Development Trick: Auto-updating & Auto-reloading
What’s neat is I’ve got it to automatically pull the latest changes from github and automatically restart my Node process.
I don’t claim this to be particularly clever, and I’m sure I should be able to trigger a pull on the server as a push happens, but this works fairly well for my development workflow (where the app needs to be online) and is pretty simple – which I like.
For those like me who don’t care about the detail, here’s exactly what I’m doing in the terminal:
$ cd /WWW/jsbin/ $ screen -S gitpull $ watch git pull CTRL+a d $ screen -S jsbin $ nodemon . CTRL+a d
Here’s what’s going on.
I’m using a linux process called screen which simply put: creates a persistent shell that you can send to the background and retrieve at a later date. This means I can run my processes inside a screen and get them back any time I want if there’s some debugging to do.
Now I’ve got a way of managing two tasks:
- Pull from github for any changes
- Restart my node process
Once you’re inside screen to detach (and return to your original shell) you use the command sequence CTRL+a d.
Here’s a few extra simple commands:
- screen -ls will show all the screen processes you’re running and the PIDs they have. You’ll need the PID to reattach the screen
- screen -r<PID> so in my case: screen -r gitpull will reattach and put me back in to the screen
Inside one screen we make use of watch which will keep running a process every 2 seconds. So I “watch” the git pull command.
Obviously this is a bit crap because it’s trying to pull from github to no avail most of the time, but it does mean that when I push new code up, this process will automatically pull.
Which leads me on to restarting…
So that’s it. Pretty simple.