feat: allow override useragent with json config

cfg/agentinfo/info.go

@@ -10,6 +10,8 @@ import (
 	"path/filepath"
 	"runtime"
 	"strings"
+
+	"github.com/aws/amazon-cloudwatch-agent/cfg/envconfig"
 )
 
 const versionFilename = "CWAGENT_VERSION"
@@ -22,6 +24,8 @@ var (
 	BuildStr      string = "No Build Date"
 	InputPlugins  []string
 	OutputPlugins []string
+
+	userAgent string
 )
 
 func Version() string {
@@ -49,7 +53,14 @@ func Plugins() string {
 }
 
 func UserAgent() string {
-	return fmt.Sprintf("%s %s", FullVersion(), Plugins())
+	if userAgent == "" {
+		ua := os.Getenv(envconfig.CWAGENT_USER_AGENT)
+		if ua == "" {
+			ua = fmt.Sprintf("%s %s", FullVersion(), Plugins())
+		}
+		userAgent = ua
+	}
+	return userAgent
 }
 
 func FullVersion() string {

cfg/agentinfo/info_test.go

@@ -4,11 +4,15 @@
 package agentinfo
 
 import (
+	"fmt"
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"runtime"
 	"strings"
 	"testing"
+
+	"github.com/aws/amazon-cloudwatch-agent/cfg/envconfig"
 )
 
 func TestVersionUseInjectedIfAvailable(t *testing.T) {
@@ -81,3 +85,28 @@ func TestPlugins(t *testing.T) {
 		t.Errorf("wrong plugins string constructed '%v', expecting '%v'", plugins, expected)
 	}
 }
+
+func TestUserAgent(t *testing.T) {
+	userAgent = ""
+	VersionStr = "VSTR"
+	BuildStr = "BSTR"
+	InputPlugins = []string{"a", "b", "c"}
+	OutputPlugins = []string{"x", "y", "z"}
+
+	ua := UserAgent()
+	expected := fmt.Sprintf("CWAgent/VSTR (%v; %v; %v) BSTR inputs:(a b c) outputs:(x y z)", runtime.Version(), runtime.GOOS, runtime.GOARCH)
+	if ua != expected {
+		t.Errorf("wrong UserAgent string constructed '%v', expecting '%v'", ua, expected)
+	}
+}
+
+func TestUserAgentEnvOverride(t *testing.T) {
+	userAgent = ""
+	os.Setenv(envconfig.CWAGENT_USER_AGENT, "CUSTOM CWAGENT USER AGENT")
+	expected := "CUSTOM CWAGENT USER AGENT"
+
+	ua := UserAgent()
+	if ua != expected {
+		t.Errorf("UserAgent should use value configured in environment variable CWAGENT_USER_AGENT, but '%v' found, expecting '%v'", ua, expected)
+	}
+}

cfg/envconfig/envconfig.go

@@ -5,9 +5,10 @@ package envconfig
 
 const (
 	//the following are the names of environment variables
-	HTTP_PROXY      = "HTTP_PROXY"
-	HTTPS_PROXY     = "HTTPS_PROXY"
-	NO_PROXY        = "NO_PROXY"
-	AWS_CSM_ENABLED = "AWS_CSM_ENABLED"
-	AWS_CA_BUNDLE   = "AWS_CA_BUNDLE"
+	HTTP_PROXY         = "HTTP_PROXY"
+	HTTPS_PROXY        = "HTTPS_PROXY"
+	NO_PROXY           = "NO_PROXY"
+	AWS_CSM_ENABLED    = "AWS_CSM_ENABLED"
+	AWS_CA_BUNDLE      = "AWS_CA_BUNDLE"
+	CWAGENT_USER_AGENT = "CWAGENT_USER_AGENT"
 )

translator/toenvconfig/toEnvConfig.go

@@ -11,16 +11,26 @@ import (
 	"github.com/aws/amazon-cloudwatch-agent/cfg/envconfig"
 	"github.com/aws/amazon-cloudwatch-agent/internal/csm"
 	"github.com/aws/amazon-cloudwatch-agent/translator/context"
+	"github.com/aws/amazon-cloudwatch-agent/translator/translate/agent"
 	"github.com/aws/amazon-cloudwatch-agent/translator/util"
 )
 
+const userAgentKey = "user_agent"
+
 func ToEnvConfig(jsonConfigValue map[string]interface{}) []byte {
 	envVars := make(map[string]string)
 	// If csm has a configuration section, then also turn on csm for the agent itself
 	if _, ok := jsonConfigValue[csm.JSONSectionKey]; ok {
 		envVars[envconfig.AWS_CSM_ENABLED] = "TRUE"
 	}
 
+	// Set CWAGENT_USER_AGENT to env config if specified by the json config in agent section
+	if agentMap, ok := jsonConfigValue[agent.SectionKey].(map[string]interface{}); ok {
+		if userAgent, ok := agentMap[userAgentKey].(string); ok {
+			envVars[envconfig.CWAGENT_USER_AGENT] = userAgent
+		}
+	}
+
 	proxy := util.GetHttpProxy(context.CurrentContext().Proxy())
 	if len(proxy) > 0 {
 		envVars[envconfig.HTTP_PROXY] = proxy[commonconfig.HttpProxy]

translator/toenvconfig/toEnvConfig_test.go

@@ -72,7 +72,9 @@ func TestLogMetricAndLog(t *testing.T) {
 
 func TestCompleteConfig(t *testing.T) {
 	resetContext()
-	expectedEnvVars := map[string]string{}
+	expectedEnvVars := map[string]string{
+		"CWAGENT_USER_AGENT": "CUSTOM USER AGENT VALUE",
+	}
 	checkIfTranslateSucceed(t, ReadFromFile("../totomlconfig/sampleConfig/complete_linux_config.json"), "linux", expectedEnvVars)
 	checkIfTranslateSucceed(t, ReadFromFile("../totomlconfig/sampleConfig/complete_windows_config.json"), "windows", expectedEnvVars)
 }

translator/totomlconfig/sampleConfig/complete_linux_config.json

@@ -3,6 +3,7 @@
     "metrics_collection_interval": 10,
     "logfile": "/opt/aws/amazon-cloudwatch-agent/logs/amazon-cloudwatch-agent.log",
     "internal": true,
+    "user_agent": "CUSTOM USER AGENT VALUE",
     "credentials": {
       "role_arn": "global_role_arn_value"
     }

translator/totomlconfig/sampleConfig/complete_windows_config.json

@@ -3,6 +3,7 @@
     "metrics_collection_interval": 60,
     "logfile": "c:\\ProgramData\\Amazon\\AmazonCloudWatchAgent\\Logs\\amazon-cloudwatch-agent.log",
     "internal": true,
+    "user_agent": "CUSTOM USER AGENT VALUE",
     "credentials": {
       "role_arn": "global_role_arn_value"
     }