Koop Provider for Elastic Search

This provider allow Koop to fetch and transform data from an Elasticsearch instance.

Install

From command line in the folder containing the project run:

npm install @koopjs/provider-elasticsearch --save

In your Koop instance, register the provider like:

  const esProvider = require('@koopjs/provider-elasticsearch')
  koop.register(esProvider)

The latest version of this provider can be installed with the Koop CLI. See the Koop CLI docs for details on setting up a Koop instance and add providers with the CLI.

Running

To suppress KoopJS warnings from the console output, run with an environment variable of KOOP_WARNINGS="suppress". In powershell, this will look like: $env:KOOP_WARNINGS="suppress" ; node main.js

Command Line

npm start

Sub-Layers

By default, all services only have a single layer, as defined in the index configuration. It is possible to configure one or more sub-layers in the subLayers section of the configuration. Each of these sub layers can be a predefined sub layer or you can create your own.

Basic Config File Structure

The following is a sample configuration file showing most capabilities

{
  "esConnections": {
    "esNameForServiceURLs": {
      "id": "esNameForServiceURLs",
      "protocol": "http://",
      "port": 9200,
      "hosts": [
        "localhost"
      ],
      "shapeIndices": {
        "states": {
          "geometryField": "geometry",
          "geometryType": "Polygon",
          "joinField": "NAME"
        }
      },
      "indices": {
        "myService1": {
          "index": "indexName",
          "allowMultiPoint": false,
          "geometryField": "geometry.coordinates",
          "geometryType": "geo_point",
          "returnFields": [
            "lastUpdate",
            "createdAt",
            "name"
          ],
          "dateFields": [
            "lastUpdate",
            "createdAt"
          ],
          "idField": "OBJECTID",
          "subLayers": [
            {"name": "geohash"}
          ],
          "maxResults": 1000
        },
        "tableService": {
          "index": "indexNoShape",
          "allowMultiPoint": false,
          "isTable": true,
          "returnFields": [
            "state",
            "county",
            "date"
          ],
          "dateFields": [
            "date"
          ],
          "maxResults": 1000
        },
        "joinService": {
          "index": "indexToJoin",
          "allowMultiPoint": false,
          "returnFields": [
            "date",
            "country",
            "state.name"
          ],
          "dateFields": [
            "date"
          ],
          "subLayers": [],
          "shapeIndex": {
            "name": "states",
            "joinField": "state.name"
          },
          "maxResults": 1000
        },
        "polyService": {
          "index": "polygonIndex",
          "allowMultiPoint": false,
          "geometryField": "geometry",
          "geometryType": "MultiPolygon",
          "reversePolygons": true,
          "returnFields": [
            "properties.date",
            "properties.count",
            "properties.state_name"
          ],
          "dateFields": [
            "properties.date"
          ],
          "subLayers": [],
          "maxResults": 1000
        }
      }
    }
  }
}

Configuration Options

• shapeIndices includes all indices that will be used for their shapes on other services. All fields are mandatory.
• indices this object has a property for every service to be created. The name of the property will be the service name.

Index Properties

• index is the name of the ElasticSearch index
• isTable treat this service as a table, ignoring geometry
• allowMultiPoint is only important for point services and allows more than one point per feature
• geometryField is the full location of the geometry
• geometryType can be geo_point, Point, MultiPoint, Polyline, MultiLineString, Polygon and MultiPolygon
• reversePolygons if the stored polygons do not follow the right-hand rule setting this to true will fix this. Polygons that do not follow the right-hand rule will not be displayed as feature services without setting this to true.
• returnFields includes all fields that will be returned by the feature service
• dateFields includes any return fields that should be treated as dates
• idField if the index includes a field that can be treated as the OBJECTID field, this should be set
• subLayers any sub-layers to be used. Provided sub layers are geohash_aggregation and geotile_aggregation but custom subLayers may be used here as well.
• maxResults the maximum features returned from a single request
• shapeIndex if the service will join to a shapeIndex for geometry list the name of the index (defined in shapeIndices) and the joinField from this index.
• vectorLayerID the 0 based index of the subLayer to use for vector output
• vectorStyle an optional map-box style to use for the vector layer

Sub-Layer Configurations

All subLayer configurations must include a name to map to a registered subLayer class. Other than that an options object contains any other needed information.

• offset which is used by both provided subLayers is the offset value passed in by esri clients. This value is in meters and is larger for higher zoom levels.
• aggregationFields can be used to pass in sub-aggregations to elastic search. The fields will be added to the output for display in pop-ups and/or for use in symbology.

GeoHash

precision is between 1-12 for geohash.

{
  "name": "geohash_aggregation",
  "options": {
    "tileConfig": [
      { "precision": 8, "offset": 16 },
      { "precision": 6, "offset": 10000 },
      { "precision": 4, "offset": 32000 },
      { "precision": 2, "offset": 640000 }
    ],
    "aggregationFields": {
      "speed_avg": {
        "avg": { "field":  "speed"}
      },
      "speed_min": {
        "min": { "field": "speed"}
      }
    }
  }
}

GeoTile

precision is between 0-29 for geotile.

{
  "name": "geotile_aggregation",
  "options": {
    "tileConfig": [
      { "precision": 22, "offset": 16 },
      { "precision": 16, "offset": 10000 },
      { "precision": 10, "offset": 32000 },
      { "precision": 4, "offset": 640000 }
    ],
    "aggregationFields": {
      "speed_avg": {
        "avg": { "field":  "speed"}
      },
      "speed_min": {
        "min": { "field": "speed"}
      }
    }
  }
}

Additional Index Configurations

mapReturnValues is an object that can contain keys that are field names that in turn have their own keys equal to field values mapped to object values. Example below. __defaultmapping is not required.

{
    "mapReturnValues": {
        "fieldName": {
            "returnedValue1": "mappedValue",
            "__defaultmapping": "defaultValue"
        }
    }
}

IN DEVELOPMENT

mapFieldNames can be used to specify a different return field than what is specified within returnFields

{
    "mapFieldNames": {
        "fieldName": "mappedFieldName"
    }
}