Drone plugin开发

Drone plugin

1. 简介

Drone plugin 是特殊的Docker容器，其中封装了执行特定任务的一段程序，可以使用来自Drone环境变量和.drone.yaml中的配置参数。

Environment Variables

Write a plugin in Bash

Write a plugin in Go

在.drone.yaml中配置传递给容器的参数，这些参数作为环境变量传递给容器，且前缀为 PLUGIN_.

kind: pipeline
type: docker
name: default

steps:
- name: webhook
  image: janecitizen/slack
  settings:
    webhook: https://hooks.slack.com/services/...
    channel: general
    text: hello

PLUGIN_CHANNEL=general
PLUGIN_WEBHOOK=https://hooks.slack.com/services/...
PLUGIN_TEXT=hello

2. 开发用于git push的插件

2.1 在docker容器中使用SSH keys

Using SSH keys inside docker container

有关添加SSH key相关的部分

# Authorize SSH Host
RUN mkdir -p /root/.ssh && \
    chmod 0700 /root/.ssh && \
    ssh-keyscan github.com > /root/.ssh/known_hosts

# Add the keys and set permissions
RUN echo "$ssh_prv_key" > /root/.ssh/id_rsa && \
    echo "$ssh_pub_key" > /root/.ssh/id_rsa.pub && \
    chmod 600 /root/.ssh/id_rsa && \
    chmod 600 /root/.ssh/id_rsa.pub

2.2 Git的SSH参数

问题：The authenticity of host ‘ip (ip)’ can’t be established.

关于Git的SSH配置：git 指定要提交的ssh key

“使用GIT_SSH_COMMAND环境变量(Git 2.3.0+)传递ssh参数：

$ GIT_SSH_COMMAND='ssh -i ~/.ssh/id_rsa -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no'   

”

2.3 插件实现

参考：

Go: appleboy/drone-git-push

Bash: muxueqz/drone-git-push-by-bash

1. 在使用参考中第一个插件时，当提供远程仓库的地址（SSH）时，出现“id_rsa invalid format”错误：

   + git remote add deploy ssh://[email protected]:xxxx/letitia/drone-test.git
   + git push deploy HEAD:master
   Warning: Permanently added '[xxx.xxx.xxx.xxx]:xxxx' (ECDSA) to the list of known hosts.
   Load key "/root/.ssh/id_rsa": invalid format
   [email protected]: Permission denied (publickey).
   fatal: Could not read from remote repository.
   
   Please make sure you have the correct access rights
   and the repository exists.
   

   在插件的脚本中 echo -n "${PLUGIN_SSH_KEY}" 可以看到变量的内容是：

   -----BEGIN RSA PRIVATE KEY-----\n.......\n.......\n.......\n-----END RSA PRIVATE KEY-----
   

   其中的\n没有被转义，如果是echo -en "${PLUGIN_SSH_KEY}"转义后，可以在steps中看到的内容是：

   [secret:git_ssh_key]
   

   可能需要转义后存放到.ssh/id_rsa

2. 当选择推送到远程仓库“origin”时，出现无法识别"could not read Username"错误：

   + git push origin HEAD:master
   fatal: could not read Username for 'http://xxx.xxx.xxx.xxx:xxxx': No such device or address
   

   原因可能是，Drone通过http的方式克隆仓库，在克隆后仓库的origin变为http://，从而产生了无法读取用户名的错误

3. 具体sh脚本的部分：

   export GIT_SSH_COMMAND='ssh -o StrictHostKeyChecking=no'
   
   mkdir /root/.ssh
   chmod 700 /root/.ssh
   echo -en "$SSH_KEY" > /root/.ssh/id_rsa
   chmod 600 /root/.ssh/id_rsa
   touch /root/.ssh/known_hosts
   chmod 600 /root/.ssh/known_hosts
   ssh-keyscan -H xxx.xxx.xxx.xxx > /etc/ssh/ssh_known_hosts 2> /dev/null
   ssh-keyscan -H xxx.xxx.xxx.xxx > /root/.ssh/known_hosts
   

   创建plugin：

   FROM alpine
   
   RUN sed -i 's/dl-cdn.alpinelinux.org/mirrors.aliyun.com/g' /etc/apk/repositories
   RUN apk update && apk upgrade && \
       apk add --no-cache ca-certificates openssh curl bash git git-lfs
   ADD script.sh /bin/
   RUN chmod +x /bin/script.sh
   ENTRYPOINT /bin/script.sh