add aws codecommit example and validation

Signed-off-by: Sanskar Jaiswal <jaiswalsanskar078@gmail.com>

cmd/flux/bootstrap_git.go

@@ -60,6 +60,9 @@ command will perform an upgrade if needed.`,
 
   # Run bootstrap for a Git repository with a private key and password
   flux bootstrap git --url=ssh://git@example.com/repository.git --private-key-file=<path/to/private.key> --password=<password>
+
+  # Run bootstrap for a Git repository on AWS CodeCommit
+  flux bootstrap git --url=ssh://<SSH-Key-ID>@git-codecommit.<region>.amazonaws.com/v1/repos/<repository> --private-key-file=<path/to/private.key> --password=<SSH-passphrase>
 `,
 	RunE: bootstrapGitCmdRun,
 }
@@ -115,6 +118,19 @@ func bootstrapGitCmdRun(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
+	if repositoryURL.Scheme == "ssh" && strings.Contains(repositoryURL.Hostname(), "git-codecommit") &&
+		strings.Contains(repositoryURL.Hostname(), "amazonaws.com") {
+		if repositoryURL.User == nil {
+			return fmt.Errorf("invalid AWS CodeCommit url: ssh username should be specified in the url")
+		}
+		if repositoryURL.User.Username() == "git" {
+			return fmt.Errorf("invalid AWS CodeCommit url: ssh username should be the SSH key ID for the provided private key")
+		}
+		if bootstrapArgs.privateKeyFile == "" {
+			return fmt.Errorf("private key file is required for bootstrapping against AWS CodeCommit using ssh")
+		}
+	}
+
 	ctx, cancel := context.WithTimeout(context.Background(), rootArgs.timeout)
 	defer cancel()