Chapter 3. Running Red Hat build of Keycloak in a container
This chapter describes how to optimize and run the Red Hat build of Keycloak container image to provide the best experience running a Red Hat build of Keycloak container.
This chapter applies only for building an image that you run in a OpenShift environment. Only an OpenShift environment is supported for this image. It is not supported if you run it in other Kubernetes distributions.
3.1. Creating a customized and optimized container image
The default Red Hat build of Keycloak container image ships ready to be configured and optimized.
For the best start up of your Red Hat build of 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.
3.1.1. Writing your optimized Red Hat build of Keycloak Dockerfile
The following Dockerfile creates a pre-configured Red Hat build of Keycloak image that enables the health and metrics endpoints, enables the token exchange feature, and uses a PostgreSQL database.
Dockerfile:
FROM registry.redhat.io/rhbk/keycloak-rhel9:22 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 registry.redhat.io/rhbk/keycloak-rhel9:22 COPY --from=builder /opt/keycloak/ /opt/keycloak/ # change these values to point to a running postgres instance ENV KC_DB=postgres 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
buildcommand to set server build options to create an optimized image. -
The files generated by the
buildstage 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.shenables 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 ADD --chown=keycloak:keycloak <MY_PROVIDER_JAR_URL> /opt/keycloak/providers/myprovider.jar
3.1.2. Installing additional RPM packages
If you try to install new software in a stage FROM registry.redhat.io/rhbk/keycloak-rhel9, you will notice that microdnf, dnf, and even rpm are not installed. Also, very few packages are available, only enough for a bash shell, and to run Keycloak itself. This is due to security hardening measures, which reduce the attack surface of the Keycloak container.
First, consider if your use case can be implemented in a different way, and so avoid installing new RPMs into the final container:
-
A
RUN curlinstruction in your Dockerfile can be replaced withADD, since that instruction natively supports remote URLs. -
Some common CLI tools can be replaced by creative use of the Linux filesystem. For example,
ip addr show tap0becomescat /sys/class/net/tap0/address - Tasks that need RPMs can be moved to a former stage of an image build, and the results copied across instead.
Here is an example. Running update-ca-trust in a former build stage, then copying the result forward:
FROM registry.access.redhat.com/ubi9 AS ubi-micro-build COPY mycertificate.crt /etc/pki/ca-trust/source/anchors/mycertificate.crt RUN update-ca-trust FROM registry.redhat.io/rhbk/keycloak-rhel9 COPY --from=ubi-micro-build /etc/pki /etc/pki
It is possible to install new RPMs if absolutely required, following this two-stage pattern established by ubi-micro:
FROM registry.access.redhat.com/ubi9 AS ubi-micro-build
RUN mkdir -p /mnt/rootfs
RUN dnf install --installroot /mnt/rootfs <package names go here> --releasever 9 --setopt install_weak_deps=false --nodocs -y && \
dnf --installroot /mnt/rootfs clean all && \
rpm --root /mnt/rootfs -e --nodeps setup
FROM registry.redhat.io/rhbk/keycloak-rhel9
COPY --from=ubi-micro-build /mnt/rootfs /
This approach uses a chroot, /mnt/rootfs, so that only the packages you specify and their dependencies are installed, and so can be easily copied into the second stage without guesswork.
Some packages have a large tree of dependencies. By installing new RPMs you may unintentionally increase the container’s attack surface. Check the list of installed packages carefully.
3.1.3. Building the container image
To build the actual container image, run the following command from the directory containing your Dockerfile:
podman build . -t mykeycloak
3.1.4. Starting the optimized Red Hat build of Keycloak container image
To start the image, run:
podman run --name mykeycloak -p 8443:8443 \
-e KEYCLOAK_ADMIN=admin -e KEYCLOAK_ADMIN_PASSWORD=change_me \
mykeycloak \
start --optimized
Red Hat build of Keycloak starts in production mode, using only secured HTTPS communication, and is available on https://localhost:8443.
Health check endpoints are available at https://localhost:8443/health, https://localhost:8443/health/ready and https://localhost:8443/health/live.
Opening up https://localhost:8443/metrics leads to a page containing operational metrics that could be used by your monitoring solution.
3.2. 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:
- Exposing the container using a port other than the default ports
podman 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.
3.3. Trying Red Hat build of Keycloak in development mode
The easiest way to try Red Hat build of Keycloak from a container for development or testing purposes is to use the Development mode. You use the start-dev command:
podman run --name mykeycloak -p 8080:8080 \
-e KEYCLOAK_ADMIN=admin -e KEYCLOAK_ADMIN_PASSWORD=change_me \
registry.redhat.io/rhbk/keycloak-rhel9:22 \
start-devInvoking this command starts the Red Hat build of Keycloak server in development mode.
This mode should be strictly avoided in production environments because it has insecure defaults. For more information about running Red Hat build of Keycloak in production, see Configuring Red Hat build of Keycloak for production.
3.4. Running a standard Red Hat build of 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 Red Hat build of Keycloak image by just running the start command. For example:
podman run --name mykeycloak -p 8080:8080 \
-e KEYCLOAK_ADMIN=admin -e KEYCLOAK_ADMIN_PASSWORD=change_me \
registry.redhat.io/rhbk/keycloak-rhel9:22 \
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 Red Hat build of 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.
Red Hat build of 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.
3.5. Provide initial admin credentials when running in a container
Red Hat build of 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
3.6. Importing A Realm On Startup
The Red Hat build of 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 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 \
registry.redhat.io/rhbk/keycloak-rhel9:22 \
start-dev --import-realmFeel free to join the open GitHub Discussion around enhancements of the admin bootstrapping process.
3.7. Relevant options
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