In this article we try to just run a command from the pipline in our server

1. Make sure you can connect to your server via your ssh-key without requiring password.
2. On gitlab, go to your repository > settings > CI/CD > Variables
3. Add a new variable SSH_PRIVATE_KEY. The value is your ssh private key (e.g content of ~/.ssh/id_rsa)
4. Add the file below to your project

.gitlab-ci.yml

before_script:
  - apt-get update -qq
  - apt-get install -qq git
  - "which ssh-agent || ( apt-get install -qq openssh-client )"
  - eval $(ssh-agent -s)
  - ssh-add <(echo "$SSH_PRIVATE_KEY")
  - mkdir -p ~/.ssh
  - '[[ -f /.dockerenv ]] && echo -e "Host *\n\tStrictHostKeyChecking no\n\n" > ~/.ssh/config'

deploy:
  type: deploy
  script:
    - ssh root@123.123.123.123 "pwd && ls"
  only:
    - main

After that you need to run this command because You need to add the public key to the server so it would be recognized as an authentication key.

cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys

Just consider to change root@123.123.123.123 the use and also the IP address.
Now if you push to the main branch it will run the pipeline and then run the command on your server :))
In the next article we use this to deploy our project to the server automatically

That is all