I have a dirty secret.
, my location-based photo request app, sends push notifications. That’s not the secret: lots of apps do that.
Still not a secret: Looxie uses (now renamed into Firebase Cloud Messaging) to send the notifications. Up until recently, before the introduction of , you had to have your own server running & following the Firebase real-time database for changes.
I am still using this architecture because, for some reason, I can’t seem to get the node.js server I created to run as a Firebase Cloud Function.
Here comes the secret: the node.js server is running on an old ASUS laptop I bought for $300. After a catastrophic HDD failure that came completely out of nowhere (OK, I punched it during a particularly challenging section in ), I replaced the hard disk with an SSD and installed Ubuntu because I was too cheap to purchase a Windows license.
Doesn’t sound too bad, right? Well, here’s where it gets good: the laptop is connected to the web using Wi-Fi. When the router starts spazzing out (which happens with alarming frequency) the connection drops and Ubuntu requests the password again before it can connect to the web. If I am not around to enter the password and press “enter”, Looxie stops sending push notifications.
Thankfully, I live minutes from my office, so when the connection drops I go there and reconnect the PC to the internet. Which is still a silly thing to do but at least it works.
So imagine how stressful it was for me to leave Cyprus for twenty days for a trip, all the while thinking “how the hell am I going to bring the server back if (or more realistically, when) the connection drops while I’m away?”
Connection drops while I’m away
Five days into the trip, Looxie stops sending push notifications.
Shit.
I call my brother and ask him to go reconnect the laptop to the internet. My brother happily obliges but, as these things tend to go, one day later the laptop disconnects again.
At that point I felt something like this:
Frustrated, I walk into a T-Mobile store in San Francisco with a plan. I buy a SIM card loaded with 2GBs of data and put my plan into action.
Termux comes into the picture
I had heard of before in the /r/androiddev subreddit. I actually had it installed on my Nexus 6P but never really used it. Having a Linux terminal emulator on your phone is one of those things that sounds cool at first but ends up having too little practical use in the end.
Not this time. This time I went
apt install git
and… what? Git was installed. After initializing a repo in Termux, I pulled the entire Looxie repository from Github.
So far, so good. But… how the hell am I going to get node.js running on here? Well, how about
apt install nodejs
It was a shot in the dark but, to my surprise, something started happening.
A couple of minutes later, I had a node.js installation running in Termux. This was as far as my luck would possibly stretch though, right?
“Well, it’s not like I have anything to lose”, I thought, as I started typing
npm install nodemon
And… holy crap, it worked!
More than a little addicted to the awesomeness, I typed
apt install nano
because I had thought of a change I could do in the JavaScript source code that would solve a minor bug in the server.
You get the idea: it worked.
It couldn’t possibly be this easy, right? Something was going to go horribly wrong when I typed
nodemon looxieapp.js
to start the server.
Nothing went horribly wrong.
Nothing.
The server started and it worked perfectly. Looxie was sending push notifications once again.
My only worry? The server stopping when the phone would go into Android’s infamous “Doze” mode — which does not work when you want it to and works when you don’t want it to.
Doze mode: does not work when you want it to and works when you don’t want it to
Termux had me covered, again: in its notification in the notification drop-down, it had the option to “acquire wakelock”.
I acquired wakelock.
And went to sleep.