"No route found for GET" on custom REST resource when posting

Question

I'm seeing really weird behavior. I've created a custom REST resource at the route /user/login-special.

This is a passwordless login resource, so I pass the mail address and then get a response that says Login email was sent!

However, when I POST to the https://abc-xyz-123.us-3.platformsh.site/user/login-special?_format=json, I get the error:

{
    "message": "No route found for \"GET https://www.abc-xyz-123.us-3.platformsh.site/user/login-special?_format=json\" (from \"https://abc-xyz-123.us-3.platformsh.site/user/login-special?_format=json\")"
}

The route definitely exists... what is going on? And why is it saying GET when I used POST?

Answer 1

Read the error carefully.

You POSTed to https://abc-xyz-123.us-3.platformsh.site/user/login-special?_format=json, but it is returning https://www-- you're getting redirected.

So the solution is to POST to https://www.abc-xyz-123.us-3.platformsh.site/user/login-special?_format=json and everything works as expected.

This might be obvious to most people, but I wasted a lot of time debugging this today, so I'm posting it here in case anyone else makes the same mistake in the future.