Using Docker Hub: Register, Login, Pull, Push Images and Set Up a Private Registry

Docker Hub

The official Docker Hub public repository hosts over 15,000 images that can be downloaded directly for most needs.

Register & Login

You can register a free Docker account at https://cloud.docker.com. Log in interactively with docker login and log out with docker logout.

$ docker login
Username: your_username
Password: ********
Login Succeeded

Pull Images

Search for images using docker search and download them with docker pull. Example:

$ docker search nginx
NAME        DESCRIPTION               STARS  OFFICIAL  AUTOMATED
nginx       Official build of Nginx  7636   [OK]

Then pull the image:

$ docker pull nginx
Using default tag: latest
latest: Pulling from library/nginx
...

Build and Push an Image

Create a Dockerfile:

$ touch Dockerfile
FROM nginx
RUN echo '<h1>Hello, Docker!</h1>' > /usr/share/nginx/html/index.html

Build the image:

$ docker build -t nginx:v1 .
Sending build context to Docker daemon  2.048kB
Step 1/2 : FROM nginx
---> 3f8a4339aadd
Step 2/2 : RUN echo '<h1>Hello, Docker!</h1>' > /usr/share/nginx/html/index.html
---> Using cache
Successfully built 4ac2d12f10cd
Successfully tagged nginx:v1

Tag the image for your Docker Hub repository (replace your_username): $ docker tag nginx:v1 your_username/nginx:v1 Push the image:

$ docker push your_username/nginx:v1
The push refers to repository [docker.io/your_username/nginx]
241cbe531d78: Pushed
a103d141fc98: Pushed
...

Private Registry

Run the official registry image to start a local private registry on port 5000:

$ docker run -d -p 5000:5000 --restart=always --name registry registry
Unable to find image 'registry:latest' locally
latest: Pulling from library/registry
...

Tag an image for the private registry (e.g., 127.0.0.1:5000) and push it:

$ docker tag nginx:latest 127.0.0.1:5000/nginx:latest
$ docker push 127.0.0.1:5000/nginx:latest
The push refers to repository [127.0.0.1:5000/nginx]
a103d141fc98: Pushed
73e2bd445514: Pushed
...

Verify the uploaded image via the registry API:

$ curl 127.0.0.1:5000/v2/_catalog
{"repositories":["nginx"]}

Remove the local image and pull it back from the private registry:

$ docker rmi 127.0.0.1:5000/nginx:latest
Untagged: 127.0.0.1:5000/nginx:latest
$ docker pull 127.0.0.1:5000/nginx:latest
latest: Pulling from nginx
Digest: sha256:926b086e1234b6ae9a11589c4cece66b267890d24d1da388c96dd8795b2ffcfb
Status: Downloaded newer image for 127.0.0.1:5000/nginx:latest

Reference: Docker — From Beginner to Practice (https://www.gitbook.com/download/pdf/book/yeasy/docker_practice)