Merge pull request #2314 from aws/feat-optimize-ua-appID

Optimize logic of retrieving user agent appID from env config

.changelog/4f0e4753f9534938a41748143638981c.json

@@ -0,0 +1,8 @@
+{
+    "id": "4f0e4753-f953-4938-a417-48143638981c",
+    "type": "feature",
+    "description": "Modify logic of retrieving user agent appID from env config",
+    "modules": [
+        "config"
+    ]
+}

config/env_config.go

@@ -69,6 +69,7 @@ const (
 
 	awsRetryMaxAttempts = "AWS_MAX_ATTEMPTS"
 	awsRetryMode        = "AWS_RETRY_MODE"
+	awsSdkAppID         = "AWS_SDK_UA_APP_ID"
 )
 
 var (
@@ -248,6 +249,9 @@ type EnvConfig struct {
 	//
 	// aws_retry_mode=standard
 	RetryMode aws.RetryMode
+
+	// aws sdk app ID that can be added to user agent header string
+	AppID string
 }
 
 // loadEnvConfig reads configuration values from the OS's environment variables.
@@ -288,6 +292,8 @@ func NewEnvConfig() (EnvConfig, error) {
 	cfg.RoleARN = os.Getenv(awsRoleARNEnvVar)
 	cfg.RoleSessionName = os.Getenv(awsRoleSessionNameEnvVar)
 
+	cfg.AppID = os.Getenv(awsSdkAppID)
+
 	if err := setEndpointDiscoveryTypeFromEnvVal(&cfg.EnableEndpointDiscovery, []string{awsEnableEndpointDiscoveryEnvVar}); err != nil {
 		return cfg, err
 	}
@@ -335,6 +341,10 @@ func (c EnvConfig) getDefaultsMode(ctx context.Context) (aws.DefaultsMode, bool,
 	return c.DefaultsMode, true, nil
 }
 
+func (c EnvConfig) getAppID(context.Context) (string, bool, error) {
+	return c.AppID, len(c.AppID) > 0, nil
+}
+
 // GetRetryMaxAttempts returns the value of AWS_MAX_ATTEMPTS if was specified,
 // and not 0.
 func (c EnvConfig) GetRetryMaxAttempts(ctx context.Context) (int, bool, error) {

config/resolve.go

@@ -113,10 +113,6 @@ func resolveAppID(ctx context.Context, cfg *aws.Config, configs configs) error {
 		return err
 	}
 
-	// if app ID is set in env var, it should precedence shared config value
-	if appID := os.Getenv(`AWS_SDK_UA_APP_ID`); len(appID) > 0 {
-		ID = appID
-	}
 	cfg.AppID = ID
 	return nil
 }