PostgreSQL in a docker container

You presumably want to make a database for your little project. I presumably want to tell how. Read on.

Creating and running the container

The command:

docker run -p 5432:5432 -d \
   -e POSTGRES_PASSWORD=postgres \
   -e POSTGRES_USER=postgres \
   -e POSTGRES_DB=database-example \
   -v pgdata:/var/lib/postgresql/data \
   postgres

The explanation:

• -p 5432:5432 — port 5432 (left) is the port on the host machine that will be used to access the container. It will map to port 5432 (right) in the container.
• -d — discrete. The container will run but will not print its log in the terminal. It will run discretely.
• -e — Environmental variables. These variables will be available within the container. We are declaring the user, password, and name of the database.
• -v pgdata:/var/lib/postgresql/data — we are creating a named volume called pgdata and mounting it at that location inside the container
• postgres — name of the image we will be using

Connecting to the container

The command:

docker exec -it <container-id> psql -U postgres database-example

The explanation:

• exec — Execute this command inside the container
• -it — Effectively makes it appear as a terminal session, so you can keep typing psql queries
• <container-id> — find by executing the command docker container ls and copying the id
• psql -U postgres database-example — a postgres command, as you may already be familiar with it, to enter the “database-example” database as the user “postgres”

What now?

You can connect to the database using the details selected above. Perhaps you may want to furnish an environments file with these little goodies:

POSTGRES_PASSWORD=postgres 
POSTGRES_USER=postgres 
POSTGRES_DB=database-example
POSTGRES_PORT=5432

Good day

Directly copied from a tutorial by the significantly more capable Ben Awad