These are instructions for creating a PostGIS server in Docker. They should work pretty much the same on Windows, Mac, or Linux.

Preparation

It is assumed that you already have Docker installed and have an account on Docker Hub.

If not,

1. Get Docker as appropriate for your OS.
2. Register on Docker Hub.

NOTE: When you first run Docker Desktop, you may get a notice that WSL (Windows Subsystem for Linux) needs to be upgraded. Open Windows PowerShell and run wsl.exe --update at the command line.

Create a PostGIS Container

We will use the PostGIS images maintained at https://hub.docker.com/r/kartoza/postgis/. Begin by opening a terminal. Remember that you can use the up and down arrows in the terminal to cycle through recently used commands. If you are working on Windows, I recommend using Windows PowerShell instead of Command Prompt because PowerShell will remember your commands from previous terminal sessions.

Each step is explained below, followed by a command. You should type or paste each command into the terminal and hit Enter after each one.

First, copy the PostGIS container image from Docker Hub (this requires an internet connection):

docker pull kartoza/postgis

Create a volume to persist your data. This is not strictly necessary, as you can stop and start a container, and new or updated data will persist. However, if you ever delete the container, you will lose any changes you made (when you re-run the container, the data will be whatever was in the original image). Creating a volume will allow you to create a new container and attach the data used previously.

docker volume create pg_data

Create the docker image:

docker create --name my_postgis -p 5433:5432 -e POSTGRES_PASS=docker -t -v pg_data:/var/lib/postgresql kartoza/postgis

Some remarks:

• --name my_postgis: The name my_postgis is arbitrary. You can use another name for the container.
• -p 5433:5432: The PostgreSQL server must listen on a specific port for client connections. 5432 is the default Postgres port. If you are already running a native Posgres server on the same machine, 5432 is probably already in use. The 5433 port on localhost is mapped to port 5432 (the usual Postgres port) in the container.
• -e POSTGRES_PASS=docker: This sets the Postgres password for the docker user to docker. Note that the Kartoza container documentation is inconsistent on this. It says that the password should automatically be docker, but also says that it is generated randomly if omitted. In practice, I found that docker did not work and the randomly generated password in the Docker logs also did not work, so we are setting the password explicitly.
• -v pg_data:/var/lib/postgresql maps the location of the data cluster in the container (/var/lib/postgresql) to the docker volume created in the previous step.
• kartoza/postgis is the name of the container image we previously pulled. Note that if you don’t pull the image first, it will be downloaded when you run docker create.

Now that the container has been created and named, starting it is easy:

docker start my_postgis

The container can also be stopped, and should be stopped before you shut down your computer. It is OK to leave the container running if you suspend or hibernate the computer.

docker stop my_postgis

At any time thereafter, you can start the container back up by running docker start my_postgis again.

The container can be removed with:

docker rm my_postgis

Note that for this course, you probably don’t want to remove your container, unless you have done something to completely bork it and want to start fresh.

Connect to the Docker Image in DBeaver

You can now connect to this database using any Postgres client. The image has a PostGIS-enabled database named gis, and has been configured with a login role (user) named docker and a password docker The connection settings for any Postgres client are therefore:

• Host: localhost
• Port: 5433
• Database: gis
• User: docker
• Password: docker

In this course, we will be using DBeaver for database management and querying. The settings in the DBeaver connection settings dialog look like this:

Later in the course, we will also be connecting to this database using QGIS, which has a similar connection dialog.

References

• https://hub.docker.com/r/kartoza/postgis/
• Set Up a PostGIS Database With Docker – Note, however, that the author is using Docker Toolbox, not Docker for Windows, and has started the container with a number of environment variables that we are not using.
• Docker Documentation
  • docker (base command)