aws-cfn-vpn-lexbot

AWS CloudFormation Stack for Lex chatbot services.

The bot can be in the different region from where this stack belongs to. Following chart shows the relationships between the resources.

CloudFormation Resources		Dynamic Resources(can be in different region)
Lambda function1 (Installer)	creates →	Lex bot calls ↓
Lambda function2 (Installer)	creates →	Lambda function3 (Handler)

Usage

stack.json

This repo contains a standard AWS CloudFormation template stack.json which can be deployed with AWS web console, AWS CLI or any other AWS CloudFormation compatible tool.

About how to do this, you may refer to a real-world example aws-cfn-vpn.

For the input parameters and the detail of the template, please check the template file.

Chat with the Bot

Supported intents:

1. Change node IP address
   • Chat syntax: Get a new IP[ for <nodename>]

1. by the Amazon Lex Web Console

Visit the Amazon Lex Web Console, choose the region you created the bot, click the Test Chatbot button in your Bot page. The chatbot should be chat-ready.

2. by the 3rd part application, such as Facebook

Check this document out: Deploying an Amazon Lex Bot on a Messaging Platform

The integration needs to be setup manually.

For Developers

1. The Lambda functions used by this template have to be inline Lambda functions to avoid the dependency of xsh aws/cfn/deploy config, because this template is going to be used as a nested template of aws-cfn-vpn. aws-cfn-vpn is able to be deployed with xsh aws/cfn/deploy which doesn't support to read config for the nested templates.

   Something you should know with the inline Lambda functions:

   1. Use the pyminifier to minimize the size of the Lambda code if the code size is greater than 4KB.

   pip install pyminifier
   pyminify LambdaLexBotInstaller.py > LambdaLexBotInstaller-pyminify.py
   pyminify LambdaCrossRegionRouterInstaller.py > LambdaCrossRegionRouterInstaller-pyminify.py
   

   1. Use import cfnresponse as the exact style, to let CloudFormation injects cfnresponse package for you.

Troubleshooting

1. The stack creation ends at CREATE_FAILED status and Lambda function LambdaCrossRegionRouterInstaller gives following log:

   An error occurred (InvalidParameterValueException) when calling
   the CreateFunction operation: The role defined for the function
   cannot be assumed by Lambda.
   

   It caused by the unavailable of the role. The role is created but is not ready yet. A 10 seconds delay is set for this, but sometimes it's not long enough.

   Try to redeploy the stack again, it should go well.

2. The stack deletion ends at DELETE_FAILED status: An error occurred (ConflictException) when calling the DeleteIntent operation: There is a conflicting operation in progress for the resource named 'GetNewIpForVpnInstance'.

   The deletion of the Lex bot is not complete yet. A 10 seconds delay is set for this, but sometimes it's not long enough.

   Try to redeploy the stack again, it should go well.

3. The Lex bot response in the chat: foo: the instance name you specified does not exist, the valid instance names are: .

   The instance takes around 15 minutes to register to the shadowsocks-manager after the stack creation is complete.

   Try to chat with the Lex bot later.

4. The stack deletion ends at DELETE_FAILED status: The following resource(s) failed to delete: [LexBotInstaller].

   Error log found in CloudWatch:

   request type: Delete
   unpublishing the bot
   An error occurred (ResourceInUseException) when calling the DeleteBotAlias operation:
   ...
   

   This error may occur if you have manually configured the Lex Bots Channels.

   Solution: Delete the integration of channel, then delete the BotAlias, Bot, and Intent. Delete the stack again.