Postgres-DB based on Docker

This guide provides step-by-step instructions on how to set up and use a PostgreSQL database using Docker and Docker Compose. Docker makes it easy to create, deploy, and run applications by using containers, while PostgreSQL is a powerful, open-source object-relational database system.

Starting the PostgreSQL Database

To start the PostgreSQL database, you need to use Docker Compose, which allows you to define and run multi-container Docker applications.

1. Open a terminal
2. Navigate to the directory that contains the docker-compose.yaml file
3. Run the following command:

docker-compose up -d

This command starts the services defined in the docker-compose.yaml file in the background (-d stands for “detached mode”).

Stopping the PostgreSQL Database

1. Open a terminal
2. Navigate to the directory with the docker-compose.yaml file
3. Run the following command:

docker-compose down

This command stops and removes containers, networks, and volumes defined in your docker-compose.yaml.

Connecting to the PostgreSQL Database

Local Computer

1. Open a terminal
2. Run the following command:

psql -h localhost -p 5432 -U postgres

This command attempts to connect to the PostgreSQL server running on localhost, on port 5432, with the username postgres. When prompted, enter the password postgres.

JDBC

To connect to the database using JDBC (Java Database Connectivity), use the following connection string:

jdbc:postgresql://localhost:5432/postgres?user=postgres&password=postgres

This connection string specifies the host (localhost), port (5432), database name (postgres), user (postgres), and password (postgres).

Using pgAdmin

pgAdmin is a popular open-source management tool for PostgreSQL.

1. Open a web browser
2. Go to http://localhost:5050
3. Login with the username admin@admin and the password admin
4. Right-click on Servers and select Create -> Server…
5. In the General tab, enter postgres as the name
6. In the Connection tab, fill out the form with the following details:
7. Host name/address: postgres
   • Port: 5432
   • Username: postgres
   • Password: postgres

Now, you should be connected to your PostgreSQL database through pgAdmin.

Docker-Compose

version: '3.8'
 
services:
  postgres:
    image: postgres:15
    environment:
      POSTGRES_USER: postgres
      POSTGRES_PASSWORD: postgres
    volumes:
      - local-postgres-db:/var/lib/postgresql
      - local-postgres-data:/var/lib/postgresql/data
    healthcheck:
      test: ['CMD-SHELL', 'pg_isready']
      interval: 30s
      timeout: 15s
      retries: 3
      start_period: 30s
    ports:
      - '5432:5432'
    restart: unless-stopped
 
  pgadmin:
    image: dpage/pgadmin4
    environment:
      PGADMIN_DEFAULT_EMAIL: admin@admin
      PGADMIN_DEFAULT_PASSWORD: admin
    volumes:
      - local-pgadmin:/root/.pgadmin
      - local-pgadmin-data:/var/lib/pgadmin
    ports:
      - '5050:80'
    restart: unless-stopped
 
volumes:
  local-postgres-db:
  local-postgres-data:
  local-pgadmin:
  local-pgadmin-data: