docker-create-custom-image.md

Creating a Custom Docker Image and Pushing it to Docker Hub

Login to Docker Hub

$ docker login

Pull a Base Docker Image

$ docker run -ti -d --name my-custom-image ubuntu:latest bash

• -ti - Enable Interactive and Terminal Typing
• -d - Dettach to container after running
• --name my-custom-image ubuntu:latest - Docker image definition --name <your-image-name> <image[:TAG]>
• bash - Corollary to -ti

Check if Container is Running

$ docker ps

Note: Copy the CONTAINER ID for later use

Attach to Container's Terminal

$ docker exec -ti <CONTAINER-ID> bash

Once successfully accessed, you should see root@<CONTAINER-ID>:/#

Make Changes to Container

$ apt-get update
$ apt-get install htop
$ exit

• apt-get update - download package information from all configured sources
• apt-get install htop - Install a new package htop
• exit - Exit the terminal

Commit The Changes

Documentation: https://docs.docker.com/engine/reference/commandline/commit/

$ docker commit <CONTAINER-ID> <image-name[:TAG]>

Note: This will create a new image with an additional layer.

Add Tag to Docker Image (Optional)

Documentation: https://docs.docker.com/engine/reference/commandline/tag/

Get the Image Id first

$ docker images

Note: See IMAGE ID.

Add Tag

$ docker tag <image-id> <my-custom-image:latest>

• docker tag <image-id> <my-custom-image:latest> - Image tag definition docker tag <image-id> <image-name:TAG>

Push to Docker Hub

$ docker push dockerhubusername/my-custom-image

Reference/s

• https://ropenscilabs.github.io/r-docker-tutorial/04-Dockerhub.html