[uWSGI] http proxying in response-route

mathieu lacage mathieu.lacage at alcmeon.com
Wed May 29 12:05:58 UTC 2019


By the way, for some reason, if you use offload threads, the above
configurations (1 and 2) do not work (the client gets a 202). I have not
yet been able to figure out what is causing this.

It is possible to either disable them entirely or disable them only for
this feature by changing the http router from "http" to "proxyhttp" which
ignores offload threads even if they are available.

Mathieu

Le mer. 29 mai 2019 à 13:46, mathieu lacage <mathieu.lacage at alcmeon.com> a
écrit :

> Hi,
>
> In case anyone stumbles upon this question, I eventually found a working
> solution, documented below. FYI, I am going to use 2. upon production
> deployments.
>
> 1. "standard" HTTP headers: this is the solution I tried to get to work
> earlier without understanding that:
>    - the rewrite plugin rewrites the variables, not the input HTTP request
>    - the http router plugin supports a third undocumented argument that is
> the PATH argument that will be injected in the forwarded query
>    - uwsgi does not support the syntax "route = http:${VAR}" where
> VAR=val1,val2,val3. Instead, it requires "route =
> http:${VAR1},${VAR2},${VAR3}"
>
> The application side:
> 222         handler.response.headers['X-Sendurl'] = 'true'
> 223         handler.response.headers['X-Sendurl-IP'] =  '%s:%d' %
> (socket.gethostbyname(url.hostname), url.port if url.port is not None else
> 80)
> 224         handler.response.headers['X-Sendurl-Host'] = url.hostname
> 225         handler.response.headers['X-Sendurl-Path-Query'] = "%s?%s" %
> (url.path, url.query)
>
> The configuration file:
>  29 collect-header = X-Sendurl X_SENDURL
>  30 response-route-if-not = empty:${X_SENDURL} goto:xsendurl
>  32 response-route-run = last:
>
>  45 response-route-label = xsendurl
>  46 collect-header = X-Sendurl-IP X_SENDURL_IP
>  47 collect-header = X-Sendurl-Host X_SENDURL_HOST
>  48 collect-header = X-Sendurl-Path-Query X_SENDURL_PATH_QUERY
>  49 response-route-run =
> http:${X_SENDURL_IP},${X_SENDURL_HOST},${X_SENDURL_PATH_QUERY}
>  51 response-route-run = last:
>
> 2. "variables". It is possible to shorten slightly the above to this:
>
> The application side:
> 216         import uwsgi
> 217         uwsgi.add_var("SEND_URL", "y")
> 218         uwsgi.add_var("SEND_URL_IP", '%s:%d' %
> (socket.gethostbyname(url.hostname), url.port if url.port is not None else
> 80))
> 219         uwsgi.add_var("SEND_URL_HOST", url.hostname)
> 220         uwsgi.add_var("SEND_URL_PATH_QUERY", "%s?%s" % (url.path,
> url.query))
>
> The configuration side:
>
>  31 response-route-if = equal:${SEND_URL};y goto:xsendurl
>  32 response-route-run = last:
>  44
>  45 response-route-label = xsendurl
>  50 response-route-run =
> http:${SEND_URL_IP},${SEND_URL_HOST},${SEND_URL_PATH_QUERY}
>  51 response-route-run = last:
>
> 3. Sadly, the even shorter version below does not work because of issue
> #1041 (https://github.com/unbit/uwsgi/issues/1041) which appears to be
> fixed by the unmerged patch:
> https://github.com/unbit/uwsgi/pull/1473/commits/b71dc90b82c1e8e640d0c449d535171b19a08d9d
>
> The application side:
> 216         import uwsgi
> 221         uwsgi.route("http", "%s:%d,%s,%s?%s" %
> (socket.gethostbyname(url.hostname), url.port if url.port is not None else
> 80, url.hostname, url.path, url.query))
>
> The configuration side: none
>
> I hope this help,
> Mathieu
>
>
> Le mar. 28 mai 2019 à 15:29, mathieu lacage <mathieu.lacage at alcmeon.com>
> a écrit :
>
>> hi,
>>
>> I am trying to implement X-sendurl in my application using uwsgi. I
>> modified my app to generate a couple of http headers:
>>
>> 215         handler.response.headers['X-Sendurlhost'] = '%s:%d,%s' %
>> (socket.gethostbyname(url.hostname), url.port if url.port is not None else
>> 80, url.hostname)
>> 216         handler.response.headers['X-Sendurlpathqs'] = "%s?%s" %
>> (url.path, url.query)
>> 217         handler.response.set_status(200)
>>
>> and I configured my uwsgi server as follows:
>>
>>  29 collect-header = X-Sendurlpathqs X_SENDURLPATHQS
>>  30 collect-header = X-Sendurlhost X_SENDURLHOST
>>  31 response-route-if-not = empty:${X_SENDURLPATHQS} goto:xsendurl
>>  32 response-route-run = last:
>>
>>  [snip]
>>
>>  45 response-route-label = xsendurl
>>  46 response-route-run = rewrite:${X_SENDURLPATHQS}
>>  48 response-route-run = http:${X_SENDURLHOST}
>>  49 response-route-run = last:
>>
>> The above configuration appears to hit and execute correctly line 48 above
>>
>> with the following values:
>>
>> X_SENDURLHOST=137.74.127.78:80,storage.gra3.cloud.ovh.net
>>
>> X_SENDURLPATHQS=/v1/AUTH_7542981824cf4bcb883cf4c4321195ae/prod/companies/8/users-profile-attachments/4165024?temp_url_sig=49d3ec9ee9d5fd5aa447fc70162e6fb72c564e99&temp_url_expires=1559049647
>>
>> I read very carefully the documentation at
>> https://uwsgi-docs.readthedocs.io/en/latest/InternalRouting.html and I
>> would expect the above to forward an HTTP request to IP 137.74.127.78 on
>> port 80 with HTTP header HOST=storage.gra3.cloud.ovh.net and
>> PATH=/v1/AUTH_7542981824cf4...
>>
>> However, tcpdump shows instead the following request:
>>
>> GET
>> /admin/8/users-profile-attachments/?user_id=5172075&site_id=154&site_type=2
>> HTTP/1.0
>> Host: localhost:9090
>> ...
>>
>> HTTP/1.1 401 Unauthorized
>> Content-Length: 131
>> Content-Type: text/html; charset=UTF-8
>> Www-Authenticate: Swift realm="8"
>> WWW-Authenticate: Keystone uri='https://auth.cloud.ovh.net/'
>> ...
>>
>> So, uwsgi is connecting to the right IP and port, but it's not sending
>> what I would expect for the HOST HTTP header and HTTP PATH.
>>
>> Is there something I should adjust in my uwsgi configuration to make it
>> forward the Host+PATH headers I want ?
>>
>> Mathieu
>> --
>> Mathieu Lacage <mathieu.lacage at alcmeon.com>
>>
>
>
> --
> Mathieu Lacage <mathieu.lacage at alcmeon.com>
>


-- 
Mathieu Lacage <mathieu.lacage at alcmeon.com>
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