PIS-30 Shared health endpoint

pom.xml

@@ -61,6 +61,7 @@
     <module>vpro-shared-hibernate-search</module>
     <module>vpro-shared-jackson2</module>
     <module>vpro-shared-logging</module>
+    <module>vpro-shared-monitoring</module>
     <module>vpro-shared-persistence</module>
     <module>vpro-shared-resteasy</module>
     <module>vpro-shared-rs</module>
@@ -394,6 +395,12 @@
         <version>${assertj.version}</version>
         <scope>test</scope>
       </dependency>
+      <dependency>
+        <groupId>com.jayway.jsonpath</groupId>
+        <artifactId>json-path-assert</artifactId>
+        <version>2.4.0</version>
+        <scope>test</scope>
+      </dependency>
       <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-web</artifactId>
@@ -736,7 +743,6 @@
           <plugin>
             <groupId>org.apache.maven.plugins</groupId>
             <artifactId>maven-javadoc-plugin</artifactId>
-            <version>3.1.0</version>
             <executions>
               <execution>
                 <id>attach-javadocs</id>

vpro-shared-bom/pom.xml

@@ -112,6 +112,11 @@
         <artifactId>vpro-shared-logging</artifactId>
         <version>${project.version}</version>
       </dependency>
+      <dependency>
+        <groupId>nl.vpro.shared</groupId>
+        <artifactId>vpro-shared-monitoring</artifactId>
+        <version>${project.version}</version>
+      </dependency>
       <dependency>
         <groupId>nl.vpro.shared</groupId>
         <artifactId>vpro-shared-persistence</artifactId>

vpro-shared-monitoring/pom.xml

@@ -0,0 +1,62 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>nl.vpro.shared</groupId>
+    <artifactId>vpro-shared-parent</artifactId>
+    <version>2.16-SNAPSHOT</version>
+  </parent>
+  <artifactId>vpro-shared-monitoring</artifactId>
+  <description>This modules contains utilities and endpoints for application deployments and monitoring.</description>
+  <dependencies>
+    <dependency>
+      <groupId>com.jayway.jsonpath</groupId>
+      <artifactId>json-path-assert</artifactId>
+      <version>2.4.0</version>
+    </dependency>
+    <dependency>
+      <groupId>nl.vpro.shared</groupId>
+      <artifactId>vpro-shared-test</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>javax.servlet</groupId>
+      <artifactId>javax.servlet-api</artifactId>
+      <version>3.1.0</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.hamcrest</groupId>
+      <artifactId>hamcrest-all</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-api</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>com.fasterxml.jackson.core</groupId>
+      <artifactId>jackson-core</artifactId>
+      <scope>compile</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.projectlombok</groupId>
+      <artifactId>lombok</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework</groupId>
+      <artifactId>spring-context</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework</groupId>
+      <artifactId>spring-web</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework</groupId>
+      <artifactId>spring-webmvc</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework</groupId>
+      <artifactId>spring-test</artifactId>
+    </dependency>
+  </dependencies>
+</project>

vpro-shared-monitoring/src/main/java/nl/vpro/monitoring/domain/Health.java

@@ -0,0 +1,11 @@
+package nl.vpro.monitoring.domain;
+
+import lombok.Builder;
+import lombok.Data;
+
+@Data
+@Builder
+public class Health {
+    private int status;
+    private String message;
+}

vpro-shared-monitoring/src/main/java/nl/vpro/monitoring/web/HealthController.java

@@ -0,0 +1,46 @@
+package nl.vpro.monitoring.web;
+
+import org.springframework.context.annotation.Lazy;
+import org.springframework.context.event.*;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+import nl.vpro.monitoring.domain.Health;
+
+@Lazy(false)
+@RestController
+@RequestMapping(value = "/health", produces = MediaType.APPLICATION_JSON_VALUE)
+public class HealthController {
+
+    private Status status = Status.STARTING;
+
+    @EventListener
+    public void onApplicationEvent(ContextRefreshedEvent refreshedEvent) {
+        status = Status.READY;
+    }
+
+    @EventListener
+    public void onApplicationEvent(ContextStoppedEvent stoppedEvent) {
+        status = Status.STOPPING;
+    }
+
+    @GetMapping
+    public ResponseEntity<Health> health() {
+        return ResponseEntity.status(status.code).body(Health.builder().status(status.code).message(status.message).build());
+    }
+
+    private enum Status {
+        STARTING(503, "Application starting"),
+        READY(200, "Application ready"),
+        STOPPING(503, "Application shutdown");
+
+        int code;
+        String message;
+
+        Status(int code, String message) {
+            this.code = code;
+            this.message = message;
+        }
+    }
+}

vpro-shared-monitoring/src/test/java/nl/vpro/monitoring/web/HealthControllerTest.java

@@ -0,0 +1,76 @@
+package nl.vpro.monitoring.web;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.event.ContextRefreshedEvent;
+import org.springframework.context.event.ContextStoppedEvent;
+import org.springframework.http.ResponseEntity;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+import org.springframework.test.context.web.WebAppConfiguration;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+import org.springframework.web.context.WebApplicationContext;
+
+import nl.vpro.monitoring.domain.Health;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.springframework.http.MediaType.APPLICATION_JSON_VALUE;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@ExtendWith(SpringExtension.class)
+@WebAppConfiguration
+@ContextConfiguration("/manage-servlet.xml")
+class HealthControllerTest {
+    @Autowired
+    private HealthController healthController;
+
+    @Autowired
+    private WebApplicationContext wac;
+
+    private MockMvc mockMvc;
+
+    @BeforeEach
+    public void setup() {
+        this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();
+    }
+
+    @Test
+    void initialValues() {
+        // Pragmatic testing of initial values. Using #wac and #mockMvc is more or less impossible.
+        ResponseEntity<Health> response = new HealthController().health();
+        assertThat(response.getStatusCodeValue()).isEqualTo(503);
+        assertThat(response.getBody()).isNotNull();
+        assertThat(response.getBody().getStatus()).isEqualTo(503);
+        assertThat(response.getBody().getMessage()).isEqualTo("Application starting");
+    }
+
+    @Test
+    void statusReady() throws Exception {
+        healthController.onApplicationEvent((ContextRefreshedEvent) null);
+
+        mockMvc.perform(
+            get("/health")
+                .accept(APPLICATION_JSON_VALUE)
+        ).andExpect(status().is(200))
+            .andExpect(jsonPath("$.status", is(200)))
+            .andExpect(jsonPath("$.message", is("Application ready")));
+    }
+
+    @Test
+    void statusStopping() throws Exception {
+        healthController.onApplicationEvent((ContextStoppedEvent) null);
+
+        mockMvc.perform(
+            get("/health")
+                .accept(APPLICATION_JSON_VALUE)
+        ).andExpect(status().is(503))
+            .andExpect(jsonPath("$.status", is(503)))
+            .andExpect(jsonPath("$.message", is("Application shutdown")));
+    }
+}

vpro-shared-monitoring/src/test/resources/manage-servlet.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:context="http://www.springframework.org/schema/context"
+       xmlns:util="http://www.springframework.org/schema/util"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
+        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd
+        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.1.xsd">
+
+  <context:annotation-config/>
+
+  <bean class="nl.vpro.monitoring.web.HealthController"/>
+
+  <bean id="jsonHttpMessageConverter"
+        class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
+    <property name="objectMapper">
+      <bean class="nl.vpro.jackson2.Jackson2Mapper" factory-method="getLenientInstance" />
+    </property>
+  </bean>
+
+  <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
+    <property name="messageConverters">
+      <util:list id="beanList">
+        <ref bean="jsonHttpMessageConverter"/>
+      </util:list>
+    </property>
+  </bean>
+
+</beans>