Gitlab CI cannot connect with SSH to remote server using SSH key - ssh

Question

So, I want to deploy my Gitlab pipelines onto a server with SSH. This is my script .gitlab-ci :
test_job:
stage: test
variables:
GIT_STRATEGY: none # Disable Gitlab auto clone
before_script:
- 'command -v ssh-agent > /dev/null || ( apk add --update openssh )'
- eval $(ssh-agent -s)
- mkdir -p ~/.ssh
- chmod 700 ~/.ssh
- echo "${SSH_PRIVATE_KEY}" | tr -d '\r' > ~/.ssh/id_rsa
- chmod 600 ~/.ssh/id_rsa
- ssh-add ~/.ssh/id_rsa
# Add server to known hosts
- ssh-keyscan ${VM_IPADDRESS} >> ~/.ssh/known_hosts
- chmod 644 ~/.ssh/known_hosts
# Verify that key has been registered
- ls ~/.ssh -al
# Verify server connection
- echo "Ping server"
- ping ${VM_IPADDRESS} -c 5
script:
# Pull Git project on remote server
- echo "Git clone from repository"
- ssh -o PreferredAuthentications=publickey ${SSH_USER}#${VM_IPADDRESS} "
rm -rf /tmp/src/${CI_PROJECT_NAME}/ &&
git clone https://gitlab-ci-token:${CI_BUILD_TOKEN}#gitlab.my-domain.fr/user/project.git /tmp/src/${CI_PROJECT_NAME}/
"
$SSH_PRIVATE_KEY contains my private SSH key I use daily to connect on that server. It works perfectly in normal time. ${SSH_USER} and ${VM_IPADDRESS} contain my username and the server address. I already checked that all the values in these parameters are correct on worker.
This is the message I have when trying this script :
Permission denied (publickey,gssapi-keyex,gssapi-with-mic,password).
I'm quite stuck with this actually :(. Any help :) ?

Answer 1

Adding my public key id_rsa.pub to ssh authorized_keys file in the server has solved the problem for me. And you need to make sure of adding your public key to your SSH keys in your Gitlab profile.
Also, it's good to note that:
"Add the public key to the services that you want to have an access to from within the build environment. If you are accessing a private GitLab repository you must add it as a deploy key."