romajs/cronit

AWS Lambda function to start and stop EC2 instances based on their cron tags

cronit

AWS Lambda function to start and stop EC2 instances based on their cron tags.

This method aims to have greater flexibility, to change scheduling times, without having to manually and directly change the schedules, and / or IDs of your EC2 instances

Once configured, it is only necessary to define the following tags in your EC2 instances

For example:

Name	Value
cronit:start	0 11 ? * MON-FRI *
cronit:stop	0 22 ? * MON-FRI *

And then run the CLI synchronization. (every time you change your cronit tags)

CLI

This CLI can sync all your lambda function schedules to start and stop EC2 instances

Requirements

• Python 2.7+
• Python PIP
• Python Virtualenv

Install

./install.sh

Authentication

See the boto3 guide for credentials

Permissions

Create the role CronitCLIRole with the following:

This role must be then associated with your current user/credentials

CronitCLIPolicy.json:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "events:ListRules",
                "events:PutRule",
                "events:DeleteRule",
                "events:PutTargets",
                "events:RemoveTargets",
                "lambda:AddPermission",
                "lambda:RemovePermission",
                "lambda:GetFunction"
            ],
            "Resource": [
                "arn:aws:events:{region}:{accountId}:rule/*",
                "arn:aws:lambda:{region}:{accountId}:function:cronit"
            ]
        }
    ]
}

CronitCLIDescribeInstancesPolicy.json:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeInstances"
            ],
            "Resource": [
                "*"
            ]
        }
    ]
}
}

Execution

Can be executed both as ./cronit.py and cronit, but then it is needed to run:

source ./.virtualenv/bin/activate
source ./bash-complete.sh

Also bash completion is enabled with this

Usage

Usage: cronit [OPTIONS] COMMAND [ARGS]...

Options:
  --log-level TEXT  Set logging level
  --help            Show this message and exit.

Commands:
  sync  Update all cronit schedules

Then execute as cronit only

AWS Lambda

The actual function that start and stop instances based on your schedules

Permissions

Create the role CronitLambdaExecutionRole with the following:

This role must be then associated with your cronit lambda function

CronitLambdaExecutionPolicy.json:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeInstances",
                "ec2:StartInstances",
                "ec2:StopInstances"
            ],
            "Resource": [
                "*"
            ]
        }
    ]
}

Configuration

• TODO

Build distribution

./build-dist.sh