Howto Remove the Cache-Control request header.

[Francis Daly]

On Sat, Jan 16, 2021 at 07:11:54PM +0100, Vincent Blondel wrote:

Hi there,

> We want nginx to remove the request header Cache-Control before to proxy
> the request to the OCS.
> We do like this ...

'proxy_set_header Cache-Control "";' appears to work for me.

Can you show one request to nginx with the header, and the matching
request to the upstream server?

When I use this config:

==
server {
    listen 7000;
    add_header X-7000 "cache :$http_cache_control:";
    location /a {
        proxy_set_header Cache-Control "";
        proxy_pass http://127.0.0.1:7001;
    }
    location /b {
        proxy_pass http://127.0.0.1:7001;
    }
}

server {
    listen 7001;
    add_header X-7001 "cache :$http_cache_control:";
    location / {
        return 200 "7001: $request_uri\n";
    }
}
==

if I make a request to port 7000 that starts with /b and includes a
Cache-Control header, I see in the X-7001 response header that that same
Cache-Control header was sent to the upstream; but if I make a request
that starts with /a, I see in the X-7001 response header that it was
removed before the request was made to the upstream.

That is:

curl -i -H Cache-control:no-cache http://127.0.0.1:7000/b1

includes

X-7001: cache :no-cache:
X-7000: cache :no-cache:

while

curl -i -H Cache-control:no-cache http://127.0.0.1:7000/a1

includes

X-7001: cache ::
X-7000: cache :no-cache:

Does your system respond differently?

	f
-- 
Francis Daly        francis at daoine.org