CloudFormation custom resource: Task definition with EFS

This project implements a CloudFormation custom resource Lambda backend to register a task definition with EFS mounts.

How to install the Lambda function?

Create an IAM policy using the task-definition-lambda-policy.json file. For example with the AWS command line tool:

$ aws --profile YOUR_PROFILE iam create-policy \
        --policy-name task-definition-lambda-policy \
        --policy-document file://./task-definition-lambda-policy.json

Make a note of the policy ARN. Then create an IAM role for the Lambda function using the above policy, and name it task-definition-lambda-role. For example with the AWS command line tool:

$ aws --profile YOUR_PROFILE iam create-role \
        --role-name task-definition-lambda-role \
        --assume-role-policy-document file://./task-definition-role-assume-policy.json
$ aws --profile YOUR_PROFILE iam attach-role-policy \
        --role-name task-definition-lambda-role \
        --policy-arn ARN_OF_PREVIOUSLY_CREATE_POLICY

Make a note of the role ARN. Finally, create the Lambda function thus:

$ ./package.sh
$ aws --profile YOUR_PROFILE lambda create-function \
        --function-name task-definition \
        --memory 128 \
        --timeout 30 \
        --role ARN_OF_PREVIOUSLY_CREATE_ROLE \
        --runtime python3.6 \
        --zip-file fileb://./task_definition.zip \
        --handler task_definition.handler

How to use the task-definition custom resource?

Checkout the cfn-test.yml file for an example of a working CloudFormation template.

In essence, just use the parameters as described in the RegisterTaskDefinition AWS API.

If you want to use the cfn-test.yml file, you will need to build and upload the timestamp-app Docker image. In order to do that, you will need to edit the timestamp-app/Dockerfile file to use your Docker hub account.

You can verify it's working by launching an EC2 instance in the same subnet you selected when deploying the CloudFormation template and mounting the EFS filesystem thus:

$ sudo mkdir /efs
$ sudo mount -t nfs4 EFSID.efs.REGION.amazonaws.com:/ /efs

EFSID is the ID of the EFS filesystem, which is shown as an output of the CloudFormation template.