Can't log into private registry between instances on Play-with-docker - docker

Question

I am very new to docker so please bear with me. I am following the documentation on https://docs.docker.com/registry/deploying/#running-a-domain-registry
I have spin up 2 nodes on play-with-docker.com for my learning.
On Node1 I am able to set up a private registry successfully using the following command
docker run -d \
-p 5000:5000 \
--restart=always \
--name registry \
-v "$(pwd)"/auth:/auth \
-e "REGISTRY_AUTH=htpasswd" \
-e "REGISTRY_AUTH_HTPASSWD_REALM=Registry Realm" \
-e REGISTRY_AUTH_HTPASSWD_PATH=/auth/htpasswd \
-v "$(pwd)"/certs:/certs \
-e REGISTRY_HTTP_TLS_CERTIFICATE=/certs/domain.crt \
-e REGISTRY_HTTP_TLS_KEY=/certs/domain.key \
registry:2
I was also able to pull and push images from Node1 to the registry. However, when I go on Node2 and try to log in to the registry it gives the following error:
[node2] (local) root#192.168.0.7 ~
$ docker login 192.168.0.8:5000
Username: testuser
Password:
Error response from daemon: Get https://192.168.0.8:5000/v2/: dial tcp 192.168.0.8:5000: connect: connection refused
please let me know what am I missing?

Answer 1

Node2 can't access port 5000 on 192.168.0.8. This looks like a network issue.
Are your nodes in the same network?
Are there firewall rules that might be blocking access to port 5000?
Are you sure 192.168.0.8 is the correct IP address of your Node1 machine?
To test your TCP connection use telnet. For example telnet 192.168.0.8 5000 (assuming 192.168.0.8 is the correct IP address).