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</head><body bgcolor="#FFFFFF" text="#000000">Hi Francis,<br>
<br>
Thank you a lot for your response - from a directive point of view - I
don't use a lot of different headers in that sense, it's really just
some settings that I would want to avoid repeating again and again - I
like clean configs - and generally speaking I really want to inherit as
much as possible from the initial server, or even http context when
possible - all I change usually can be things like the expires header,
the proxy_cache_valid directive, or adding an additional header (CORS
for example).<br>
<br>
I do use some of the openresty modules such as the ngx_headers_more
module, and it's pretty explicit about it's inheritance.<br>
<br>
And thank you for the pointer regarding the _module_ctx and
_merge_loc_conf functions, it gave me enough information regarding the
http_proxy module as an example - it seem as long as there a
"offsetof(ngx_http_proxy_loc_conf_t" - then it can be inherited, or it's
a coincidence that it's missing the "offsetoff" for all directives that
doesn't inherit in that module from top of my head.<br>
<br>
Thanks again!<br>
<br>
<br>
<span>Francis Daly wrote:</span><br>
<blockquote cite="mid:20171006202252.GH20907@daoine.org" type="cite">
<pre wrap="">On Fri, Oct 06, 2017 at 07:32:51PM +0000, Lucas Rolff wrote:
Hi there,
</pre>
<blockquote type="cite"><pre wrap="">I know that there’s some settings such as proxy_pass which can’t inherit from the parent location or server block, however – is there any semi-easy way to figure out if a directive in nginx or it’s modules gets inherited or not? (I don’t mind digging around in some nginx source code)
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<blockquote type="cite"><pre wrap="">I wonder if someone either knows a good way to figure out, or any document on the web that goes extensively into explaining what (might) inherit based on general design patterns.
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<pre wrap=""><!---->
My quick response, without doing too much research, is:
* "rewrite" module directives (if, return) don't inherit
* "handler" directives (proxy_pass, fastcgi_pass) don't inherit
* pretty much anything else that is valid in "location" does inherit
(That's probably not correct, but could be a good starting point for
experimentation.)
And be aware that inheritance is by replacement, or not at all -- so one
"add_header" in a location means that the only "add_header" relevant
to that location is the one that is there; while no "add_header" in a
location means that all of the ones inherited from server{} are relevant.
If you want the full details, it's a matter of Read The Fine Source --
each module has a "_module_ctx" which includes a function typically named
"_merge_loc_conf" which shows how each directive is set if it is not
defined in this location: unset, set to a default value, or inherited
from the previous level.
f
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<br>
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