Setting up Private Docker Registry in Nexus

  1. Set up Nexus via Docker
  2. Run the following command to start Nexus in Docker: docker run -d --name nexus -p 8081:8081 -p 5000:5000 sonatype/nexus3

  3. Access Nexus at http://localhost:8081 and set up the admin user and password.

  4. Create a new Nexus repository: In the Nexus web interface, go to Repositories > Create Repository. Choose Docker as the repository type and give it a name ( e.g., "my-private-registry"). Make sure to select the correct Docker repository format e.g., "Docker (Hosted)".

  1. Configure Docker Server for Allowing HTTP Connections
  2. As we set HTTP instead of HTTPS in the previous step, we need to configure Docker to allow HTTP connections. This can be done by setting the insecure-registries option in the Docker daemon configuration file. You can do this by adding the following line to the /etc/docker/daemon.json file:
vi /etc/docker/daemon.json

{
    "insecure-registries": ["http://localhost:5000"] // adjust the IP of Nexus server and port as needed
}
  1. Restart Docker Service
  2. After modifying the Docker daemon configuration file, restart the Docker service to apply the changes: sudo systemctl restart docker (on Ubuntu-based systems) or sudo service docker restart (on CentOS-based systems).
  3. Verify that the Docker service is running and listening on the correct port: sudo systemctl status docker (on Ubuntu-based systems) or sudo service docker status (on CentOS-based systems).

  4. You can also check the Docker logs for any errors: sudo journalctl -u docker (on Ubuntu-based systems) or sudo docker logs (on CentOS-based systems).

  5. Realms and Authentication

  6. In Nexus, go to Security > Realms and create a new realm.

  1. Restart Nexus Service
  2. After configuring Docker to allow HTTP connections, restart the Nexus service to apply the changes: docker restart nexus.
  3. Verify that the Nexus service is running and listening on the correct port: docker ps -a | grep nexus.
  4. You can also check the Nexus logs for any errors: docker logs nexus.

  5. Access Nexus at http://localhost:8081 and verify that the Docker repository is available.

  6. Login to Docker Registry

  7. You can now login to the Docker registry using the following command: docker login http://localhost:5000

  8. Use the credentials you created in Nexus to login. You can verify that you are logged in by running docker info which should display the registry information.
  9. You can now push and pull images to and from your private Docker registry. For example, you can push an image using the following command: docker tag my-image:latest http://localhost:5000/ my-image:latest followed by docker push http://localhost:5000/my-image:latest.
  10. You can also use the docker push command with the -t option to specify the registry and tag in one step: docker push -t http://localhost:5000/my-image:latest my-image:latest.
  11. You can also use the docker pull command to pull an image from your private registry: docker pull http://localhost:5000/my-image:latest.