Lambder

Serverless cron jobs written in python and scheduled as AWS Lambdas.

We used to implement maintenance jobs like RDS snapshots and starting/stopping instances outside of business hours as CI server builds. This always seemed hacky. When scheduled Lambdas were released, we got to work re-implementing these scripts. Unfortunately, scheduled Lambdas have a steep learning curve. You have to understand IAM roles, CloudWatch Events, and how to deploy and update Lambda function code.

Lambder simplifies the creation and deployment of these scheduled jobs.

Installation

If you don't use pipsi, you're missing out. Here are installation instructions.

Simply run:

$ pipsi install lambder

Getting Started

Lambder uses boto3 to access AWS. You'll need to configure it with your access keys and default region by following these instructions.

To create a new Lambda Function project, specify a name and an S3 bucket to store the code zipfile.

1. lambder functions new --name foo --bucket mys3bucket
2. cd lambder-foo
3. lambder functions deploy
4. lambder functions list
5. lambder functions invoke

Usage

Get help

lambder --help

Managing Events

Schedule an existing AWS Lambda

lambder events add \
  --name EbsBackups \
  --function-name Lambder-ebs-backup \
  --cron 'cron(0 6 ? * * *)'

Remove an event (a scheduled Lambda)

lambder events rm --name EbsBackups

Disable an event

lambder events disable --name EbsBackups

Re-enable a disabled event

lambder events enable --name EbsBackups

Load events from a json file

lambder events load --file example_events.json

List all events created by lambder

lambder events list

Managing Functions

Create a new AWS Lambda project. Specify a name and an S3 bucket to store the Lambda function code. Optionally specify function configuration like timeout, memory size, and description.

lambder functions new \
  --name ebs-backups \
  --bucket my-s3-bucket \
  --timeout 30 \
  --memory 128 \
  --description "ebs backup function"

You can also deploy your Lambda functions to your VPC.

lambder functions new \
  --name curl-backend-site \
  --bucket my-s3-bucket \
  --timeout 30 \
  --memory 128 \
  --description "curl a site on a  private subnet" \
  --subnet-ids  "subnet-1abcdef,subnet-2abcdef" \
  --security-group-ids "sg-12345678"

Deploy the Lambda function (from within the project directory)

lambder functions deploy

Invoke the Lambda in AWS (from within the project directory)

lambder functions invoke

Invoke the function with input (from within the project directory)

lambder functions invoke --input input/ping.json

List all functions

lambder functions list

Delete a function (from within the project directory)

lambder functions rm

Sample Lambda Functions

• https://github.com/LeafSoftware/lambder-create-images
• https://github.com/LeafSoftware/lambder-start-instances
• https://github.com/LeafSoftware/lambder-stop-instances
• https://github.com/LeafSoftware/lambder-prune-snapshots
• https://github.com/LeafSoftware/lambder-create-snapshots
• https://github.com/LeafSoftware/lambder-replicate-snapshots
• https://github.com/LeafSoftware/lambder-create-rds-snapshots
• https://github.com/LeafSoftware/lambder-implement-best-practices

TODO:

• add code to add site packages from virtualenvwrapper to zip
• add lambda name autodetection to 'lambder events add'
• add pagination where needed (lambda:list-functions)