Access GitLab running in a docker container - docker

Question

I'm trying to set up GitLab as a docker container in an internal server. Let's assume the server's IP is 10.10.10.10. Below is my docker-compose file that I use to bring up the container. I'm unable to access the http url via localhost:4080 (from a browser within the server) OR via the IP 10.10.10.10:4080. I'd like to understand what I'm missing here.
version: '2'
services:
gitlab:
image: gitlab-ee-img:12.0.9-ee.0
container_name: gitlab
restart: always
hostname: 'localhost:4080'
# environment:
# GITLAB_OMNIBUS_CONFIG: |
# # Add any other gitlab.rb configuration here, each on its own line
# # external_url 'https://gitlab.example.com'
# external_url 'http://127.0.0.1:4080'
ports:
- '4080:80'
- '4443:443'
- '4022:22'
volumes:
- '/data/gitlab/config:/etc/gitlab'
- '/data/gitlab/logs:/var/log/gitlab'
- '/data/gitlab/data:/var/opt/gitlab'

Answer 1

Not entirely sure about if there's something else not working there but I'm fairly sure that the hostname: 'localhost:4080' block is not correct. It should be just the hostname without a port. Try to comment out that line and try without defining a hostname at all for testing.
src: https://docs.docker.com/compose/compose-file/#domainname-hostname-ipc-mac_address-privileged-read_only-shm_size-stdin_open-tty-user-working_dir

Answer 2

For anyone hitting this SO question:
The answer is to NOT map a custom port on to 80 in docker. Instead, this will work:
version: '2'
services:
gitlab:
image: gitlab-ee-img:12.0.9-ee.0
container_name: gitlab
restart: always
hostname: '10.10.10.10'
environment:
GITLAB_OMNIBUS_CONFIG: |
# Add any other gitlab.rb configuration here, each on its own line
# external_url 'https://gitlab.example.com'
external_url 'http://10.10.10.10:4080'
gitlab_rails['gitlab_shell_ssh_port'] = 4022
ports:
- '4080:4080'
- '4443:443'
- '4022:22'
volumes:
- '/data/gitlab/config:/etc/gitlab'
- '/data/gitlab/logs:/var/log/gitlab'
- '/data/gitlab/data:/var/opt/gitlab'
The reason is explained in this thread - Specifically, this answer
To summarize here (quoting the original answer),
The default port of gitlab is 80, but when you use the external_url
clause, gitlab changes the ngnix port to which it is going to listen
or resolve, it is not just an alias.
If you inside the container executes the command curl
http://localhost, after having placed external_url
http://10.10.10.10:4080, it will not answer for port 80, you can try
with the command curl http://10.10.10.10:4080