TapChat is an OpenSource IRC Client for Android. It provides push notifications with the help of a Node.js server application that serves as an IRC bouncer.
While the TapChat website provides setup instructions for a Debian based system where
sudo rights, this post is about setting the thing up as a permanent
service on an unprivileged Uberspace SSH account. It might be helpful
for use on similar accounts with other providers as well, however I do make
use of some of uberspace’s helper scripts. But wait…
Bouncer is just IRC lingo for proxy - an IRC bouncer is just a piece of software running somewhere on a server that stays connected to your IRC networks of choice all the time.
Whenever a client (in this case, the TapChat Android app) connects to the bouncer, the latter can provide a replay of all the messages that occured since the client was last seen. In addition to that, the bouncer can react to what happens in the channels you joined while you are offline or not running the TapChat app on your phone, which is what it does to send out push notifications whenever your nick name is mentioned in a channel.
Where to run the thing
This is the kind of task where having a shell account at a reliable hoster comes in very handy. I’m a happy customer of Uberspace, they provide everything you need (and most probably a lot more) together with stellar support and a pay what you want pricing model. Hard to beat if you ask me.
So if you want to follow along and not already have an account there, give them a try.
Ok let’s do it
The next commands assume you are logged into your uberspace account.
First of all some Node.js setup. Node is already installed, we just need some personal configuration for NPM, telling it where to install stuff:
I’m no Node.js export, so I cannot explain why the last step is necessary, but without it tapchat refused to start.
You will now be asked for a port number, username and password. The port will be the port that you will later connect to from Android / your browser. Uberspace has some guidelines for choosing port numbers, it boils down to
- only use ports between 61000 and 65535
- to have your port made accessible from the rest of the internet, just ask
- before you do that, check if the port is still unused on your machine:
netstat -tulpen | grep YOUR_PORT
So pick a port number, drop them a line and continue. Take note of the SSL fingerprint the setup process writes out at the end. You can set up an SSH tunnel from your local machine for the time until they opened up the port (replace PORT with your port number of course)
Now point your browser to
https://localhost:PORT. Your browser will complain about the certificate - just compare the certificate’s fingerprint
with the one from earlier on and if they match, accept the certificate
permanently. You should now be able to log in using the username and password
you picked. There’s not much to see but what is there is pretty self
explanatory. Basically this is the place where you configure any IRC networks
that you wish to connect to.
Once Uberspace confirmed that your port is open you can ditch the tunnel and connect directly to
https://servername.uberspace.de:PORT. Now you can also set up your Android
app by pointing it to
servername.uberspace.de:PORT and entering your username
and password. Since all IRC connections are already configured in the bouncer web app, there’s not much more to configure here.
Make it right
Using the uberspace-provided daemontools helper scripts it is super easy to turn TapChat into a managed system service. This way it will be restarted when needed, and you will be notified if there’s anything wrong (i.e. if it keeps crashing).
The Uberspace Daemontools wiki
page has been a very helpful
resource here, basically it’s just copy’n’paste. First, set up daemontools for your account in case you haven’t yet,
then, create a
tapchat managed service:
-f makes tapchat stay in the foreground, which is a requirement for
daemontools to be able to manage it properly.
You may now start / stop the service at will using these commands:
Make sure you stop any already running tapchat instance (
stop) before trying this.
Bonus points - custom highlight words
The major problem I had with TapChat was it’s lack of a custom higlight word list, which let me configure additional terms that, when they occur in a channel I joinded, would trigger a push notification. There’s a Github issue for this already, but for the time being, I hacked this into the TapChat server, which turned out to be really easy. It’s written in Coffee Script, so the hardest thing actually was to find out how to recompile the thing.
All you need to do is open
~/node/lib/node_modules/tapchat/src/tapchat/connections.coffee and modify
shouldHighlight method which was located on line 330 at the time of
this writing. We have a convention to prefix what we call public service
announcements with the string
PSA at Planio so here’s
shouldHighlight method looks like now:
As you can see, no big deal. In order to compile the changed source into proper
npm install one more time:
Don’t forget to restart the tapchat service so it picks up the changes.