Install Keycloak Inside Docker Container in Linux

Keycloak is an identity and access management service. Users can be authenticated with Keycloak instead of individual applications. It means that applications don't need to deal with login forms, users storage, management and authentication.

This tutorial explains how to install Keycloak inside a Docker container in the Linux. Commands have been tested on Ubuntu.

Prepare environment

Make sure you have installed Docker in your system. If you are using Ubuntu, installation instructions can be found in the post.

You also need to have a running PostgreSQL container. Instructions can be found in the post.

Install Keycloak

Before starting, create keycloak database:

docker exec -it postgresql psql -U postgres -c "CREATE DATABASE keycloak"

• Host network

Run the following command to create a container for Keycloak that uses host network:

docker run -d --name=keycloak --restart=always --network=host \
    -e KEYCLOAK_ADMIN_USER=admin \
    -e KEYCLOAK_ADMIN_PASSWORD=pwd123 \
    -e KEYCLOAK_DATABASE_USER=postgres \
    -e KEYCLOAK_DATABASE_PASSWORD=pwd123 \
    -e KEYCLOAK_DATABASE_NAME=keycloak \
    -e KEYCLOAK_DATABASE_HOST=127.0.0.1 \
    bitnami/keycloak

PostgreSQL container should run on host network as well.

• User-defined bridge network

User-defined bridge network can be used for listening on different port. By default, Keycloak service is listening on port 8080. It can be changed with -p option.

docker network create app-net

docker run -d --name=keycloak --restart=always --network=app-net \
    -p 8081:8080 \
    -e KEYCLOAK_ADMIN_USER=admin \
    -e KEYCLOAK_ADMIN_PASSWORD=pwd123 \
    -e KEYCLOAK_DATABASE_USER=postgres \
    -e KEYCLOAK_DATABASE_PASSWORD=pwd123 \
    -e KEYCLOAK_DATABASE_NAME=keycloak \
    -e KEYCLOAK_DATABASE_HOST=postgresql \
    bitnami/keycloak

PostgreSQL container should run on the same user-defined bridge network as well.

Notes:

• It might take a while before initialization is finished and the Docker container starts to respond to requests.
• Don't forget to change admin password for Keycloak using KEYCLOAK_ADMIN_PASSWORD.
• The KEYCLOAK_DATABASE_USER and KEYCLOAK_DATABASE_PASSWORD can be used to specify PostgreSQL credentials.
• When user-defined bridge network is used, don't forget to change KEYCLOAK_DATABASE_HOST. It contains PostgreSQL container name.

Testing Keycloak

Open a web browser and go to http://<IP_ADDRESS>:8080, where <IP_ADDRESS> is the IP address of the system. Log in to the dashboard with the admin username and password.

Uninstall Keycloak

To completely remove Keycloak, remove its container:

docker rm --force keycloak

Remove Keycloak image:

docker rmi bitnami/keycloak

If a user-defined bridge network was created, you can delete it as follows:

docker network rm app-net