DineMine capstone backend

DineMine_Backend supports the CRUD routes for the Web-app

1. Flask
2. Flask SQLAlchemy
3. Postgress db
4. Heroku

1. FORK AND CLONE THE REPO

   git clone 'CLONED REPO CODE'

2. INSTALL FLASK

   pip install flask

   Inside the Terminal enter your project root folder and run the following commands

3. ACTIVATE VIRTUAL ENVIRONMENT

    $ python3 -m venv venv
    
    $ source venv/bin/activate
    
    (venv) $ # You're in activated virtual environment!

4. DOWNLOAD REQUIREMENTS

   (venv) $ pip install -r requirements.txt

5. INSTALL FLASK-CORS

   pip install flask-cors

6. INSTALL SQLALCHEMY

   pip install sqlalchemy

7. IN THE POSTGRES -U PSQL

   git clone 'CLONED REPO CODE'

8. Setting up development databases

   git clone 'CLONED REPO CODE'

9. Run flask db init.

   flask db init

   After you make your first model, run the other commands

   $ flask db migrate

   and

   $ flask db upgrade

10. RUN FLASK

    $ flask run and $ FLASK_ENV=development flask run

11. SETTING UP .ENV FILE

    Create a file named .env.

    Create two environment variables that will hold your database URLs.

    SQLALCHEMY_DATABASE_URI to hold the path to your development database [OPTIONAL] SQLALCHEMY_TEST_DATABASE_URI to hold the path to your development database Your .env may look like this:

    SQLALCHEMY_DATABASE_URI=postgresql+psycopg2://postgres:postgres@localhost:5432/dinemine_backend_api_development
    SQLALCHEMY_TEST_DATABASE_URI=postgresql+psycopg2://postgres:postgres@localhost:5432/dinemine_backend_api_test

12. DEPLOYMENT

    Follow the directions to install the Heroku CLI  :

    $ brew tap heroku/brew && brew install heroku
    
    

    This command runs two separate commands. The && joins them into one convenient copy/paste-able unit.

    The first command brew tap heroku/brew tells Homebrew to add an additional source of software packages (termed a tap in Homebrew-speak). The second command  brew install heroku uses Homebrew to install the Heroku CLI, which it will be able to find with the tap we just configured.

    Log In to the Heroku CLI

    The Heroku CLI needs to authenticate our user account. Follow the directions to log into the Heroku CLI  :

    $ heroku login
    
    

    We'll be prompted to press any key to go to a web browser to complete our login. The CLI will then log us in automatically.

    Configure Our Flask App for Heroku

    Although Heroku will do a lot of the work of hosting, running, and maintaining our API server, we need to add a small amount of configuration to our project.

    Check Dependencies for gunicorn

    We will use a Python package named gunicorn  to launch our Flask API on Heroku.

    gunicorn is capable of running Flask apps so that they can handle multiple simultaneous requests, which is very important for production web applications.

    We should confirm that the package gunicorn is in the project's requirements.txt file.

    If gunicorn does not appear in our requirement.txt, we can add it by installing it locally with:

    (venv) $ pip install gunicorn
    
    

    After it has installed, we can update our requirements.txt by running:

    (venv) $ pip freeze > requirements.txt
    
    

    Heroku makes use of our requirements.txt file to install our app dependencies, so it is very important to ensure that all of our dependencies are properly listed.

    If we needed to update our requirements.txt, we should be sure to add and commit this change.

    Create a Procfile for Heroku

    [Procfile](https://devcenter.heroku.com/articles/procfile)  is a file specifically used in codebases deployed on Heroku.

    We'll use our Procfile to define how to start our Flask web server.

    First, create a Procfile inside the project root. This file must be named exactly Procfile, with no file extension.

    $ touch Procfile
    
    

    Then, fill the Procfile with this content:

    web: gunicorn 'app:create_app()'
    
    

    Commit

    Save this file. Then, create a Git commit that contains this change.

    Create a Heroku App

    For each project we deploy, we will need to create and manage a Heroku app. Our Heroku app will give us visibility, access, and tools to manage our deployed app.

    After cding to our project root, we can create a Heroku app using the Heroku CLI. From the command line we should pick either of these options:

    1. We can create a Heroku app with an automatically generated app name using:

    $ heroku create
    
    

    OR 2. We can create our app with the name your-app-name using:

    $ heroku create your-app-name
    
    

    Replace your-app-name with the desired name of the app.

    Our Heroku app doesn't have access to our Flask API code yet, so we'll see a default Heroku message.

    Our New Heroku App

    We have officially created a Heroku app that is accessible online! We can follow the link from the heroku create output.

    

    Verify the New Heroku Remote

    Creating a Heroku app will add a new Git remote to our project! A Git remote is a destination to which we can git push!

    The new Git remote will be named heroku. This Git remote points exactly to where Heroku keeps and serves our code!

    Confirm that we have a heroku remote by running this command:

    $ git remote -v
    
    

    We should see the heroku remote listed alongside our origin remote.

    Verify in the Dashboard

    Creating a Heroku app will associate this app to our Heroku account.

    Visit the Heroku dashboard and see your new app listed! We'll visit this dashboard whenever we need details about our Heroku app.

    

    Push Code to the Heroku Remote

    We should send our project codebase to our heroku remote.

    This command will push our project's Git history to a remote named heroku. It will push the default master branch on our computer to Heroku's default main branch on our new Heroku virtual computer.

    $ git push heroku master:main
    
    

    Every time we want to push our Git history to our Heroku app, we will need to push to the heroku remote.

    Create a Database in Heroku

    Now that we've created our Heroku app for the first time, we need to tell the app that we're interested in adding a Postgres database to our deployed Heroku app.

    This command uses the Heroku CLI to add a Postgres database to the app.

    $ heroku addons:create heroku-postgresql:hobby-dev
    
    

    Verify in the Dashboard

    We can verify that our Heroku app has added a Postgres database by checking the Heroku dashboard  .

    We can use the Heroku dashboard to view our Heroku app. In the "Overview" tab, in the "Installed add-ons" section, we should see "Heroku Postgres."

    

    Alternatively, in the "Resources" tab, in the "Add-ons" section, we should see "Heroku Postgres."

    

    Set Environment Variables in Heroku

    Our current app sets the SQLALCHEMY_DATABASE_URI environment variable using our .env file. Our Flask code accesses this environment variable with the code os.environ.get("SQLALCHEMY_DATABASE_URI").

    Instead of giving Heroku our .env file, we need to add our environment variables to Heroku using the Heroku dashboard.

    Find the Database URL in Heroku

    First, let's find the connection string that will connect to our Heroku database, instead of a local database.

    When we added the Postgres database add-on above, Heroku created this connection string.

    In the Heroku dashboard, in the "Settings" tab, there is a section titled "Config Vars."

    

    Once we locate this section, we should:

    1. Click "Reveal Config Vars"
    2. Find the automatically generated variable named "DATABASE_URL"
    3. Copy the value of this connection string

    Setup and Initialize the Database in Heroku

    Now that our Flask app is on Heroku and can connect to a database, we need to initialize the database in Heroku once.

    We can run the following:

    $ heroku run flask db upgrade
    
    

    This will migrate the empty database in our remote Postgres connection to the latest schema configuration we have generated from our models.

    Verify

    Our Flask project is on a Heroku machine, running, and connected to an initialized database. Now is the time to verify whether our API is accessible by web!

    As a convenient shortcut, the Heroku CLI gives us this command to automatically open our Heroku app in the browser:

    $ heroku open
    
    

    This command needs to be run inside of our project folder.

    Use Postman

    We can use Postman to make and verify all sorts of HTTP requests to our API!

    Use Heroku Logs

    During local development on our own machines, when we ran $ flask run, the server's logs were output into our terminal. We could see the details about every HTTP request our server received and every HTTP response it returned. We could also see output for any errors.

    We can access the server logs of our Heroku app from the Heroku dashboard by finding the "More" menu and selecting "View logs."