Most of the CI/CD (Continuous Integration/Continuous Delivery) tools nowadays supports some form of configuration file so you can properly version control them. For example Travis CI, Gitlab CI, Circle CI and Drone CI uses YAML file. Jenkins uses its own DSL. These YAML-based configuration files are easy to read and edit, but they don’t scale very well when the file grows big. This problem can be solved by using a nice data templating language called Jsonnet. In this post we’ll be demonstrating Drone CI v1.0 configuration file format, but the idea can be easily applied to other CI tool.
When building websites or web apps, creating a “Download as file” link is quite useful. For example if you want to allow user to export some data as JSON, CSV or plain text files so they can open them in external programs or load them back later. Usually this requires a web server to format the file and serve it. But actually you can export arbitrary JavaScript variable to file entirely on the client side. I have implemented that function in one of my project, MozApoy, and here I’ll explain how I did that.
Terraform has some great documentation on Route 53, but it’s a little bit hard to understand how all the resources works together. So to demonstrate, we are going to build an REST API that is deployed to multiple AWS regions, which has one public-facing URL, which is load balanced through Route 53. There are some additional requirements:
API is done using API Gateway + Lambda
The same API is deployed to multiple AWS regions. To demonstrate this we’ll deploy to EU Frankfurt (eu-central-1) and N.Virginia, US (us-east-1).
The API in each region will get a public facing URL for easy debugging. So there will be https://api-eu.example.com and https://api-us.example.com pointing to the API gateway in each region.
There will be a global URL, https://api.example.com which points to the underlying https://api-eu.example.com and https://api-us.example.com endpoints.
The global URL will do a 50%-50% active-active load balancing to each region. In other words 50% of the traffic will go to each region.
The health of the regional APIs are monitored, if one of it goes down, all the traffic will be routed to the other alive one.
Sometimes you may wonder, how many commits or lines of code did I contributed to a git repository? Here are some easy one liners to help you count that.
My first ever video course is now live on Udemy, Safari Books and Packt. It really took me a long time and I’d love to share with you what I’ve prepared for you.
What’s this course about?
This course is about the Rust programming language, but it’s not those general introductory course on basic Rust syntax. This course focus on the code reuse aspect of the Rust language. So we won’t be touch every language feature, but we’ll help you understand how a selected set of features will help you achieve code reuse.
What’s so special about it?
Since these course is not a general introduction course, it is structured in a way that is bottom-up and help you learn how the features are actually used out in the wild.