.gitlab.ci.yml for SSH with private key.

.gitlab.ci.yml

# Image neeeds to have ssh-client
image: docker:git

services:
  - docker:dind

stages:
  - staging
before_script:
  - docker login -u gitlab-ci-token -p $CI_BUILD_TOKEN $CI_REGISTRY
  - mkdir -p ~/.ssh
  # Paste the PRIVATE key into a gitlab variable. Pay attention to the linebreak at the end when pasting
  - echo "$DEPLOY_SERVER_PRIVATE_KEY" | tr -d '\r' > ~/.ssh/id_rsa
  - chmod 600 ~/.ssh/id_rsa
  - eval "$(ssh-agent -s)"
  - ssh-add ~/.ssh/id_rsa
  - ssh-keyscan -H 'your.server.hostname' >> ~/.ssh/known_hosts

staging:
  stage: staging
  tags:
    - docker
  only:
    - staging
  script:
    - docker build --pull -t $CI_REGISTRY_IMAGE:staging .
    - docker push $CI_REGISTRY_IMAGE:staging
    # your own server details here
    - ssh $SERVER_USER@$SERVER_HOSTNAME < deploy.sh