I have been experimenting with docker over the years off and on but never took the time to apply it to a real project. Today that was going to change with a quick experiment building up a an nginx image and apply the output of a Jekyll site.

Dockerfile

A Dockerfile is a document that specifies a source image and commands you wish to apply to that image where each command is a delta from the previous action. This allows you to have a repeatable process of getting your image created.

FROM nginx:1.17.1
COPY site/_site /usr/share/nginx/html

This a rather trivial example but takes a tag of nginix version 1.17.1. I wanted to be sure to specify a known version as using latest while helpful could result in an image that no longer works as you have not control over what latest actually is when building. The COPY command simply copies files from a source location to a destination location inside of the image.

build-container.sh

Since the Dockerfile can only execute commands inside of the image I was unsure how to get the Jekyll site built from the start. After a bit of searching it was recommended to create a simple sh script that executes the commands and then the corresponding docker build . command at the end.

cd site && bundle exec jekyll build
cd ..
docker build . -t markcoleman/viking-mill:latest

run-site.sh

Now that we have the image built and tagged lets run it like any other image we have pulled and map a port of exposed port 8080 to container port 80 which is exposed by nginix.

docker run -d -p 8080:80 -i -t markcoleman/viking-mill:latest

Site running in an ngnix container

Simple but yet very effective and allowed me to learn a bit more, next up how to automate this using gitlab.