Docker-compose: PostgreSQL and PgAdmin

docker-compose.yml

# Use postgres/example user/password credentials
version: '3.1'

services:
  db:
    image: "postgres:10.6"
    restart: always
    ports:
      - 5432:5432
    environment:
      POSTGRES_USER: ${POSTGRES_USER:-postgres}
      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-changeme}
    volumes:
      - database-data:/var/lib/postgresql/data/ # persist data even if container shuts down
      - ./bootstrap:/docker-entrypoint-initdb.d

  pgadmin:
    image: adminer
    restart: always
    ports:
      - 8080:8080

volumes:
  database-data: # named volumes can be managed easier using docker-compose

Running PostgreSQL 13.x container via command line:

docker run --name cdc-postgres -p 5432:5432 -e POSTGRES_PASSWORD=postgres -d postgres:13.3

We can start and stop the container as well:

docker container start cdc-postgres
docker container stop cdc-postgres

Running pg_activity to monitoring Postgres instance:

Just run the commands below to install in the container where the postgres is running:

docker-compose exec <pg_server_name> bash # or docker exec -i -t postgres bash
apt update && apt install pg-activity && pg_activity -U postgres

For more details, see this Reddit comment.