Update cloud_sql_proxy.go

Author: lychung83

cmd/cloud_sql_proxy/cloud_sql_proxy.go

@@ -81,6 +81,10 @@ can be removed automatically by this program.`)
 	token     = flag.String("token", "", "When set, the proxy uses this Bearer token for authorization.")
 	tokenFile = flag.String("credential_file", "", `If provided, this json file will be used to retrieve Service Account credentials.
 You may set the GOOGLE_APPLICATION_CREDENTIALS environment variable for the same effect.`)
+	
+        // Set when gcloud execution failed.
+        gcloudErrStr string
+
 )
 
 const (
@@ -328,33 +332,36 @@ func listInstances(ctx context.Context, cl *http.Client, projects []string) ([]s
 }
 
 func gcloudProject() []string {
-	buf := new(bytes.Buffer)
-	cmd := exec.Command("gcloud", "--format", "json", "config", "list", "core/project")
-	cmd.Stdout = buf
-
-	if err := cmd.Run(); err != nil {
-		if strings.Contains(err.Error(), "executable file not found") {
-			// gcloud not installed; ignore the error
-			return nil
-		}
-		logging.Errorf("Error detecting gcloud project: %v", err)
-		return nil
-	}
-
-	var data struct {
-		Core struct {
-			Project string
-		}
-	}
-
-	if err := json.Unmarshal(buf.Bytes(), &data); err != nil {
-		logging.Errorf("Failed to unmarshal bytes from gcloud: %v", err)
-		logging.Errorf("   gcloud returned:\n%s", buf)
-		return nil
-	}
-
-	logging.Infof("Using gcloud's active project: %v", data.Core.Project)
-	return []string{data.Core.Project}
+        const gcloudResultErrStr = "gcloud failed to get project list. See log for detail."
+        buf := new(bytes.Buffer)
+        cmd := exec.Command("gcloud", "--format", "json", "config", "list", "core/project")
+        cmd.Stdout = buf
+
+        if err := cmd.Run(); err != nil {
+                if strings.Contains(err.Error(), "executable file not found") {
+                        gcloudErrStr = "gcloud could not be found in the system path"
+                        return nil
+                }
+                gcloudErrStr = gcloudResultErrStr
+                logging.Errorf("Error detecting gcloud project: %v", err)
+                return nil
+        }
+
+        var data struct {
+                Core struct {
+                        Project string
+                }
+        }
+
+        if err := json.Unmarshal(buf.Bytes(), &data); err != nil {
+                gcloudErrStr = gcloudResultErrStr
+                logging.Errorf("Failed to unmarshal bytes from gcloud: %v", err)
+                logging.Errorf("   gcloud returned:\n%s", buf)
+                return nil
+        }
+
+        logging.Infof("Using gcloud's active project: %v", data.Core.Project)
+        return []string{data.Core.Project}
 }
 
 // Main executes the main function of the proxy, allowing it to be called from tests.