QWC OGC Service

Provide OGC services with permission filters as a proxy to a QGIS server.

Note: requires a QGIS server running on default_qgis_server_url.

Configuration

The static config and permission files are stored as JSON files in $CONFIG_PATH with subdirectories for each tenant, e.g. $CONFIG_PATH/default/*.json. The default tenant name is default.

Service config

• JSON schema
• File location: $CONFIG_PATH/<tenant>/ogcConfig.json

Example:

{
  "$schema": "https://raw.githubusercontent.com/qwc-services/qwc-ogc-service/v2/schemas/qwc-ogc-service.json",
  "service": "ogc",
  "config": {
    "default_qgis_server_url": "http://localhost:8001/ows/"
  },
  "resources": {
    "wms_services": [
      {
        "name": "qwc_demo",
        "wms_url": "http://localhost:8001/ows/qwc_demo",
        "online_resources": {
          "service": "http://localhost:5013/qwc_demo",
          "feature_info": "http://localhost:5013/qwc_demo",
          "legend": "http://localhost:5013/qwc_demo"
        },
        "root_layer": {
          "name": "qwc_demo",
          "layers": [
            {
              "name": "edit_demo",
              "layers": [
                {
                  "name": "edit_points",
                  "title": "Edit Points",
                  "attributes": [
                    "id", "name", "description", "num", "value", "type", "amount", "validated", "datetime", "geometry", "maptip"
                  ],
                  "queryable": true
                },
                {
                  "name": "edit_lines",
                  "title": "Edit Lines",
                  "attributes": [
                    "id", "name", "description", "num", "value", "type", "amount", "validated", "datetime", "geometry", "maptip"
                  ],
                  "queryable": true
                },
                {
                  "name": "edit_polygons",
                  "title": "Edit Polygons",
                  "attributes": [
                    "id", "name", "description", "num", "value", "type", "amount", "validated", "datetime", "geometry", "maptip"
                  ],
                  "queryable": true
                }
              ]
            },
            {
              "name": "geographic_lines"
            },
            {
              "name": "country_names"
            },
            {
              "name": "states_provinces"
            },
            {
              "name": "countries",
              "title": "Countries",
              "attributes": [
                "name", "formal_en", "pop_est", "subregion", "geometry"
              ],
              "queryable": true
            }
          ]
        },
        "print_url": "http://localhost:5013/qwc_demo",
        "print_templates": ["A4 Landscape"],
        "internal_print_layers": ["bluemarble_bg", "osm_bg"]
      }
    ],
    "wfs_services": [
      {
        "name": "qwc_demo",
        "wfs_url": "http://localhost:8001/ows/qwc_demo_wfs",
        "online_resource": "http://localhost:5013/qwc_demo",
        "layers": [
          {
            "name": "edit_points",
            "attributes": [
              "id", "name", "description", "num", "value", "type", "amount", "validated", "datetime", "geometry"
            ]
          },
          {
            "name": "edit_lines",
            "attributes": [
              "id", "name", "description", "num", "value", "type", "amount", "validated", "datetime", "geometry"
            ]
          }
        ]
      }
    ]
  }
}

Note: wfs_services example for a separate QGIS project qwc_demo_wfs with WFS enabled.

Permissions

• JSON schema
• File location: $CONFIG_PATH/<tenant>/permissions.json

Example:

{
  "$schema": "https://raw.githubusercontent.com/qwc-services/qwc-services-core/master/schemas/qwc-services-permissions.json",
  "users": [
    {
      "name": "demo",
      "groups": ["demo"],
      "roles": []
    }
  ],
  "groups": [
    {
      "name": "demo",
      "roles": ["demo"]
    }
  ],
  "roles": [
    {
      "role": "public",
      "permissions": {
        "wms_services": [
          {
            "name": "qwc_demo",
            "layers": [
              {
                "name": "qwc_demo"
              },
              {
                "name": "edit_demo"
              },
              {
                "name": "edit_points",
                "attributes": [
                  "id", "name", "description", "num", "value", "type", "amount", "validated", "datetime", "geometry", "maptip"
                ]
              },
              {
                "name": "edit_lines",
                "attributes": [
                  "id", "name", "description", "num", "value", "type", "amount", "validated", "datetime", "geometry", "maptip"
                ]
              },
              {
                "name": "edit_polygons",
                "attributes": [
                  "id", "name", "description", "num", "value", "type", "amount", "validated", "datetime", "geometry", "maptip"
                ]
              },
              {
                "name": "geographic_lines"
              },
              {
                "name": "country_names"
              },
              {
                "name": "states_provinces"
              },
              {
                "name": "countries",
                "attributes": [
                  "name", "formal_en", "pop_est", "subregion", "geometry"
                ]
              },
              {
                "name": "bluemarble_bg"
              },
              {
                "name": "osm_bg"
              }
            ],
            "print_templates": ["A4 Landscape"]
          }
        ]
      },
      "wfs_services": [
        {
          "name": "qwc_demo",
          "layers": [
            {
              "name": "edit_points",
              "attributes": [
                "id", "name", "description", "num", "value", "type", "amount", "validated", "datetime", "geometry"
              ]
            },
            {
              "name": "edit_lines",
              "attributes": [
                "id", "name", "description", "num", "value", "type", "amount", "validated", "datetime", "geometry"
              ]
            }
          ]
        }
      ]
    }
  ]
}

Note: layers in wms_services is a flat list of all permitted layers, group layers and internal print layers.

Basic Auth

OGC services can require password authentication using Basic authentication.

Example:

  "config": {
    "default_qgis_server_url": "http://qwc-qgis-server/ows/",
    "basic_auth_login_url": ["http://qwc-auth-service:9090/verify_login"]
  },

Marker params

The OGC service supports specifying marker parameters to insert a SLD styled marker into GetMap requests via QGIS Server HIGHLIGHT_SYMBOL and HIGHLIGHT_GEOM. To use this feature, provide a SLD template and parameter definitions in the ogc service config, for example:

"marker_template": "<StyledLayerDescriptor><UserStyle><se:Name>Marker</se:Name><se:FeatureTypeStyle><se:Rule><se:Name>Single symbol</se:Name><se:PointSymbolizer><se:Graphic><se:Mark><se:WellKnownName>circle</se:WellKnownName><se:Fill><se:SvgParameter name=\"fill\">$FILL$</se:SvgParameter></se:Fill><se:Stroke><se:SvgParameter name=\"stroke\">$STROKE$</se:SvgParameter><se:SvgParameter name=\"stroke-width\">$STROKE_WIDTH$</se:SvgParameter></se:Stroke></se:Mark><se:Size>$SIZE$</se:Size></se:Graphic></se:PointSymbolizer></se:Rule></se:FeatureTypeStyle></UserStyle></StyledLayerDescriptor>",
"marker_params": {
  "size": {
    "default": 10,
    "type": "number"
  },
  "fill": {
    "default": "FFFFFF",
    "type": "color"
  },
  "stroke": {
    "default": "FF0000",
    "type": "color"
  },
  "stroke_width": {
    "default": 5,
    "type": "number"
  }

Note:

• Use $<PARAM_NAME>$ as parameter placeholders in the SLD template.
• You can selectively override the default values via environment variables by setting MARKER_<PARAM_NAME> (i.e. MARKER_SIZE) to the desired values.

You can then specify the MARKER URL query parameter in GetMap requests to inject a marker as follows:

...?SERVICE=WMS&REQUEST=GetMap&...&MARKER=X->123456|Y->123456|STROKE->000FFA...

X and Y are compulsory and specify the marker position in map CRS, any other additional parameters are optional and will override the default values if provided. All parameters have to written in uppercase.

Usage

Set the CONFIG_PATH environment variable to the path containing the service config and permission files when starting this service (default: config).

Set the DEFAULT_QGIS_SERVER_URL environment variable to the QGIS server URL when starting this service. (default: http://localhost:8001/ows/ on qwc-qgis-server container)

Base URL:

http://localhost:5013/

Service API:

http://localhost:5013/api/

Sample requests:

curl 'http://localhost:5013/qwc_demo?VERSION=1.1.1&SERVICE=WMS&REQUEST=GetCapabilities'

Docker usage

To run this docker image you will need a running QGIS server.

The following steps explain how to download the QGIS server docker image and how to run the qwc-ogc-service service with docker-compose.

Step 1: Clone qwc-docker

git clone https://github.com/qwc-services/qwc-docker
cd qwc-docker

Step 2: Create docker-compose.yml file

cp docker-compose-example.yml docker-compose.yml

Step 3: Start docker containers

docker-compose up qwc-ogc-service

For more information please visit: https://github.com/qwc-services/qwc-docker

Development

Create a virtual environment:

virtualenv --python=/usr/bin/python3 --system-site-packages .venv

Without system packages:

python3 -m venv .venv

Activate virtual environment:

source .venv/bin/activate

Install requirements:

pip install -r requirements.txt
pip install flask_cors

Start local service:

CONFIG_PATH=/PATH/TO/CONFIGS/ python src/server.py