msa-geohash

Base32 Geoashing as a service. From wikipedia:

Geohash is a geocoding system invented by Gustavo Niemeyer and placed into the public domain. It is a hierarchical spatial data structure which subdivides space into buckets of grid shape.

Geohashes offer properties like arbitrary precision and the possibility of gradually removing characters from the end of the code to reduce its size (and gradually lose precision).

Built with pygeohash and geojson.

Quick start

Execute the microservice container with the following command :

docker run -ti -p 9907:80 msagency/msa-geohash

Example(s)

To get a geohash from a pair of coordinates, you can use the /encode url :

$ curl 'http://localhost:9907/geohash/encode?lat=45.53617&lon=-73.62075'
{
  "geohash": "f25eh9x52jq4"
}

The same url also handles geojson points, via a http POST :

$ curl -XPOST 'http://localhost:9907/geohash/encode' -H 'Content-Type: application/json' -d '{
  "coordinates": [
    -73.62075,
    45.53617
  ],
  "type": "Point"
}'

{
  "geohash": "f25eh9x52jq4"
}

Decoding the geohash will return the coordinates, in geojson :

$ curl 'http://localhost:9907/geohash/decode/f25eh9x52jq4'
{
  "coordinates": [
    -73.62075,
    45.53617
  ],
  "type": "Point"
}

Geohashes can be shortened to modify the area they cover, this can be evaluated with the /precision url :

$ curl 'http://localhost:9907/geohash/precision/f25eh9x52jq4'
{
  "precision": {
    "number": 0.6,
    "unit": "meters"
  }
}

$ curl 'http://localhost:9907/geohash/precision/f25eh9'
{
  "precision": {
    "number": 610,
    "unit": "meters"
  }
}

By default the /decode function will return the center of the geohash area, however it's possible to get a more accurate decoding with the exact=true parameter. With this parameter a geojson polygon will be returned instead of a point, taking into account the margin of error of the geohash :

$ curl 'http://localhost:9907/geohash/decode/f25eh9?exact=true'
{
  "coordinates": [
    [
      [
        -73.63037109375,
        45.538330078125
      ],
      [
        -73.63037109375,
        45.5328369140625
      ],
      [
        -73.619384765625,
        45.5328369140625
      ],
      [
        -73.619384765625,
        45.538330078125
      ],
      [
        -73.63037109375,
        45.538330078125
      ]
    ]
  ],
  "type": "Polygon"
}

Endpoints

• GET /geohash/encode/?lat=XX.XX&lon=XX.XX Computes a geohash from the given lat,lon
• POST /geohash/encode Computes a geohash from the given geojson point
• GET /geohash/decode/:geohash Decode a geohash, returns a geojson point
• GET /geohash/decode/:geohash?exact=true Decodes a geohash, return a geojson polygon
• GET /geohash/precision/:geohash Estimate the precision of a geohash

Standard endpoints

• GET /ms/version : returns the version number
• GET /ms/name : returns the name
• GET /ms/readme.md : returns the readme in markdown
• GET /ms/readme.html : returns the readme as html
• GET /swagger/swagger.json : returns the swagger api documentation
• GET /swagger/#/ : returns swagger-ui displaying the api documentation
• GET /nginx/stats.json : returns stats about Nginx
• GET /nginx/stats.html : returns a dashboard displaying the stats from Nginx

About

A project by the Microservices Agency.