Installation
To have the Docker / Kubernetes images that will be created during the Lab, among several excellent repositories, I preferred the official Docker one, it is simple and light, with more resources, perhaps I would use Jfrog, Gitlab also has a Registry, but it is based exactly on this Docker one, so I opt for the simplest one now.
registry – Official Image | Docker Hub
The image is based on alpine, so it’s very small.
I’ll create a docker and assign an IP 172.21.5.76, in DNS as registry.devops-db.local.
An important point is to map the container’s /var/lib/registry folder to a Host folder or a Docker Volume, so there’s no problem of having to recreate the container and losing the images.
version: "3"
services:
srv-registry-01:
container_name: srv-registry-01
image: registry:2
environment:
- REGISTRY_STORAGE_DELETE_ENABLED=true
ports:
- "5000:5000/tcp"
- "5000:5000/udp"
volumes:
- /work/registry:/var/lib/registry
restart: unless-stopped
networks:
- registry_bridge
networks:
registry_bridge:
name: registry_bridge
driver: bridgeWith docker compose, all you have to do is create the container:
$ docker-compose up -d
Creating network "registry_bridge" with driver "bridge"
Creating srv-registry-01 ... done$ docker container ls -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
5cb3e3200141 registry:2 "/entrypoint.sh /etc…" 53 seconds ago Up 52 seconds 0.0.0.0:5000->5000/tcp, 0.0.0.0:5000->5000/udp, :::5000->5000/tcp, :::5000->5000/udp srv-registry-01New DNS entry responding:
Tests
To test this, use another host with Docker:
Do a pull of any image, in the example, that of Ubuntu:
$ docker image pull ubuntu:22.04
22.04: Pulling from library/ubuntu
Digest: sha256:77906da86b60585ce12215807090eb327e7386c8fafb5402369e421f44eff17e
Status: Downloaded newer image for ubuntu:22.04
docker.io/library/ubuntu:22.04Assign the tag with the address:registry container port:
$ docker image tag ubuntu:22.04 registry.devops-db.internal:5000/ubuntu:22.04Push the image to the Registry:
$ docker image push registry.devops-db.internal:5000/ubuntu:22.04
The push refers to repository [registry.devops-db.internal:5000/ubuntu]
a510ae0f066c: Pushed
22.04: digest: sha256:6bb9faf5914e1c3ffcace129df01d3894635eccb3c4e452a4d0d83919dea246a size: 529It may be that when pushing the image, docker returns the error:
Error response from daemon: Get "https://registry.devops-db.internal:5000/v2/": http: server gave HTTP response to HTTPS clientThis means that because it is not https, the destination (registry) is “untrustworthy”, in this case, it is necessary to add an exception in Docker.
sudo vi /etc/docker/daemon.json
add:
{
"insecure-registries":["172.21.5.76:5000","registry.devops-db.internal:5000","registry.lab.devops-db.info:5000"]
}At this point the Registry already has the image stored and ready to use.
There is an “API” provided by the Registry, Example:
http://registry.devops-db.internal:5000/v2/_catalog
{"repositories":["ubuntu"]}
http://registry.devops-db.internal:5000/v2/ubuntu/tags/list
{"name":"ubuntu","tags":["22.04"]}
To check whether the images can be used, remove them locally:
$ docker image rmi registry.devops-db.internal:5000/ubuntu:22.04
Untagged: registry.devops-db.internal:5000/ubuntu:22.04
Untagged: registry.devops-db.internal:5000/ubuntu@sha256:6bb9faf5914e1c3ffcace129df01d3894635eccb3c4e452a4d0d83919dea246a$ docker image rmi ubuntu:22.04
Untagged: ubuntu:22.04
Untagged: ubuntu@sha256:77906da86b60585ce12215807090eb327e7386c8fafb5402369e421f44eff17eCheck:
$ docker image ls '*ubuntu*'
REPOSITORY TAG IMAGE ID CREATED SIZE
$ docker image ls '*/ubuntu*'
REPOSITORY TAG IMAGE ID CREATED SIZENow pull the image from the local Registry:
$ docker image pull registry.devops-db.internal:5000/ubuntu:22.04docker image ls '*/ubuntu*'
REPOSITORY TAG IMAGE ID CREATED SIZE
registry.devops-db.internal:5000/ubuntu 22.04 52882761a72a 4 weeks ago 77.9MBImage ready, test with a container:
$ docker run -ti --rm registry.devops-db.internal:5000/ubuntu:22.04
root@18f7701b070d:/#This site uses Akismet to reduce spam. Learn how your comment data is processed.
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