This is a bit complex, so please bear with me:

1. I have a local DNS server at 192.168.1.52 which allows me to give domain names to all our self-hosted applications (in a subdomain of our main address)
2. I execute OneDev from a docker container
3. To be able to access my DNS server, I added these instructions to the docker-compose.yml file of OneDev:

    dns:
      - "192.168.1.52"
    network_mode: "bridge"

Result: it works fine and when accessing bash from within the OneDev docker container, I can cat /etc/resolv.conf and the result is correct:

search lan.***.com
nameserver 192.168.1.52

I also checked the translation from the domain name to the IP address with host and it works.

Now that the DNS server is accessible and working from my OneDev docker container, I feel justified to use the domain name address of my docker registry instead of its IP Address when pushing an image to the registry at reg.lan.***.com:5000.

Unfortunately, It does not work and docker throws an error that proves that the DNS server is no longer recognized when executing an instruction from the Server Shell Executor:

17:05:54Get "http://reg.lan.***.com:5000/v2/": dial tcp: lookup reg.lan.***.com on 8.8.8.8:53: no such host
17:05:54The push refers to repository [reg.lan.***.com:5000/vsr-bas]
17:05:54Get "http://reg.lan.***.com:5000/v2/": dial tcp: lookup reg.lan.***.com on 8.8.8.8:53: no such host
17:05:54Step "build" is failed: Command failed with exit code 1

Instead the Server Shell Executor is relying on docker's default DNS server, Google's.