In this article, we will look at how to install PostgreSQL and the pgAdmin4 panel in a Docker container using docker-compose.
 

But first, we need to update the OS packages. 
 

apt update

Install the necessary packages and add a new repository:
 

apt install apt-transport-https ca-certificates curl gnupg-agent software-properties-common

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

Update the packages with the new repository:
 

apt update

Now let's install Docker itself.
 

apt-get install docker-ce docker-ce-cli containerd.io

Check the version:
 

docker --version

Check the status:

systemctl status docker

If it didn't start, then start it:

systemctl start docker

And add it to autostart.

systemctl enable docker

curl -L "https://github.com/docker/compose/releases/download/1.25.5/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose

Set the execution rights. 

chmod +x /usr/local/bin/docker-compose

Check how Docker-Compose was installed:

docker-compose --version

Create a *.yaml file for Docker-Compose.

To keep track of what we have installed in the future, let's create a separate folder for this project in the /home directory and navigate to it.

mkdir /home/postgres && cd /home/postgres

You can also use another directory  to place this and other projects. 

Let's use the repository to create the docker-compose.yaml file from the link https://hub.docker.com/_/postgres

Create the file docker-compose.yaml or docker-compose.yml,

vim docker-compose.yaml

And add the following code to it:

version: '3.8'
services:
  db_postgres:
    image: postgres
    container_name: postgres
    restart: always
    environment:
      POSTGRES_USER: root
      POSTGRES_PASSWORD: root
      POSTGRES_DB: test_db
    ports:
      - "54320:5432"
    volumes:
      - local_pgdаta:/var/lib/postgresql/data
  pgadmin4:
    container_name: pgadmin4
    image: dpage/pgadmin4
    restart: always
    environment:
      PGADMIN_DEFAULT_EMAIL: [email protected]
      PGADMIN_DEFAULT_PASSWORD: root
    ports:
      - "5050:80"
    volumes:
      - pgadmin-dаta:/var/lib/pgadmin
volumes:
  local_pgdаta:
  pgadmin-dаta:

Where:

container_name: the name of your container;
POSTGRES_USER: User for the created database;
POSTGRES_PASSWORD: password for the user being created;
POSTGRES_DB: database name;
PGADMIN_DEFAULT_EMAIL: email/user for authorization in pgadmin;
PGADMIN_DEFAULT_PASSWORD: password for the pgadmin user;
5050:80: port on which pgadmin works.

Run our script (to do this, you need to be in the directory where our file was created. In this case, it is /home/postgres):

docker-compose up -d 

Wait for the images to download and deploy.

Check:

docker-compose ps

or 

docker ps

Now to connect to the database, you can use the container's IP with port 54320, or the container name postgres with port 54320 (IP:54320 or postgres:54320) 

To view the logs, use the command: 

docker logs -f postgres

To configure pgadmin — open a browser and go to the address — http://YOUR_IP_SERVER:5050/. In the connection details for the host name, specify the name of the postgreSQL container or the email you specified in PGADMIN_DEFAULT_EMAIL and the password root

Now let's connect the postgreSQL database server to pgadmin4.


Enter the data specified in docker-compose.yaml


 Now you can create postgreSQL databases in pgadmin4.