func ValidateInputAndStartSession()

in src/sessionmanagerplugin/session/session.go [130:218]
79 lines of code
19 McCabe index (conditional complexity)

func ValidateInputAndStartSession(args []string, out io.Writer) {
	var (
		err                error
		session            Session
		startSessionOutput ssm.StartSessionOutput
		response           []byte
		region             string
		operationName      string
		profile            string
		ssmEndpoint        string
		target             string
	)
	log := log.Logger(true, "session-manager-plugin")
	uuid.SwitchFormat(uuid.CleanHyphen)

	if len(args) == 1 {
		fmt.Fprint(out, "\nThe Session Manager plugin was installed successfully. "+
			"Use the AWS CLI to start a session.\n\n")
		return
	} else if len(args) == 2 && args[1] == "--version" {
		fmt.Fprintf(out, "%s\n", string(version.Version))
		return
	} else if len(args) >= 2 && len(args) < LegacyArgumentLength {
		fmt.Fprintf(out, "\nUnknown operation %s. \nUse "+
			"session-manager-plugin --version to check the version.\n\n", string(args[1]))
		return

	} else if len(args) == LegacyArgumentLength {
		// If arguments do not have Profile passed from AWS CLI to Session-Manager-Plugin then
		// should be upgraded to use Session Manager encryption feature
		session.IsAwsCliUpgradeNeeded = true
	}

	for argsIndex := 1; argsIndex < len(args); argsIndex++ {
		switch argsIndex {
		case 1:
			if strings.HasPrefix(args[1], "AWS_SSM_START_SESSION_RESPONSE") == true {
				response = []byte(os.Getenv(args[1]))
				if err = os.Unsetenv(args[1]); err != nil {
					log.Errorf("Failed to remove temporary session env parameter: %v", err)
				}
			} else {
				response = []byte(args[1])
			}
		case 2:
			region = args[2]
		case 3:
			operationName = args[3]
		case 4:
			profile = args[4]
		case 5:
			// args[5] is parameters input to aws cli for StartSession api call
			startSessionRequest := make(map[string]interface{})
			json.Unmarshal([]byte(args[5]), &startSessionRequest)
			target = startSessionRequest["Target"].(string)
		case 6:
			ssmEndpoint = args[6]
		}
	}
	sdkutil.SetRegionAndProfile(region, profile)
	clientId := uuid.NewV4().String()

	switch operationName {
	case StartSessionOperation:
		if err = json.Unmarshal(response, &startSessionOutput); err != nil {
			log.Errorf("Cannot perform start session: %v", err)
			fmt.Fprintf(out, "Cannot perform start session: %v\n", err)
			return
		}

		session.SessionId = *startSessionOutput.SessionId
		session.StreamUrl = *startSessionOutput.StreamUrl
		session.TokenValue = *startSessionOutput.TokenValue
		session.Endpoint = ssmEndpoint
		session.ClientId = clientId
		session.TargetId = target
		session.DataChannel = &datachannel.DataChannel{}

	default:
		fmt.Fprint(out, "Invalid Operation")
		return
	}

	if err = startSession(&session, log); err != nil {
		log.Errorf("Cannot perform start session: %v", err)
		fmt.Fprintf(out, "Cannot perform start session: %v\n", err)
		return
	}
}