Still new to nginx, and having some basic problems.

I'm having a config file 'proxy.conf' which I normally include in locations, which should be proxied.

for one location I'd like to override a header specified in the proxy.conf file.

what I tried

location /blabla { include.proxy.conf; proxy_set_header Host custum_val }

However this just appends my customval to the already existing 'Host' header.

Is there a way to override a header?

I considered changing the variable $host

However: I don't know the syntax to do this. I don't know who else uses the variable $host, thus I'm not sure whether some side effects would show up.

How do you handle such situations?