Lipwig is an AWS SAM/Lambda application that posts SNS messages to external services, like Slack.
Publishing a message to an SNS topics is a common way to notify subscribers of some event in your system. For example, a dead letter queue topic lets publish events that your lambda function failed to handle.
But what if you want a person or team of people to know of the message? Out of the box, SNS only supports email (slow), push messages to an app that you own, or SMS (not free).
Lipwig provides lambda functions that you can subscribe to an SNS topic in order to publish its events to additional services that you use.
- Deploy the Lipwig app in your environment. You can use:
S3_BUCKET=your_deploy_bucket make publish- Either subscribe Lipwig lambda functions directly to SNS topics via the AWS console or CLI, or use
Fn::ImportValueto add the subscription in your own CloudFormation template (see this walkthrough for an example).
Log SNS messages to CloudWatch Logs.
No additional configuration is needed for this function. Look for its log stream in CloudWatch to see the messages.
The CloudWatch function is exported as lipwig-CloudWatchLogsFunction.
Post SNS messages to Slack.
- Create a Slack app.
- Give your app the
chat:write:botpermission scope. - Make the app's OAuth access token available to Lipwig:
- Either add it to the lambda function's environment variables, as an encrypted variable, with the key
SLACK_TOKEN. - Or add it to SSM ParameterStore, as an encrypted parameter, with the key
/Lipwig/SlackToken.
- Either add it to the lambda function's environment variables, as an encrypted variable, with the key
- You can control the channel that messages are posted to by adding an environment variable with the key
SLACK_CHANNEL. If you do not specify a channel, then#lipwigis used by default.
The Slack function is exported as lipwig-SlackFunction.
The name is a reference to Moist von Lipwig, the Ankh-Morpork Postmaster General in Terry Pratchett's novel Going Postal.
Lipwig can post message anywhere, just like the revitalized Ankh-Morpork postal service under von Lipwig.
