What Docker Registry is?
Docker Registry is a stateless, highly scalable server side application that stores and lets you distribute Docker images. The Registry is open-source, under the permissive Apache license.
Why use it
You should use the Registry if you want to:
- tightly control where your images are being stored
- fully own your images distribution pipeline
- integrate image storage and distribution tightly into your in-house development workflow
Install Docker Registry and WEB UI
Install Docker Registry
Run under command:
docker run -d -p 5000:5000 --restart=always --name registry-srv registry:2
Explain:
- registry-srv -> container name
- -p 5000:5000 -> map port 5000 of host and container
- –restart=always -> alway start container
- registry:2 -> image name
Install Web UI for Registry
Make config file:
mkdir -p /opt/conf cd /opt/conf nano config.yml
File content:
registry: # Docker registry url url: http://registry-srv:5000/v2 # Docker registry fqdn name: localhost:5000 # To allow image delete, should be false readonly: false auth: # Disable authentication enabled: false
Explain:
- readonly: false -> can delete image
- enabled: false -> Disable authentication
Install Web UI for Registry :
docker run -it -p 8080:8080 --restart=always --name registry-web --link registry-srv -v $(pwd)/config.yml:/conf/config.yml:ro hyper/docker-registry-web
Explain:
- registry-web -> container name
- -p 8080:8080 -> map port 8080 of host and container
- –restart=always -> alway start container
- hyper/docker-registry-web -> image name
Access http://IP:8080
How to use Docker Registry
Pull Centos Image
[root@localhost ~]# docker pull centos:latest Trying to pull repository docker.io/library/centos ... latest: Pulling from docker.io/library/centos aeb7866da422: Pull complete Digest: sha256:67dad89757a55bfdfabec8abd0e22f8c7c12a1856514726470228063ed86593b Status: Downloaded newer image for docker.io/centos:latest [root@localhost ~]# docker images REPOSITORY TAG IMAGE ID CREATED SIZE docker.io/centos latest 75835a67d134 33 hours ago 200 MB [root@localhost ~]#
Make image tag
docker image tag centos 192.168.1.93:5000/centos:latest
Push image to Docker Registry
Https error:
[root@localhost ~]# docker push 192.168.1.93:5000/centos:latest The push refers to a repository [192.168.1.93:5000/centos] Get https://192.168.1.93:5000/v1/_ping: http: server gave HTTP response to HTTPS client
How to Fix?
- For docker-io edit file /etc/docker/daemon.json and add { “insecure-registries”:[“192.168.1.93:5000”] }
- For docker ce: edit file /usr/lib/systemd/system/docker.service. Find ExecStart=/usr/bin/dockerd
and replace ExecStart=/usr/bin/dockerd –insecure-registry 192.168.1.93:5000 -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock - Restart service by command: systemctl daemon-reload and systemctl restart docker
Try push image again
[root@localhost ~]# docker push 192.168.1.93:5000/centos:latest The push refers to a repository [192.168.1.93:5000/centos] f972d139738d: Pushed latest: digest: sha256:dc29e2bcceac52af0f01300402f5e756cc8c44a310867f6b94f5f7271d4f3fec size: 529
Refresh Web UI page
Try pull pushed image
[root@localhost ~]# docker pull 192.168.1.93:5000/centos:latest Trying to pull repository 192.168.1.93:5000/centos ... latest: Pulling from 192.168.1.93:5000/centos aeb7866da422: Pull complete Digest: sha256:dc29e2bcceac52af0f01300402f5e756cc8c44a310867f6b94f5f7271d4f3fec Status: Downloaded newer image for 192.168.1.93:5000/centos:latest
