fix: add runtime version to user agent if present

cmd/root.go

@@ -86,6 +86,7 @@ type Command struct {
 	httpAddress                string
 	httpPort                   string
 	quiet                      bool
+	runtime                    string
 
 	// impersonationChain is a comma separated list of one or more service
 	// accounts. The first entry in the chain is the impersonation target. Any
@@ -344,6 +345,8 @@ func NewCommand(opts ...Option) *Command {
 	pflags.BoolP("version", "v", false, "Print the cloud-sql-proxy version")
 
 	// Global-only flags
+	pflags.StringVar(&c.runtime, "runtime", "",
+		"(for internal use only) Runtime and version, e.g. cloud-sql-proxy-operator/0.0.1")
 	pflags.StringVarP(&c.conf.Token, "token", "t", "",
 		"Use bearer token as a source of IAM credentials.")
 	pflags.StringVarP(&c.conf.CredentialsFile, "credentials-file", "c", "",
@@ -492,6 +495,11 @@ func parseConfig(cmd *Command, conf *proxy.Config, args []string) error {
 		cmd.logger.Infof("Ignoring --disable-traces because --telemetry-project was not set")
 	}
 
+	if userHasSet("runtime") {
+		userAgent += " " + cmd.runtime
+		conf.UserAgent = userAgent
+	}
+
 	if userHasSet("sqladmin-api-endpoint") && conf.APIEndpointURL != "" {
 		_, err := url.Parse(conf.APIEndpointURL)
 		if err != nil {

cmd/root_test.go

@@ -21,6 +21,7 @@ import (
 	"net/http"
 	"os"
 	"path/filepath"
+	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -81,6 +82,42 @@ func invokeProxyCommand(args []string) (*Command, error) {
 	return c, err
 }
 
+func TestUserAgentWithOperatorVersionEnvVar(t *testing.T) {
+	os.Setenv("CSQL_PROXY_RUNTIME", "cloud-sql-proxy-operator/0.0.1")
+	defer os.Unsetenv("CSQL_PROXY_RUNTIME")
+
+	cmd, err := invokeProxyCommand([]string{"proj:region:inst"})
+	if err != nil {
+		t.Fatalf("want error = nil, got = %v", err)
+	}
+
+	want := "cloud-sql-proxy-operator/0.0.1"
+	got := cmd.conf.UserAgent
+	if !strings.Contains(got, want) {
+		t.Errorf("expected userAgent to contain: %v; got: %v", want, got)
+	}
+}
+
+func TestUserAgentWithOperatorVersionFlag(t *testing.T) {
+
+	cmd, err := invokeProxyCommand(
+		[]string{
+			"--runtime",
+			"cloud-sql-proxy-operator/0.0.1",
+			"proj:region:inst",
+		},
+	)
+	if err != nil {
+		t.Fatalf("want error = nil, got = %v", err)
+	}
+
+	want := "cloud-sql-proxy-operator/0.0.1"
+	got := cmd.conf.UserAgent
+	if !strings.Contains(got, want) {
+		t.Errorf("expected userAgent to contain: %v; got: %v", want, got)
+	}
+}
+
 func TestNewCommandArguments(t *testing.T) {
 	tcs := []struct {
 		desc string