Create Your Own Private Docker Registry

This is a post in a series discussing using spring-boot and docker for deployment. Refer to the end of the first post for a table of contents.

Shortly after you start building docker containers you will realize that you need some place to publish your images. You could push to the central docker registry. However, the central registry is public. Not a great idea if you are working on a private project.

If this is your case, you can simply run a local docker registry. To install and run your private registry run $ docker run -p 5000:5000 -d registry

Surprise!!! It is ran in a docker container.

You can now start pushing to your local repository. As an example, I will pull the latest postgres image and push version 9.4 to my local registry.

$ docker pull postgres
$ docker tag postgres:9.4 localhost:5000/postgres:9.4
$ docker push localhost:5000/postgres

Outputs:

The push refers to a repository [localhost:5000/postgres] (len: 1)
Sending image list
Pushing repository localhost:5000/postgres (1 tags)
511136ea3c5a: Image successfully pushed
ec3443b7b068: Image successfully pushed
06af7ad6cff1: Image successfully pushed
37eae31ff4e9: Image successfully pushed
83e30bf01299: Image successfully pushed
499da968a652: Image successfully pushed
bf09bd07d760: Image successfully pushed
1eee820e762b: Image successfully pushed
7bf9287ccfce: Image successfully pushed
288b8d534217: Image successfully pushed
f20dbf0acb45: Image successfully pushed
bd511e81a5ed: Image successfully pushed
8fe7eb38aea1: Image successfully pushed
464263a50f65: Image successfully pushed
1f58a67adecd: Image successfully pushed
a99fb4ee814d: Image successfully pushed
6112f975feab: Image successfully pushed
6dff1b5c2259: Image successfully pushed
Pushing tag for rev [6dff1b5c2259] on {http://localhost:5000/v1/repositories/postgres/tags/9.4}

Looking at the current images, you will notice that the version tagged with localhost and the official images have the same information.

Notice that I had to retag the image with the location of the repository. I thought the requirement to put the location address as part of the image name was a little odd. However, after using docker longer, it makes sense. It ensures you know where the image was originally pulled.

$ docker images
postgres                  9.4                 6dff1b5c2259        5 days ago          244.4 MB
localhost:5000/postgres   9.4                 6dff1b5c2259        5 days ago          244.4 MB

Since docker tags are not permanent, and newer version of the postgres:9.4 image could be pushed to the public registry. When you self-host images, you are in control of when updates are pushed to any base image that you have extended. Someday I intend to learn how to build an image completely from scratch.

Docker-ize All the Things!