I’m trying to deploy code from a Gitlab repository into remote servers.

Running the pipeline, a Permission denied error shows up

$ ssh $SSH_USER@$SSH_HOST "cd $WORK_DIR && git checkout $PRELIVE_BRANCH && git pull && exit"
Load key "/root/.ssh/id_rsa": error in libcrypto
Permission denied, please try again.
Permission denied, please try again.
deployer@XXX: Permission denied (publickey,password).

For the deployer user I’ve created an SSH key and saved it into repository’s CI/CD variables (as SSH_PRIVATE_KEY).
I’ve also saved the public key into deployer’s .ssh/authorized_keys file.

This is the pipeline I’m running

stages:
  - deploy

deploy:
  image: alpine:latest
  stage: deploy
  only: 
    - prelive
  before_script:
    - apk update
    - apk add openssh-client
    - install -m 600 -D /dev/null ~/.ssh/id_rsa
    - echo "$SSH_PRIVATE_KEY" | base64 -d > ~/.ssh/id_rsa
    - ssh-keyscan -H $SSH_HOST > ~/.ssh/known_hosts
  script:
    - ssh $SSH_USER@$SSH_HOST "cd $WORK_DIR && git checkout $PRELIVE_BRANCH && git pull && exit"
  after_script:
    - rm -rf ~/.ssh

Am I missing something?