Chapter 2. Installing the OpenShift Serverless Operator
Installing the OpenShift Serverless Operator enables you to install and use Knative Serving, Knative Eventing, and the Knative broker for Apache Kafka on a OpenShift Container Platform cluster. The OpenShift Serverless Operator manages Knative custom resource definitions (CRDs) for your cluster and enables you to configure them without directly modifying individual config maps for each component.
2.1. OpenShift Serverless Operator resource requirements
The following sample setup might help you to estimate the minimum resource requirements for your OpenShift Serverless Operator installation. Your specific requirements might be significantly different, and might grow as your use of OpenShift Serverless increases.
The test suite used in the sample setup has the following parameters:
An OpenShift Container Platform cluster with:
- 10 workers (8 vCPU, 16GiB memory)
- 3 workers dedicated to Kafka
- 2 workers dedicated to Prometheus
- 5 workers remaining for both Serverless and test deployments
- 89 test scenarios running in parallel, mainly focused on using the control plane. Testing scenarios typically have a Knative Service sending events through an in-memory channel, a Kafka channel, an in-memory broker, or a Kafka broker to either a Deployment or a Knative Service.
- 48 re-creation scenarios, where the testing scenario is repeatedly being deleted and re-created.
- 41 stable scenarios, where events are sent throughout the test run slowly but continuously.
The test setup contains, in total:
- 170 Knative Services
- 20 In-Memory Channels
- 24 Kafka Channels
- 52 Subscriptions
- 42 Brokers
- 68 Triggers
The following table details the minimal resource requirements for a Highly-Available (HA) setup discovered by the test suite:
Component | RAM resources | CPU resources |
---|---|---|
OpenShift Serverless Operator | 1GB | 0.2 core |
Knative Serving | 5GB | 2.5 cores |
Knative Eventing | 2GB | 0.5 core |
Knative broker for Apache Kafka | 6GB | 1 core |
Sum | 14GB | 4.2 cores |
The following table details the minimal resource requirements for a non-HA setup discovered by the test suite:
Component | RAM resources | CPU resources |
---|---|---|
OpenShift Serverless Operator | 1GB | 0.2 core |
Knative Serving | 2.5GB | 1.2 cores |
Knative Eventing | 1GB | 0.2 core |
Knative broker for Apache Kafka | 6GB | 1 core |
Sum | 10.5GB | 2.6 cores |
2.2. Installing the OpenShift Serverless Operator from the web console
You can install the OpenShift Serverless Operator from the OperatorHub by using the OpenShift Container Platform web console. Installing this Operator enables you to install and use Knative components.
Prerequisites
- You have cluster administrator permissions on OpenShift Container Platform, or you have cluster or dedicated administrator permissions on Red Hat OpenShift Service on AWS or OpenShift Dedicated.
- For OpenShift Container Platform, your cluster has the Marketplace capability enabled or the Red Hat Operator catalog source configured manually.
- You have logged in to the web console.
Procedure
-
In the web console, navigate to the Operators
OperatorHub page. - Scroll, or type the keyword Serverless into the Filter by keyword box to find the OpenShift Serverless Operator.
- Review the information about the Operator and click Install.
On the Install Operator page:
-
The Installation Mode is All namespaces on the cluster (default). This mode installs the Operator in the default
openshift-serverless
namespace to watch and be made available to all namespaces in the cluster. -
The Installed Namespace is
openshift-serverless
. Select an Update Channel.
- The stable channel enables installation of the latest stable release of the OpenShift Serverless Operator. The stable channel is the default.
- To install another version, specify the corresponding stable-x.y channel, for example stable-1.29.
- Select the stable channel as the Update Channel. The stable channel will enable installation of the latest stable release of the OpenShift Serverless Operator.
- Select Automatic or Manual approval strategy.
-
The Installation Mode is All namespaces on the cluster (default). This mode installs the Operator in the default
- Click Install to make the Operator available to the selected namespaces on this OpenShift Container Platform cluster.
From the Catalog
Operator Management page, you can monitor the OpenShift Serverless Operator subscription’s installation and upgrade progress. - If you selected a Manual approval strategy, the subscription’s upgrade status will remain Upgrading until you review and approve its install plan. After approving on the Install Plan page, the subscription upgrade status moves to Up to date.
- If you selected an Automatic approval strategy, the upgrade status should resolve to Up to date without intervention.
Verification
After the Subscription’s upgrade status is Up to date, select Catalog
If it does not:
-
Switch to the Catalog
Operator Management page and inspect the Operator Subscriptions and Install Plans tabs for any failure or errors under Status. -
Check the logs in any pods in the
openshift-serverless
project on the WorkloadsPods page that are reporting issues to troubleshoot further.
If you want to use Red Hat OpenShift distributed tracing with OpenShift Serverless, you must install and configure Red Hat OpenShift distributed tracing before you install Knative Serving or Knative Eventing.
2.3. Installing the OpenShift Serverless Operator from the CLI
You can install the OpenShift Serverless Operator from the OperatorHub by using the CLI. Installing this Operator enables you to install and use Knative components.
Prerequisites
- You have cluster administrator permissions on OpenShift Container Platform, or you have cluster or dedicated administrator permissions on Red Hat OpenShift Service on AWS or OpenShift Dedicated.
- For OpenShift Container Platform, your cluster has the Marketplace capability enabled or the Red Hat Operator catalog source configured manually.
- You have logged in to the cluster.
Procedure
Create a YAML file containing
Namespace
,OperatorGroup
, andSubscription
objects to subscribe a namespace to the OpenShift Serverless Operator. For example, create the fileserverless-subscription.yaml
with the following content:Example subscription
--- apiVersion: v1 kind: Namespace metadata: name: openshift-serverless --- apiVersion: operators.coreos.com/v1 kind: OperatorGroup metadata: name: serverless-operators namespace: openshift-serverless spec: {} --- apiVersion: operators.coreos.com/v1alpha1 kind: Subscription metadata: name: serverless-operator namespace: openshift-serverless spec: channel: stable 1 name: serverless-operator 2 source: redhat-operators 3 sourceNamespace: openshift-marketplace 4
- 1
- The channel name of the Operator. The
stable
channel enables installation of the most recent stable version of the OpenShift Serverless Operator. To install another version, specify the correspondingstable-x.y
channel, for examplestable-1.29
. - 2
- The name of the Operator to subscribe to. For the OpenShift Serverless Operator, this is always
serverless-operator
. - 3
- The name of the CatalogSource that provides the Operator. Use
redhat-operators
for the default OperatorHub catalog sources. - 4
- The namespace of the CatalogSource. Use
openshift-marketplace
for the default OperatorHub catalog sources.
Create the
Subscription
object:$ oc apply -f serverless-subscription.yaml
Verification
Check that the cluster service version (CSV) has reached the Succeeded
phase:
Example command
$ oc get csv
Example output
NAME DISPLAY VERSION REPLACES PHASE serverless-operator.v1.25.0 Red Hat OpenShift Serverless 1.25.0 serverless-operator.v1.24.0 Succeeded
If you want to use Red Hat OpenShift distributed tracing with OpenShift Serverless, you must install and configure Red Hat OpenShift distributed tracing before you install Knative Serving or Knative Eventing.
2.4. Global configuration
The OpenShift Serverless Operator manages the global configuration of a Knative installation, including propagating values from the KnativeServing
and KnativeEventing
custom resources to system config maps. Any updates to config maps which are applied manually are overwritten by the Operator. However, modifying the Knative custom resources allows you to set values for these config maps.
Knative has multiple config maps that are named with the prefix config-
. All Knative config maps are created in the same namespace as the custom resource that they apply to. For example, if the KnativeServing
custom resource is created in the knative-serving
namespace, all Knative Serving config maps are also created in this namespace.
The spec.config
in the Knative custom resources have one <name>
entry for each config map, named config-<name>
, with a value which is be used for the config map data
.
2.5. Additional resources for OpenShift Container Platform
2.6. Next steps
- After the OpenShift Serverless Operator is installed, you can install Knative Serving or install Knative Eventing.