Publishing data from a DB table

In this section, we will publish a dataset on GeoNode, which is already present on a Database table.

In particular, these steps will allow us to convert the Test Layer (the empty dataset created in the previous sections) to a Mercator Projected one and publish it on GeoNode again:

1. Download the Test Layer as an ESRI Shapefile

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

3. Use the GDAL ogr2ogr utilities to import the file into a local Database.

4. Publish the dataset on GeoServer.

5. Publish the dataset on GeoNode.

6. Try to edit it again using an external client (QGIS).

Download the Dataset as an ESRI Shapefile

• Go to the Test Layer details page, click on Export and select the file format Shapefile

  

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

Project to EPSG:3857

• Open a terminal window (Ctrl+Alt+T) and navigate 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 utilities to reproject it from World Geodetic System 1984 EPSG:4326 (the LatLon coordinate reference system used in GPS) to Spherical Mercator EPSG:3857 (the meters projected coordinate system used for rendering maps in Google Maps, OpenStreetMap, and tiled datasets 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 utilities to import the file into a local Database

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

• Login into GeoServer as an admin

  

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

  

• Select geonode:geonode_data (the data store connected to the geonode_data DB, which is 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 Dataset into GeoNode

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

  workon geonode
  cd /opt/geonode
  

• Execute the updatelayers management command to publish the new dataset 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 GeoServer.
    -u USER, --user USER  Name of the user account which should own the imported layers
    -f FILTER, --filter FILTER
                          Only update data of the layers that match the given filter
    -s STORE, --store STORE
                          Only update data of 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 -w geonode -f test_layer_3857
  

• Verify that the new dataset has been created on GeoNode and is correct.

  

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

  

  

• Verify on GeoNode that the geometry changes have been committed (remember to clear the image browser cache to see the changes)

Next Section: Optimizing, publishing and styling GeoTIFF data