Quick References

As a constant learner, I get to touch upon many ideas in different areas. This category is for me to capture those ideas which I felt people may reference to get ahead of their tasks. Most of the time, I do come back to this section of my blog to remember what I had learnt in the past.

How I built my Raspberry Pi 3 CCTV using a motionEyeOS image for home surveillance

When I bought my Raspberry Pi 2, I also bought the first version of the Raspberry Camera Module just for the fun of it. After setting up my Raspberry Pi 2 as a TV box for my wife, that camera module became an ornament. Feeling bad about such wastage, I bought another Raspberry Pi 3 to utilise the camera module in performing home surveillance.

This post documents the steps that I took to build my Raspberry Pi 3 CCTV via a MotionEyeOS image for home surveillance.

Ensuring that your Supervisor subprocesses can run your Python applications properly behind your http proxy on Ubuntu Server 14.0.4

I had been using Supervisor to run my Python application for quite a while on a Ubuntu Server 14.0.4 box.

There was this OAuth feature that I had implemented on my Python Flask application to allow my users to sign in with their social account.

After completing the OAuth feature and ensuring that it worked fine on my development environment, I deployed the feature on my Ubuntu Server 14.0.4 instance.

However, my Python application encountered a HTTP request timeout error when it attempted to contact the OAuth server to authenticate my user login.

It turned out that there was no HTTP and HTTPS proxy settings available for my Python application to use when it tried to contact the OAuth server which is sitting somewhere in the Internet.

This post documents three ways which I had considered for propagating HTTP and HTTPS proxy settings to my Python application via the http_proxy and https_proxy environment variables.

The steps that I took to build my Raspberry Pi 2 TV box via the OpenELEC Mediacenter image

After I got my new Raspberry Pi 3 to incubate my new WordPress website, I freed up my Raspberry Pi 2 for other things. Since my wife had been yearning for a TV box to watch her favourite videos on our TV, I decided to convert my Raspberry Pi 2 into a TV box.

This post documents the steps that I took to build my Raspberry Pi 2 TV Box with an OpenELEC Mediacenter image.

Setting up a free CA signed SSL certificate from Let’s Encrypt for my LEMP server on my Raspberry Pi 3 with an Ubuntu Server 15.10.3 image to secure my WordPress site

After setting up a LEMP web server on Raspberry Pi 3 with an Ubuntu Server 15.10.3 image to host my new WordPress website, a good colleague of mine recommended me to try implementing a free certified SSL certificate. The intelligent and generous folks from Let’s Encrypt had created a free and open Certificate Authority and an automated workflow for websites to generate certified SSL certificates for serving trusted and encrypted communication.

Since, there is no cost involved in implementing the SSL certificate, I went on to try and implement one on the Nginx server on my Raspberry Pi 3.

This post documents my process on setting up a Let’s Encrypt certified SSL certificate for my Nginx server on my Raspberry Pi 3.

Adding swap space for my Ubuntu Server 15.10.3 image running on my Raspberry Pi 3

A swap space. also known as virtual memory, is a dedicated area on a writable medium that acts like the RAM for Linux processes to remember things while they are running. For laptop and desktop computers, that writable medium is usually a hard disk. For my Raspberry Pi 3, it is the microSD card which I had written my Ubuntu 15.10.3 image on.

While running the Let’s Encrypt application to set up a free CA signed SSL certificate for my LEMP server on my Raspberry Pi 3 to secure connections to my WordPress site, the Let’s Encrypt application hanged while it was trying to install the Python dependencies that it needed. This prompted me to turn to swap space for increasing the total memory that processes on my Ubuntu 15.10.3 image can utilize.

This post documents the steps that I took to add some swap space on my Ubuntu 15.10.3 image running on my Raspberry Pi 3 so that processes can use more than 1GB of memory.

How I resized the file system of my Ubuntu Server 15.10.3 image to utilize the entire microSD card space on my Raspberry Pi 3

After setting up a LEMP web server on Raspberry Pi 3 with an Ubuntu Server 15.10.3 image to host my new WordPress website, I decided to create some swap space to complement the 1GB ram on my Raspberry Pi 3 in running more services.

When I tried to create a 4GB swap file, the fallocate command complained that there was no space left on my Raspberry Pi 3:

Home directory of the LocalSystem account in Windows Server 2012

Quite a few applications that I had encountered throughout my career provide the option to look for custom configurations inside the home directory of user accounts that had started them. One such example is the Git command, which looks for the private key to communicate with a GitHub repository inside a .ssh directory located inside the home directory of the user that runs it.

This post documents the home directory of the LocalSystem account in my Windows Server 2012.

Supervisor configurations to ensure that my Python Flask application releases binded port(s) during a supervisor restart

We use Supervisor to help keep our Python based applications running. One of our applications was built on the Python Flask framework to provide a RESTful api to connecting clients.

With continuous integration in place, we need to restart all our Supervisor managed applications whenever there is a change being merged to the master branch in our Git repository.

This post documents the Supervisor configurations to ensure that my Python Flask application releases any port that it had binded to when Jenkins send the command to restart the Supervisor and the processes that it manages.

Setting up a LEMP web server on Raspberry Pi 3 with an Ubuntu Server 15.10.3 image to host a WordPress website

I was trying to start a new WordPress site. Before hosting it on a Digital Ocean droplet, I decided to incubate the WordPress site on a Raspberry Pi 3 to clock some content. This post documents the steps that I took to set up a LEMP web server on Raspberry Pi 3 with an Ubuntu server 15.10.3 image to host a new WordPress site.