PostgreSQL with Adminer Docker Compose Setup

This repository contains a Docker Compose configuration for setting up a PostgreSQL database container along with an Adminer container for a web-based database management interface.

Prerequisites

• Docker Engine installed on your machine
• Docker Compose installed on your machine

Getting Started

1. Clone this repository or copy the docker-compose.yml file to your local machine.

2. Navigate to the directory containing the docker-compose.yml file.

3. Run the following command to start the containers:

docker-compose up -d

This command will start the PostgreSQL and Adminer containers in detached mode.

Configuration

The docker-compose.yml file is configured as follows:

version: "3"
services:
  db:
    image: postgres
    restart: always
    volumes:
      - ./data/db:/var/lib/postgresql/data
    ports:
      - 5432:5432
    environment:
      - POSTGRES_DB=postgres
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=postgres

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

PostgreSQL Container

• image: postgres: Uses the official PostgreSQL Docker image.
• restart: always: Ensures that the container restarts automatically if it stops for any reason.
• volumes: Mounts a local directory (./data/db) to the container's /var/lib/postgresql/data directory, which is where PostgreSQL stores its data. This allows data persistence across container restarts or removals.
• ports: Maps the host's port 5432 to the container's port 5432, allowing access to the PostgreSQL server from the host machine.
• environment: Sets the following environment variables:
  • POSTGRES_DB: The name of the default database to be created.
  • POSTGRES_USER: The username for the default user.
  • POSTGRES_PASSWORD: The password for the default user.

Adminer Container

• image: adminer: Uses the official Adminer Docker image.
• restart: always: Ensures that the container restarts automatically if it stops for any reason.
• ports: Maps the host's port 8080 to the container's port 8080, allowing access to the Adminer web interface from the host machine.

Accessing the Database

Using psql

To access the PostgreSQL database running in the Docker container, you can use a PostgreSQL client like psql.

1. Find the container ID or name using the docker ps command.

2. Connect to the database using the following command:

docker exec -it <container-id-or-name> psql -U postgres

Replace <container-id-or-name> with the actual container ID or name of the PostgreSQL container.

3. When prompted, enter the password specified in the docker-compose.yml file (postgres in this case).

You can now interact with the PostgreSQL database using the psql prompt.

Using Adminer

To access the Adminer web interface, open your web browser and navigate to http://localhost:8080.

You should see the Adminer login page. Enter the following credentials:

• System: PostgreSQL
• Server: db (or the container name/ID of the PostgreSQL container)
• Username: postgres
• Password: postgres
• Database: postgres

Click "Login" to access the Adminer interface and manage your PostgreSQL database.

Data Persistence

The PostgreSQL data is stored in the ./data/db directory on your local machine, which is mounted to the container's /var/lib/postgresql/data directory. This ensures that your data persists even if you stop or remove the container.

Cleanup

To stop and remove the PostgreSQL and Adminer containers, run the following command:

docker-compose down

This command will stop and remove the containers, as well as the associated network.

If you want to remove the persistent data stored in the ./data/db directory, you can manually delete it after stopping the containers.

rm -rf ./data/db

Change permissions of the ./data/db directory if needed.

Access psql in the container

docker exec -it <container-id-or-name "postgres-db-1"> bash
psql -U postgres