Rails PostGIS TIGER Geocoder API

This is an example PostGIS geocoder API built using TIGER census data and providing a simple search?address= endpoint via Rails.

The PostGIS DB configuration is based off of the examples provided in PostGIS in Action.

Requirements

• Ruby 2.4.3
• Postgres 9.6 with PostGIS 2.3
• unzip
• wget

Building Geocoder

• Copy the example.env file to .env
• Specify your local settings for each of the configuration options in the .env file:
  • GIS_DATA_DIR= path to a directory you have permission to write to where gis data will be staged before being added to the db
  • UNZIPTOOL= path to your unzip binary
  • WGETTOOL= path to your wget binary
  • PGBIN=path to your postgres binary directory
  • PGUSER= postgres user name
  • PGPASSWORD= postgres password or '' if none
  • STATES= a comma separated list of US State and Territory two letter postal codes. The full list can be found in the example.env file, but beware, running this on all states will require a significant amount of time and 100's GB of disk space
  • Initialize the db with rails: rake db:create db:migrate
  • Run the geocoder create_db rake task to download state data and build the geocoder indexes! rake geocoder:create_db

Once that is done, run rails s and start geocoding at: http://localhost:5000/geocoder_api/geocode/search?address=

Geocoding Results:

Results will be returned as JSON in a results object and are sorted by closest match (smallest rating value):

http://localhost:5000/geocoder_api/geocode/search?address=1500%20fleet%20street%20baltimore%20md
{
  "results": [
    {
      "rating": 1,
      "lng": -76.596,
      "lat": 39.28454,
      "lat_lng": "39.28454, -76.596",
      "address": "1500 Fleet St, Baltimore, MD 21231"
    },
    {
      "rating": 8,
      "lng": -76.58034,
      "lat": 39.28519,
      "lat_lng": "39.28519, -76.58034",
      "address": "2526 Fleet St, Baltimore, MD 21224"
    }
  ]
}

If no results were found: { "results": "no results" } is returned.

States Codes

The example.env is configured for MD only. Here is a list of all valid US State 2 letter codes:

  STATES=AK,AL,AR,AS,AZ,CA,CO,CT,DC,DE,FL,GA,GU,HI,IA,ID,IL,IN,KS,KY,LA,MA,MD,ME,MI,MN,MO,MP,MS,MT, \
  NC,ND,NE,NH,NJ,NM,NV,NY,OH,OK,OR,PA,PR,RI,SC,SD,TN,TX,UT,VA,VI,VT,WA,WI,WV,WY