ebirah

Experimental Docker image for Dist::Zilla

Features

• Encapsulates Dist::Zilla and dzil in a Docker container, so you do not have to install and maintain Dist::Zilla and all it's magnificent dependencies
• Offers interaction with the dzil command from the comfort of your terminal as ebirah
• It can be used for continuous integration pipelines

Ebirah supports all the following Dist::Zilla commands, so you can replace dzil with ebirah for using the Docker image (please see the section on summoning Ebirah):

• ebirah help - show helps message
• ebirah commands - lists available commands
• ebirah new - sets up a new distribution
• ebirah build - builds the distribution
• ebirah clean - cleans the build
• ebirah test - tests the build
• ebirah smoke - smoke tests the build
• ebirah install - installs the distribution
• ebirah add - adds an additional component to the distribution
• ebirah listdeps - lists runtime dependencies for the distribution
• ebirah authordeps - lists Dist::Zilla dependencies used the toolchain, Ebirah in this case
• ebirah run - runs a executable in the context of the distribution
• ebirah nop - a no-operation primarily for diagnostic purposes
• ebirah xtest - tests the build using the contents of the xt directory

All command options are supported.

Please see the documentation at dzil.org for more details on dzil use.

Ebirah does not currently support:

• ebirah release - release the distribution to PAUSE/CPAN
• ebirah setup - runs interactive configuration process, resulting in $HOME/.dzil/config.ini file

This is on the road map.

Ebirah does also not handle the definition of prerequisites in the dist.ini file.

Specification

The Docker image is based on the official Perl Docker image, using the latest available stable version of this image. See the Dockerfile for details.

It is based on the larger image, not the slim version since Dist::Zilla and extensions require a toolchain for XS based Perl distributions.

A note on DockerHub

The images are build from the GitHub repository master branch.

The recommended use is to use the latest release with a version tag. See Changelog.md for details. Whereas the tag latest just reflect the latest build based on the master branch.

The master branch might contain changes not tagged as released yet and can be regarded as unstable or experimental. Changes such as corrections to documentation etc. will not be tagged until separately as a general rule, unless the changes are significant, but the aim is to keep the documentation relevant and up to date.

Summoning Ebirah

Ebirah is available on DockerHub, or you can build it yourself based on this repository, see the section below on building Ebirah.

docker pull jonasbn/ebirah:0.8.0

docker run --rm --volume $PWD:/opt jonasbn/ebirah:0.8.0

And if you are want the latest build from DockerHub:

docker pull jonasbn/ebirah:latest

docker run --rm --volume $PWD:/opt jonasbn/ebirah:latest

As mentioned latest can be considered unstable or experimental. Development is kept in branches, but new experimental features might make into master for wider evaluation.

Using the image available from GitHub instead of DockerHub, do note this repository is in beta:

docker pull ghcr.io/jonasbn/ebirah:0.8.0

docker run --rm --volume $PWD:/opt ghcr.io/jonasbn/ebirah:0.8.0

Using a script

The feature listing assumes the script is named ebirah

#!/bin/bash

# REF:http://jonasbn.github.io/til/bash/write_safe_shell_scripts.html
set -euf -o pipefail

# run ebirah docker image in current directory and cleanup the image afterwards
docker run --rm --volume $PWD:/opt jonasbn/ebirah "$@"

Using an alias

# run ebirah docker image in current directory and cleanup the image afterwards
alias ebirah='docker run --rm --volume $PWD:/opt jonasbn/ebirah'

Using Ebirah for Continuous Integration

Ebirah was built with continuous integration (CI) in mind, meaning that encapsulating Dist::Zilla in a easily distributable container.

First attempt at getting this to work has been implemented as a GitHub Action.

The action can easily be implemented and current relies on Dist::Zilla using repositories.

The GitHub Action performs the following steps:

1. Installs Perl dependencies, specified in the repository (currently only support the presences of a cpanfile, this might be extended and/or changed in the future based on requirements)
2. Executes dzil with parameters specified in the GitHub Action configuration

An example configuration:

name: CI Action
on: push

jobs:
  build:
    name: Continuous Integration
    runs-on: ubuntu-latest
    steps:
    # REF: https://help.github.com/en/actions/configuring-and-managing-workflows/configuring-a-workflow#using-the-checkout-action
    - name: "Checkout repository"
      uses: actions/checkout@v3
    - name: "Installing dependencies and testing all using dzil"
      uses: jonasbn/github-action-perl-dist-zilla@0.2.0
      with:
          dzil-arguments: 'test --all'

Lifted from: .github/workflows/ci.yml from perl-app-yak.

Examples are available here:

• App::Yak

Please see the documentation on the GitHub Action for Dist::Zilla for more details

Diagnostics

no configuration (e.g, dist.ini)

This error indicates that you have forgotten to invoke the Docker command with --volume

1. Add --volume as specified in the documentation to your invocation

docker run --rm --volume $PWD:/opt jonasbn/ebirah

Invalid selection, please try again:

If you are executing the setup command and you have forgotten to invoke the Docker command with --volume. You will get a lot of repeated messages:

Invalid selection, please try again: Invalid selection, please try again:

For now the setup command is not supported.

docker run --rm --volume $PWD:/opt jonasbn/ebirah

Also you have to shut down the running container with the Docker kill command:

$ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES
240e33386a0b        ebirah:latest       "dzil setup"        3 seconds ago       Up 1 second                             kind_hopper
$ docker kill 240e33386a0b
240e33386a0b

Cannot detect source of 'xt'!

If you are executing the xtest command and the xt directory does either not exist or does not contain any tests.

1. Either add a xt directory with tests
2. Add tests to your empty xt directory
3. Do not use the xtest command since it does not make sense in the context you are running

Building ebirah

If you choose to build the image yourself, the above information has to be adjusted accordingly to reflect the image name

Building the Docker Image

docker build -t jonasbn/ebirah .

Running the Docker Image

docker run --rm -v $PWD:/opt jonasbn/ebirah

Do note you can use the short-form ebirah for the image name, I just use the fully qualified name matching my own usage pattern and the examples and documentation above.

Acknowledgements

A list of contributors in alphabetical order:

• Alceu Rodrigues de Freitas Junior (@glasswalk3r)
• Ed Sabol (@esabol)

About

Ebirah is one of the Godzilla characters (kaiju), since Dist::Zilla namewise also originates from the Godzilla (kaiju) universe, Ebirah was a good candidate for a project name with the marine relation, making sense in Docker backdrop.

The logo used is by the artist ZappaZee. I found it via Deviant Art and it is used here with permission.

Resources and References

• Blog post by Andrew Lock: "Packaging CLI programs into Docker images to avoid dependency hell"
• GitHub repository
• Docker Documentation: run reference for docker cli
• DockerHub: Perl
• DockerHub: Ebirah
• dzil.org
• MetaCPAN: Dist::Zilla
• GitHub: "Getting Started with the GitHub Container Registry