theia

Planning the next-generation Floating Forests pipeline

Etymology

Theia is the Greek goddess of sight and of the blue sky. She is the mother of the sun, the moon, and the dawn. Our hope is to use Theia to acquire satellite images and find blue skies!

Tech

The proposed tech stack for Theia is:

• Django / GeoDjango
• Django REST Framework
• Requests / Requests OAuth
• Postgres
• Celery
• gdal
• Pillow
• Docker / Kubernetes

Getting started

Docker environment

Ensure that you have docker & docker-compose installed.

Then run

docker-compose build to build the image

To create the environment, including the postgres and redis servers and a web app and worker node

docker-compose up -d

To, for example, create a second worker node

docker-compose up --scale worker=2 -d

To halt instances

docker-compose down

Note that you can also remove the volumes (they will need to be recreated next time)

docker-compose down -v

To develop in the docker containers via bash docker-compose run --rm --service-ports app bash

this will provide you with access to python, libraries and all dependent services needed for development, e.g. from the bash console run: pytest to test the application setup local databases pipenv run create_local_db pipenv run drop_local_db Run Django app locally (applying migrations if necessary): pipenv run server Run the Celery worker locally (does not apply migrations): pipenv run worker

On Windows (for either local environment or Docker environment):

If you are having trouble running app and are using a Windows machine, this could be due to "funny line endings" within start_server.sh and start_worker.sh that are seen in Windows, but not on other machines or in git.

To mitigate you must run the following in your terminal:

• Run od -c start_server.sh and od -c start_worker.sh to check for "funny line endings"
• Install dos2unix with apt-get update then apt-get install dos2unix
• convert files with dos2unix start_server.sh and dos2unix start_worker.sh

Local environment

Make sure that you have an entry in your /etc/hosts file that looks like this:

127.0.0.1 postgres

so that we can find the postgres server when the app is running locally

Install the correct version of postgres:

brew install postgresql@9.4

If you already had a postgres install, you should be able to select your postgres version this way:

brew switch postgresql 9.4

If not, you can also use this keg-only formula by force-linking it:

brew link postgresql@9.4 --force

Add the user theia with password theia:

createuser theia -d -P

Make sure that you have an entry in your /etc/hosts file that looks like this:

127.0.0.1 redis

so that we can find the redis server when the app is running locally

Install the current version of redis:

brew install redis

Ensure that you have a modern python:

brew install python

and follow the installation notes to put the versionless alias on your $PATH.

Then install pipenv package and virtual environment manager

pip install pipenv

Then use pipenv to install dependencies:

pipenv install --dev

Install GIS related dependencies:

brew install postgis gdal

Install other related dependencies:

brew install libtiff

To drop or create the local DB that theia will be using:

pipenv run create_local_db

pipenv run drop_local_db

Run Django app locally (applying migrations if necessary):

pipenv run server

Run the Celery worker locally (does not apply migrations):

pipenv run worker

• If you find yourself running into the following error while attempting to run the above:

File "/Users/chelseatroy/.pyenv/versions/3.7.4/lib/python3.7/ssl.py", line 98, in <module>
    import _ssl             # if we can't import it, let the error propagate
ImportError: dlopen(/Users/chelseatroy/.local/share/virtualenvs/theia-LYdUFkJN/lib/python3.7/lib-dynload/_ssl.cpython-37m-darwin.so, 2): Library not loaded: /usr/local/opt/openssl/lib/libssl.1.0.0.dylib
  Referenced from: /Users/chelseatroy/.local/share/virtualenvs/theia-LYdUFkJN/lib/python3.7/lib-dynload/_ssl.cpython-37m-darwin.so
  Reason: image not found

You can follow the instructions here.

Short Version—run this:

brew uninstall openssl; brew uninstall openssl; brew install https://github.com/tebelorg/Tump/releases/download/v1.0.0/openssl.rb

Accessing the app

Regardless of whether you're running it locally or inside the image, the Django app can be accessed at http://localhost:8080/

Running the tests

Locally:

Make sure that you have done all of the above, and if you have never run the server you may also need to run the migrations:

pipenv run migrate

and then you can run the tests with

pipenv run tests

In the container: docker-compose run --rm app bash

Then from the bash shell in the container python manage.py migrate setup the db pytest --cov=theia run the tests