Dockerfile

Jets uses Docker to build and deploy your application by default. This page covers how it works and how to customize the Docker build process.

The Jets remote runner calls docker build and pushes the Docker image to ECR. Jets generates a Dockerfile, which is managed by the Jets remote build process. The generated Dockerfile can be customized for your purposes. This page covers Docker customization options.

1. Jets Managed Dockerfile: Jets auto-detects the framework and builds and manages Dockerfile for you. IE: You don’t have to.
2. Custom Dockerfile: You can use a custom Dockerfile. Jets will build using your Dockerfile.
3. Prebuilt Docker Image: When there’s a config.docker.image config set. Jets uses your provided prebuilt Docker image.

Option #1, Jets Managed Dockerfile, is recommended. It’s powerful, flexible, and customizable, with a plethora of options to customize the generated Dockerfile.

Options #2 and #3 require more effort and work on your part because you need to manage the Dockerfile and are responsible for updating it entirely. You must make sure the Docker image is Lambda compatible. IE: It has the Lambda Runtime Interface Client installed as an entrypoint, a Lambda handler, any required dependencies, and patches.

Jets Managed Dockerfile

The Jets Docker build process adds conveniences such as auto-detecting your web framework, building a managed Dockerfile, auto-tagging the image, and making sure the image is Lambda compatible.

See: Jets Managed Dockerfile

Custom Dockerfile

To use a custom Dockerfile and let Jets build it. You can activate it.

Jets.deploy.configure do
  config.dockerfile.custom = true
end

Jets will attempt to build the Docker image using your custom Dockerfile. You will have to mimic what Jets does with the Jets Managed Dockerfile. Jets scripts will get updated over time, and you must keep them up-to-date. Using your own Dockerfile is also less powerful than the Jets-generated Dockerfile because Jets cannot inject dynamic logic, such as installing system packages based on gem auto-detection.

Note: You can also provide a String as a path config.dockerfile.custom = "dockerfiles/Dockerfile1"

Prebuilt Docker Image

You can also use a prebuilt Docker image. This can be useful if you already have your own CI build process and want to use the Docker image it produces. You use JETS_DOCKER_IMAGE. Example:

JETS_DOCKER_IMAGE=my/image:v1 jets deploy

The Docker build process will be skipped. Jets will push the image to ECR, though. Lambda has faster access to this image because it’s within the AWS network.

Reference

The table below covers each setting. Each option is configured with config.OPTION. The config. portion is not shown for conciseness. IE: logger.level vs config.logger.level.

See Full Config Reference