thinkWhere / geopython17

Flask Geospatial Microservice sample code for GeoPython 2017

GeoPython 2017

Intro

This repo contains the accompanying code from the Build your own Geospatial Microservice using Python/Flask/PostGIS workshop thinkWhere gave at GeoPython 2017

Dependencies

Following must be available locally:

• Python 3.6 - Python 3.6 install here

Optional

The sample app ships with a Dockerfile that allows you to run PostGIS within a Docker container. Alternatively if you have access to an existing PostGIS db you can connect the application to a new database there.

• Docker CE install here

Building the Microservice

• Create a Python Virtual Environment, using Python 3.6:
  • python -m venv ./venv
• Activate your virtual environment and install dependencies:
  • Linux/Mac:
    • . ./venv/bin/activate
    • pip install -r requirements.txt
  • Windows (use installer because of precompiled libs):
    • .\venv\scripts\activate
    • pip install -r requirements.txt

Build and run the PostGIS Dockerfile

• From the root of the project:
  • docker build -t geopython-db ./devops/docker
• The image should be downloaded and build locally. Once complete you should see it listed, with
  • docker images
• You can now run the image (this will run PostGIS in a docker container, with port 5432 mapped to localhost):
  • docker run -d -p 5432:5432 geopython-db
• Confirm the image is running successfully:
  • docker ps

App Config (only required if not using Docker PostGIS)

If you are not using the supplied PostGIS docker container you will need to set the SQLALCHEMY_DATABASE_URI found in ./micro/config.py to point to your database, eg:

SQLALCHEMY_DATABASE_URI=postgresql://user:pass@host/your-new-database

Creating the DB

With everything now setup We use Flask-Migrate to create the database from the migrations directory. Create the database as follows:

python manage.py db upgrade

Running Locally

Finally we can run the application, as follows:

python manage.py runserver -d

Versions

You can see how we got to the version from Flask hello world to v1.0 of our microservice by checking out the tagged releases as follows:

git checkout -b version1 v0.1

It may help to run git clean to tidy up any empty dirs for clarity as you work thru the versions, eg:

git clean -fd

Useful Links

HTTP and Rest

• HTTP and REST
• HTTP Status Codes
• HTTP Status Dogs

Libraries

• Flask
• Flask-Script
• Flask-Restful
• Flask-Swagger
• Flask-SQLAlchemy
• Geoalchemy
• Flask-Migrate
• geojson

Ideas in practice

• HOT Tasking Manager v3 - Built by thinkWhere using these ideas