Cloudwatch Alert Router

Cloudwatch Alert Router is a simple lambda that will take cloudwatch alarms (via event bridge) and deliver them to Slack and/or PagerDuty depending.

Slack channels and PagerDuty delivery can be configured via AWS tags on the Cloudwatch alarms.

API keys

Minimum required environment variables

These are required to be set, otherwise the application may not run correctly.

Environment variable	Description	Example
DEFAULT_SLACK_CHANNEL	Default slack channel where alarms are sent if no channel can be inferred	test-alarms
SLACK_TOKEN_SSM_KEY	The SSM Parameter name where your Slack Oauth access token is stored	/lambda/my-lambda-name/slack/app/oauth/access_token
PAGERDUTY_DEFAULT_ROUTING_KEY	Default PagerDuty routing key (otherwise some logic is used to search for a key in SSM)	xxxxxxx
IMAGE_BUCKET	Name of the S3 bucket where temporary graphs are stored	my-bucket-name
IMAGE_BUCKET_REGION	Region of the bucket	us-west-2
IMAGE_HOST		https://my-bucket-cdn.mysite.com

Optional environment variables

The following environment variables are optional

Environment variable	Description	Default	Example
IMAGE_BUCKET_ROLE_ARN	Role we need to assume to write to the image bucket (leave empty to use the lambda role)	""	arn:aws:iam::123456789012:role/role_with_bucket_access
LOG_LEVEL	Log level	INFO	DEBUG
OWNER_TAG_KEY	AWS tag to determine who owns the alarm - used to infer the slack channel name (-alarms)	owner
APP_NAME_TAG_KEY	AWS tag for the service that owns the alarm - used to infer a pagerduty routing key from ssm (eg: /service/cw_alert_router/pagerduty/routing_keys/)	service

Getting started

A simple example of how to get the lambda up and running:

package main

import (
	log "github.com/sirupsen/logrus"
	"github.com/tidal-open-source/cw-alert-router/lambda"
)

func main() {
	cfg, err := lambda.NewConfig()

	if err != nil {
		log.Fatalf("Error initializing lambda: %v", err)
	}

	lambda.SetConfig(cfg)
	lambda.Start()
}

Compile and upload the lambda - then set the required (and/or optional) environment variables to configure the service to your needs.