[Pywps-dev] process discovery

[Tom Kralidis]

Hi Luís: consider this PyWPS 4 based application wrapper:
https://github.com/geopython/demo.pywps.org/blob/master/PyWPS/wps.wsgi.
I specifically have to call out the processes when initializing the
application, i.e.:

from pywps.app import Service
from cite.processes import HelloWorld
os.environ['PYWPS_CFG'] = 'cite/cite.cfg'
application = Service(processes=[HelloWorld()])

I would much rather do:

from pywps.app import Service
from cite.processes import HelloWorld
os.environ['PYWPS_CFG'] = 'cite/cite.cfg'
os.environ['PYWPS_PROCESSES'] = '/path/to/a/dir/of/processes'  # or
this could also be specified in the configuration if desired

application = Service()  # PYWPS_CFG and PYWPS_PROCESSES drive the application

This way I don't have to update any application code if I add
processes via some other workflow.  In addition, I can use this single
WSGI file setup and have, say, Apache settings like:

WSGIScriptAlias /wps1 /osgeo/demo.pycsw.org/pycsw/csw.wsgi
WSGIScriptAlias /wps2 /osgeo/demo.pycsw.org/pycsw/csw.wsgi
...
WSGIScriptAlias /wps1000 /osgeo/demo.pycsw.org/pycsw/csw.wsgi


SetEnvIf Request_URI "/wps1" PYCSW_CONFIG=/path/to/wps1.cfg
SetEnvIf Request_URI "/wps2" PYCSW_CONFIG=/path/to/wps2.cfg
...
SetEnvIf Request_URI "/wps1000" PYCSW_CONFIG=/path/to/wps1000.cfg

Hope this helps clarify things?

..Tom

On Wed, Aug 3, 2016 at 3:00 AM, Luí­s de Sousa
<luis.de.sousa at protonmail.ch> wrote:
> Tom,
>
> I am not sure I entirely understand this. What do you mean by "mapping
> endpoints"?
>
> PyWPS-4 is now just a library, or an API, if you will. It is totally
> insulated from web server aspects. On a first glance, these scalability
> issues must be solved at application level.
>
> Cheers,
>
> Luís
>
> -------- Original Message --------
> Subject: Re: [Pywps-dev] process discovery
> Local Time: 2 August 2016 10:58 PM
> UTC Time: 2 August 2016 20:58
> From: tomkralidis at gmail.com
> To: pywps-dev at lists.osgeo.org
>
> All: as per today's PSC meeting bringing this thread up again.
>
> Per below, a great feature of PyWPS 3 is multi-tenancy against
> a single deployment. For example, I can have a single WSGI
> wrapper along with environ['PYWPS_CFG'] and
> environ['PYWPS_PROCESSES'] as part of the process.
>
> This, in combination with mapping endpoints to environment
> variables allows PyWPS to scale with 1..n WPS endpoints which
> use the same single WSGI wrapper. One can have 1000 PyWPS
> configuration files and this approach scales accordingly. As
> well, one can scale processes on a single server with the same
> approach.
>
> Unless I am mistaken (which is quite possible) it appears that
> PyWPS master/moving forward to PyWPS 4 requires that a
> simple wrapper explicitly define processes [1].
>
> Is there another way to accomplish the pluggable features
> of PyWPS 3 currently?
>
>
> [1] https://github.com/geopython/pywps-demo/blob/master/demo.py#L60
>
>
>>>
>>> -------- Original Message --------
>>> Subject: [Pywps-dev] process discovery
>>> Local Time: March 4, 2016 1:20 AM
>>> UTC Time: March 4, 2016 1:20 AM
>>> From: tomkralidis at gmail.com
>>> To: pywps-dev at lists.osgeo.org
>>>
>>> Hi all: I'm setting up http://demo.pywps.org as a demo space to
>>> serve PyWPS instances as required. The goal here is a minimal
>>> configuration (assuming a PyWPS install), along with some Apache
>>> setup.
>>>
>>> In PyWPS 3, there was functionality to define a PYWPS_PROCESSES
>>> environment variable. There was also the ability to define this in the
>>> PyWPS
>>> config. Looks like this is not available in master branch
>>> anymore.
>>>
>>> Any plans on adding this back in the codebase? The value here is being
>>> able to deploy a single WPS (in my case WSGI) wrapper which operates
>>> against multiple configurations and processes setups driven by a given
>>> endpoint.
>>>
>>> Or is there another/better way to acheive this?
>>>
>>> ..Tom
>>> _______________________________________________
>>> pywps-dev mailing list
>>> pywps-dev at lists.osgeo.org
>>> http://lists.osgeo.org/mailman/listinfo/pywps-dev
>>>
>>>
>>
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