[Pywps-dev] process discovery

[Tom Kralidis]

Sorry, copy/paste fumbling.  The examples below point to a csw.wsgi
but this is really a wps.wsgi type file.

On Wed, Aug 3, 2016 at 2:28 PM, Tom Kralidis <tomkralidis at gmail.com> wrote:
> 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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