Is there any way to install gitlab and redmine on the same Debian Server?
When taking is accusing error on both.
If you want to use both on the same Droplet, the simplest way would be to use Nginx as a reverse proxy in front of both apps. I’d start with GitLab as it uses an “omnibus” installer which bundles a number of components including Nginx. Many of these bundled components can be configured in /etc/gitlab/gitlab.rb See this doc for more information on how to configure Nginx settings through it.
You can add a custom include directive to the Nginx configuration. This will allow you to set up a separate Nginx config file for your Redmine instance. In /etc/gitlab/gitlab.rb add:
external_url "http://gitlab.example.com"
nginx['custom_nginx_config'] = "include /etc/nginx/conf.d/*.conf;"
You can now create a server block for your main site in the /etc/nginx/conf.d/ directory. Then run gitlab-ctl reconfigure to pick up the changes.
You can also disable the bundled Nginx all together and install the distro version if you want by adding:
nginx['enable'] = false
Now you should be able to install and configure Redmine as you normally would. See their docs on using it with Nginx for more info.