Drone CI: git clone with ssh in the clone step

.drone.yml

---
kind: pipeline
type: docker
name: default

clone:
  disable: true

steps:
- name: clone
  image: alpine/git
  pull: if-not-exists
  environment:
    SSH_KEY:
      from_secret: SSH_KEY
    SSH_HOST:
      from_secret: SSH_HOST
    SSH_PORT:
      from_secret: SSH_PORT
  commands:
  - mkdir $HOME/.ssh && echo "$SSH_KEY" > $HOME/.ssh/id_rsa && chmod 600 $HOME/.ssh/id_rsa
  - |
    [[ -n "$${SSH_PORT}" ]] && [[ -n "$${SSH_HOST}" ]] && ssh-keyscan -p $${SSH_PORT} $${SSH_HOST} >> $HOME/.ssh/known_hosts
  - |
    [[ -z "$${SSH_PORT}" ]] && [[ -n "$${SSH_HOST}" ]] && ssh-keyscan $${SSH_HOST} >> $HOME/.ssh/known_hosts
  - git clone ${DRONE_GIT_SSH_URL} .
  - git checkout ${DRONE_COMMIT_BRANCH}
- name: greeting
  image: alpine
  pull: if-not-exists
  commands:
  - echo "hello, world"
  - ls -ahl
  - pwd

如果要放到git上的确实会不安全，我这里没放，都是直接在本地编辑的。