Kevin Jiang's Technical Blog

This week I encountered some issues with Terraform (and, well, Kubernetes) again. This time, the problem was way more interesting than I thought.

Recently, I started to build an application with Go, it is a quite simple application that does something very basic and then sends an notification to a telegram bot. It's quite obvious to me this kind of application is quite suitable to run as Lambda, and that's where I decided to deploy my application to once it is working well locally. It turned out that I had to solve several issues I encountered. Here I share how I solved those issues, so you don't have to scratch your head when encounter them.

Steps:

• Download the bin file needed to upgrade the package
• Create a list of all the installed packages on current version using opkg list-installed | cut -f 1 -d ' ' > /root/installed_packages.txt
• Choose one of the following methods to flash:
  • Flash the file from the Luci interface
    OR
  • Download the file to the /tmp and then flash using sysupgrade /tmp/*.bin
    Read more »

Like it or not, 2020 has been a year where video conference are used a lot. For me, most of the meetings happens in Zoom. Finding the link to the meeting in the calendar and then clicking on it to join the meeting had gradually become a new norm and something I really don't like (the fact that after clicking on the Zoom link brings up your browser instead of Zoom itself, and prompting you to click again to open Zoom is really a pain). As someone who would like to automate things as much as possible, I did eventually find a solution that works for me albeit several third party tools are required.

Problem Statement: Automatically join a Zoom call for a meeting scheduled in calendar without user interaction (on MacOS X).

Prerequisite:

• Alfred
  (Unclear if you need to be a paid user to create custom workflows, the author is a paid user)
• zoom-calendar.alfredworkflow
  (Yep, I found this alfred workflow by chance and based my work and this blog on this workflow, it is very handy and I would really like thank the author for creating this.)
• Automator
  (The builtin automation app in MacOS from Apple)
  Read more »

As a developer, you will sometimes face weird problems, it is important to come up with reliable and repeatable ways to solve this problems, so when such problems come up again, you would be able to find a solution easier. As for myself, one of the tools that I found most useful on Unix-like system is jq, which is a tool to process json files. Let me demonstrate how I use this tool to solve some problems I encountered during work.

What would be the easiest way to remove all but one word from the end of each line in Vim?

Today, I found a challenge on vimgolf and thought it might be interesting to share my solutions.

Here is the original file

1
2
3
4

abcd 1 erfg 7721231
acd 2 erfgasd 324321
acd 3 erfgsdasd 23432
abcd 5 erfgdsad 123556

Here is the desired result:

1
2
3
4

7721231
324321
23432
123556

The challenge is quite straightforward, delete all but the last characters in the file. I found several ways to tackle this challenge, so let me show you all:

This week, I was tasked with creating basic infrastructure for one of our newwebsites. We use Fastly for our CDN and New Relic as a log aggregation tool, most of our infrastructure is setup using Terraform, which is a popular infrastructure as code (IaC) platform. Terraform supports Fastly through a custom plugin, which also has the capability of New Relic. We need to customize the format of New Relic so that we can find the logs easily in New Relic. As expected, the plugin actually provide a pretty straight forward to accomplish this -- what you need to do is to come up with a proper json string that align with the format that Fastly provided in their document. This seemingly straightforward task ended up took me some time to debug.

Recently, I have been eager to get the data saver on Android to work automatically for me. My goal is to have Tasker automatically enable the built-in data saver when my data is low. Before I came up with this idea, I have search the web to see if there is any solutions exist already so I don't have to reinventing the wheel. Unfortunately, I couldn't find anything on this topic so I have to create my own solution. Upon 1 week of testing, things to work as I expected so I decided to share in this article how I did it.

Prerequisite

• An rooted Android phone -- Unfortunately, the solution I came up with only works on rooted Android phone, I'm running Android 9.0.
• A way to get to know you current data usage -- Some carriers allow you to get you data usage through SMS, some might only allow you to use USSD to get data usage. I am only covering the case of using SMS here (my case).
  Read more »

Recently, I decided to convert my QEMU based virtual machine installed on my Manjaro Linux to the VirtualBox format. The reason behind this is that I would like to be able to use the same VM across different host system (specifically Manjaro Linux and Windows 7). It is not a easy thing to do, so I decided to document it for future references.

Prerequisite?

• An existing image created using QEMU (My VM file end with .img, for example)
• VirtualBox
  Read more »

Why Tasker?

This is probably an article that is long overdue to me personally. I have been an Android user since 2011, started with my Nexus S that I bought for use in college. It seems to me, the app Tasker had been very famous in the Andorid community, especially among users who know how to program.
For those who have never heard of this app, this is a powerful app that allows you to automate almost anything that you can think of on the Android system.For me,It was not until August of last year when I bought the tasker app that I started to realize how powerful this app is. I am really not a big fan of its old school UI and design so I didn't start using it until this year. After uisng it for a while, I did come to realize that there is no other apps close to it, if I were to move to iOS, this is probably among one the apps that I will miss. In this article I will explain how I used takser to automate things for myself, it is some boring stuff, but it did become something that I'm using everyday.

What can you use it for?

I will list one of the most used Tasks/Profiles that I created and used in this app: