Adding step to the codespaces setup instruction to start the DB prior…

[ngillux]

… to running prisma.

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• [x] My pull request has a descriptive title (not a vague title like Update index.md)

Due to recent workflow changes in the Codespace setup instructions I'm adding a step that isn't explicitly show in the instructions, but is a step that I think is needed to add prior to running npx prisma studio.

[lloydchang]

@ngillux @utsab If this needs to be clarified live, we can schedule a call to discuss it further. Thanks!

This sudo service postgresql start manual step is redundant because there is already a db container that runs PostgreSQL on TCP port 5432, so there isn't a need to start the PostgreSQL service inside the app container.

There are two containers simultaneously running in GitHub Codespaces:

1. app container
2. db container

The app container is configured in the top part of the .devcontainer/docker-compose.yml file via: https://github.com/freeCodeCamp/classroom/blob/main/.devcontainer/docker-compose.yml#L1-L30

# https://github.com/microsoft/vscode-dev-containers/blob/main/containers/javascript-node-postgres/.devcontainer/docker-compose.yml

version: '3.8'

services:
  app:
    build:
      context: .
      dockerfile: Dockerfile
      args:
        # Update 'VARIANT' to pick an LTS version of Node.js: 20, 18, 16, 20-bookworm, 18-bookworm, 16-bookworm 20-bullseye, 18-bullseye, 16-bullseye, 20-buster, 18-buster, 16-buster
        # Append -bullseye or -buster to pin to an OS version.
        # Use -bookworm, and -bullseye variants on local arm64/Apple Silicon.
        VARIANT: 20-bookworm

    volumes:
      - ..:/workspace:cached

    # Overrides default command so things don't shut down after the process ends.
    command: sleep infinity

    # Runs app on the same network as the database container, allows "forwardPorts" in devcontainer.json function.
    network_mode: service:db

    # Uncomment the next line to use a non-root user for all processes.
    # user: node

    # Use "forwardPorts" in **devcontainer.json** to forward an app port locally.
    # (Adding the "ports" property to this file will not forward from a Codespace.)

The db container is configured in the bottom part of the .devcontainer/docker-compose.yml file via: https://github.com/freeCodeCamp/classroom/blob/main/.devcontainer/docker-compose.yml#L31-L45

  db:
    image: postgres:latest
    restart: unless-stopped
    volumes:
      - postgres-data:/var/lib/postgresql/data
    environment:
      POSTGRES_PASSWORD: postgres
      POSTGRES_USER: postgres
      POSTGRES_DB: postgres

    # Add "forwardPorts": ["5432"] to **devcontainer.json** to forward PostgreSQL locally.
    # (Adding the "ports" property to this file will not forward from a Codespace.)

volumes:
  postgres-data:

and its TCP 5432 port is forwarded to the app container via https://github.com/freeCodeCamp/classroom/blob/main/.devcontainer/devcontainer.json#L36-L38

    // Use 'forwardPorts' to make a list of ports inside the container available locally.
    // This can be used to network with other containers or with the host.
    "forwardPorts": [3000, 3001, 5432, 5555],

To recap: If this needs to be clarified live, we can schedule a call to discuss it further. Thanks!

Relates to https://github.com/freeCodeCamp/classroom/pull/390 and https://github.com/freeCodeCamp/classroom/issues/395