Kubernetes not using docker registry - docker

Question

I have kubernetes cluster with 7 worker nodes running behind proxy. Deploying application on cluster and scaling application is consuming too much of internet bandwidth. Therefore I decided to deploy Docker Registry acting as pull through cache server. But deployments are not pulling images from the registry. What is the issue here?
Docker daemon.json
...
"registry-mirrors": [
"https://myregistry",
"https://myregistry:443"
]
Docker version
Client: Docker Engine - Community
Version: 20.10.5
API version: 1.40
Go version: go1.13.15
Git commit: 55c4c88
Built: Tue Mar 2 20:33:55 2021
OS/Arch: linux/amd64
Context: default
Experimental: true
Server: Docker Engine - Community
Engine:
Version: 19.03.14
API version: 1.40 (minimum version 1.12)
Go version: go1.13.15
Git commit: 5eb3275d40
Built: Tue Dec 1 19:19:17 2020
OS/Arch: linux/amd64
Experimental: false
containerd:
Version: 1.4.3
GitCommit: 269548fa27e0089a8b8278fc4fc781d7f65a939b
runc:
Version: 1.0.0-rc92
GitCommit: ff819c7e9184c13b7c2607fe6c30ae19403a7aff
docker-init:
Version: 0.18.0
GitCommit: fec3683
Kubernetes version
Server Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.15", GitCommit:"73dd5c840662bb066a146d0871216333181f4b64", GitTreeState:"clean", BuildDate:"2021-01-13T13:14:05Z", GoVersion:"go1.13.15", Compiler:"gc", Platform:"linux/amd64"
Docker registry configuration
version: 0.1
log:
fields:
service: registry
storage:
cache:
blobdescriptor: inmemory
filesystem:
rootdirectory: /data
http:
addr: :5000
headers:
X-Content-Type-Options: [nosniff]
health:
storagedriver:
enabled: true
interval: 10s
threshold: 3
proxy:
remoteurl: https://index.docker.io/v1/

Answer 1

To access the Docker Registry, your Kubernetes cluster needs to be able to make an outbound connection to the registry. If your proxy server is blocking this connection, then the deployments will not be able to retrieve the images from the registry. You may need to configure your proxy server to allow outbound connections to the registry.
The API server is not able to access any of the services running inside of the Docker container. This could be due to a misconfiguration or a firewall blocking the connection. In order for the API server to access the services running inside the container, it needs to have access to the Docker daemon, which is responsible for managing the containers. In order to allow the API server to access the Docker services deployed registry on another host with docker-compose, you will need to configure the appropriate ports to be accessible from the API server. You will need to open port 2375 on the Docker host, which is the default port used by the Docker Remote API. Additionally, you will need to ensure that port 5000 is open on the Docker host, as this is the default port used by the Docker Registry. Once you have opened up the necessary ports, you should be able to access the Docker services deployed registry on the Docker host from the API server.
Set the imagePullPolicy to Never, otherwise Kubernetes will try to download the image.
Refer to this document for more information.