If you don’t want to input username and password when you push git repo to gitlab server, try ssh public-key authentication.
First generate your public key if you have not already done by running the following on you computer:
$ ssh-keygen -t rsa
You will see two files are generated. One is private. The other one is public.
Next open the public one, and copy it to the gitlab server.
Now , add the private key to your ssh agent by typing the command below.
(maybe you should write this command to ~/.bashrc file)
You can push your code to gitlabserver now.