uduinc/packer-post-processor-docker-dockerfile

A Packer post-processor plugin that sets Dockerfile metadata on Docker images

Packer Dockerfile post-processor

This is a Packer post-processor plugin which allows setting Docker metadata on an artifact from the docker-tag post-processor.

Normally, Docker images built using Packer cannot include entrypoint, cmd, user, environment variables and other metadata that is available in Dockerfiles. This plugin will create a temporary Dockerfile and run docker build in an annonymous context. Most Dockerfile instructions are supported as json parametersp

Caveats

• RUN, ADD, COPY, and ONBUILD are not supported because packer provisioners should be used for their functionality.
• Docker no longer supports digests in FROM, thus a chained docker-tag post-processor is required.

Usage

In your packer template, configure the post processor:

{
  ...
  "post-processors": [
    [
      {
        "type": "docker-tag",
        "repository": "localhost/example"
      },
      {
        "type": "docker-dockerfile",
        "volume": ["/data"]
        "expose": [8080],
        "entrypoint": ["/entrypoint.sh"],
        "cmd": ["bash"],
        "env": {
          "FOO": "bar"
        }
      }
    ]
  ]
  ...
}

cmd and entrypoint can have either array or string values, this mirrors the Dockerfile format and functionality

See the Dockerfile reference for details.

Building

Install the necessary dependencies

$ go get -d ./...

To compile the Packer plugin, run go build.

$ go build

Put the binary packer-post-processor-docker-dockerfile into the bin directory of your choice

Acknowledgement

• Avishai Ish-Shalom's original plugin
• James G. Kim's re-write

Sponsors

This plugin was made possible by Shiftgig

License

This plugin is released under the Apache License, Version 2.0.

Support

Please file an issue on the github repository if you think anything isn't working properly or an improvement is required.

This plugin was developed against Docker 1.8.1 and Packer 0.8.6.