Why does nginx strip trailing headers from a proxied backend? How can I prevent it?

[Alan Chandler]

On 09/06/2020 02:51, Maxim Dounin wrote:
> Hello!
>
> On Mon, Jun 08, 2020 at 10:29:23PM +0100, Alan Chandler wrote:
>
>> On 08/06/2020 21:58, Maxim Dounin wrote:
>>> On Mon, Jun 08, 2020 at 08:57:56PM +0100, Alan Chandler wrote:
>>>
>>>> I have nginx acting as the static file server for a single page
>>>> web app I am developing. It acts as a proxy server for the
>>>> "/api" portion on my url space.
>>> Trailers are only supported in gRPC proxying (grpc_pass), where
>>> they are required for gRPC.  Trailers are not supported by
>>> proxy_pass.
>>>
>> That is a shame.
> You are welcome to work on this if you think this is needed.

HA:  I'm still working on a Single Page Application I started in 2013 to 
move a client from Microsoft Access/Sqlserver app to

a web app (still with sqlserver).  Until I do so I cannot retire, and 
that client is the only one I have left and I am currently 69.

The work I was trying to use trailers for is a hobby, but with a 
deadline of September this year. Trailers was just me exploring

options to support my api handler throwing an error mid stream. I can 
think of other options to handle my use case.

Besides it has been almost 40 years (early 1980s)  since I last coded in 
C or C++

> Some lengthy discussion on trailers support happened in the past
> here (TL;DR: net effect is that there are no trailers support in
> the Fetch Standard now):
>
> https://github.com/whatwg/fetch/issues/34
>
Having read through that, trailers is definitely not a rabbit hole I 
want to go down.

Alan Chandler