Introduction

As a developer, I am an avid blogger :no_mouth: and I'd like to share a Docker image that can help both me and the community get started with the best static site generator for blogs:

Most of the images found for working with Jekyll tend to have certain issues that this implementation aims to address (or tries to):

• They often have a considerable size compared to what is believed to be necessary
• They usually run with the root user, which can cause minor difficulties in managing permissions between the local development environment and the container's remote environment
• It is believed that in a production environment, there is a strong dependency on the web server that will serve the static content. Therefore, providing this service embedded in the image is thought to allow for a much cleaner implementation in this environment

In this way, with the goal of solving these problems and providing an easy-to-use solution, this image:

• Is based on the Alpine image of Nginx to attempt to ensure that it does not have more size than necessary and provide a web server with a recommended out-of-the-box configuration
• Comes with the jekyll user for working with it in development environments, which can be used in Dev Containers or similar setups (this user has the necessary permissions to install Ruby gems).
• Similar to the Nginx image, this image also makes it easy to create configuration files with environment variables. For example, it allows the creation of a configuration file that receives the URL of the site/environment where it will run.

In the following section, these aspects are elaborated upon, along with an explanation of how to use the image.

Usage

This image comes with configuration templates for both Nginx and Jekyll.

(Note: Configuration templates are simply files that capture values from the environment in which they are running to create the final files that the services will use)

In this way, both the Nginx configuration template and the Jekyll configuration template rely on the ${HOST} environment variable. This environment variable should point to the URL that the site will use, so both Nginx and the Jekyll site are correctly configured.

Production use

To use this image in a production environment (or any environment that is not for development purposes), you could use, for example:

docker run -d -p 80:80 --env HOST=example.com d3p1/jekyll:nginx-alpine3.18

Where example.com is the domain that the site will use in that environment.

Development use

To use this image in a development environment, you could use, for example:

docker run -d -p 80:80 --env HOST=example.test d3p1/jekyll:nginx-alpine3.18 bundle exec jekyll build --watch --config _config.yml,_config.env.yml

Where example.test is the domain that our site will use in that environment.

(Note: The container is passed the command bundle exec jekyll build --watch --config _config.yml,_config.env.yml, which allows it to build with every change made in the source code, providing a smooth development experience)

Brief technical overview

The container already comes with a default Jekyll site at /var/www, so it can be used and worked on. This location is defined in the ${DOCUMENT_ROOT} environment variable, which is used for certain web server configurations, so it is usually not recommended to modify it unless you know what you are doing.

Regarding Nginx, a standard/recommended/optimized configuration file is provided to serve Jekyll content. This configuration file will use the value of ${HOST} to correctly point its server_name to the site's URL and handle requests coming from there.

Regarding Jekyll, the ${HOST} value will be used for the url value, which is used to define the URLs of the site's links. When the container starts, the configuration file will be created at ${DOCUMENT_ROOT}/_config.env.yml, so that a site build can be performed using it: bundle exec jekyll build --config _config.yml,_config.env.yml.

Changelog

Detailed changes for each release are documented in CHANGELOG.md.

License

This work is published under MIT License.

Author

Always happy to receive a greeting on:

• LinkedIn
• Web