GitLab merge request notification to Slack Terraform module

This module creates an API Gateway and an AWS Lambda function that send notifications to Slack for each merge request event you want to be subscribed to.

GitLab will send a webhook notification to your lambda when you open/update a merge request. The lambda will then send a message to Slack channels depending on the labels applied to the merge request and the configuration specified when invoking the Terraform module.

Requirements

• Set up an incoming webhook integration in your Slack workspace
• Create the project labels you want to apply to your merge requests

Supported Features

• AWS Lambda runtime Ruby 2.7
• Create API Gateway
• Create AWS Lambda
• Configuration as Terraform code
• Potentially all features from lambda and apigatewayv2 community modules

Usage

module "gitlab_mr_to_slack" {
  source  = "https://github.com/Coolomina/terraform-gitlab-mr-to-slack"

  slack_webhook_url = "https://hooks.slack.com/services/XXX/YYY/ZZZ"
  labels_to_notify  = {
	  "SRE": "#sre-pr-reviews"
	  "DEV": "#dev-reviews"
	  "QA": "#qa-reviews"
  }
}

GitLab configuration

After applying, you can run $ terraform output -raw webhook_endpoint and paste that endpoint in your GitLab webhook integration URL. You'll want to specify only Merge request events, as you'll be billed for each invocation of the lambda.

Requirements

Name	Version
terraform	>= 0.13.1
local	>= 2.1

Providers

Name	Version
local	2.1.0

Modules

Name	Source	Version
api_gateway	terraform-aws-modules/apigateway-v2/aws	v1.5.1
lambda_function	terraform-aws-modules/lambda/aws	v2.34.0

Resources

Name	Type
local_file.config	resource

Inputs

Name	Description	Type	Default	Required
api_gateway_cors_allow_headers	API Gateway allowed headers	list(string)	[ "content-type", "x-amz-date", "authorization", "x-api-key", "x-amz-security-token", "x-amz-user-agent" ]	no
api_gateway_cors_allow_methods	API Gateway allowed headers	list(string)	[ "POST" ]	no
api_gateway_cors_allow_origins	List of origins to allow traffic from.	list(string)	[ "*" ]	no
api_gateway_description	API Gateway description	string	"API that derives POST notifications from Gitlab to the associated lambda"	no
custom_uri_path	Custom path for the API Gateway endpoint	string	"/"	no
gitlab_subscribe_events	Gitlab Merge Request events to subscribe to	string	"open,update"	no
labels_to_notify	A map of labels and corresponding slack channels to notify	map(string)	n/a	yes
lambda_description	Description of the lambda functionality	string	"This lambda will receive http events from API gateway and will ship them to a Slack channel."	no
name	Name of the stack	string	"gitlab-to-slack"	no
slack_username	Slack username to send notifications as	string	"Gitlab MR webhook"	no
slack_webhook_url	Integration URL of Slack Webhook. Eg. https://hooks.slack.com/services/XX/YYYYY/ZZZZZZ	string	n/a	yes

Outputs

Name	Description
webhook_endpoint	The public full URL of your lambda