Tethys Platform
Table Of Contents
Table Of Contents

New Tethys App Project

Last Updated: June 2022

In this tutorial you will create a new Tethys App project using the scaffold. The following topics will be reviewed in this tutorial:

  • Scaffolding New Tethys Apps

  • Managing App Dependencies

  • Adding a Custom Icon

  • Customizing App Theme Color


1. Generate Scaffold

To generate a new Tethys App using the scaffold, open a terminal and execute the following commands:

# Activate the tethys environment
conda activate tethys
# Create a working directory (if it doesn't exist already)
mkdir ~/tethysdev
cd ~/tethysdev
# Scaffold a new Tethys app
tethys scaffold earth_engine

You will be prompted to enter metadata about the app such as, proper name, version, author, and description. All of these metadata are optional. You can accept the default values by pressing enter, repeatedly.

In a file browser change into your Home directory and open the tethysdev directory. If the scaffolding worked, you should see a directory called tethysapp-earth_engine. All of the source code for your app is located in this directory. For more information about the app project structure, see App Project Structure.

2. Add App Dependencies to install.yml

App dependencies should be managed using the install.yml instead of the setup.py. This app will require the earthengine-api and oauthclient packages to allow it to use Google Earth Engine services. Both packages are available on conda-forge, which is the preferred Conda channel for Tethys. Open tethysapp-earth_engine/install.yml and add these dependencies to the requirements.conda section of the file:

# This file should be committed to your app code.
version: 1.0
# This should match the app - package name in your setup.py
name: earth_engine

  # Putting in a skip true param will skip the entire section. Ignoring the option will assume it be set to False
  skip: false
      - conda-forge
      - earthengine-api
      - oauth2client


3. Development Installation

Install the app and it's dependencies into your development Tethys Portal. In a terminal, change into the tethysapp-earth_engine directory and execute the tethys install -d command.

cd ~/tethysdev/tethysapp-earth_engine
tethys install -d

4. Customize App Icon and Theme Color

Download this Google Earth Engine App Icon or find one that you like and save it to the public/images directory. Modify the icon property of your app class to reference the new image. Also change the color property to the #524745 color:

class EarthEngine(TethysAppBase):
    Tethys app class for Google Earth Engine Tutorial.

    name = 'Google Earth Engine Tutorial'
    index = 'earth_engine:home'
    icon = 'earth_engine/images/earth-engine-logo.png'
    package = 'earth_engine'
    root_url = 'earth-engine'
    color = '#524745'

5. View Your New App

Start up the development server to view the new app:

tethys manage start


To stop the development server press CTRL-C.

If you get errors related to Tethys not being able to connect to the database, start the database by running:

tethys db start

You can also stop the Tethys database by running:

tethys db stop

Browse to http://localhost:8000/apps/earth-engine in a web browser and login. The default portal user is:

  • username: admin

  • password: pass

Verify the following:

  1. The default app icon should be replaced with the custom image you added in step 4.

  2. The primary color for the app should be a dark grey (see screenshot at the beginning of the tutorial).

6. Solution

This concludes the New App Project portion of the GEE Tutorial. You can view the solution on GitHub at https://github.com/tethysplatform/tethysapp-earth_engine/tree/new-app-project-solution-3.0 or clone it as follows:

git clone https://github.com/tethysplatform/tethysapp-earth_engine.git
cd tethysapp-earth_engine
git checkout -b new-app-project-solution new-app-project-solution-4.0