In my Azure Function project I had two problems:
- I wanted my Azure Functions to have a path with v1 in it
- I wanted to always return a response header with a version identifier
Here’s how I solved.
Response Header Version Info
Let’s say you want to return an API version in the response header. The response header could be something like this below.
[caption id="attachment_4740” align="aligncenter” width="618”]
spl-version: 2018-08-03[/caption]
If we were using ASP.NET Core we could write a piece of middleware to return this. With Azure Functions we don’t have this full framework goodness but we do have a useful tool: Proxies.
You can edit the proxies via the web UI or locally, if you have a local project. If it’s the latter you need a proxies.json file at the root of your project.
The key piece is line 10. What we’re doing is setting a response override. In other words: always return this. In my case I choose to return a date. You can enter whatever you like.
Version Number in Path
By default Azure Functions will give you a URL line this:
https://.azurewebsites.net/api/
I wanted it to have a version number in the path. I want something like this:
https://.azurewebsites.net/api/v1/
To do this, I need to two things:
- Define a route. You can see it in line 6. What this is saying it “anything ending with /api/v1/” send it to the path at line 8. The value {*restOfPath} is a variable
- Line 8 has the destination. I’m saying: “take whatever was after v1 and put it here.
Note how I am using https://localhost. Using this means I can avoid a round trip to my destination URL.
Voila - all done!