dgraziotin/jekyll-imagemagick6

Jekyll Docker image with Imagemagick6 instead of ImageMagick7

This Docker image extende https://hub.docker.com/r/jekyll/jekyll/ to use ImageMagick6 instead of ImageMagick7.

Build

Build the image with

docker build . -t dgraziotin/jekyll-imagemagick6:stable

You can target any Jekyll version https://hub.docker.com/r/jekyll/jekyll/tags, just replace the instances of the word stable in the Dockerfile and the build command with the tag of interest.)

Pull

Instead of building the image, you can pull it from the Docker Hub registry.

docker pull dgraziotin/jekyll-imagemagick6:stable

Run

Run your new image with the following command:

/usr/bin/env docker run --rm \
  --volume="$PWD:/srv/jekyll" \
  -it dgraziotin/jekyll-imagemagick6:stable \
  jekyll build

And that is it! You can serve your Jekyll site locally with:

/usr/bin/env docker run --rm \
  --volume="$PWD:/srv/jekyll" \
  -p 4000:4000 \
  -it dgraziotin/jekyll-imagemagick6:stable \
  jekyll serve

The site will be reachable at [***]

The container will behave the same as https://github.com/envygeeks/jekyll-docker/blob/master/README.md. Head there to learn more.

Why?

If you are using Jekyll under macOS, several issues might be happening right now:

1. Something is broken under Big Sur.
2. HomeBrew installs Ruby 3.x.x, for which something is not ready yet.
3. A plugin requires ImageMagik6 or RMagick (like the excellent https://github.com/wildlyinaccurate/jekyll-responsive-image.

Issues 2 and 3 might even happen if you are using GNU/Linux, by the way.

After several downgrade and upgrade tries, I got sick of trying to brew and rvm the issue. I moved to docker for this, too.

Luckily, there is https://github.com/envygeeks/jekyll-docker/blob/master/README.md for this. This is a wonderful image. It even allows you to add Alpine Linux packages to it by specifying their name in a .apk file. This fixes issue 1 and issue 2.

Unfortunately, jekyll-docker does not fix issue 3, because it https://github.com/envygeeks/jekyll-docker/blob/master/repos/jekyll/Dockerfile#L82. Using it as-is will result in the following error:

ruby 2.7.1p83 (2020-03-31 revision a0c7c23c9c) [x86_64-linux-musl]
Configuration file: /srv/jekyll/_config.yml
 Theme Config file: /usr/gem/gems/no-style-please-0.1.0/_config.yml
            Source: /srv/jekyll
       Destination: /srv/jekyll/_site
 Incremental build: disabled. Enable with --incremental
      Generating...
       Jekyll Feed: Generating feed for posts
  Liquid Exception: NoDecodeDelegateForThisImageFormat `JPEG' @ error/constitute.c/ReadImage/562 in /srv/jekyll/_posts/2011-04-10-contributing-on-arora-browser-quickview-mode.md
                    ------------------------------------------------
      Jekyll 4.1.1   Please append `--trace` to the `build` command
                     for any additional information or backtrace.
                    ------------------------------------------------
Traceback (most recent call last):

[...]

/usr/gem/gems/jekyll-responsive-image-1.5.5/lib/jekyll-responsive-image/image_processor.rb:12:in `read': NoDecodeDelegateForThisImageFormat `JPEG' @ error/constitute.c/ReadImage/562 (Magick::ImageMagickError)

This image will revert to ImageMagick6 and fix the issues.