Automating Things That Should Already Be Automated With Selenium and Node.js
So I had invited my parents over a while back, and it came up that I don’t often lock my front door. Of course being good parents they chided me about it saying that I should really do so. I really have no excuse because I even have an app that allows me to to it remotely (yay home automation) but the be honest I’m just forgetful when it comes to things like that. However I decided to heed their warning and do something about it. I decided if I was going to get diligent about locking my door, I couldn’t be the one in charge of actually doing it, I’d have to make a computer do it. The problem is, that while my home security provider does offer a web app, and a phone app for locking the door and a very basic ‘rule’ system (arm the panel when the door is locked, vice versa) there are no time based controls, so I’d still have to actually do something. Totally unacceptable.
After some investigation I found as I had figured that my security provider does not offer any sort of API. Nor would it be easy to try and replicate the post request that is send from the app to trigger the lock door command due to numerous session variables and cookies and things include unique to each login session. Nope, if I was going to automate this it seemed like I’d actually have to interact with the browser as much as the thought displeased me (I’m all for dirty hacks, but c’mon). At first I looked at python for a solution, but as seems to often be the case with python every discussion of a solution was disjointed with no clear path and generally unsatisfactory (sorry python). Instead I turned to Node to see what potential solutions awaited me there. After a bit of looking around I found Selenium for Node. While it’s obvious and stated focus was on automated web app testing, not intentional browser automation scripts I could see no reason it wouldn’t work.
Then simply tell Selenium to populate the boxes and click the login button.
Thankfully just through dumb luck when creating this my session had timed out and I found out the login page accepted a return url parameter that it would direct the browser to after successful login. So now, if the login goes smoothly, the browser should be at the screen where I can control the locks. A different button is used to lock or unlock the door and only one is visible at a time. So writing my function in such a way that it accepted boolean ‘lock’ (where false would be unlock) param and then failing if it’s not able to find the button is a safe way to ensure I don’t unlock the door when I mean to lock it and vice versa.
I don’t know Selenium super well yet, but it seems that after the login button is clicked the driver waits until it can retrieve the title of the page (which is a easy way to tell the page has at least somewhat loaded) and when it has then run the inner logic for clicking the proper button. Honestly I’m not totally sure, but it works and that’s the important thing 😛
It’s just a function that is called via setInterval every hour. It checks the current hour against my two predefined lock and unlock times. I used a couple variables to track if the door has been locked or unlocked so if I reduce the time on the event loop it’s not attempting to lock/unlock the door every few minutes and wearing out the batteries on the motor. Obviously omitted from this is my alarm_username and alarm_password variables stored higher up in the script. With this event loop and the Selenium automation function I now have one less thing to worry about. Now if I could just find a Node.Js host that supported Selenium (damn you Heroku). So if anything, I’d say this is the take away: Don’t do manually what you can automate, and browser automation with Selenium is crazy easy. So easy that when it all worked I was almost disappointed that it seemed like I didn’t do anything.
Till next time!
Also, be sure to check out the addendum to this project in my next blog post where I added automatic operations with a geofence. https://iwritecrappycode.wordpress.com/2015/10/21/automating-things-that-should-already-be-automated-with-selenium-and-node-js/