UTM to LatLong microservice

A python micro service template for transforming a JSON entity stream. This service is designed to be used as a microservice system with the HTTP transform in a Sesam service instance.

It converts UTM33 (EUREF89 aka GAB) coordinates to LatLong (GPS coordinates aka WGS84).

Running locally in a virtual environment

cd utmtolatlong-microservice/service
virtualenv --python=python3 venv
. venv/bin/activate
pip install -r requirements.txt

python transform-service.py
 * Running on http://0.0.0.0:5001/ (Press CTRL+C to quit)
 * Restarting with stat
 * Debugger is active!
 * Debugger pin code: 260-787-156

The service listens on port 5001 on localhost.

Running in Docker

cd utmtolatlong-microservice
docker build -t utmtolatlong-microservice .
docker run -it --rm --name utmtolatlong-microservice -p 5001:5001 utmtolatlong-microservice

Get the IP from docker:

docker inspect -f '{{.Name}} - {{.NetworkSettings.IPAddress }}' utmtolatlong-microservice

Example

JSON entities can be posted to 'http://localhost:5001/transform'. The result is streamed back to the client. Exchange "localhost" with the Docker IP if running in Docker.

$ curl -s -XPOST 'http://localhost:5001/transform' -H "Content-type: application/json" -d '[{ "_id": "jane", "northing": "12344", "easting": "6543", "zone": "32"}]' | jq -S .
[
  {
    "_id": "jane",
    "message": "Hello world!",
    "name": "Jane Doe",
    "northing": "12344",
    "easting": "6543",
    "zone": "32",
    "lat": 0.11134243423572525,
    "lon": 4.569868852874141
  }
]

Note the example uses curl to send the request and jq prettify the response.

Configuration

You can configure the service with the following environment variables:

Variable	Description	Default
EASTING_PROPERTY	The name of the property holding the "easting" value. The value itself can be either a string, float, int or decimal. If a string, it must be castable to a float.	"easting"
NORTHING_PROPERTY	The name of the property holding the "northing" value. The value itself can be either a string, float, int or decimal. If a string, it must be castable to a float.	"northing"
ZONE_PROPERTY	The name of the property holding the "zone" value. The value itself can be either a string, float, int or decimal. It must be castable to an int.	"zone"
ZONE_DEFAULT	The default "zone" value if none are found in the entity. The value itself can be either a string, float, int or decimal. It must be castable to an int.	"32"
HEMI_PROPERTY	The name of the property holding the "hemisphere" value. The value itself can be either a string, float, int or decimal. It must be castable to an int. A 0 value means northern hemisphere, any other value means southern hemisphere.	"hemi"
HEMI_DEFAULT	The default "hemisphere" value. The value itself can be either a string, float, int or decimal. It must be castable to an int. A 0 value means northern hemisphere, any other value means southern hemisphere.	"0"
LAT_PROPERTY	The name of the property that will hold the converted "latitude" value.	"lat"
LONG_PROPERTY	The name of the property that will hold the converted "longitude" value.	"long"
INCLUDE_LAT_LONG	A flag to indicate wheter to include a lat_long value in the returned entity. A value of "true" means yes. Any other value means no.	"false"
LAT_LONG_PROPERTY	The name of the property that will hold the converted "lat_long" value ("lat, long"). It is only inserted in the returned entity if INCLUDE_LAT_LONG evaluates to yes.	"lat_long"

When running in Docker you can either specify this in a file (see https://docs.docker.com/compose/env-file/) or on the command line with "docker run .. -e VAR1=VAL1 -e VAR2=VAL2 .."