Getting started with pygeoapi processes
Today’s post is a quick introduction to pygeoapi, a Python server implementation of the OGC API suite of standards. OGC API provides many different standards but I’m particularly interested in OGC API – Processes which standardizes geospatial data processing functionality. pygeoapi implements this standard by providing a plugin architecture, thereby allowing developers to implement custom processing workflows in Python.
I’ll provide instructions for setting up and running pygeoapi on Windows using Powershell. The official docs show how to do this on Linux systems. The pygeoapi homepage prominently features instructions for installing the dev version. For first experiments, however, I’d recommend using a release version instead. So that’s what we’ll do here.
As a first step, lets install the latest release (0.16.1 at the time of writing) from conda-forge:
conda create -n pygeoapi python=3.10
conda activate pygeoapi
mamba install -c conda-forge pygeoapiNext, we’ll clone the GitHub repo to get the example config and datasets:
cd C:\Users\anita\Documents\GitHub\
git clone https://github.com/geopython/pygeoapi.git
cd pygeoapi\To finish the setup, we need some configurations:
cp pygeoapi-config.yml example-config.yml
# There is a known issue in pygeoapi 0.16.1: https://github.com/geopython/pygeoapi/issues/1597
# To fix it, edit the example-config.yml: uncomment the TinyDB option in the server settings (lines 51-54)
$Env:PYGEOAPI_CONFIG = "F:/Documents/GitHub/pygeoapi/example-config.yml"
$Env:PYGEOAPI_OPENAPI = "F:/Documents/GitHub/pygeoapi/example-openapi.yml"
pygeoapi openapi generate $Env:PYGEOAPI_CONFIG --output-file $Env:PYGEOAPI_OPENAPINow we can start the server:
pygeoapi serveAnd once the server is running, we can send requests, e.g. the list of processes:
curl.exe http://localhost:5000/processesAnd, of course, execute the example “hello-world” process:
curl.exe --% -X POST http://localhost:5000/processes/hello-world/execution -H "Content-Type: application/json" -d "{\"inputs\":{\"name\": \"hi there\"}}"As you can see, writing JSON content for curl is a pain. Luckily, pyopenapi comes with a nice web GUI, including Swagger UI for playing with all the functionality, including the hello-world process:
It’s not really a geospatial hello-world example, but it’s a first step.
Finally, I wan’t to leave you with a teaser since there are more interesting things going on in this space, including work on OGC API – Moving Features as shared by the pygeoapi team recently:
So, stay tuned.
