[Repo Assist] feat(envutil): add GetEnvDuration + configurable MCP_GATEWAY_SESSION_TIMEOUT

internal/envutil/envutil.go

@@ -4,6 +4,7 @@ import (
 	"os"
 	"strconv"
 	"strings"
+	"time"
 )
 
 // GetEnvString returns the value of the environment variable specified by envKey.
@@ -28,6 +29,18 @@ func GetEnvInt(envKey string, defaultValue int) int {
 	return defaultValue
 }
 
+// GetEnvDuration returns the time.Duration value of the environment variable specified by envKey.
+// If the environment variable is not set, is empty, or cannot be parsed by time.ParseDuration,
+// it returns the defaultValue. Accepts any string valid for time.ParseDuration (e.g. "2h", "30m", "90s").
+func GetEnvDuration(envKey string, defaultValue time.Duration) time.Duration {
+	if envValue := os.Getenv(envKey); envValue != "" {
+		if d, err := time.ParseDuration(envValue); err == nil && d > 0 {
+			return d
+		}
+	}
+	return defaultValue
+}
+
 // GetEnvBool returns the boolean value of the environment variable specified by envKey.
 // If the environment variable is not set or is empty, it returns the defaultValue.
 // Truthy values (case-insensitive): "1", "true", "yes", "on"

internal/envutil/envutil_test.go

@@ -3,10 +3,130 @@ package envutil
 import (
 	"os"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 )
 
+func TestGetEnvDuration(t *testing.T) {
+	tests := []struct {
+		name         string
+		envKey       string
+		envValue     string
+		setEnv       bool
+		defaultValue time.Duration
+		expected     time.Duration
+	}{
+		{
+			name:         "env var set to '2h' - returns 2 hours",
+			envKey:       "TEST_DURATION_VAR",
+			envValue:     "2h",
+			setEnv:       true,
+			defaultValue: 30 * time.Minute,
+			expected:     2 * time.Hour,
+		},
+		{
+			name:         "env var set to '30m' - returns 30 minutes",
+			envKey:       "TEST_DURATION_VAR",
+			envValue:     "30m",
+			setEnv:       true,
+			defaultValue: 2 * time.Hour,
+			expected:     30 * time.Minute,
+		},
+		{
+			name:         "env var set to '90s' - returns 90 seconds",
+			envKey:       "TEST_DURATION_VAR",
+			envValue:     "90s",
+			setEnv:       true,
+			defaultValue: 2 * time.Hour,
+			expected:     90 * time.Second,
+		},
+		{
+			name:         "env var not set - returns default",
+			envKey:       "TEST_DURATION_VAR",
+			setEnv:       false,
+			defaultValue: 2 * time.Hour,
+			expected:     2 * time.Hour,
+		},
+		{
+			name:         "env var empty string - returns default",
+			envKey:       "TEST_DURATION_VAR",
+			envValue:     "",
+			setEnv:       true,
+			defaultValue: 2 * time.Hour,
+			expected:     2 * time.Hour,
+		},
+		{
+			name:         "env var with invalid value - returns default",
+			envKey:       "TEST_DURATION_VAR",
+			envValue:     "invalid",
+			setEnv:       true,
+			defaultValue: 2 * time.Hour,
+			expected:     2 * time.Hour,
+		},
+		{
+			name:         "env var with zero duration - returns default",
+			envKey:       "TEST_DURATION_VAR",
+			envValue:     "0s",
+			setEnv:       true,
+			defaultValue: 2 * time.Hour,
+			expected:     2 * time.Hour,
+		},
+		{
+			name:         "env var with negative duration - returns default",
+			envKey:       "TEST_DURATION_VAR",
+			envValue:     "-1h",
+			setEnv:       true,
+			defaultValue: 2 * time.Hour,
+			expected:     2 * time.Hour,
+		},
+		{
+			name:         "env var with mixed units - returns parsed duration",
+			envKey:       "TEST_DURATION_VAR",
+			envValue:     "1h30m",
+			setEnv:       true,
+			defaultValue: 2 * time.Hour,
+			expected:     90 * time.Minute,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			os.Unsetenv(tt.envKey)
+			defer os.Unsetenv(tt.envKey)
+
+			if tt.setEnv {
+				os.Setenv(tt.envKey, tt.envValue)
+			}
+
+			result := GetEnvDuration(tt.envKey, tt.defaultValue)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+// TestGetEnvDurationRealWorldScenarios tests realistic usage scenarios
+func TestGetEnvDurationRealWorldScenarios(t *testing.T) {
+	t.Run("session timeout configuration", func(t *testing.T) {
+		os.Unsetenv("MCP_GATEWAY_SESSION_TIMEOUT")
+		defer os.Unsetenv("MCP_GATEWAY_SESSION_TIMEOUT")
+
+		// Default case
+		result := GetEnvDuration("MCP_GATEWAY_SESSION_TIMEOUT", 2*time.Hour)
+		assert.Equal(t, 2*time.Hour, result)
+
+		// Override with shorter timeout
+		os.Setenv("MCP_GATEWAY_SESSION_TIMEOUT", "30m")
+		result = GetEnvDuration("MCP_GATEWAY_SESSION_TIMEOUT", 2*time.Hour)
+		assert.Equal(t, 30*time.Minute, result)
+
+		// Override with longer timeout
+		os.Setenv("MCP_GATEWAY_SESSION_TIMEOUT", "4h")
+		result = GetEnvDuration("MCP_GATEWAY_SESSION_TIMEOUT", 2*time.Hour)
+		assert.Equal(t, 4*time.Hour, result)
+	})
+}
+
 func TestGetEnvString(t *testing.T) {
 	tests := []struct {
 		name         string

internal/server/transport.go

@@ -4,6 +4,7 @@ import (
 	"net/http"
 	"time"
 
+	"github.com/github/gh-aw-mcpg/internal/envutil"
 	"github.com/github/gh-aw-mcpg/internal/logger"
 	sdk "github.com/modelcontextprotocol/go-sdk/mcp"
 )
@@ -35,9 +36,9 @@ func CreateHTTPServerForMCP(addr string, unifiedServer *UnifiedServer, apiKey st
 
 		return unifiedServer.server
 	}, &sdk.StreamableHTTPOptions{
-		Stateless:      false,                                         // Support stateful sessions
-		Logger:         logger.NewSlogLoggerWithHandler(logTransport), // Integrate SDK logging with project logger
-		SessionTimeout: 2 * time.Hour,                                 // 2h accommodates long-running workflows with idle periods
+		Stateless:      false,                                                              // Support stateful sessions
+		Logger:         logger.NewSlogLoggerWithHandler(logTransport),                      // Integrate SDK logging with project logger
+		SessionTimeout: envutil.GetEnvDuration("MCP_GATEWAY_SESSION_TIMEOUT", 2*time.Hour), // Configurable; 2h default accommodates long-running workflows with idle periods
 	})
 
 	// Apply standard middleware stack (SDK logging → shutdown check → auth)