[GIS] Retrieve WMS service from GeoWebCache with OpenLayers

geoservergeowebcacheopenlayers-2standalonewms

Ok guys, here we go !
For my needs, I basically added a standalone version of GeoWebCache.
After some configuration, the GeoWebCache retrieve the data from GeoServer using Capabilities.

Now, in my OpenLayers code, I would like to question GeoWebCache to retrieve my data, and not GeoServer (if it is possible).

For the moment, I have something like this (working) :

    var fond_carto = new OpenLayers.Layer.WMS(
        "Fond cartographique 2", 
        "http://179.172.277.77:8080/geoserver/wms",
        {
            layers: 'departement',
            TILED: 'true'
        }

I tried stuff like that (not working) :

    var fond_carto = new OpenLayers.Layer.WMS(
        "Fond cartographique 2", 
        "http://179.172.277.77:8080/geowebcache/sevice/wms",
        {
            layers: 'departement',
            TILED: 'true'
        }

Is there a way to accomplish that ?
After some reading, I assume I'm a bit lost with this standalone version of GeoWebCache. It is written it works as a proxy between client (OpenLayers) and server (GeoServer). But I read that the TILED: 'true' option means that GeoServer will send the layers for tiling to GeoWebCache. As I desactivated the integrated version of GeoWebCache in GeoServer, and as my WMS request are still tiled, I assume this is true. But then it's not really a proxy.

Could it works as follow:

openlayers => standalone geowebcache => geoserver => standalone geowebcache => openlayers

Or it has to work that way :

openlayers => geoserver => standalone geowebcache => geoserver => openlayers

Thanks for any tips or any clarifications 🙂 !

EDIT

After some more configuration in geowebcache.xml, I still have the error but I can add some details to help.
This is the URL of the request that is not displaying (pink tiles) :

http://179.172.277.77:8088/geowebcache/sevice/wms?LAYERS=departement&TILED=true&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&FORMAT=image%2Fjpeg&SRS=EPSG%3A4326&BBOX=2.8125,48.515625,3.515625,49.21875&WIDTH=256&HEIGHT=256:8080/geowebcache/sevice/wms?LAYERS=departement&TILED=true&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&FORMAT=image%2Fjpeg&SRS=EPSG%3A4326&BBOX=2.8125,48.515625,3.515625,49.21875&WIDTH=256&HEIGHT=256 :

and when I try to copy/paste this url, I got a GWC error :

400: Thread 35 Unknown layer departement. Check the logfiles, it may not have loaded properly.

I don't get why I got this error. Here's my geowebcache.xml description of the layer :

<wmsLayer>
  <name>departement</name>
  <mimeFormats>
    <string>image/gif</string>
    <string>image/jpeg</string>
    <string>image/png</string>
    <string>image/png8</string>
  </mimeFormats>
  <gridSubsets>
    <gridSubset>
      <gridSetName>EPSG:4326</gridSetName>
    </gridSubset>
  </gridSubsets>
  <wmsUrl>
    <string>http://179.172.277.77:8080/geoserver/wms</string>
  </wmsUrl>
  <wmsLayers>aaz:departement</wmsLayers>
</wmsLayer>

Best Answer

Your Geoserver Instance and GeoWebCache should be running on different ports if on the same machine.

Then your GeoWebCache end point should be something like: 

http://179.172.277.77:PORT/geowebcache/service/wms?

The flow is Openlayers => Standalone GeoWebCache => GeoServer

EDIT: (For Additional Question)

You look like you are using workspace aaz so your reference to the layer in geoWebCache should be aaz:departement not departement

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