Docker Private Registry with Frontend UI

Hey! In this DevOps learning post, I've done my experiment on Docker Registry-Server connecting with the docker registry UI as a frontend. To support this Frontend service, we have an Apache HTTP server container used as a docker-registry-frontend image.

Docker Registry Server connect with Frontend UI

Step 1: Go to the docker hub search for 'docker-registry-frontend' given version Pull the image to your local system.

docker pull registry 
docker pull konkardkleine/docker-registry-frontend:v2 
docker images 

docker network create registry 
docker network ls

Step 2: Create the registry server using a docker container run command which expose the port as 5000 and the network that we have created in the step1. This separate network creation will be easy to isolate with other containers running on the same host.

docker run --rm -d -p 5000:5000 --name registry-server \
--network registry 
To verify the access of registry-server
docker logs registry-server -f

Step 3: You can find many other web UI options on the Docker Hub, Here I've selected the web-ui image - konradkleine/docker-registry-frontend:v2. Here we have two environment variables need to set HOST and PORT. To access this registry web page we need to open the port with -p option. 

Create the registry-ui container as follows:

docker run \
  -d --rm --name registry-ui --network registry \
  -e ENV_DOCKER_REGISTRY_HOST=192.168.33.250 \
  -e ENV_DOCKER_REGISTRY_PORT=5000 \
  -p 8080:80 \
  konradkleine/docker-registry-frontend:v2
             

Step 4: To verify the access logs of registry-ui web server run the following command:

docker logs registry-ui -f

Step 5: Open a duplicate terminal and do the following image tag to use it on our private registry.

docker tag busybox dockerhost.test.com:5000/busybox
docker images 

docker push localhost:5000/nginx

Now let's see on the browser where we can access the registry-ui which is actually running with Apache HTTPD 2 webserver

Docker Private Registry Web 

Step 6: After push you can see the images on the registry-ui same you can check with curl command as well like this:

 curl -X GET http://localhost:5000/v2/_catalog
{"repositories":["nginx"]}

Please write your comments and share if you like and think that it will be helpful for other.

Publishing to Docker hub your own Docker Images

 Hey DevOps Engineer, In this post I would like to share my experiment on Docker image creation and pushing to the public repository. Docker Hub is the world's easiest way to create, manage, and deliver your images with the teams who are working for microservices applications that runs on containers.

Docker Hub allows you to pull docker images that are built by other community members, organizations on the Hub. 

Docker Hub is a cloud-based registry service that allows you to link to code repositories, build your images and test them, store manually pushed images, and links to Docker Cloud so you can deploy images to your docker hosts.

Publishing custom Image to Docker Hub

Steps to publish the image

Please use the following steps:

1. Register with Docker Hub
2. Login to docker hub from your Docker Host 
3. Commit and Pushing to Docker Hub registry
4. Docker tag

Create an account/ Docker ID. If you have already then signed into it.

Login into the docker hub from the docker host 

 
  docker login 

Create your customization inside the container and commit as an image using else use Dockerfile create a fresh image.

 docker pull oraclelinux:8-slim
docker run -dit --name c1 oraclelinux:8-slim
docker exec -it c1 bash
mkdir custom-dir
 echo "echo Welcome to BhavaniShekhar Oracle Linux Image" >~/.bashrc
exit
docker ps

Push the image to hub

 docker commit -a BhavaniShekhar -m "Custom OL 8-slim" c1 bhavanishekhar07/myol:8-slim
 docker images

Docker Hub repository showing your custom image 

Docker Hub published Image

Test the published image

Conclusion

Docker custom image created from the container, pushed to your docker repository as public and can be pulled from any Docker Host 

Please write your commants/Suggstions on the above post!

How to setup the Docker Private Registry on Ubuntu 19.04 with Docker 19.03.2?

What is Docker registry? There are various situations where a team could work on the microservices. Every time you connect to the internet and pull the images will be cost & time-consuming process. In an organization level if we set up the docker registry, where we can pull the images and all team members will reuse it by using the internal network.

Docker  public registry

A central place to store all organizational required docker images were distributed. There are several implementations of docker registries where it is build up with the following:

• A simple webserver to make access to docker images available
• A complete web application with user access
• Docker builds are available in two services: DockerHub, Docker Trusted Registry

DockerHub is a public repository where you publish your contribution to any image that you made with tag [versions] which can be downloaded by anyone from the internet. It should be searchable. It all depends on the stars, the number of downloads, trust in official category of images. People will consider the comments. 



To create the Docker registry we have two options:

• without security
• with security

Here I would like to share the secure option as follows:

Docker container Registry 

Let's use the docker registry container which is officially published by Docker team on the docker Hub. The latest version of registry image is v2 now. This edocker registry supporst the following features: 

• layer oriented
• layer ID are randomly assigned
• JSON object corresponding to each layer reflecting a parent
• naming accomplished through tags

Docker private registry with Security setting up 

Steps to configure local private docker registry:
1. Create a certificate directory"/docker_data/certs" to hold the TLS certs
check openssl exists, if not run the following installation command:

mkdir -p "/docker_data/certs"
yum -y install openssl

On Ubuntu instance:

apt install -y openssl

2. Generate an SSL/TLS certificate to secure our private docker registry

openssl req -newkey rsa:4096 -nodes -sha256 -keyout /docker_data/certs/domain.key -x509 -days 365 -out /docker_data/certs/domain.crt

# Enter the hostname fqdn 3. Create a directory to store docker images "/docker_data/images"

mkdir -p /docker_data/images

4. Run a docker registry container in docker host "docker-registry"

docker search registry
docker login 

# login with docker user [you must signup for this if not yet had]

docker run -d -p 5000:5000 \
-v /docker_data/images:/var/lib/registry \
 -v /docker_data/certs:/certs \
  -e REGISTRY_HTTP_TLS_CERTIFICATE=/certs/domain.crt \
  -e REGISTRY_HTTP_TLS_KEY=/certs/domain.key \
  --restart on-failure \
  --name devops-registry \
  docker.io/registry

# check for the registry container in the list

docker container ls

# rename images which you would like to push to your private registry this is a recommendation

docker pull nginx
docker tag docker.io/nginx mydev.devopshunter.com:5000/my-nginx

# Now list of images to see the above image tag was created out of Nginx image.

docker image ls

5. Pull required docker images to docker host "docker-registry" from docker hub, rename (tag) with our local registry

docker tag docker.io/nginx mydev.devopshunter.com:5000/myweb
docker tag python mydev.devopshunter.com:5000/mypython

6. Push those pulled docker images to our docker private registry container

docker push mydev.devopshunter.com:5000/mypython
docker push mydev.devopshunter.com:5000/myweb

Let's confirm this by looking into the following path

ls -l /docker_data/images/docker/registry/v2/repositories/

# You can see two folders were created for each image, that indicates clearly what we had pushed are successful.
7. Remove old docker images from local docker-host.

 docker rmi ubuntu python nginx  

8. Configure all docker clients to use our certificates
9. docker clients can pull and push docker images into our private docker registry in registry server

curl -X GET http://localhost:5000/v2/_catalog

This is the end of the story of hosting your own docker private registry.

 References:

1. Docker Host and Docker client communication on Ubuntu 19 
2. Docker installation on CentOS 
3. Docker Concepts