b/library/kotlin/src/io/envoyproxy/envoymobile/EnvoyBuilder.kt
index 9825782566..cae9d8b43b 100644
--- a/library/kotlin/src/io/envoyproxy/envoymobile/EnvoyBuilder.kt
+++ b/library/kotlin/src/io/envoyproxy/envoymobile/EnvoyBuilder.kt
@@ -71,7 +71,12 @@ open class EnvoyBuilder internal constructor(
    * @return A new instance of Envoy.
    */
   fun build(): Envoy {
-    return Envoy(engineType(), EnvoyConfiguration(configYAML, connectTimeoutSeconds, dnsRefreshSeconds, statsFlushSeconds), logLevel)
+    val config = if (configYAML == null) {
+      EnvoyConfiguration(connectTimeoutSeconds, dnsRefreshSeconds, statsFlushSeconds)
+    } else {
+      EnvoyConfiguration(configYAML)
+    }
+    return Envoy(engineType(), config, logLevel)
   }
 
   /**
diff --git a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
index 882a7edeab..134018bf1e 100644
--- a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
+++ b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
@@ -43,4 +43,38 @@ class EnvoyBuilderTest {
     assertThat(envoy.logLevel).isEqualTo(LogLevel.DEBUG)
   }
 
+  @Test
+  fun `specifying connection timeout overrides default`() {
+    `when`(envoyConfiguration.templateString()).thenReturn(TEST_CONFIG)
+    builder = EnvoyBuilder(envoyConfiguration)
+    builder.addEngineType { engine }
+
+    builder.addConnectTimeoutSeconds(1234)
+    val envoy = builder.build()
+    assertThat(envoy.envoyConfiguration.connectTimeoutSeconds).isEqualTo(1234)
+  }
+
+  @Test
+  fun `specifying DNS refresh overrides default`() {
+    `when`(envoyConfiguration.templateString()).thenReturn(TEST_CONFIG)
+    builder = EnvoyBuilder(envoyConfiguration)
+    builder.addEngineType { engine }
+
+    builder.addDNSRefreshSeconds(1234)
+    val envoy = builder.build()
+    assertThat(envoy.envoyConfiguration.dnsRefreshSeconds).isEqualTo(1234)
+  }
+
+  @Test
+  fun `specifying stats flush overrides default`() {
+    `when`(envoyConfiguration.templateString()).thenReturn(TEST_CONFIG)
+    builder = EnvoyBuilder(envoyConfiguration)
+    builder.addEngineType { engine }
+
+    builder.addStatsFlushSeconds(1234)
+    builder.build()
+    val envoy = builder.build()
+    assertThat(envoy.envoyConfiguration.statsFlushSeconds).isEqualTo(1234)
+
+  }
 }
diff --git a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyTest.kt b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyTest.kt
index 85fd3a412e..08ba2da627 100644
--- a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyTest.kt
+++ b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyTest.kt
@@ -19,7 +19,7 @@ class EnvoyTest {
 
   private val engine = mock(EnvoyEngine::class.java)
   private val stream = mock(EnvoyHTTPStream::class.java)
-  private val config = EnvoyConfiguration("", 0, 0, 0)
+  private val config = EnvoyConfiguration("")
 
   @Test
   fun `starting a stream on envoy sends headers`() {

From 1c37fb1fda1d4b1a7786e7327a5654ad37eea27f Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Tue, 3 Sep 2019 12:39:12 -0700
Subject: [PATCH 08/17] fix

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../engine/EnvoyConfiguration.java            | 33 +++++++++++++++----
 .../envoymobile/engine/EnvoyEngineImpl.java   |  4 +--
 .../engine/EnvoyConfigurationTest.kt          |  4 +--
 3 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
index 68a8658292..49c9a5f702 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
@@ -7,6 +7,11 @@ public class EnvoyConfiguration {
   public final Integer dnsRefreshSeconds;
   public final Integer statsFlushSeconds;
 
+  /**
+   * Create an EnvoyConfiguration with a user provided configuration YAML.
+   *
+   * @param configYAML configuration to be used for starting Envoy.
+   */
   public EnvoyConfiguration(String configYAML) {
     this.configYAML = configYAML;
     this.connectTimeoutSeconds = null;
@@ -14,16 +19,32 @@ public EnvoyConfiguration(String configYAML) {
     this.statsFlushSeconds = null;
   }
 
-  public EnvoyConfiguration(int connectTimeoutSeconds, int dnsRefreshSeconds, int statsFlushSeconds) {
+  /**
+   * Create an EnvoyConfiguration with a user provided configuration values.
+   *
+   * @param connectTimeoutSeconds timeout for new network connections to hosts in the cluster.
+   * @param dnsRefreshSeconds rate in seconds to refresh DNS.
+   * @param statsFlushSeconds interval at which to flush Envoy stats.
+   */
+  public EnvoyConfiguration(int connectTimeoutSeconds, int dnsRefreshSeconds,
+                            int statsFlushSeconds) {
     this.configYAML = null;
     this.connectTimeoutSeconds = connectTimeoutSeconds;
     this.dnsRefreshSeconds = dnsRefreshSeconds;
     this.statsFlushSeconds = statsFlushSeconds;
   }
 
-
-
-  public String resolve(String defaultConfigurationYAML) {
+  /**
+   * Resolves the provided default configuration with the field values:
+   * - connectTimeoutSeconds
+   * - dnsRefreshSeconds
+   * - statsFlushSeconds
+   *
+   * @param defaultConfigurationYAML the default template configuration.
+   * @return String, the resolved template.
+   * @throws ConfigurationException, when the template provided is not fully resolved.
+   */
+  String resolveTemplate(String defaultConfigurationYAML) {
     String resolvedConfiguration =
         defaultConfigurationYAML
             .replace("{{ connect_timeout }}", String.format("%ss", connectTimeoutSeconds))
@@ -37,8 +58,6 @@ public String resolve(String defaultConfigurationYAML) {
   }
 
   static class ConfigurationException extends RuntimeException {
-    ConfigurationException() {
-      super("Unresolved Template Key");
-    }
+    ConfigurationException() { super("Unresolved Template Key"); }
   }
 }
diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
index 34ab997f29..70e53d1c7c 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
@@ -46,8 +46,8 @@ public int runWithConfig(EnvoyConfiguration envoyConfiguration, String logLevel)
     try {
 
       String resolvedConfig = envoyConfiguration.configYAML == null
-              ? envoyConfiguration.resolve(JniLibrary.templateString())
-              : envoyConfiguration.configYAML;
+                                  ? envoyConfiguration.resolveTemplate(JniLibrary.templateString())
+                                  : envoyConfiguration.configYAML;
       return JniLibrary.runEngine(resolvedConfig, logLevel);
     } catch (Throwable throwable) {
       // TODO: Need to have a way to log the exception somewhere
diff --git a/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt b/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
index d3b4437ad9..3d11caa260 100644
--- a/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
+++ b/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
@@ -17,7 +17,7 @@ class EnvoyConfigurationTest {
   fun `resolving with default configuraiton resolves with values`() {
     val envoyConfiguration = EnvoyConfiguration(123, 234, 345)
 
-    val resolvedTemplate = envoyConfiguration.resolve(TEST_CONFIG)
+    val resolvedTemplate = envoyConfiguration.resolveTemplate(TEST_CONFIG)
     assertThat(resolvedTemplate).contains("connect_timeout: 123s")
     assertThat(resolvedTemplate).contains("dns_refresh_rate: 234s")
     assertThat(resolvedTemplate).contains("stats_flush_interval: 345s")
@@ -28,6 +28,6 @@ class EnvoyConfigurationTest {
   fun `resolve templates with invalid templates will throw on build`() {
     val envoyConfiguration = EnvoyConfiguration(123, 234, 345)
 
-    envoyConfiguration.resolve("{{ }}")
+    envoyConfiguration.resolveTemplate("{{ }}")
   }
 }

From 3272f7eeefb85686d6485d33dd8c600987369c40 Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Tue, 3 Sep 2019 12:53:50 -0700
Subject: [PATCH 09/17] OOOOPS

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../envoymobile/engine/EnvoyConfiguration.java           | 1 +
 .../test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt   | 9 +++------
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
index 49c9a5f702..ed1820be98 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
@@ -39,6 +39,7 @@ public EnvoyConfiguration(int connectTimeoutSeconds, int dnsRefreshSeconds,
    * - connectTimeoutSeconds
    * - dnsRefreshSeconds
    * - statsFlushSeconds
+   * This default configuration is provided by the native layer
    *
    * @param defaultConfigurationYAML the default template configuration.
    * @return String, the resolved template.
diff --git a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
index 134018bf1e..979883580d 100644
--- a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
+++ b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
@@ -45,8 +45,7 @@ class EnvoyBuilderTest {
 
   @Test
   fun `specifying connection timeout overrides default`() {
-    `when`(envoyConfiguration.templateString()).thenReturn(TEST_CONFIG)
-    builder = EnvoyBuilder(envoyConfiguration)
+    builder = EnvoyBuilder()
     builder.addEngineType { engine }
 
     builder.addConnectTimeoutSeconds(1234)
@@ -56,8 +55,7 @@ class EnvoyBuilderTest {
 
   @Test
   fun `specifying DNS refresh overrides default`() {
-    `when`(envoyConfiguration.templateString()).thenReturn(TEST_CONFIG)
-    builder = EnvoyBuilder(envoyConfiguration)
+    builder = EnvoyBuilder()
     builder.addEngineType { engine }
 
     builder.addDNSRefreshSeconds(1234)
@@ -67,8 +65,7 @@ class EnvoyBuilderTest {
 
   @Test
   fun `specifying stats flush overrides default`() {
-    `when`(envoyConfiguration.templateString()).thenReturn(TEST_CONFIG)
-    builder = EnvoyBuilder(envoyConfiguration)
+    builder = EnvoyBuilder()
     builder.addEngineType { engine }
 
     builder.addStatsFlushSeconds(1234)

From f94cb71772917cbee0a2a2917ad939a8f569d1c9 Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Tue, 3 Sep 2019 12:55:40 -0700
Subject: [PATCH 10/17] period

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
index ed1820be98..4a83c77856 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
@@ -39,7 +39,7 @@ public EnvoyConfiguration(int connectTimeoutSeconds, int dnsRefreshSeconds,
    * - connectTimeoutSeconds
    * - dnsRefreshSeconds
    * - statsFlushSeconds
-   * This default configuration is provided by the native layer
+   * This default configuration is provided by the native layer.
    *
    * @param defaultConfigurationYAML the default template configuration.
    * @return String, the resolved template.

From bf2bca687e70f4436eb7037e2bf6dde41b5a4a79 Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Tue, 3 Sep 2019 13:05:04 -0700
Subject: [PATCH 11/17] spellcheck

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt b/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
index 3d11caa260..72376636c4 100644
--- a/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
+++ b/library/java/test/io/envoyproxy/envoymobile/engine/EnvoyConfigurationTest.kt
@@ -14,7 +14,7 @@ mock_template:
 class EnvoyConfigurationTest {
 
   @Test
-  fun `resolving with default configuraiton resolves with values`() {
+  fun `resolving with default configuration resolves with values`() {
     val envoyConfiguration = EnvoyConfiguration(123, 234, 345)
 
     val resolvedTemplate = envoyConfiguration.resolveTemplate(TEST_CONFIG)

From af59361343b7a5e819f4493192ae77eca2390b7a Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Tue, 3 Sep 2019 13:27:08 -0700
Subject: [PATCH 12/17] fix things

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../envoymobile/engine/EnvoyEngine.java       |  6 ++---
 .../envoymobile/engine/EnvoyEngineImpl.java   | 24 ++++++++-----------
 .../src/io/envoyproxy/envoymobile/Envoy.kt    | 16 +++++++++----
 .../io/envoyproxy/envoymobile/EnvoyBuilder.kt |  8 +++----
 .../envoymobile/EnvoyBuilderTest.kt           |  8 +++----
 5 files changed, 32 insertions(+), 30 deletions(-)

diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngine.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngine.java
index aacb67b4b3..351aa988fc 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngine.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngine.java
@@ -14,15 +14,15 @@ public interface EnvoyEngine {
   /**
    * Run the Envoy engine with the provided envoyConfiguration and log level.
    *
-   * @param config The configuration file with which to start Envoy.
+   * @param configurationYAML The configuration yaml with which to start Envoy.
    * @return A status indicating if the action was successful.
    */
-  int runWithConfig(EnvoyConfiguration envoyConfiguration);
+  int runWithConfig(String configurationYAML, String logLevel);
 
   /**
    * Run the Envoy engine with the provided envoyConfiguration and log level.
    *
-   * @param config   The configuration file with which to start Envoy.
+   * @param envoyConfiguration The EnvoyConfiguration used to start Envoy.
    * @param logLevel The log level to use when starting Envoy.
    * @return int A status indicating if the action was successful.
    */
diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
index 70e53d1c7c..ba1cad1916 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
@@ -26,32 +26,28 @@ public EnvoyHTTPStream startStream(EnvoyObserver observer) {
   /**
    * Run the Envoy engine with the provided envoyConfiguration and log level.
    *
-   * @param envoyConfiguration The configuration file with which to start Envoy.
+   * @param configurationYAML The configuration yaml with which to start Envoy.
    * @return A status indicating if the action was successful.
    */
   @Override
-  public int runWithConfig(EnvoyConfiguration envoyConfiguration) {
-    return runWithConfig(envoyConfiguration, "info");
+  public int runWithConfig(String configurationYAML, String logLevel) {
+    try {
+      return JniLibrary.runEngine(configurationYAML, logLevel);
+    } catch (Throwable throwable) {
+      // TODO: Need to have a way to log the exception somewhere
+      return 1;
+    }
   }
 
   /**
    * Run the Envoy engine with the provided envoyConfiguration and log level.
    *
-   * @param envoyConfiguration   The configuration file with which to start Envoy.
+   * @param envoyConfiguration The EnvoyConfiguration used to start Envoy.
    * @param logLevel The log level to use when starting Envoy.
    * @return int A status indicating if the action was successful.
    */
   @Override
   public int runWithConfig(EnvoyConfiguration envoyConfiguration, String logLevel) {
-    try {
-
-      String resolvedConfig = envoyConfiguration.configYAML == null
-                                  ? envoyConfiguration.resolveTemplate(JniLibrary.templateString())
-                                  : envoyConfiguration.configYAML;
-      return JniLibrary.runEngine(resolvedConfig, logLevel);
-    } catch (Throwable throwable) {
-      // TODO: Need to have a way to log the exception somewhere
-      return 1;
-    }
+    return runWithConfig(envoyConfiguration.resolveTemplate(JniLibrary.templateString()), logLevel);
   }
 }
diff --git a/library/kotlin/src/io/envoyproxy/envoymobile/Envoy.kt b/library/kotlin/src/io/envoyproxy/envoymobile/Envoy.kt
index 62ba780f40..c6b35400a8 100644
--- a/library/kotlin/src/io/envoyproxy/envoymobile/Envoy.kt
+++ b/library/kotlin/src/io/envoyproxy/envoymobile/Envoy.kt
@@ -20,17 +20,23 @@ enum class LogLevel(internal val level: String) {
 /**
  * Wrapper class that allows for easy calling of Envoy's JNI interface in native Java.
  */
-class Envoy constructor(
+class Envoy private constructor(
     private val engine: EnvoyEngine,
-    internal val envoyConfiguration: EnvoyConfiguration,
-    internal val logLevel: LogLevel = LogLevel.INFO
+    internal val envoyConfiguration: EnvoyConfiguration?,
+    internal val configurationYAML: String?,
+    internal val logLevel: LogLevel
 ) : Client {
 
-  constructor(engine: EnvoyEngine, envoyConfiguration: EnvoyConfiguration) : this(engine, envoyConfiguration, LogLevel.INFO)
+  constructor(engine: EnvoyEngine, envoyConfiguration: EnvoyConfiguration, logLevel: LogLevel = LogLevel.INFO) : this(engine, envoyConfiguration, null, logLevel)
+  constructor(engine: EnvoyEngine, configurationYAML: String, logLevel: LogLevel = LogLevel.INFO) : this(engine, null, configurationYAML, logLevel)
 
   // Dedicated thread for running this instance of Envoy.
   private val runner: Thread = Thread(ThreadGroup("Envoy"), Runnable {
-    engine.runWithConfig(envoyConfiguration, logLevel.level)
+    if (envoyConfiguration == null) {
+      engine.runWithConfig(configurationYAML, logLevel.level)
+    }else {
+      engine.runWithConfig(envoyConfiguration, logLevel.level)
+    }
   })
 
   /**
diff --git a/library/kotlin/src/io/envoyproxy/envoymobile/EnvoyBuilder.kt b/library/kotlin/src/io/envoyproxy/envoymobile/EnvoyBuilder.kt
index cae9d8b43b..0f24258e2f 100644
--- a/library/kotlin/src/io/envoyproxy/envoymobile/EnvoyBuilder.kt
+++ b/library/kotlin/src/io/envoyproxy/envoymobile/EnvoyBuilder.kt
@@ -71,12 +71,12 @@ open class EnvoyBuilder internal constructor(
    * @return A new instance of Envoy.
    */
   fun build(): Envoy {
-    val config = if (configYAML == null) {
-      EnvoyConfiguration(connectTimeoutSeconds, dnsRefreshSeconds, statsFlushSeconds)
+    val configurationYAML = configYAML
+    if (configurationYAML == null) {
+      return Envoy(engineType(), EnvoyConfiguration(connectTimeoutSeconds, dnsRefreshSeconds, statsFlushSeconds), logLevel)
     } else {
-      EnvoyConfiguration(configYAML)
+      return Envoy(engineType(), configurationYAML, logLevel)
     }
-    return Envoy(engineType(), config, logLevel)
   }
 
   /**
diff --git a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
index 979883580d..eb18f3ef0e 100644
--- a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
+++ b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyBuilderTest.kt
@@ -29,7 +29,7 @@ class EnvoyBuilderTest {
 
     builder.addConfigYAML("mock_template:")
     val envoy = builder.build()
-    assertThat(envoy.envoyConfiguration.configYAML).isEqualTo("mock_template:")
+    assertThat(envoy.configurationYAML).isEqualTo("mock_template:")
   }
 
   @Test
@@ -50,7 +50,7 @@ class EnvoyBuilderTest {
 
     builder.addConnectTimeoutSeconds(1234)
     val envoy = builder.build()
-    assertThat(envoy.envoyConfiguration.connectTimeoutSeconds).isEqualTo(1234)
+    assertThat(envoy.envoyConfiguration!!.connectTimeoutSeconds).isEqualTo(1234)
   }
 
   @Test
@@ -60,7 +60,7 @@ class EnvoyBuilderTest {
 
     builder.addDNSRefreshSeconds(1234)
     val envoy = builder.build()
-    assertThat(envoy.envoyConfiguration.dnsRefreshSeconds).isEqualTo(1234)
+    assertThat(envoy.envoyConfiguration!!.dnsRefreshSeconds).isEqualTo(1234)
   }
 
   @Test
@@ -71,7 +71,7 @@ class EnvoyBuilderTest {
     builder.addStatsFlushSeconds(1234)
     builder.build()
     val envoy = builder.build()
-    assertThat(envoy.envoyConfiguration.statsFlushSeconds).isEqualTo(1234)
+    assertThat(envoy.envoyConfiguration!!.statsFlushSeconds).isEqualTo(1234)
 
   }
 }

From 075ddea817243a6828dd70b59b451e43973599be Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Wed, 4 Sep 2019 09:14:21 -0700
Subject: [PATCH 13/17] missed deletion

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../envoymobile/engine/EnvoyConfiguration.java     | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
index 4a83c77856..5a3867c136 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
@@ -2,23 +2,10 @@
 
 public class EnvoyConfiguration {
 
-  public final String configYAML;
   public final Integer connectTimeoutSeconds;
   public final Integer dnsRefreshSeconds;
   public final Integer statsFlushSeconds;
 
-  /**
-   * Create an EnvoyConfiguration with a user provided configuration YAML.
-   *
-   * @param configYAML configuration to be used for starting Envoy.
-   */
-  public EnvoyConfiguration(String configYAML) {
-    this.configYAML = configYAML;
-    this.connectTimeoutSeconds = null;
-    this.dnsRefreshSeconds = null;
-    this.statsFlushSeconds = null;
-  }
-
   /**
    * Create an EnvoyConfiguration with a user provided configuration values.
    *
@@ -28,7 +15,6 @@ public EnvoyConfiguration(String configYAML) {
    */
   public EnvoyConfiguration(int connectTimeoutSeconds, int dnsRefreshSeconds,
                             int statsFlushSeconds) {
-    this.configYAML = null;
     this.connectTimeoutSeconds = connectTimeoutSeconds;
     this.dnsRefreshSeconds = dnsRefreshSeconds;
     this.statsFlushSeconds = statsFlushSeconds;

From fdf2442b6a5f3fdea750afcc0f128479eed9db72 Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Wed, 4 Sep 2019 09:27:38 -0700
Subject: [PATCH 14/17] pr feedback

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../envoymobile/engine/EnvoyConfiguration.java        | 11 ++++-------
 .../io/envoyproxy/envoymobile/engine/EnvoyEngine.java |  4 ++--
 .../envoymobile/engine/EnvoyEngineImpl.java           |  2 +-
 3 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
index 5a3867c136..e15f78658d 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
@@ -21,19 +21,16 @@ public EnvoyConfiguration(int connectTimeoutSeconds, int dnsRefreshSeconds,
   }
 
   /**
-   * Resolves the provided default configuration with the field values:
-   * - connectTimeoutSeconds
-   * - dnsRefreshSeconds
-   * - statsFlushSeconds
+   * Resolves the provided configuration template using properties on this configuration.
    * This default configuration is provided by the native layer.
    *
-   * @param defaultConfigurationYAML the default template configuration.
+   * @param templateYAML the default template configuration.
    * @return String, the resolved template.
    * @throws ConfigurationException, when the template provided is not fully resolved.
    */
-  String resolveTemplate(String defaultConfigurationYAML) {
+  String resolveTemplate(String templateYAML) {
     String resolvedConfiguration =
-        defaultConfigurationYAML
+        templateYAML
             .replace("{{ connect_timeout }}", String.format("%ss", connectTimeoutSeconds))
             .replace("{{ dns_refresh_rate }}", String.format("%ss", dnsRefreshSeconds))
             .replace("{{ stats_flush_interval }}", String.format("%ss", statsFlushSeconds));
diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngine.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngine.java
index 351aa988fc..785fdfc70e 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngine.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngine.java
@@ -12,7 +12,7 @@ public interface EnvoyEngine {
   EnvoyHTTPStream startStream(EnvoyObserver observer);
 
   /**
-   * Run the Envoy engine with the provided envoyConfiguration and log level.
+   * Run the Envoy engine with the provided yaml string and log level.
    *
    * @param configurationYAML The configuration yaml with which to start Envoy.
    * @return A status indicating if the action was successful.
@@ -20,7 +20,7 @@ public interface EnvoyEngine {
   int runWithConfig(String configurationYAML, String logLevel);
 
   /**
-   * Run the Envoy engine with the provided envoyConfiguration and log level.
+   * Run the Envoy engine with the provided EnvoyConfiguration and log level.
    *
    * @param envoyConfiguration The EnvoyConfiguration used to start Envoy.
    * @param logLevel The log level to use when starting Envoy.
diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
index ba1cad1916..6e8cfa6667 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java
@@ -24,7 +24,7 @@ public EnvoyHTTPStream startStream(EnvoyObserver observer) {
   }
 
   /**
-   * Run the Envoy engine with the provided envoyConfiguration and log level.
+   * Run the Envoy engine with the provided yaml string and log level.
    *
    * @param configurationYAML The configuration yaml with which to start Envoy.
    * @return A status indicating if the action was successful.

From 9e326dd1eecc09305f21231e930cf9d72842dead Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Wed, 4 Sep 2019 10:46:43 -0700
Subject: [PATCH 15/17] cool

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 .../io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java   | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
index e15f78658d..dda717e2e0 100644
--- a/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
+++ b/library/java/src/io/envoyproxy/envoymobile/engine/EnvoyConfiguration.java
@@ -30,8 +30,7 @@ public EnvoyConfiguration(int connectTimeoutSeconds, int dnsRefreshSeconds,
    */
   String resolveTemplate(String templateYAML) {
     String resolvedConfiguration =
-        templateYAML
-            .replace("{{ connect_timeout }}", String.format("%ss", connectTimeoutSeconds))
+        templateYAML.replace("{{ connect_timeout }}", String.format("%ss", connectTimeoutSeconds))
             .replace("{{ dns_refresh_rate }}", String.format("%ss", dnsRefreshSeconds))
             .replace("{{ stats_flush_interval }}", String.format("%ss", statsFlushSeconds));
 

From 1dddd8e2f2fbdb94eaaca5c4b6ca0b4a1ffd6158 Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Wed, 4 Sep 2019 13:24:16 -0700
Subject: [PATCH 16/17] fix

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 library/kotlin/src/io/envoyproxy/envoymobile/ResponseHandler.kt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/library/kotlin/src/io/envoyproxy/envoymobile/ResponseHandler.kt b/library/kotlin/src/io/envoyproxy/envoymobile/ResponseHandler.kt
index 0ab40afc2b..8c533c6b28 100644
--- a/library/kotlin/src/io/envoyproxy/envoymobile/ResponseHandler.kt
+++ b/library/kotlin/src/io/envoyproxy/envoymobile/ResponseHandler.kt
@@ -17,7 +17,7 @@ class ResponseHandler(val executor: Executor) {
     override fun getExecutor(): Executor = responseHandler.executor
 
     override fun onHeaders(headers: Map<String, List<String>>, endStream: Boolean) {
-      val statusCode = headers!![":status"]?.first()?.toIntOrNull() ?: 0
+      val statusCode = headers[":status"]?.first()?.toIntOrNull() ?: 0
       responseHandler.onHeadersClosure(headers, statusCode, endStream)
     }
 

From 3cdc7d5a771fbc94a2d4ce3c3311bb7190e571b2 Mon Sep 17 00:00:00 2001
From: Alan Chiu <achiu@lyft.com>
Date: Wed, 4 Sep 2019 13:29:17 -0700
Subject: [PATCH 17/17] fix

Signed-off-by: Alan Chiu <achiu@lyft.com>
---
 library/kotlin/test/io/envoyproxy/envoymobile/EnvoyTest.kt | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyTest.kt b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyTest.kt
index 08ba2da627..8ef1a161f8 100644
--- a/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyTest.kt
+++ b/library/kotlin/test/io/envoyproxy/envoymobile/EnvoyTest.kt
@@ -13,13 +13,13 @@ import org.mockito.Mockito.`when`
 import org.mockito.Mockito.mock
 import org.mockito.Mockito.verify
 import java.nio.ByteBuffer
-import java.util.concurrent.Executor;
+import java.util.concurrent.Executor
 
 class EnvoyTest {
 
   private val engine = mock(EnvoyEngine::class.java)
   private val stream = mock(EnvoyHTTPStream::class.java)
-  private val config = EnvoyConfiguration("")
+  private val config = EnvoyConfiguration(0,0,0)
 
   @Test
   fun `starting a stream on envoy sends headers`() {