An OGC API to geospatial data

pygeoapi.io

OSGeo Community Project

Table of contents

  • Geospatial API evolution
  • REST/JSON/OpenAPI/Swagger
  • OGC activity
  • Say hello to pygeoapi
  • Core capabilities
  • Deploying
  • Production instances
  • Roadmap
  • Support

Geospatial API evolution

1990s

  • Spirit of XML-RPC/CORBA
  • SOAP/WSDL/UDDI
  • Service Oriented Architecture (SOA)
  • Strong concept of RDBMS as the backend
  • OGC WMS (1999)

2000s

  • Web 2.0
  • JavaScript/AJAX/Google Maps
  • Slippy maps, tiles
  • OGC WFS (2002), WCS (2003), WPS (2005), CSW (2007)

Realities of OGC web services

  • Key Value Parameters (KVP) or XML encodings
  • Requests using HTTP GET, HTTP POST and SOAP
  • Responses as XML (GML)
  • Error handling as custom ExceptionReport within an HTTP 200 response
  • Exhaustive specifications/requirements

Sample response from an OGC WFS 1.0/2.0 service

More realities

  • Complex machinery/architectures (e.g. ldproxy) for services to be crawlable
  • Challenging for web developers to implement
  • Challenging for mainstream web integration (search indexing)
  • Geonovum testbed showed OGC world can easily be made crawlable, and crafted LDProxy

REST/JSON/OpenAPI/ Swagger

REST

  • REpresentational State Transfer (REST)
  • HTTP verbs (GET/PUT/POST/DELETE)
  • HTTP codes (200, 201, 404, etc.)
  • Uses URI to identify resources
  • Content negotiation (media types)
  • Stateless

JSON

  • JavaScript Object Notation
  • Easy to write and understand
  • Very popular among web developers
  • JSON is first class in RESTful web services
  • No rigid standards (for better or worse)

OpenAPI

  • Specification on how to describe a REST API
  • Defines endpoints, request parameters, response
  • Programming language agnostic
  • Formerly Swagger

Swagger

  • OpenAPI client tooling
  • Robust, web developer focused
  • Automated documentation, testing, code generation

OGC activity

https://ogcapi.ogc.org

W3C Spatial Data on the Web Best Practices (2017)

Design patterns

  • Being webby (humans, search engines)
  • Developer friendly
  • Lightweight specification development
  • Removing HTTP use as a tunnel
    • /ows?request=GetFeature&typename=roads&featureid=5
    • /api/collections/roads/items/5
  • Modular specification development
    • Core and extensions

Timeline

  • 2017: W3C Spatial Data on the Web Best Practices
  • 2017: OGC API Whitepaper
  • 2018: WFS3 Hackathon, Weather on the Web API Hackathon
  • 2019-2020: OGC API Hackathons
  • OGC API Roadmap

Future OGC standards

  • OGC API - Common (OWS Common)
  • OGC API - Features (WFS)
  • OGC API - Coverages (WCS)
  • OGC API - Maps (WMS)
  • OGC API - Tiles (WMTS)
  • OGC API - Processes (WPS)
  • OGC API - Records (CSW)
  • OGC API - Styles (SE/SLD)

OGC activity on GitHub

  • webby
  • Specification development
  • Issue tracking/discussion/collaboration
  • Standards written in AsciiDoc (!)
  • Standards released as HTML (!) or traditional PDF/etc.
  • Gitter chat

Say hello to pygeoapi

Project Overview

  • Geospatial data API framework
  • OGC Compliant (already!)
  • OSGeo Community Project
  • International team (Canada, Netherlands, Greece, Italy, New Zealand)
    • Numerous core contributors
    • 21000 upstream contributors (dependencies)

Technical Overview

  • Publishing (leaves data pristine/alone)
    • Fits to the data (not the inverse)
  • Leverages powerful ecosystem of Python packages

Technical Overview

  • Core abstract API; web framework agnostic (default Flask)
  • YAML configuration (metadata, dataset connections
  • Automated OpenAPI document generation (data binding)
  • Robust plugin framework (data connections, formats, processing)
  • Easy deployment (pip install, Docker, conda, UbuntuGIS)
  • Minimal dependencies

Feature Data Providers

Elasticsearch CSV Spatialite* GeoJSON*

* also via GDAL-OGR Provider

Feature Data Providers - GDAL/OGR

  • Via OGR-Python bindings
  • Unleashes ~100 Vector Formats! (WFS 1/2, GeoPackage, Shapefile, GeoJSON, PostGIS, ...)
  • Paging, reprojection, spatial/attribute query
  • Unlock existing WFS 1/2s!

Coverage Data Providers

xarray rasterio
  • NetCDF, Cloud Optimized GeoTIFF (COG)

Tile Data Providers

minio ZXY directory tree
  • MapBox Vector Tiles via tippecanoe

schema.org

  • Lower the barrier to data search
  • HTML encoding is annotated as schema.org/Dataset to facilitate search engines
  • Google dataset search locates pygeoapi datasets

Linked Data - JSON-LD

  • JSON-LD provided as additional representation
  • Default out of the box functionality for most pygeoapi resources / endpoints
  • Additional configuration

Core Capabilities

OpenAPI

OGC API - Features

OGC API - Coverages

OGC API - Tiles

OGC API - Processes

SpatioTemporal Asset Catalog (STAC)

Deploying

Packaging

Numerous deployment options

  • PyPI
  • UbuntuGIS
  • Docker
  • Conda
  • FreeBSD
  • Coming to OSGeoLive

Docker overview

Docker
  • pygeoapi Docker Images on DockerHub
  • Images create Linux containers running content
  • Use Docker Images to test locally or deploy in server

Docker options

  • Custom config via Docker Volume Mapping
  • Run with Docker Compose
  • Subpath running via Flask SCRIPT_NAME environment variable
  • Examples

Scaling pygeoapi

Docker scale Cloud clustering with high availability

Production instances

Canada

Meteorological Service of Canada GeoMet platform

  • OGC web services platform of Canadian weather, climate and water data
  • Realtime weather
  • Numerical weather prediction
  • Hydrometric and Climate archives

MSC pygeoapi implementation

GLOSIS - Global Soil Information

Roadmap

  • More OGC APIs: Maps, Tiles, Records
  • OGC API Improvements: Processes
  • More data providers
  • Advanced filters (CQL)
  • Transactions
  • Content negotiation (e.g. Response as GeoPackage, GML,...)
  • OSGeoLive

Support


Need support for WFS3.0???

GeoCat can help you


justobjects.nl


GeoComvos ltd


Geobeyond Srl

Links

Thank you!

@tomkralidis @JMendesDeJesus @normanbarker @perrygeo @justb4 @pvgenuchten @tzotsos @alpha-beta-soup @francbartoli