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.
When I started the blog, I didn’t add a message board below each article because I don’t have the time to deal with spam. Due to broken windows theory, if I leave the spam unattended my blog will soon become a landfill for spammers. But nowadays many e-commerce site or brand sites have a live chatting box, which will solve my problem because I can simply ignore spam, while interested readers can ask questions and provide feedbacks easily. That’s why when my sponsor, Chatra.io, approached me with their great tool, I fell in love with it right away and must share it with everyone.