# Docker Compose

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`docker-compose` allows us to launch multiple containers using a single configuration file, so that we don't have to run multiple complex `docker run` commands separately.

Docker compose makes use of YAML files. Here's the `docker-compose.yaml` file:

```yaml
services:
  pgdatabase:
    image: postgres:18
    environment:
      POSTGRES_USER: "root"
      POSTGRES_PASSWORD: "root"
      POSTGRES_DB: "ny_taxi"
    volumes:
      - "ny_taxi_postgres_data:/var/lib/postgresql"
    ports:
      - "5432:5432"

  pgadmin:
    image: dpage/pgadmin4
    environment:
      PGADMIN_DEFAULT_EMAIL: "admin@admin.com"
      PGADMIN_DEFAULT_PASSWORD: "root"
    volumes:
      - "pgadmin_data:/var/lib/pgadmin"
    ports:
      - "8085:80"



volumes:
  ny_taxi_postgres_data:
  pgadmin_data:
```

### Explanation

* We don't have to specify a network because `docker compose` takes care of it: every single container (or "service", as the file states) will run within the same network and will be able to find each other according to their names (`pgdatabase` and `pgadmin` in this example).
* All other details from the `docker run` commands (environment variables, volumes and ports) are mentioned accordingly in the file following YAML syntax.

## Start Services with Docker Compose

We can now run Docker compose by running the following command from the same directory where `docker-compose.yaml` is found. Make sure that all previous containers aren't running anymore:

```bash
docker-compose up
```

### Detached Mode

If you want to run the containers again in the background rather than in the foreground (thus freeing up your terminal), you can run them in detached mode:

```bash
docker-compose up -d
```

## Stop Services

You will have to press `Ctrl+C` in order to shut down the containers when running in foreground mode. The proper way of shutting them down is with this command:

```bash
docker-compose down
```

## Other Useful Commands

```bash
# View logs
docker-compose logs

# Stop and remove volumes
docker-compose down -v
```

## Benefits of Docker Compose

- Single command to start all services
- Automatic network creation
- Easy configuration management
- Declarative infrastructure

## Running the Ingestion Script with Docker Compose

If you want to re-run the dockerized ingest script when you run Postgres and pgAdmin with `docker compose`, you will have to find the name of the virtual network that Docker compose created for the containers.

```bash
# check the network link:
docker network ls

# it's pipeline_default (or similar based on directory name)
# now run the script:
docker run -it --rm\
  --network=pipeline_default \
  taxi_ingest:v001 \
    --pg-user=root \
    --pg-pass=root \
    --pg-host=pgdatabase \
    --pg-port=5432 \
    --pg-db=ny_taxi \
    --target-table=yellow_taxi_trips
```

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