A web API to ingest and report back IoT data for the Topics in CS course
TO activate the virtual environment run Scripts\activate from the root
Requirement: install flask pip install flask
if your venv is missing pip, install it first: python -m ensurepip --default-pip
then (cmd works best) .\Script\activate #activates the virtualenv pip install -r requirements.txt
you will also need postges as a database to work with locally You can set environment variables in a .env file in the root of the directory /.env
export APP_SETTING="config.DevelopmentConfig" export DATABASE_URL="postgresql://user:pass@localhost:5432/sensor" export FLASK_APP="app"
add a new pyenv.cfg file to the datalogger folder with path and version info of your python interpreter example below
home = C:\Users\msudo\AppData\Local\Microsoft\WindowsApps include-system-site-packages = false version = 3.10.9
Then create a database with the same name in pgAdmin owned by the user in the environment variable string then
flask run or python -m flask run
should bring up the app, running the required database migrations
postman https://www.postman.com/downloads/ is a great way to test your local functionality [POST] http://localhost:5000/api/data/jbriggs/add?string1=test&device_id=jb&key=1000&temperature=27.0 [GET] http://localhost:5000/api/data/jbriggs/jb/test/1000
should create and then retrieve data
example, adding a column to the database locally, adjust the model by adding to the table model, for example in src/models/data.py
add some new columns
class Data(db.model): ... ... time_created = db.Column(db.DateTime(timezone=True), server_default=db.func.now()) time_updated = db.Column(db.DateTime(timezone=True), onupdate=db.func.now(), server_default=db.func.now())
in cmd> flask db migrate #that will generate a migration file based on those changes in /migrations/version/<random#>/py
look at that file and edit it as necessary
in cmd> flask db upgrade applies your migrations to the local database
if you have the heroku-cli, upgrading the production database is
heroku run flask db upgrade provided you have permissions.
In general a best practice on db upgrades is 1 - migration to add new columns that don't affect existing code 2 - updates to code to not use the old columns anymore, instead using the new columns 3 - a migration to remove unused columns
To deploy changes to the EPS server, run the following:
- install heroku and create a heroku account (you may need permissions to publish as well - see Mr. Briggs for this)
- from command line run
heroku git:remote --app eps-datalogger - then
git push heroku main
output should look something like this:
C:\Users\msudo\GitHub\datalogger\src\data>git push heroku main Enumerating objects: 9, done. Counting objects: 100% (9/9), done. Delta compression using up to 8 threads Compressing objects: 100% (4/4), done. Writing objects: 100% (5/5), 426 bytes | 106.00 KiB/s, done. Total 5 (delta 3), reused 0 (delta 0), pack-reused 0 remote: Compressing source files... done. remote: Building source: remote: remote: -----> Building on the Heroku-20 stack remote: -----> Using buildpack: heroku/python remote: -----> Python app detected remote: -----> No Python version was specified. Using the same version as the last build: python-3.10.4 remote: To use a different version, see: https://devcenter.heroku.com/articles/python-runtimes remote: -----> No change in requirements detected, installing from cache remote: -----> Using cached install of python-3.10.4 remote: -----> Installing pip 22.0.4, setuptools 60.10.0 and wheel 0.37.1 remote: -----> Installing SQLite3 remote: -----> Installing requirements with pip remote: -----> Discovering process types remote: Procfile declares types -> web remote: remote: -----> Compressing... remote: Done: 65.9M remote: -----> Launching... remote: Released v16 remote: https://eps-datalogger.herokuapp.com/ deployed to Heroku remote: remote: Verifying deploy... done. To https://git.heroku.com/eps-datalogger.git e9bf002..812ce7e main -> main