Demo #3B: Producer and Consumer with Kafka with FastAPI

Now, I want to have a input to specify the position of the players. For example, I want to create 5 goalkeepers, rather than 5 random players. How would I achieve that?

Here's what you need to modify in your previous code to achieve this:

Modify the Command Class: Update the CreatePeopleCommand class in your commands.py to include a field for the player's position. If you don't have a way to specify the position in the current structure, this is the step you'll need to take.
```
# commands.py
from pydantic import BaseModel

class CreatePeopleCommand(BaseModel):
   count: int
   position: str
```

Update the API Endpoint: Modify the create_soccer_players function in main.py to use the specified position instead of randomly selecting one.

# main.py
@app.post('/api/soccer_players', status_code=201, response_model=List[SoccerPlayer])
async def create_soccer_players(cmd: CreatePeopleCommand):
   ...
   # Remove the positions list, as you'll use the position from the cmd parameter
   # positions = ["Forward", "Midfielder", "Defender", "Goalkeeper"]

   # Generate random soccer player data based on the given count.
   for _ in range(cmd.count):
      soccer_player = SoccerPlayer(
            id=str(uuid.uuid4()), 
            name=faker.name(), 
            position=cmd.position,  # Use the specified position.
            speed=random.randint(0, 10),
            stamina=random.randint(0, 10),
            strength=random.randint(0, 10),
            technique=random.randint(0, 10)
      )
      ...

Position Validation (Optional but Recommended): You might want to validate the incoming position to ensure it's one of the expected values. Add this check at the beginning of the create_soccer_players function:

valid_positions = ["Forward", "Midfielder", "Defender", "Goalkeeper"]
if cmd.position not in valid_positions:
   raise ValueError(f"Invalid position: {cmd.position}. Expected one of {valid_positions}.")

With these changes, you can now specify the position of the players you want to create. When you make a request to your API, you can now send both the count and the position as part of the request body, like so:

{
    "count": 5,
    "position": "Goalkeeper"
}

This request would create 5 goalkeepers. Adjust the "position" value as needed for different positions.

Scripts used in the demo

Last update: 2023-11-01
Created: 2023-11-01