Add LAMB_WORKERS configuration support for Docker next deployment

[xezpeleta]

Closes #361

Overview

This PR adds support for configuring Uvicorn worker processes via the LAMB_WORKERS environment variable in the Docker next deployment.

Changes Made

1. backend/docker-entrypoint.py

• Added logic to detect LAMB_WORKERS environment variable
• Automatically injects --workers N flag into uvicorn command
• Validates that workers is a positive integer
• Only applies to uvicorn commands (not other commands)
• Prevents duplicate --workers flags

2. docker-compose.next.yaml

• Added LAMB_WORKERS environment variable pass-through to lamb service
• Uses empty string as default to maintain backward compatibility

3. .env.next.example

• Added LAMB_WORKERS documentation in OPTIONAL VARIABLES section
• Included usage recommendations (2-4 workers for production)
• Clearly marked as commented/optional

Usage

Option 1 - Via .env file:

# Add to your .env file
LAMB_WORKERS=4
docker compose -f docker-compose.next.yaml up

Option 2 - Command line:

LAMB_WORKERS=4 docker compose -f docker-compose.next.yaml up

Option 3 - Override in compose file:

services:
  lamb:
    environment:
      LAMB_WORKERS: 4

Behavior

• Not set/empty → Single worker (development mode, uvicorn default)
• Positive integer (e.g., 4) → Multiple workers (production mode)
• 0 or invalid → Ignored, defaults to single worker
• Smart detection → Won't duplicate if --workers already in command

Testing

All test cases passed:

• ✓ With LAMB_WORKERS=4
• ✓ With LAMB_WORKERS not set
• ✓ With LAMB_WORKERS=0 (ignored)
• ✓ With --workers already present (not duplicated)
• ✓ Non-uvicorn command (not affected)

Recommendations

• Development: Leave unset (single worker)
• Production: Set to 2-4 workers based on CPU cores and expected load

[juananpe]

Looks good to me!

[juananpe]

Looks good to me!

Please, next time use dev for the PR

[xezpeleta]

You're right, I've changed to dev.