Help with chaining of sub-requests
agentzh at gmail.com
Tue Apr 17 07:19:56 UTC 2012
On Tue, Apr 17, 2012 at 5:51 AM, Ashish S <ashishs.dev at gmail.com> wrote:
> I have 3 existing http backend web-services S1, S2 and S3. I am
> trying to use nginx for a use-case where i need to first get a "key"
> from service S1, use this key along with some input data, to query S2,
> and based on S2's response, query S3. My question is, would
> sub-request chaining be the best method to go about this? I can use
> the upstream method to connect to S1. Am i doing something wrong, if
> I then fire a sub-request (request to S2) from within the content
> handler (process header) method registered for this upstream?. How do
> i then initiate the sub-request to S3 ?
> Any pointers or example that i might be able to follow, for something
> like the above?
Regarding chained subrequest implementation, see ngx_echo module's
echo_subrequest directive for an example:
Also ngx_lua's ngx.location.capture() and ngx.location.capture_multi()
worth a look too:
Regarding non-subrequest upstream communication, ngx_lua supports the
cosocket API which implements something similar to (but more general
Hope these helps,
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