Casting Agency API

This project is an API that helps manage actors and movies. Actors and movies can be created, retrieved, updated, and deleted at the corresponding resources. The relationship between actors and movies can also be updated from either resources.

The project follows Pep8 style guidelines for formatting code.

Getting Started

PosgtreSQL Database

A PostgreSQL database is needed to run the application. A url can be provided to the application via the DATABASE_URL environment variable. Alternatively, the application accepts the database name, username, host, and password can be provided with the DB_NAME, DB_USER, DB_HOST, DB_PASSWORD environment variables.

PostgreSQL should be installed locally for local development. Installation instructions can be found on the Postgres site. Alternatively, Digitalocean offers a great tutorial for installing PostgreSQL on Ubuntu, CentOS, and Debian system.

By default, the application connects to a database at localhost using port 5432. The default username is casting_api. The database user must have a database password when the application is run from a Linux distro such as Ubuntu.

Local Database Setup (Linux System)

Follow these steps to set up the database:

• Activate the postgres user with the command:

  sudo -i -u postgres
  

• Create a database named casting with the command:

  createdb casting
  

• Create a test database named casting_test with the command:

  createdb casting_test
  

• Create a user named casting_api with the command:

  createuser --interactive
  

  • The command will ask a series of questions that can all be answered with a no
  • NOTE: Answering no to all the questions is fine since the user is only needed to give the app access to the database and does not need to manage the database or tables
• Run the psql interpretor with the command:

  psql
  

• To change the database user password, run the psql command:

  \password casting_api
  

  • This password is needed to connect the application to the local database
  • NOTE: This step is necessary to connect to the database using password based authentication on Linux machines instead of peer based authentication. By default, password based authentication is required by the psycopg2 library when connecting to postgres on some Linux distros
• Exit the psql interpretor using the psql command \q
• From the root project directory, run the command:

  flask db upgrade
  

  • The command will create the tables defined in the migrations directory
• Run the exit command to exit out of the postgres user shell login

Verify Local Database Setup Works

Connect to the database with the command:

psql casting --username casting_api --host localhost

• Providing the --host or -h flag will ask for the database user password instead of attempting peer authentication using the system user

Display the casting database tables with the commannd:

\dt

Display the actor schema with the command:

\d questions

Display the actor table rows using the command:

SELECT * FROM questions;

Flask Web API

The web API uses Python and Flask. For this project, Anaconda is used to manage Python packages and the virtual environments. Installation instructions can be found on the Conda documentation page. For a lean installation of just the conda command, there are instructions for installing Miniconda as well.

Virtual Environment

Creating a virtual environment is recommended to keep the project packages separate from any Python packages that may be installed on the host computer. The conda command provided by Anaconda or Miniconda, will be used to manage the virtual environment.

To create the python environment run the command:

conda env create --file environment.yml

To use a different environment name, use the --name flag when running the command:

conda env create --file environment.yml --name alternate_name

To export the current environment, run the command:

conda env export --file environment.yml

The last line in the environment.yml file can be removed, since it contains the path where the environment is installed on the host computer and does not affect the creation of the environment on other computers.

Additional Dependencies

On a Linux system, it may be neccessary to install additional dependencies to allow the psycopg2 Python library to communicate with PostgreSQL. The dependencies are python-psycopg2 and libpq-dev and can be installed on Ubuntu using the command:

apt install python-psycopg2 libpq-dev

Running the Web API

Activate the virtual environment with the command:

conda activate casting_agency 

Traverse to the root project directory and create these Flask app environment variables:

export FLASK_APP=app
export FLASK_ENV=development

• FLASK_APP tells Flask the name of the file or module the app is located in
• When FLASK_ENV is set to developmet, Flask restarts the app whenever a file is updated

From the root project directory, run the command

flask run

The application will also run using the command:

python app.py

There will be a message similar to:

 * Serving Flask app "app" (lazy loading)
 * Environment: development
 * Debug mode: on
 * Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)
 * Restarting with stat
 * Debugger is active!
 * Debugger PIN: 867-874-182

The web API will be available at the url in the output. In this case at http://127.0.0.1:5000/.

Running Integration Tests

The integration tests are located in tests directory and are split into separate files for each resource endpoint. The tests expect the database name to be casting_test. The tests also expect authentication bearer tokens to be provided for Assistant, Director, and Executive roles using the ASSISTANT_TOKEN, DIRECTOR_TOKEN, and EXECUTIVE_TOKEN environment variables, respectively.

Run the tests with the command:

python -m unittest

Run specific tests by appending the relative test filename:

python -m unittest tests/test_health.py

NOTE: The tests only run from the root project directory.