The goal is to have a webhook that listens to github events. The purpose of this webhook would be to trigger a git pull from the origin server and run any subsequent commands needed.
The approach is to have a webserver listen on a particular port. For security reasons, this webhook ensures that the right github secret is passed and then triggers a git pull to update the local git repository.
The requirements must be values that must be passed in as environment variables. These can be placed in a .env file that would be loaded as early as possible.
- GITHUB_WEBHOOK_SECRET: The secret used when setting up the webhook at Github
- GITHUB_REPO_BRANCH: The online branch to pull the changes from
- LOCAL_REPO_DIR: The local repository path that needs to be updated after the webhook trigger
- PORT: The port on which the webserver is listening on
The first step is to create a service with the command sudo nano /etc/systemd/system/webhook.service. Since the file is named webhook.service, it implies that the service is called webhook. You can change it to whatever you want. The next steps is to add instructions as to how systemd should run the script. A typical instruction could be as follows:
[Unit]
Description=Github webhook
After=network.target
[Service]
Environment=NODE_PORT=3500
Type=simple
User=<your_github_username>
ExecStart=/usr/bin/nodejs /home/<your_github_username>/NodeWebhooks/webhook.js
Restart=on-failure
[Install]
WantedBy=multi-user.target
At this stage, the new service needs to be enabled so that it starts when the system boots up. This can be done using sudo systemctl enable webhook.service. The service can also be manually started using sudo systemctl start webhook. The status of the service can be checked using sudo systemctl status webhook.