Running Keycloak in a container

Excerpt

Keycloak is an open source identity and access management solution

Keycloak handles containerized environments such as Kubernetes or OpenShift as first-class citizens. This guide describes how to optimize and run the Keycloak container image to provide the best experience running a Keycloak container.

Creating a customized and optimized container image

The default Keycloak container image ships ready to be configured and optimized.

For the best start up of your Keycloak container, build an image by running the build step during the container build. This step will save time in every subsequent start phase of the container image.

Building your optimized Keycloak docker image

The following Dockerfile creates a pre-configured Keycloak image that enables the health and metrics endpoints, enables the token exchange feature, and uses a PostgreSQL database.

Dockerfile:

FROM quay.io/keycloak/keycloak:latest as builder

# Enable health and metrics support
ENV KC_HEALTH_ENABLED=true
ENV KC_METRICS_ENABLED=true

# Configure a database vendor
ENV KC_DB=postgres

WORKDIR /opt/keycloak
# for demonstration purposes only, please make sure to use proper certificates in production instead
RUN keytool -genkeypair -storepass password -storetype PKCS12 -keyalg RSA -keysize 2048 -dname "CN=server" -alias server -ext "SAN:c=DNS:localhost,IP:127.0.0.1" -keystore conf/server.keystore
RUN /opt/keycloak/bin/kc.sh build

FROM quay.io/keycloak/keycloak:latest
COPY --from=builder /opt/keycloak/ /opt/keycloak/

# change these values to point to a running postgres instance
ENV KC_DB_URL=<DBURL>
ENV KC_DB_USERNAME=<DBUSERNAME>
ENV KC_DB_PASSWORD=<DBPASSWORD>
ENV KC_HOSTNAME=localhost
ENTRYPOINT ["/opt/keycloak/bin/kc.sh"]

The build process includes multiple stages:

• Run the build command to set server build options to create an optimized image.

• The files generated by the build stage are copied into a new image.

• In the final image, additional configuration options for the hostname and database are set so that you don’t need to set them again when running the container.

• In the entrypoint, the kc.sh enables access to all the distribution sub-commands.

To install custom providers, you just need to define a step to include the JAR file(s) into the /opt/keycloak/providers directory:

# A example build step that downloads a JAR file from a URL and adds it to the providers directory
RUN curl -sL <MY_PROVIDER_JAR_URL> -o /opt/keycloak/providers/myprovider.jar

Building the docker image

To build the actual docker image, run the following command from the directory containing your Dockerfile:

podman|docker build . -t mykeycloak

Starting the optimized Keycloak docker image

To start the image, run:

podman|docker run --name mykeycloak -p 8443:8443 \
        -e KEYCLOAK_ADMIN=admin -e KEYCLOAK_ADMIN_PASSWORD=change_me \
        mykeycloak \
        start --optimized

Keycloak starts in production mode, using only secured HTTPS communication, and is available on [https://localhost:8443](https://localhost:8443/).

Opening up [https://localhost:8443/metrics](https://localhost:8443/metrics) leads to a page containing operational metrics that could be used by your monitoring solution.

Exposing the container to a different port

By default, the server is listening for http and https requests using the ports 8080 and 8443, respectively.

If you want to expose the container using a different port, you need to set the hostname-port accordingly:

1. Exposing the container using a port other than the default ports

podman|docker run --name mykeycloak -p 3000:8443 \
        -e KEYCLOAK_ADMIN=admin -e KEYCLOAK_ADMIN_PASSWORD=change_me \
        mykeycloak \
        start --optimized --hostname-port=3000

By setting the hostname-port option you can now access the server at [https://localhost:3000](https://localhost:3000/).

Trying Keycloak in development mode

The easiest way to try Keycloak from a container for development or testing purposes is to use the Development mode. You use the start-dev command:

podman|docker run --name mykeycloak -p 8080:8080 \
        -e KEYCLOAK_ADMIN=admin -e KEYCLOAK_ADMIN_PASSWORD=change_me \
        quay.io/keycloak/keycloak:latest \
        start-dev

Invoking this command starts the Keycloak server in development mode.

This mode should be strictly avoided in production environments because it has insecure defaults. For more information about running Keycloak in production, take a look at the Configuring Keycloak for production guide.

Running a standard keycloak container

In keeping with concepts such as immutable infrastructure, containers need to be re-provisioned routinely. In these environments, you need containers that start fast, therefore you need to create an optimized image as described in the preceding section. However, if your environment has different requirements, you can run a standard Keycloak image by just running the start command. For example:

podman|docker run --name mykeycloak -p 8080:8080 \
        -e KEYCLOAK_ADMIN=admin -e KEYCLOAK_ADMIN_PASSWORD=change_me \
        quay.io/keycloak/keycloak:latest \
        start \
        --db=postgres --features=token-exchange \
        --db-url=<JDBC-URL> --db-username=<DB-USER> --db-password=<DB-PASSWORD> \
        --https-key-store-file=<file> --https-key-store-password=<password>

Running this command starts a Keycloak server that detects and applies the build options first. In the example, the line --db=postgres --features=token-exchange sets the database vendor to PostgreSQL and enables the token exchange feature.

Keycloak then starts up and applies the configuration for the specific environment. This approach significantly increases startup time and creates an image that is mutable, which is not the best practice.

Provide initial admin credentials when running in a container

Keycloak only allows to create the initial admin user from a local network connection. This is not the case when running in a container, so you have to provide the following environment variables when you run the image:

# setting the admin username
-e KEYCLOAK_ADMIN=<admin-user-name>

# setting the initial password
-e KEYCLOAK_ADMIN_PASSWORD=change_me

Importing A Realm On Startup

The published Keycloak containers have a directory /opt/keycloak/data/import. If you put one or more import files in that directory via a volume mount or other means and add the startup argument --import-realm, the Keycloak container will import that data on startup! This may only make sense to do in Dev mode.

podman|docker run --name keycloak_unoptimized -p 8080:8080 \
        -e KEYCLOAK_ADMIN=admin -e KEYCLOAK_ADMIN_PASSWORD=change_me \
        -v /path/to/realm/data:/opt/keycloak/data/import
        quay.io/keycloak/keycloak:latest \
        start-dev --import-realm

Feel free to join the open GitHub Discussion around enhancements of the admin bootstrapping process.

Relevant options

db

The database vendor.

db-password

The password of the database user.

db-url

The full database JDBC URL.

db-username

The username of the database user.

features

Enables a set of one or more features.

health-enabled

If the server should expose health check endpoints.

hostname

Hostname for the Keycloak server.

https-key-store-file

The key store which holds the certificate information instead of specifying separate files.

https-key-store-password

The password of the key store file.

metrics-enabled

If the server should expose metrics.