A mobile app to run scripts on servers
Over the years, whether I was working with a Raspberry Pi or running a server, there would often be one-off scripts that I would want to run. The usual pattern would be:
- SSH into the server
- Run a single command
- Logout
I always thought it would be nice to have a phone app that could easily run those scripts.
I'd try some mobile SSH client but those felt clunky; a full-blown terminal was overkill. I just wanted to quickly run a single script.
Other times I'd write a quick Flask app to listen on obscure ports and URLs to trigger a script. This also felt like overkill, though, because I really didn't want to have to expose some HTTP server on some port just to run a script on occasion.
So I decided to bite the bullet and write the app that I wanted.
Hooks
The app is simple. It works as follows:
- Add a server's SSH credentials
- You'll see a list of the executable files in ~/.hooks-app/hooks
- Tap one of them and it will run
I myself have started to use this for a few things, including making sure all the containers are running properly on this server.
What I learned
This was the first time I used React and it's libraries. I have to say that using it, particularly together with Redux, felt elegant and safe. The fact that a global state defines the UI really makes things simpler.
Working with React Native was also a treat. Hot Loading is a wonderful feature that will update your app when you save a file, while maintaining your app's state. This makes UI work so much easier.
I also got to write some native Android code. I used the JSch Java library to do the SSH communication, so I had to write a bridge between that library and the app's JavaScript. Basically, you write a new Java class that implements method (annotated with @ReactMethod) where certain Java types map to the JS types.
Finally, I learned that ES6 is the bomb. Special shoutouts to the feature listed below.
Shorthand property names:
return { foo, bar, baz }
Object destructuring:
let { width: screenWidth } = Dimensions.get('window')
Arrow functions:
[1, 2, 3].map(x => x + 5)
Object spread operator:
{ ...currentState, ...newState }
Async / await:
let x = await somePromiseReturningMethod()
Get the app
I haven't written an iOS version of the native SSH bridge, so for now, the app only works on Android.