AroundMe

This is a Demo of using Spatial Search feature in ElasticSearch

Setup

This project is build using grunt, to get started read here

Once grunt is installed cd to AroundMe and run grunt, however for convinince index.js in build folder is also checked in.

You will need to install ElasticSearch, read about installing it here, also install marvel plugin for configuration and testing.

The data used here is from Geofabrik.

I have used points.shp file from the Great-Britain shape file download, but you can use any other country as well.

To extract the data,I wrote a quick python script using pyshp

you can easily install it by typing sudo easy_install pyshp.

Before running the script you will have to create an Index and add schema to it.

Assuming that elastic search is running, you can issue a command from marvel.

PUT /places
{
    "mappings": {
        "place": {
            "properties": {
                "id": {"type": "double"},
                "name": {"type": "string"},
                "type": {"type": "string"},
                "location": {"type": "geo_point"}
            }
        }
    }
}

Modify the path in script below to the source file, "points" in this case and run the script.

import shapefile
import urllib2
import json
sf = shapefile.Reader("points")
sr = sf.shapeRecords()

for r in sr:
    try :
        if r.record[2].strip() and r.record[3].strip():
            req = urllib2.Request('http://localhost:9200/places/place/')
            req.add_header('Content-Type', 'application/json')
            data = {'id': r.record[0].strip(),'name':r.record[2].strip(),'type':r.record[3].strip(),'location':{'lat':r.shape.points[0][1],'lon':r.shape.points[0][0]}}
            response = urllib2.urlopen(req, json.dumps(data))
            print r.record[2]
    except Exception,e: 
        print e
        #print "ERROR ",r.record[0],r.record[2],r.record[3] , r.shape.points[0][0], r.shape.points[0][1]
        pass

The script inserts all records which have a valid name and type column into index.

To get the count of records in index

GET places/_count

To search by geodistance (a.k.a find near)

GET places/_search
{
  "sort" : [
      {
          "_geo_distance" : {
              "location" : {
                    "lat": 51.5286416,
                "lon": -0.10159870000006777
              }, 
              "order" : "asc",
              "unit" : "km"
          }
      }
  ],
  "query": {
    "filtered" : {
        "query" : {
            "match_all" : {}
        },
        "filter" : {
            "geo_distance" : {
                "distance" : "20km",
                "location" : {
                   "lat": 51.5286416,
                "lon": -0.10159870000006777
                }
            }
        }
    }
  }
}

To search by geodistance and filter term

GET places / _search ? size = 100 & from = 0 {
    "sort": [{
        "_geo_distance": {
            "location": {
                "lat": 51.5286416,
                "lon": -0.10159870000006777
            },
            "order": "asc",
            "unit": "km"
        }
    }],
    "query": {
        "filtered": {
            "query": {
                "bool": {
                    "should": [{
                        "term": {
                            "type": "pub"
                        }
                    }]
                }
            },
            "filter": {
                "geo_distance": {
                    "distance": "1km",
                    "location": {
                        "lat": 51.5286416,
                        "lon": -0.10159870000006777
                    }
                }
            }
        }

    }
}

Final step is to configure a proxy to server html and to route ajax requests to localhost9200.

In this case the server in use is nginx, below is the minimal configuration, The localhost:80 is mapped to server contents of AroundMe folder and the proxy is mapped to route requests /elastic to localhost:9200

server {
        listen       80;
        server_name  localhost;

        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        location / {
            root   /Users/varunpant/Documents/Github/AroundMe;
            index  index.html index.htm;
        }
        location /elastic/ {
            proxy_pass http://localhost:9200/;
        }

        #error_page  404              /404.html;

        # redirect server error pages to the static page /50x.html
        #
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        } 
    }

Once configured restart the server and browse to localhost :)

I hope you find it useful.

If you like or use this project somewhere please contact me at varun@varunpant.com.