Invoke Lambda from CodePipeline with multiple UserParameters - amazon-web-services

Question

This tutorial shows how to Invoke a Lambda from CodePipeline passing a single parameter:
http://docs.aws.amazon.com/codepipeline/latest/userguide/how-to-lambda-integration.html
I've built a slackhook lambda that needs to get 2 parameters:
webhook_url
message
Passing in JSON via the CodePipeline editor results in the JSON block being sent in ' ' so it can't be parsed directly.
UserParameter passed in:
{
"webhook":"https://hooks.slack.com/services/T0311JJTE/3W...W7F2lvho",
"message":"Staging build awaiting approval for production deploy"
}
User Parameter in Event payload
UserParameters: '{
"webhook":"https://hooks.slack.com/services/T0311JJTE/3W...W7F2lvho",
"message":"Staging build awaiting approval for production deploy"
}'
When trying to apply multiple UserParameters directly in the CLoudFormation like this:
Name: SlackNotification
ActionTypeId:
Category: Invoke
Owner: AWS
Version: '1'
Provider: Lambda
OutputArtifacts: []
Configuration:
FunctionName: aws-notify2
UserParameters:
- webhook: !Ref SlackHook
- message: !Join [" ",[!Ref app, !Ref env, "build has started"]]
RunOrder: 1
Create an error - Configuration must only contain simple objects or strings.
Any guesses on how to get multiple UserParameters passing from a CloudFormation template into a Lambda would be much appreciated.
Here is the lambda code for reference:
https://github.com/byu-oit-appdev/aws-codepipeline-lambda-slack-webhook

Answer 1

You should be able to pass multiple UserParameters as a single JSON-object string, then parse the JSON in your Lambda function upon receipt.
This is exactly how the Python example in the documentation handles this case:
try:
# Get the user parameters which contain the stack, artifact and file settings
user_parameters = job_data['actionConfiguration']['configuration']['UserParameters']
decoded_parameters = json.loads(user_parameters)
Similarly, using JSON.parse should work fine in Node.JS to parse a JSON-object string (as shown in your Event payload example) into a usable JSON object:
> JSON.parse('{ "webhook":"https://hooks.slack.com/services/T0311JJTE/3W...W7F2lvho", "message":"Staging build awaiting approval for production deploy" }')
{ webhook: 'https://hooks.slack.com/services/T0311JJTE/3W...W7F2lvho',
message: 'Staging build awaiting approval for production deploy' }