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Chapter 3. Manually creating IAM for GCP
In environments where the cloud identity and access management (IAM) APIs are not reachable, or the administrator prefers not to store an administrator-level credential secret in the cluster kube-system
namespace, you can put the Cloud Credential Operator (CCO) into manual mode before you install the cluster.
3.1. Alternatives to storing administrator-level secrets in the kube-system project
The Cloud Credential Operator (CCO) manages cloud provider credentials as Kubernetes custom resource definitions (CRDs). You can configure the CCO to suit the security requirements of your organization by setting different values for the credentialsMode
parameter in the install-config.yaml
file.
If you prefer not to store an administrator-level credential secret in the cluster kube-system
project, you can choose one of the following options when installing OpenShift Container Platform:
Use manual mode with GCP Workload Identity:
You can use the CCO utility (
ccoctl
) to configure the cluster to use manual mode with GCP Workload Identity. When the CCO utility is used to configure the cluster for GCP Workload Identity, it signs service account tokens that provide short-term, limited-privilege security credentials to components.NoteThis credentials strategy is supported for only new OpenShift Container Platform clusters and must be configured during installation. You cannot reconfigure an existing cluster that uses a different credentials strategy to use this feature.
Manage cloud credentials manually:
You can set the
credentialsMode
parameter for the CCO toManual
to manage cloud credentials manually. Using manual mode allows each cluster component to have only the permissions it requires, without storing an administrator-level credential in the cluster. You can also use this mode if your environment does not have connectivity to the cloud provider public IAM endpoint. However, you must manually reconcile permissions with new release images for every upgrade. You must also manually supply credentials for every component that requests them.Remove the administrator-level credential secret after installing OpenShift Container Platform with mint mode:
If you are using the CCO with the
credentialsMode
parameter set toMint
, you can remove or rotate the administrator-level credential after installing OpenShift Container Platform. Mint mode is the default configuration for the CCO. This option requires the presence of the administrator-level credential during an installation. The administrator-level credential is used during the installation to mint other credentials with some permissions granted. The original credential secret is not stored in the cluster permanently.
Prior to a non z-stream upgrade, you must reinstate the credential secret with the administrator-level credential. If the credential is not present, the upgrade might be blocked.
Additional resources
For a detailed description of all available CCO credential modes and their supported platforms, see About the Cloud Credential Operator.
3.2. Manually create IAM
The Cloud Credential Operator (CCO) can be put into manual mode prior to installation in environments where the cloud identity and access management (IAM) APIs are not reachable, or the administrator prefers not to store an administrator-level credential secret in the cluster kube-system
namespace.
Procedure
Change to the directory that contains the installation program and create the
install-config.yaml
file by running the following command:$ openshift-install create install-config --dir <installation_directory>
where
<installation_directory>
is the directory in which the installation program creates files.Edit the
install-config.yaml
configuration file so that it contains thecredentialsMode
parameter set toManual
.Example
install-config.yaml
configuration fileapiVersion: v1 baseDomain: cluster1.example.com credentialsMode: Manual 1 compute: - architecture: amd64 hyperthreading: Enabled ...
- 1
- This line is added to set the
credentialsMode
parameter toManual
.
Generate the manifests by running the following command from the directory that contains the installation program:
$ openshift-install create manifests --dir <installation_directory>
where
<installation_directory>
is the directory in which the installation program creates files.From the directory that contains the installation program, obtain details of the OpenShift Container Platform release image that your
openshift-install
binary is built to use by running the following command:$ openshift-install version
Example output
release image quay.io/openshift-release-dev/ocp-release:4.y.z-x86_64
Locate all
CredentialsRequest
objects in this release image that target the cloud you are deploying on by running the following command:$ oc adm release extract quay.io/openshift-release-dev/ocp-release:4.y.z-x86_64 \ --credentials-requests \ --cloud=gcp
This command creates a YAML file for each
CredentialsRequest
object.Sample
CredentialsRequest
objectapiVersion: cloudcredential.openshift.io/v1 kind: CredentialsRequest metadata: name: <component-credentials-request> namespace: openshift-cloud-credential-operator ... spec: providerSpec: apiVersion: cloudcredential.openshift.io/v1 kind: GCPProviderSpec predefinedRoles: - roles/storage.admin - roles/iam.serviceAccountUser skipServiceCheck: true ...
Create YAML files for secrets in the
openshift-install
manifests directory that you generated previously. The secrets must be stored using the namespace and secret name defined in thespec.secretRef
for eachCredentialsRequest
object.Sample
CredentialsRequest
object with secretsapiVersion: cloudcredential.openshift.io/v1 kind: CredentialsRequest metadata: name: <component-credentials-request> namespace: openshift-cloud-credential-operator ... spec: providerSpec: apiVersion: cloudcredential.openshift.io/v1 ... secretRef: name: <component-secret> namespace: <component-namespace> ...
Sample
Secret
objectapiVersion: v1 kind: Secret metadata: name: <component-secret> namespace: <component-namespace> data: service_account.json: <base64_encoded_gcp_service_account_file>
ImportantThe release image includes
CredentialsRequest
objects for Technology Preview features that are enabled by theTechPreviewNoUpgrade
feature set. You can identify these objects by their use of therelease.openshift.io/feature-set: TechPreviewNoUpgrade
annotation.- If you are not using any of these features, do not create secrets for these objects. Creating secrets for Technology Preview features that you are not using can cause the installation to fail.
- If you are using any of these features, you must create secrets for the corresponding objects.
To find
CredentialsRequest
objects with theTechPreviewNoUpgrade
annotation, run the following command:$ grep "release.openshift.io/feature-set" *
Example output
0000_30_capi-operator_00_credentials-request.yaml: release.openshift.io/feature-set: TechPreviewNoUpgrade
From the directory that contains the installation program, proceed with your cluster creation:
$ openshift-install create cluster --dir <installation_directory>
ImportantBefore upgrading a cluster that uses manually maintained credentials, you must ensure that the CCO is in an upgradeable state.
Additional resources
3.3. Mint mode
Mint mode is the default Cloud Credential Operator (CCO) credentials mode for OpenShift Container Platform on platforms that support it. In this mode, the CCO uses the provided administrator-level cloud credential to run the cluster. Mint mode is supported for AWS and GCP.
In mint mode, the admin
credential is stored in the kube-system
namespace and then used by the CCO to process the CredentialsRequest
objects in the cluster and create users for each with specific permissions.
The benefits of mint mode include:
- Each cluster component has only the permissions it requires
- Automatic, on-going reconciliation for cloud credentials, including additional credentials or permissions that might be required for upgrades
One drawback is that mint mode requires admin
credential storage in a cluster kube-system
secret.
3.4. Mint mode with removal or rotation of the administrator-level credential
Currently, this mode is only supported on AWS and GCP.
In this mode, a user installs OpenShift Container Platform with an administrator-level credential just like the normal mint mode. However, this process removes the administrator-level credential secret from the cluster post-installation.
The administrator can have the Cloud Credential Operator make its own request for a read-only credential that allows it to verify if all CredentialsRequest
objects have their required permissions, thus the administrator-level credential is not required unless something needs to be changed. After the associated credential is removed, it can be deleted or deactivated on the underlying cloud, if desired.
Prior to a non z-stream upgrade, you must reinstate the credential secret with the administrator-level credential. If the credential is not present, the upgrade might be blocked.
The administrator-level credential is not stored in the cluster permanently.
Following these steps still requires the administrator-level credential in the cluster for brief periods of time. It also requires manually re-instating the secret with administrator-level credentials for each upgrade.
3.5. Next steps
Install an OpenShift Container Platform cluster:
- Installing a cluster quickly on GCP with default options on installer-provisioned infrastructure
- Install a cluster with cloud customizations on installer-provisioned infrastructure
- Install a cluster with network customizations on installer-provisioned infrastructure