Simple Tasks API

A simple FastAPI application that allows you to manage tasks. You can create, update, retrieve, and delete tasks from a PostgreSQL database.

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Prerequisites

1. Python (3.9+)
2. PostgreSQL (Database server)

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Installing and Configuring PostgreSQL Locally

Below is a quick guide to installing PostgreSQL on an Ubuntu-like distribution. Adapt the steps if you are using a different OS.

1. Update your package list:

   sudo apt update

2. Install PostgreSQL and its additional modules:

   sudo apt install postgresql postgresql-contrib

3. Switch to the postgres user:

   sudo -i -u postgres

4. Enter the PostgreSQL shell:

   psql

5. Create a new database (for example, simpletasks):

   CREATE DATABASE tasksdb;

6. Create a user (for example, myuser) and set a password:

   CREATE USER myuser WITH PASSWORD '123';

7. Grant privileges for the user on the new database:

   GRANT ALL PRIVILEGES ON DATABASE simpletasks TO myuser;

8. Exit the PostgreSQL shell:

   \q

9. Exit the myuser user session:

   exit

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Setting Up the .env File

In the project root directory, create a file named .env. Add your database connection string:

POSTGRES_URL="postgresql://myuser:123@localhost:5432/tasksdb"

Adjust the user, password, host, and port according to your local PostgreSQL configuration.

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Local Development Setup

1. Clone the repository (or download the source code) and navigate to the project directory.
2. (Optional) Create and activate a virtual environment:

   python3 -m venv venv
   source venv/bin/activate

3. Install the required dependencies:

   pip install -r requirements.txt

4. Run the application (using any ASGI server, such as uvicorn):

   uvicorn app.main:app --host 0.0.0.0 --port 8000

   Alternatively, you can use the built-in uvicorn runner in your code or another process manager of your choice.

Once the server is running, open your browser or HTTP client at: http://127.0.0.1:8000/docs

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Deploying on a Linux Server with systemd

Below is an example of how to set up your systemd service to run the application using gunicorn with the Uvicorn worker.

Before proceeding, make sure:

1. Your PostgreSQL service is installed and running. You can verify by:

   sudo systemctl status postgresql
   # or for version-specific:
   sudo systemctl status postgresql-17

   If it’s not running, start it:

   sudo systemctl start postgresql

2. The required Python packages (gunicorn, uvicorn, etc.) are installed in an env on the server:

   pip install -r requirements.txt

3. Your .env file is in place with the correct database connection string.

4. PostgreSQL is properly configured with your database and user.

5. Create a systemd Service File (for example, /etc/systemd/system/simple-tasks.service) with the following content:

   [Unit]
   Description=Simple Tasks API
   After=network.target
   
   [Service]
   Type=simple
   User=youruser
   Group=yourgroup
   WorkingDirectory=/path/to/your/project
   Environment="PATH=/path/to/your/env/bin"
   ExecStart=/path/to/your/env/bin/gunicorn --worker-class uvicorn.workers.UvicornWorker --bind 0.0.0.0:7000 app.main:app
   Restart=always
   
   [Install]
   WantedBy=multi-user.target

   Notes:

   • Adjust User and Group to match your setup.
   • Update WorkingDirectory to the path to your project.
   • Change the Environment line to the path to your Python environment.
   • The ExecStart line reference should match the path where gunicorn is installed.

6. Reload systemd and enable/start the service:

   sudo systemctl daemon-reload
   sudo systemctl enable simple-tasks.service
   sudo systemctl start simple-tasks.service

7. Check the service status:

   systemctl status simple-tasks.service

Your FastAPI application will now run as a background service managed by systemd on port 7000.

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API Endpoints

Below is a summary of each endpoint provided by the tasks router:

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1. Create a Task

• Method: POST /tasks
• Request Body (JSON):

  {
    "title": "<string>",
    "is_completed": "<boolean>",
    "description": "<string or null>"
  }

• Description: Creates a new task in the database.
• Returns:

  {
    "message": "Task created successfully",
    "data": {"id": "<created task id>"},
    "timestamp": "<creation time>"
  }

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2. Retrieve a Single Task

• Method: GET /tasks/{task_id}
• URL Parameter:
  • task_id (int): The ID of the task to retrieve.
• Description: Retrieves the details of a specific task by its ID.
• Returns:

  {
    "message": "Task retrieved successfully",
    "data": {
      "id": "<task id>",
      "title": "<string>",
      "is_completed": "<boolean>",
      "description": "<string or null>",
      "created_at": "<datetime>"
    },
    "timestamp": "<time of retrieval>"
  }

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3. Retrieve All Tasks

• Method: GET /tasks
• Description: Retrieves all tasks in the system.
• Returns:

  {
    "message": "Tasks retrieved successfully",
    "data": {
      "tasks": [
        {
          "id": "<task id>",
          "title": "<string>",
          "is_completed": "<boolean>",
          "description": "<string or null>",
          "created_at": "<datetime>"
        },
        ...
      ]
    },
    "timestamp": "<time of retrieval>"
  }

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4. Update a Task

• Method: PUT /tasks/{task_id}
• URL Parameter:
  • task_id (int): The ID of the task to update.
• Request Body (JSON):

  {
    "title": "<string or null>",
    "is_completed": "<boolean or null>",
    "description": "<string or null>"
  }

• Description: Updates the specified fields of a task.
• Returns:

  {
    "message": "Task updated successfully",
    "data": {
      "id": "<task id>",
      "title": "<string>",
      "is_completed": "<boolean>",
      "description": "<string or null>",
      "created_at": "<datetime>"
    },
    "timestamp": "<time of update>"
  }

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5. Delete a Task

• Method: DELETE /tasks/{task_id}
• URL Parameter:
  • task_id (int): The ID of the task to delete.
• Description: Deletes the specified task from the system.
• Returns:

  {
    "message": "Task deleted successfully",
    "data": null,
    "timestamp": "<time of deletion>"
  }

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Contact

If you have any questions or issues, feel free to contact:

• Email: sahashemi072@gmail.com