Persist CWA mode so -m onPremise is honored

cfg/envconfig/envconfig.go

@@ -20,6 +20,7 @@ const (
 	AWS_USE_DUALSTACK_ENDPOINT  = "AWS_USE_DUALSTACK_ENDPOINT" //nolint:revive
 	CWAGENT_USER_AGENT          = "CWAGENT_USER_AGENT"         //nolint:revive
 	CWAGENT_LOG_LEVEL           = "CWAGENT_LOG_LEVEL"          //nolint:revive
+	CWAGENT_MODE                = "CWAGENT_MODE"               //nolint:revive
 	CWAGENT_ROLE                = "CWAGENT_ROLE"               //nolint:revive
 	CWAGENT_USAGE_DATA          = "CWAGENT_USAGE_DATA"         //nolint:revive
 	IMDS_NUMBER_RETRY           = "IMDS_NUMBER_RETRY"          //nolint:revive

translator/context/context.go

@@ -7,6 +7,7 @@ import (
 	"log"
 	"os"
 
+	"github.com/aws/amazon-cloudwatch-agent/cfg/envconfig"
 	"github.com/aws/amazon-cloudwatch-agent/translator/config"
 )
 
@@ -90,7 +91,15 @@ func (ctx *Context) SetOutputTomlFilePath(outputTomlFilePath string) {
 
 func (ctx *Context) Mode() string {
 	if ctx.mode == "" {
-		ctx.mode = config.ModeEC2
+		// Try to read mode from environment variable first (set by env-config.json)
+		// This is used when the agent starts up and reads the persisted mode
+		envMode := os.Getenv(envconfig.CWAGENT_MODE)
+		if envMode != "" {
+			return envMode
+		}
+		// Default to EC2 mode if not set
+		// Note: We return directly without caching to allow SetMode() to override later
+		return config.ModeEC2
 	}
 	return ctx.mode
 }

translator/tocwconfig/tocwconfig_test.go

@@ -73,6 +73,7 @@ func TestBaseContainerInsightsConfig(t *testing.T) {
 	t.Setenv(envconfig.AWS_CA_BUNDLE, "/etc/test/ca_bundle.pem")
 	expectedEnvVars := map[string]string{
 		"AWS_CA_BUNDLE": "/etc/test/ca_bundle.pem",
+		"CWAGENT_MODE":  "ec2",
 	}
 	checkTranslation(t, "base_container_insights_config", "linux", expectedEnvVars, "")
 	checkTranslation(t, "base_container_insights_config", "darwin", nil, "")
@@ -1039,7 +1040,21 @@ func checkIfEnvTranslateSucceed(t *testing.T, jsonStr string, targetOs string, e
 		var actualEnvVars = make(map[string]string)
 		err := json.Unmarshal(envVarsBytes, &actualEnvVars)
 		assert.NoError(t, err)
-		assert.Equal(t, expectedEnvVars, actualEnvVars, "Expect to be equal")
+
+		// Automatically add the current mode to expected values since it's now always persisted
+		expectedWithMode := make(map[string]string)
+		for k, v := range expectedEnvVars {
+			expectedWithMode[k] = v
+		}
+		// Add the mode from context if not already specified in expected values
+		if _, exists := expectedWithMode[envconfig.CWAGENT_MODE]; !exists {
+			currentMode := context.CurrentContext().Mode()
+			if currentMode != "" {
+				expectedWithMode[envconfig.CWAGENT_MODE] = currentMode
+			}
+		}
+
+		assert.Equal(t, expectedWithMode, actualEnvVars, "Expect to be equal")
 	} else {
 		t.Logf("Got error %v", err)
 		t.Fail()

translator/tocwconfig/toenvconfig/toEnvConfig.go

@@ -19,6 +19,7 @@ const (
 	debugKey          = "debug"
 	awsSdkLogLevelKey = "aws_sdk_log_level"
 	usageDataKey      = "usage_data"
+	modeKey           = "mode"
 )
 
 func ToEnvConfig(jsonConfigValue map[string]interface{}) []byte {
@@ -76,6 +77,12 @@ func ToEnvConfig(jsonConfigValue map[string]interface{}) []byte {
 		envVars[envconfig.CWAgentLogsBackpressureMode] = backpressureMode
 	}
 
+	// Persist the agent mode so it can be used when the agent starts
+	mode := context.CurrentContext().Mode()
+	if mode != "" {
+		envVars[envconfig.CWAGENT_MODE] = mode
+	}
+
 	bytes, err := json.MarshalIndent(envVars, "", "\t")
 	if err != nil {
 		log.Panicf("Failed to create json map for environment variables. Reason: %s", err.Error())

translator/tocwconfig/toenvconfig/toEnvConfig_test.go

@@ -25,11 +25,14 @@ func TestToEnvConfig(t *testing.T) {
 		contextSetup func()
 	}{
 		{
-			name:        "empty config",
-			input:       map[string]interface{}{},
-			envVars:     map[string]string{},
-			expectedEnv: map[string]string{},
+			name:    "empty config",
+			input:   map[string]interface{}{},
+			envVars: map[string]string{},
+			expectedEnv: map[string]string{
+				envconfig.CWAGENT_MODE: "ec2", // Default mode
+			},
 			contextSetup: func() {
+				context.ResetContext()
 				context.CurrentContext().SetProxy(map[string]string{})
 				context.CurrentContext().SetSSL(map[string]string{})
 			},
@@ -50,8 +53,10 @@ func TestToEnvConfig(t *testing.T) {
 				envconfig.CWAGENT_LOG_LEVEL:  "DEBUG",
 				envconfig.AWS_SDK_LOG_LEVEL:  "DEBUG",
 				envconfig.CWAGENT_USAGE_DATA: "FALSE",
+				envconfig.CWAGENT_MODE:       "ec2",
 			},
 			contextSetup: func() {
+				context.ResetContext()
 				context.CurrentContext().SetProxy(map[string]string{})
 				context.CurrentContext().SetSSL(map[string]string{})
 			},
@@ -66,8 +71,10 @@ func TestToEnvConfig(t *testing.T) {
 			envVars: map[string]string{},
 			expectedEnv: map[string]string{
 				envconfig.AWS_USE_DUALSTACK_ENDPOINT: "true",
+				envconfig.CWAGENT_MODE:               "ec2",
 			},
 			contextSetup: func() {
+				context.ResetContext()
 				context.CurrentContext().SetProxy(map[string]string{})
 				context.CurrentContext().SetSSL(map[string]string{})
 			},
@@ -82,8 +89,10 @@ func TestToEnvConfig(t *testing.T) {
 			envVars: map[string]string{},
 			expectedEnv: map[string]string{
 				envconfig.AWS_USE_DUALSTACK_ENDPOINT: "false",
+				envconfig.CWAGENT_MODE:               "ec2",
 			},
 			contextSetup: func() {
+				context.ResetContext()
 				context.CurrentContext().SetProxy(map[string]string{})
 				context.CurrentContext().SetSSL(map[string]string{})
 			},
@@ -106,8 +115,10 @@ func TestToEnvConfig(t *testing.T) {
 				envconfig.AWS_USE_DUALSTACK_ENDPOINT: "true",
 				envconfig.HTTP_PROXY:                 "http://proxy.test",
 				envconfig.AWS_CA_BUNDLE:              "/test/ca-bundle.pem",
+				envconfig.CWAGENT_MODE:               "ec2",
 			},
 			contextSetup: func() {
+				context.ResetContext()
 				context.CurrentContext().SetProxy(map[string]string{
 					"http_proxy": "http://proxy.test",
 				})
@@ -123,8 +134,11 @@ func TestToEnvConfig(t *testing.T) {
 					agent.UseDualStackEndpointKey: "true",
 				},
 			},
-			expectedEnv: map[string]string{},
+			expectedEnv: map[string]string{
+				envconfig.CWAGENT_MODE: "ec2",
+			},
 			contextSetup: func() {
+				context.ResetContext()
 				context.CurrentContext().SetProxy(map[string]string{})
 				context.CurrentContext().SetSSL(map[string]string{})
 			},
@@ -136,8 +150,11 @@ func TestToEnvConfig(t *testing.T) {
 					agent.UseDualStackEndpointKey: 1,
 				},
 			},
-			expectedEnv: map[string]string{},
+			expectedEnv: map[string]string{
+				envconfig.CWAGENT_MODE: "ec2",
+			},
 			contextSetup: func() {
+				context.ResetContext()
 				context.CurrentContext().SetProxy(map[string]string{})
 				context.CurrentContext().SetSSL(map[string]string{})
 			},
@@ -149,8 +166,11 @@ func TestToEnvConfig(t *testing.T) {
 					agent.UseDualStackEndpointKey: nil,
 				},
 			},
-			expectedEnv: map[string]string{},
+			expectedEnv: map[string]string{
+				envconfig.CWAGENT_MODE: "ec2",
+			},
 			contextSetup: func() {
+				context.ResetContext()
 				context.CurrentContext().SetProxy(map[string]string{})
 				context.CurrentContext().SetSSL(map[string]string{})
 			},
@@ -161,11 +181,13 @@ func TestToEnvConfig(t *testing.T) {
 			input:   map[string]interface{}{},
 			envVars: map[string]string{},
 			expectedEnv: map[string]string{
-				envconfig.HTTP_PROXY:  "http://proxy.example.com",
-				envconfig.HTTPS_PROXY: "https://proxy.example.com",
-				envconfig.NO_PROXY:    "localhost,127.0.0.1",
+				envconfig.HTTP_PROXY:   "http://proxy.example.com",
+				envconfig.HTTPS_PROXY:  "https://proxy.example.com",
+				envconfig.NO_PROXY:     "localhost,127.0.0.1",
+				envconfig.CWAGENT_MODE: "ec2",
 			},
 			contextSetup: func() {
+				context.ResetContext()
 				context.CurrentContext().SetProxy(map[string]string{
 					"http_proxy":  "http://proxy.example.com",
 					"https_proxy": "https://proxy.example.com",
@@ -180,8 +202,10 @@ func TestToEnvConfig(t *testing.T) {
 			envVars: map[string]string{},
 			expectedEnv: map[string]string{
 				envconfig.AWS_CA_BUNDLE: "/path/to/ca-bundle.pem",
+				envconfig.CWAGENT_MODE:  "ec2",
 			},
 			contextSetup: func() {
+				context.ResetContext()
 				context.CurrentContext().SetProxy(map[string]string{})
 				context.CurrentContext().SetSSL(map[string]string{
 					"ca_bundle_path": "/path/to/ca-bundle.pem",
@@ -196,8 +220,10 @@ func TestToEnvConfig(t *testing.T) {
 			},
 			expectedEnv: map[string]string{
 				envconfig.CWAgentLogsBackpressureMode: "fd_release",
+				envconfig.CWAGENT_MODE:                "ec2",
 			},
 			contextSetup: func() {
+				context.ResetContext()
 				context.CurrentContext().SetProxy(map[string]string{})
 				context.CurrentContext().SetSSL(map[string]string{})
 			},
@@ -216,8 +242,10 @@ func TestToEnvConfig(t *testing.T) {
 				envconfig.CWAGENT_LOG_LEVEL:  "DEBUG",
 				envconfig.HTTP_PROXY:         "http://proxy.test",
 				envconfig.AWS_CA_BUNDLE:      "/test/ca-bundle.pem",
+				envconfig.CWAGENT_MODE:       "ec2",
 			},
 			contextSetup: func() {
+				context.ResetContext()
 				context.CurrentContext().SetProxy(map[string]string{
 					"http_proxy": "http://proxy.test",
 				})
@@ -226,6 +254,20 @@ func TestToEnvConfig(t *testing.T) {
 				})
 			},
 		},
+		{
+			name:    "mode persistence",
+			input:   map[string]interface{}{},
+			envVars: map[string]string{},
+			expectedEnv: map[string]string{
+				envconfig.CWAGENT_MODE: "onPremise",
+			},
+			contextSetup: func() {
+				context.ResetContext()
+				context.CurrentContext().SetMode("onPremise")
+				context.CurrentContext().SetProxy(map[string]string{})
+				context.CurrentContext().SetSSL(map[string]string{})
+			},
+		},
 	}
 
 	for _, tt := range tests {
@@ -262,8 +304,10 @@ func TestToEnvConfig_TypeAssertions(t *testing.T) {
 			input: map[string]interface{}{
 				agent.SectionKey: "invalid",
 			},
-			envVars:     map[string]string{},
-			expectedEnv: map[string]string{},
+			envVars: map[string]string{},
+			expectedEnv: map[string]string{
+				envconfig.CWAGENT_MODE: "ec2",
+			},
 		},
 		{
 			name: "invalid user_agent type",
@@ -272,8 +316,10 @@ func TestToEnvConfig_TypeAssertions(t *testing.T) {
 					userAgentKey: 123,
 				},
 			},
-			envVars:     map[string]string{},
-			expectedEnv: map[string]string{},
+			envVars: map[string]string{},
+			expectedEnv: map[string]string{
+				envconfig.CWAGENT_MODE: "ec2",
+			},
 		},
 		{
 			name: "invalid debug type",
@@ -282,16 +328,20 @@ func TestToEnvConfig_TypeAssertions(t *testing.T) {
 					debugKey: "true",
 				},
 			},
-			envVars:     map[string]string{},
-			expectedEnv: map[string]string{},
+			envVars: map[string]string{},
+			expectedEnv: map[string]string{
+				envconfig.CWAGENT_MODE: "ec2",
+			},
 		},
 		{
 			name: "invalid logs section type",
 			input: map[string]interface{}{
 				logs.SectionKey: "invalid",
 			},
-			envVars:     map[string]string{},
-			expectedEnv: map[string]string{},
+			envVars: map[string]string{},
+			expectedEnv: map[string]string{
+				envconfig.CWAGENT_MODE: "ec2",
+			},
 		},
 	}
 
@@ -307,6 +357,7 @@ func TestToEnvConfig_TypeAssertions(t *testing.T) {
 				}
 			}()
 
+			context.ResetContext()
 			context.CurrentContext().SetProxy(map[string]string{})
 			context.CurrentContext().SetSSL(map[string]string{})
 			result := ToEnvConfig(tt.input)