Publishing data from a DB table

In this section we are going to publish on GeoNode a layer which is already present on a DB table.

In particular those are the steps that will allow us to convert the Test Layer, the empty layer created in the previous sections, to a Mercator Projected one and publish it again on GeoNode:

1. Download the Test Layer as an ESRI Shapefile
2. Use the GDAL ogr2ogr utitlities to reproject it from World Geodetic System 1984 EPSG:4326, LatLon coordinate reference system used in GPS, to Spherical Mercator EPSG:3857, meters projected coordinate system used for rendering maps in Google Maps, OpenStreetMap, and tiled layers in general.
3. Use the GDAL ogr2ogr utitlities to import the file into a local Data Base.
4. Publish the layer on GeoServer.
5. Publish the layer on GeoNode.
6. Try to edit it again from an external client (QGIS).

Download the Layer as an ESRI Shapefile

• Go to the Test Layer details page, move to Download Layer > Data > Zipped Shapefile

  

• Store it on a local folder, e.g. Downloads (this is the default target folder used by the browser)

Project to EPSG:3857

• Open a terminal windows and move to the Downloads folder

  

    cd
    cd Downloads
  

• Create a folder named test_layer and unzip the contents of the downloaded archive inside it

    mkdir test_layer
    cd test_layer/
    unzip ../test_layer.zip
  

• Use the GDAL ogr2ogr utitlities to reproject it from World Geodetic System 1984 EPSG:4326, LatLon coordinate reference system used in GPS, to Spherical Mercator EPSG:3857, meters projected coordinate system used for rendering maps in Google Maps, OpenStreetMap, and tiled layers in general

    # ogr2ogr <target srs> <source srs> <format> <target filename> <source filename>
    ogr2ogr -t_srs "EPSG:3857" -s_srs "EPSG:4326" -f 'ESRI Shapefile' test_layer_3857.shp test_layer.shp
  

• A new Shapefile will be created inside the same folder

    geonode-vm-321@geonodevm-3:~/Downloads/test_layer$ ll
    total 48
    drwxrwxr-x 2 geonode-vm-321 geonode-vm-321 4096 Oct 12 15:17 ./
    drwxr-xr-x 3 geonode-vm-321 geonode-vm-321 4096 Oct 12 15:14 ../
    -rw-rw-r-- 1 geonode-vm-321 geonode-vm-321  532 Oct 12 15:17 test_layer_3857.dbf
    -rw-rw-r-- 1 geonode-vm-321 geonode-vm-321  425 Oct 12 15:17 test_layer_3857.prj    <-- the SRS definition file
    -rw-rw-r-- 1 geonode-vm-321 geonode-vm-321  300 Oct 12 15:17 test_layer_3857.shp    <-- the new projected file
    -rw-rw-r-- 1 geonode-vm-321 geonode-vm-321  108 Oct 12 15:17 test_layer_3857.shx
    -rw-rw-r-- 1 geonode-vm-321 geonode-vm-321    5 Oct 12 14:10 test_layer.cst
    -rw-rw-r-- 1 geonode-vm-321 geonode-vm-321  531 Oct 12 14:10 test_layer.dbf
    -rw-rw-r-- 1 geonode-vm-321 geonode-vm-321  335 Oct 12 14:10 test_layer.prj
    -rw-rw-r-- 1 geonode-vm-321 geonode-vm-321  300 Oct 12 14:10 test_layer.shp
    -rw-rw-r-- 1 geonode-vm-321 geonode-vm-321  108 Oct 12 14:10 test_layer.shx
    -rw-rw-r-- 1 geonode-vm-321 geonode-vm-321  219 Oct 12 14:10 wfsrequest.txt
  

Publish as a DB Table

• Use the GDAL ogr2ogr utitlities to import the file into a local Data Base

    ogr2ogr -f "PostgreSQL" PG:"host=localhost user=geonode password=geonode dbname=geonode_data" -overwrite test_layer_3857.shp
  

• Login into GeoServer as an admin

  

• Move to Data > Layers and click on Add new Layer

  

• Select geonode:geonode_data, the data store connected to the geonode_data DB, created and managed by GeoNode

  

• From the list of available tables, select test_layer_3857 and click on Publish

  

• Scroll down to the Bounding Boxes section, generate the bboxes and Save

  

Publish the Layer into GeoNode

• Go back to the terminal, activate the geonode virtual environment and move to /opt/geonode

    workon geonode
    cd /opt/geonode
  

• Execute the updatelayers management command in order to publish the new layer from GeoServer

    ./manage_dev.sh updatelayers -h
    usage: manage.py updatelayers [-h] [-i] [--skip-unadvertised] [--skip-geonode-registered] [--remove-deleted] [-u USER] [-f FILTER] [-s STORE] [-w WORKSPACE] [-p PERMISSIONS] [--version] [-v {0,1,2,3}]
                                  [--settings SETTINGS] [--pythonpath PYTHONPATH] [--traceback] [--no-color] [--force-color]
  
    Update the GeoNode application with data from GeoServer
  
    optional arguments:
      -h, --help            show this help message and exit
      -i, --ignore-errors   Stop after any errors are encountered.
      --skip-unadvertised   Skip processing unadvertised layers from GeoSever.
      --skip-geonode-registered
                            Just processing GeoServer layers still not registered in GeoNode.
      --remove-deleted      Remove GeoNode layers that have been deleted from GeoSever.
      -u USER, --user USER  Name of the user account which should own the imported layers
      -f FILTER, --filter FILTER
                            Only update data the layers that match the given filter
      -s STORE, --store STORE
                            Only update data the layers for the given geoserver store name
      -w WORKSPACE, --workspace WORKSPACE
                            Only update data on specified workspace
      -p PERMISSIONS, --permissions PERMISSIONS
                            Permissions to apply to each layer
      --version             show program's version number and exit
      -v {0,1,2,3}, --verbosity {0,1,2,3}
                            Verbosity level; 0=minimal output, 1=normal output, 2=verbose output, 3=very verbose output
      --settings SETTINGS   The Python path to a settings module, e.g. "myproject.settings.main". If this isn't provided, the DJANGO_SETTINGS_MODULE environment variable will be used.
      --pythonpath PYTHONPATH
                            A directory to add to the Python path, e.g. "/home/djangoprojects/myproject".
      --traceback           Raise on CommandError exceptions
      --no-color            Don't colorize the command output.
      --force-color         Force colorization of the command output.
  

    ./manage_dev.sh updatelayers --skip-geonode-registered -u test_user1 -w geonode -f test_layer_3857
  

• Verify that the new layer has been created on GeoNode and it belongs to test_user1

  

• Refresh the QGIS Desktop connection, load the new layer and try modifying the geometries

  

  

• Verify on GeoNode that the geometries have been committed; remember to clear the image browser cache in order to see the changes

  

Next Section: Optimizing, publishing and styling GeoTIFF data