After installing OpenShift Container Platform, you can further expand and customize your cluster to your requirements, including taking steps to prepare for users.
The OpenShift Container Platform control plane includes a built-in OAuth server. Developers and administrators obtain OAuth access tokens to authenticate themselves to the API.
As an administrator, you can configure OAuth to specify an identity provider after you install your cluster.
By default, only a kubeadmin
user exists on your cluster. To specify an
identity provider, you must create a custom resource (CR) that describes
that identity provider and add it to the cluster.
OpenShift Container Platform user names containing |
You can configure the following types of identity providers:
Identity provider | Description |
---|---|
Configure the |
|
Configure the |
|
Configure the |
|
Configure a |
|
Configure a |
|
Configure a |
|
Configure a |
|
Configure a |
|
Configure an |
After you define an identity provider, you can use RBAC to define and apply permissions.
The following parameters are common to all identity providers:
Parameter | Description |
---|---|
|
The provider name is prefixed to provider user names to form an identity name. |
|
Defines how new identities are mapped to users when they log in. Enter one of the following values:
|
When adding or changing identity providers, you can map identities from the new
provider to existing users by setting the mappingMethod parameter to
add .
|
The following custom resource (CR) shows the parameters and default values that you use to configure an identity provider. This example uses the htpasswd identity provider.
apiVersion: config.openshift.io/v1
kind: OAuth
metadata:
name: cluster
spec:
identityProviders:
- name: my_identity_provider (1)
mappingMethod: claim (2)
type: HTPasswd
htpasswd:
fileData:
name: htpass-secret (3)
1 | This provider name is prefixed to provider user names to form an identity name. |
2 | Controls how mappings are established between this provider’s
identities and user objects. |
3 | An existing secret containing a file generated using
htpasswd . |
Understand and apply role-based access control.
Role-based access control (RBAC) objects determine whether a user is allowed to perform a given action within a project.
Cluster administrators can use the cluster roles and bindings to control who has various access levels to the OpenShift Container Platform platform itself and all projects.
Developers can use local roles and bindings to control who has access to their projects. Note that authorization is a separate step from authentication, which is more about determining the identity of who is taking the action.
Authorization is managed using:
Authorization object | Description |
---|---|
Rules |
Sets of permitted verbs on a set of objects. For example,
whether a user or service account can |
Roles |
Collections of rules. You can associate, or bind, users and groups to multiple roles. |
Bindings |
Associations between users and/or groups with a role. |
There are two levels of RBAC roles and bindings that control authorization:
RBAC level | Description |
---|---|
Cluster RBAC |
Roles and bindings that are applicable across all projects. Cluster roles exist cluster-wide, and cluster role bindings can reference only cluster roles. |
Local RBAC |
Roles and bindings that are scoped to a given project. While local roles exist only in a single project, local role bindings can reference both cluster and local roles. |
A cluster role binding is a binding that exists at the cluster level. A role binding exists at the project level. The cluster role view must be bound to a user using a local role binding for that user to view the project. Create local roles only if a cluster role does not provide the set of permissions needed for a particular situation.
This two-level hierarchy allows reuse across multiple projects through the cluster roles while allowing customization inside of individual projects through local roles.
During evaluation, both the cluster role bindings and the local role bindings are used. For example:
Cluster-wide "allow" rules are checked.
Locally-bound "allow" rules are checked.
Deny by default.
OpenShift Container Platform includes a set of default cluster roles that you can bind to users and groups cluster-wide or locally.
It is not recommended to manually modify the default cluster roles. Modifications to these system roles can prevent a cluster from functioning properly. |
Default cluster role | Description |
---|---|
|
A project manager. If used in a local binding, an |
|
A user that can get basic information about projects and users. |
|
A super-user that can perform any action in any project. When bound to a user with a local binding, they have full control over quota and every action on every resource in the project. |
|
A user that can get basic cluster status information. |
|
A user that can get or view most of the objects but cannot modify them. |
|
A user that can modify most objects in a project but does not have the power to view or modify roles or bindings. |
|
A user that can create their own projects. |
|
A user who cannot make any modifications, but can see most objects in a project. They cannot view or modify roles or bindings. |
Be mindful of the difference between local and cluster bindings. For example,
if you bind the cluster-admin
role to a user by using a local role binding,
it might appear that this user has the privileges of a cluster administrator.
This is not the case. Binding the cluster-admin
to a user in a project
grants super administrator privileges for only that
project to the user. That user has the permissions of the cluster role
admin
, plus a few additional permissions like the ability to edit rate limits,
for that project.
This binding can be confusing via the web console UI, which does not list
cluster role bindings that are bound to true cluster administrators. However, it
does list local role bindings that you can use to locally bind cluster-admin
.
The relationships between cluster roles, local roles, cluster role bindings, local role bindings, users, groups and service accounts are illustrated below.
OpenShift Container Platform evaluates authorization by using:
The user name and list of groups that the user belongs to.
The action you perform. In most cases, this consists of:
Project: The project you access. A project is a Kubernetes namespace with additional annotations that allows a community of users to organize and manage their content in isolation from other communities.
Verb : The action itself: get
, list
, create
, update
, delete
, deletecollection
, or watch
.
Resource name: The API endpoint that you access.
The full list of bindings, the associations between users or groups with a role.
OpenShift Container Platform evaluates authorization by using the following steps:
The identity and the project-scoped action is used to find all bindings that apply to the user or their groups.
Bindings are used to locate all the roles that apply.
Roles are used to find all the rules that apply.
The action is checked against each rule to find a match.
If no matching rule is found, the action is then denied by default.
Remember that users and groups can be associated with, or bound to, multiple roles at the same time. |
Project administrators can use the CLI to view local roles and bindings, including a matrix of the verbs and resources each are associated with.
The cluster role bound to the project administrator is limited in a project through a local binding. It is not bound cluster-wide like the cluster roles granted to the cluster-admin or system:admin. Cluster roles are roles defined at the cluster level but can be bound either at the cluster level or at the project level. |
The default admin, edit, view, and cluster-reader cluster roles support cluster role aggregation, where the cluster rules for each role are dynamically updated as new rules are created. This feature is relevant only if you extend the Kubernetes API by creating custom resources.
A Kubernetes namespace provides a mechanism to scope resources in a cluster. The Kubernetes documentation has more information on namespaces.
Namespaces provide a unique scope for:
Named resources to avoid basic naming collisions.
Delegated management authority to trusted users.
The ability to limit community resource consumption.
Most objects in the system are scoped by namespace, but some are excepted and have no namespace, including nodes and users.
A project is a Kubernetes namespace with additional annotations and is the central vehicle by which access to resources for regular users is managed. A project allows a community of users to organize and manage their content in isolation from other communities. users must be given access to projects by administrators, or if allowed to create projects, automatically have access to their own projects.
Projects can have a separate name
, displayName
, and description
.
The mandatory name
is a unique identifier for the project and is most visible when using the CLI tools or API. The maximum name length is 63 characters.
The optional displayName
is how the project is displayed in the web console (defaults to name
).
The optional description
can be a more detailed description of the project and is also visible in the web console.
Each project scopes its own set of:
Object | Description |
---|---|
|
Pods, services, replication controllers, etc. |
|
Rules for which users can or cannot perform actions on objects. |
|
Quotas for each kind of object that can be limited. |
|
Service accounts act automatically with designated access to objects in the project. |
Cluster administrators can create projects and delegate administrative rights for the project to any member of the user community. Cluster administrators can also allow developers to create their own projects.
Developers and administrators can interact with projects by using the CLI or the web console.
OpenShift Container Platform comes with a number of default projects, and projects
starting with openshift-
are the most essential to users.
These projects host master components that run as pods and other infrastructure
components. The pods created in these namespaces that have a
critical pod annotation
are considered critical, and the have guaranteed admission by kubelet.
Pods created for master components in these namespaces are already marked as
critical.
You cannot assign an SCC to pods created in one of the default namespaces: |
You can use the oc
CLI to view cluster roles and bindings by using the
oc describe
command.
Install the oc
CLI.
Obtain permission to view the cluster roles and bindings.
users with the cluster-admin
default cluster role bound cluster-wide can
perform any action on any resource, including viewing cluster roles and bindings.
To view the cluster roles and their associated rule sets:
$ oc describe clusterrole.rbac
Name: admin
Labels: kubernetes.io/bootstrapping=rbac-defaults
Annotations: rbac.authorization.kubernetes.io/autoupdate: true
PolicyRule:
Resources Non-Resource URLs Resource Names Verbs
--------- ----------------- -------------- -----
.packages.apps.redhat.com [] [] [* create update patch delete get list watch]
imagestreams [] [] [create delete deletecollection get list patch update watch create get list watch]
imagestreams.image.openshift.io [] [] [create delete deletecollection get list patch update watch create get list watch]
secrets [] [] [create delete deletecollection get list patch update watch get list watch create delete deletecollection patch update]
buildconfigs/webhooks [] [] [create delete deletecollection get list patch update watch get list watch]
buildconfigs [] [] [create delete deletecollection get list patch update watch get list watch]
buildlogs [] [] [create delete deletecollection get list patch update watch get list watch]
deploymentconfigs/scale [] [] [create delete deletecollection get list patch update watch get list watch]
deploymentconfigs [] [] [create delete deletecollection get list patch update watch get list watch]
imagestreamimages [] [] [create delete deletecollection get list patch update watch get list watch]
imagestreammappings [] [] [create delete deletecollection get list patch update watch get list watch]
imagestreamtags [] [] [create delete deletecollection get list patch update watch get list watch]
processedtemplates [] [] [create delete deletecollection get list patch update watch get list watch]
routes [] [] [create delete deletecollection get list patch update watch get list watch]
templateconfigs [] [] [create delete deletecollection get list patch update watch get list watch]
templateinstances [] [] [create delete deletecollection get list patch update watch get list watch]
templates [] [] [create delete deletecollection get list patch update watch get list watch]
deploymentconfigs.apps.openshift.io/scale [] [] [create delete deletecollection get list patch update watch get list watch]
deploymentconfigs.apps.openshift.io [] [] [create delete deletecollection get list patch update watch get list watch]
buildconfigs.build.openshift.io/webhooks [] [] [create delete deletecollection get list patch update watch get list watch]
buildconfigs.build.openshift.io [] [] [create delete deletecollection get list patch update watch get list watch]
buildlogs.build.openshift.io [] [] [create delete deletecollection get list patch update watch get list watch]
imagestreamimages.image.openshift.io [] [] [create delete deletecollection get list patch update watch get list watch]
imagestreammappings.image.openshift.io [] [] [create delete deletecollection get list patch update watch get list watch]
imagestreamtags.image.openshift.io [] [] [create delete deletecollection get list patch update watch get list watch]
routes.route.openshift.io [] [] [create delete deletecollection get list patch update watch get list watch]
processedtemplates.template.openshift.io [] [] [create delete deletecollection get list patch update watch get list watch]
templateconfigs.template.openshift.io [] [] [create delete deletecollection get list patch update watch get list watch]
templateinstances.template.openshift.io [] [] [create delete deletecollection get list patch update watch get list watch]
templates.template.openshift.io [] [] [create delete deletecollection get list patch update watch get list watch]
serviceaccounts [] [] [create delete deletecollection get list patch update watch impersonate create delete deletecollection patch update get list watch]
imagestreams/secrets [] [] [create delete deletecollection get list patch update watch]
rolebindings [] [] [create delete deletecollection get list patch update watch]
roles [] [] [create delete deletecollection get list patch update watch]
rolebindings.authorization.openshift.io [] [] [create delete deletecollection get list patch update watch]
roles.authorization.openshift.io [] [] [create delete deletecollection get list patch update watch]
imagestreams.image.openshift.io/secrets [] [] [create delete deletecollection get list patch update watch]
rolebindings.rbac.authorization.k8s.io [] [] [create delete deletecollection get list patch update watch]
roles.rbac.authorization.k8s.io [] [] [create delete deletecollection get list patch update watch]
networkpolicies.extensions [] [] [create delete deletecollection patch update create delete deletecollection get list patch update watch get list watch]
networkpolicies.networking.k8s.io [] [] [create delete deletecollection patch update create delete deletecollection get list patch update watch get list watch]
configmaps [] [] [create delete deletecollection patch update get list watch]
endpoints [] [] [create delete deletecollection patch update get list watch]
persistentvolumeclaims [] [] [create delete deletecollection patch update get list watch]
pods [] [] [create delete deletecollection patch update get list watch]
replicationcontrollers/scale [] [] [create delete deletecollection patch update get list watch]
replicationcontrollers [] [] [create delete deletecollection patch update get list watch]
services [] [] [create delete deletecollection patch update get list watch]
daemonsets.apps [] [] [create delete deletecollection patch update get list watch]
deployments.apps/scale [] [] [create delete deletecollection patch update get list watch]
deployments.apps [] [] [create delete deletecollection patch update get list watch]
replicasets.apps/scale [] [] [create delete deletecollection patch update get list watch]
replicasets.apps [] [] [create delete deletecollection patch update get list watch]
statefulsets.apps/scale [] [] [create delete deletecollection patch update get list watch]
statefulsets.apps [] [] [create delete deletecollection patch update get list watch]
horizontalpodautoscalers.autoscaling [] [] [create delete deletecollection patch update get list watch]
cronjobs.batch [] [] [create delete deletecollection patch update get list watch]
jobs.batch [] [] [create delete deletecollection patch update get list watch]
daemonsets.extensions [] [] [create delete deletecollection patch update get list watch]
deployments.extensions/scale [] [] [create delete deletecollection patch update get list watch]
deployments.extensions [] [] [create delete deletecollection patch update get list watch]
ingresses.extensions [] [] [create delete deletecollection patch update get list watch]
replicasets.extensions/scale [] [] [create delete deletecollection patch update get list watch]
replicasets.extensions [] [] [create delete deletecollection patch update get list watch]
replicationcontrollers.extensions/scale [] [] [create delete deletecollection patch update get list watch]
poddisruptionbudgets.policy [] [] [create delete deletecollection patch update get list watch]
deployments.apps/rollback [] [] [create delete deletecollection patch update]
deployments.extensions/rollback [] [] [create delete deletecollection patch update]
catalogsources.operators.coreos.com [] [] [create update patch delete get list watch]
clusterserviceversions.operators.coreos.com [] [] [create update patch delete get list watch]
installplans.operators.coreos.com [] [] [create update patch delete get list watch]
packagemanifests.operators.coreos.com [] [] [create update patch delete get list watch]
subscriptions.operators.coreos.com [] [] [create update patch delete get list watch]
buildconfigs/instantiate [] [] [create]
buildconfigs/instantiatebinary [] [] [create]
builds/clone [] [] [create]
deploymentconfigrollbacks [] [] [create]
deploymentconfigs/instantiate [] [] [create]
deploymentconfigs/rollback [] [] [create]
imagestreamimports [] [] [create]
localresourceaccessreviews [] [] [create]
localsubjectaccessreviews [] [] [create]
podsecuritypolicyreviews [] [] [create]
podsecuritypolicyselfsubjectreviews [] [] [create]
podsecuritypolicysubjectreviews [] [] [create]
resourceaccessreviews [] [] [create]
routes/custom-host [] [] [create]
subjectaccessreviews [] [] [create]
subjectrulesreviews [] [] [create]
deploymentconfigrollbacks.apps.openshift.io [] [] [create]
deploymentconfigs.apps.openshift.io/instantiate [] [] [create]
deploymentconfigs.apps.openshift.io/rollback [] [] [create]
localsubjectaccessreviews.authorization.k8s.io [] [] [create]
localresourceaccessreviews.authorization.openshift.io [] [] [create]
localsubjectaccessreviews.authorization.openshift.io [] [] [create]
resourceaccessreviews.authorization.openshift.io [] [] [create]
subjectaccessreviews.authorization.openshift.io [] [] [create]
subjectrulesreviews.authorization.openshift.io [] [] [create]
buildconfigs.build.openshift.io/instantiate [] [] [create]
buildconfigs.build.openshift.io/instantiatebinary [] [] [create]
builds.build.openshift.io/clone [] [] [create]
imagestreamimports.image.openshift.io [] [] [create]
routes.route.openshift.io/custom-host [] [] [create]
podsecuritypolicyreviews.security.openshift.io [] [] [create]
podsecuritypolicyselfsubjectreviews.security.openshift.io [] [] [create]
podsecuritypolicysubjectreviews.security.openshift.io [] [] [create]
jenkins.build.openshift.io [] [] [edit view view admin edit view]
builds [] [] [get create delete deletecollection get list patch update watch get list watch]
builds.build.openshift.io [] [] [get create delete deletecollection get list patch update watch get list watch]
projects [] [] [get delete get delete get patch update]
projects.project.openshift.io [] [] [get delete get delete get patch update]
namespaces [] [] [get get list watch]
pods/attach [] [] [get list watch create delete deletecollection patch update]
pods/exec [] [] [get list watch create delete deletecollection patch update]
pods/portforward [] [] [get list watch create delete deletecollection patch update]
pods/proxy [] [] [get list watch create delete deletecollection patch update]
services/proxy [] [] [get list watch create delete deletecollection patch update]
routes/status [] [] [get list watch update]
routes.route.openshift.io/status [] [] [get list watch update]
appliedclusterresourcequotas [] [] [get list watch]
bindings [] [] [get list watch]
builds/log [] [] [get list watch]
deploymentconfigs/log [] [] [get list watch]
deploymentconfigs/status [] [] [get list watch]
events [] [] [get list watch]
imagestreams/status [] [] [get list watch]
limitranges [] [] [get list watch]
namespaces/status [] [] [get list watch]
pods/log [] [] [get list watch]
pods/status [] [] [get list watch]
replicationcontrollers/status [] [] [get list watch]
resourcequotas/status [] [] [get list watch]
resourcequotas [] [] [get list watch]
resourcequotausages [] [] [get list watch]
rolebindingrestrictions [] [] [get list watch]
deploymentconfigs.apps.openshift.io/log [] [] [get list watch]
deploymentconfigs.apps.openshift.io/status [] [] [get list watch]
controllerrevisions.apps [] [] [get list watch]
rolebindingrestrictions.authorization.openshift.io [] [] [get list watch]
builds.build.openshift.io/log [] [] [get list watch]
imagestreams.image.openshift.io/status [] [] [get list watch]
appliedclusterresourcequotas.quota.openshift.io [] [] [get list watch]
imagestreams/layers [] [] [get update get]
imagestreams.image.openshift.io/layers [] [] [get update get]
builds/details [] [] [update]
builds.build.openshift.io/details [] [] [update]
Name: basic-user
Labels: <none>
Annotations: openshift.io/description: A user that can get basic information about projects.
rbac.authorization.kubernetes.io/autoupdate: true
PolicyRule:
Resources Non-Resource URLs Resource Names Verbs
--------- ----------------- -------------- -----
selfsubjectrulesreviews [] [] [create]
selfsubjectaccessreviews.authorization.k8s.io [] [] [create]
selfsubjectrulesreviews.authorization.openshift.io [] [] [create]
clusterroles.rbac.authorization.k8s.io [] [] [get list watch]
clusterroles [] [] [get list]
clusterroles.authorization.openshift.io [] [] [get list]
storageclasses.storage.k8s.io [] [] [get list]
users [] [~] [get]
users.user.openshift.io [] [~] [get]
projects [] [] [list watch]
projects.project.openshift.io [] [] [list watch]
projectrequests [] [] [list]
projectrequests.project.openshift.io [] [] [list]
Name: cluster-admin
Labels: kubernetes.io/bootstrapping=rbac-defaults
Annotations: rbac.authorization.kubernetes.io/autoupdate: true
PolicyRule:
Resources Non-Resource URLs Resource Names Verbs
--------- ----------------- -------------- -----
*.* [] [] [*]
[*] [] [*]
...
To view the current set of cluster role bindings, which shows the users and groups that are bound to various roles:
$ oc describe clusterrolebinding.rbac
Name: alertmanager-main
Labels: <none>
Annotations: <none>
Role:
Kind: ClusterRole
Name: alertmanager-main
Subjects:
Kind Name Namespace
---- ---- ---------
ServiceAccount alertmanager-main openshift-monitoring
Name: basic-users
Labels: <none>
Annotations: rbac.authorization.kubernetes.io/autoupdate: true
Role:
Kind: ClusterRole
Name: basic-user
Subjects:
Kind Name Namespace
---- ---- ---------
Group system:authenticated
Name: cloud-credential-operator-rolebinding
Labels: <none>
Annotations: <none>
Role:
Kind: ClusterRole
Name: cloud-credential-operator-role
Subjects:
Kind Name Namespace
---- ---- ---------
ServiceAccount default openshift-cloud-credential-operator
Name: cluster-admin
Labels: kubernetes.io/bootstrapping=rbac-defaults
Annotations: rbac.authorization.kubernetes.io/autoupdate: true
Role:
Kind: ClusterRole
Name: cluster-admin
Subjects:
Kind Name Namespace
---- ---- ---------
Group system:masters
Name: cluster-admins
Labels: <none>
Annotations: rbac.authorization.kubernetes.io/autoupdate: true
Role:
Kind: ClusterRole
Name: cluster-admin
Subjects:
Kind Name Namespace
---- ---- ---------
Group system:cluster-admins
user system:admin
Name: cluster-api-manager-rolebinding
Labels: <none>
Annotations: <none>
Role:
Kind: ClusterRole
Name: cluster-api-manager-role
Subjects:
Kind Name Namespace
---- ---- ---------
ServiceAccount default openshift-machine-api
...
You can use the oc
CLI to view local roles and bindings by using the
oc describe
command.
Install the oc
CLI.
Obtain permission to view the local roles and bindings:
users with the cluster-admin
default cluster role bound cluster-wide can
perform any action on any resource, including viewing local roles and bindings.
users with the admin
default cluster role bound locally can view and manage
roles and bindings in that project.
To view the current set of local role bindings, which show the users and groups that are bound to various roles for the current project:
$ oc describe rolebinding.rbac
To view the local role bindings for a different project, add the -n
flag
to the command:
$ oc describe rolebinding.rbac -n joe-project
Name: admin
Labels: <none>
Annotations: <none>
Role:
Kind: ClusterRole
Name: admin
Subjects:
Kind Name Namespace
---- ---- ---------
user kube:admin
Name: system:deployers
Labels: <none>
Annotations: openshift.io/description:
Allows deploymentconfigs in this namespace to rollout pods in
this namespace. It is auto-managed by a controller; remove
subjects to disa...
Role:
Kind: ClusterRole
Name: system:deployer
Subjects:
Kind Name Namespace
---- ---- ---------
ServiceAccount deployer joe-project
Name: system:image-builders
Labels: <none>
Annotations: openshift.io/description:
Allows builds in this namespace to push images to this
namespace. It is auto-managed by a controller; remove subjects
to disable.
Role:
Kind: ClusterRole
Name: system:image-builder
Subjects:
Kind Name Namespace
---- ---- ---------
ServiceAccount builder joe-project
Name: system:image-pullers
Labels: <none>
Annotations: openshift.io/description:
Allows all pods in this namespace to pull images from this
namespace. It is auto-managed by a controller; remove subjects
to disable.
Role:
Kind: ClusterRole
Name: system:image-puller
Subjects:
Kind Name Namespace
---- ---- ---------
Group system:serviceaccounts:joe-project
You can use the oc adm
administrator CLI to manage the roles and bindings.
Binding, or adding, a role to users or groups gives the user or group the access
that is granted by the role. You can add and remove roles to and from users and
groups using oc adm policy
commands.
You can bind any of the default cluster roles to local users or groups in your project.
Add a role to a user in a specific project:
$ oc adm policy add-role-to-user <role> <user> -n <project>
For example, you can add the admin
role to the alice
user in joe
project
by running:
$ oc adm policy add-role-to-user admin alice -n joe
You can alternatively apply the following YAML to add the role to the user:
|
View the local role bindings and verify the addition in the output:
$ oc describe rolebinding.rbac -n <project>
For example, to view the local role bindings for the joe
project:
$ oc describe rolebinding.rbac -n joe
Name: admin
Labels: <none>
Annotations: <none>
Role:
Kind: ClusterRole
Name: admin
Subjects:
Kind Name Namespace
---- ---- ---------
user kube:admin
Name: admin-0
Labels: <none>
Annotations: <none>
Role:
Kind: ClusterRole
Name: admin
Subjects:
Kind Name Namespace
---- ---- ---------
user alice (1)
Name: system:deployers
Labels: <none>
Annotations: openshift.io/description:
Allows deploymentconfigs in this namespace to rollout pods in
this namespace. It is auto-managed by a controller; remove
subjects to disa...
Role:
Kind: ClusterRole
Name: system:deployer
Subjects:
Kind Name Namespace
---- ---- ---------
ServiceAccount deployer joe
Name: system:image-builders
Labels: <none>
Annotations: openshift.io/description:
Allows builds in this namespace to push images to this
namespace. It is auto-managed by a controller; remove subjects
to disable.
Role:
Kind: ClusterRole
Name: system:image-builder
Subjects:
Kind Name Namespace
---- ---- ---------
ServiceAccount builder joe
Name: system:image-pullers
Labels: <none>
Annotations: openshift.io/description:
Allows all pods in this namespace to pull images from this
namespace. It is auto-managed by a controller; remove subjects
to disable.
Role:
Kind: ClusterRole
Name: system:image-puller
Subjects:
Kind Name Namespace
---- ---- ---------
Group system:serviceaccounts:joe
1 | The alice user has been added to the admins RoleBinding . |
You can create a local role for a project and then bind it to a user.
To create a local role for a project, run the following command:
$ oc create role <name> --verb=<verb> --resource=<resource> -n <project>
In this command, specify:
<name>
, the local role’s name
<verb>
, a comma-separated list of the verbs to apply to the role
<resource>
, the resources that the role applies to
<project>
, the project name
For example, to create a local role that allows a user to view pods in the
blue
project, run the following command:
$ oc create role podview --verb=get --resource=pod -n blue
To bind the new role to a user, run the following command:
$ oc adm policy add-role-to-user podview user2 --role-namespace=blue -n blue
You can create a cluster role.
To create a cluster role, run the following command:
$ oc create clusterrole <name> --verb=<verb> --resource=<resource>
In this command, specify:
<name>
, the local role’s name
<verb>
, a comma-separated list of the verbs to apply to the role
<resource>
, the resources that the role applies to
For example, to create a cluster role that allows a user to view pods, run the following command:
$ oc create clusterrole podviewonly --verb=get --resource=pod
When you manage a user or group’s associated roles for local role bindings using the
following operations, a project may be specified with the -n
flag. If it is
not specified, then the current project is used.
You can use the following commands for local RBAC management.
Command | Description |
---|---|
|
Indicates which users can perform an action on a resource. |
|
Binds a specified role to specified users in the current project. |
|
Removes a given role from specified users in the current project. |
|
Removes specified users and all of their roles in the current project. |
|
Binds a given role to specified groups in the current project. |
|
Removes a given role from specified groups in the current project. |
|
Removes specified groups and all of their roles in the current project. |
You can also manage cluster role bindings using the following
operations. The -n
flag is not used for these operations because
cluster role bindings use non-namespaced resources.
Command | Description |
---|---|
|
Binds a given role to specified users for all projects in the cluster. |
|
Removes a given role from specified users for all projects in the cluster. |
|
Binds a given role to specified groups for all projects in the cluster. |
|
Removes a given role from specified groups for all projects in the cluster. |
The cluster-admin
role is required to perform administrator
level tasks on the OpenShift Container Platform cluster, such as modifying
cluster resources.
You must have created a user to define as the cluster admin.
Define the user as a cluster admin:
$ oc adm policy add-cluster-role-to-user cluster-admin <user>
OpenShift Container Platform creates a cluster administrator, kubeadmin
, after the
installation process completes.
This user has the cluster-admin
role automatically applied and is treated
as the root user for the cluster. The password is dynamically generated
and unique to your OpenShift Container Platform environment. After installation
completes the password is provided in the installation program’s output.
For example:
INFO Install complete!
INFO Run 'export KUBECONFIG=<your working directory>/auth/kubeconfig' to manage the cluster with 'oc', the OpenShift CLI.
INFO The cluster is ready when 'oc login -u kubeadmin -p <provided>' succeeds (wait a few minutes).
INFO Access the OpenShift web-console here: https://console-openshift-console.apps.demo1.openshift4-beta-abcorp.com
INFO Login to the console with user: kubeadmin, password: <provided>
After you define an identity provider and create a new cluster-admin
user, you can remove the kubeadmin
to improve cluster security.
If you follow this procedure before another user is a |
You must have configured at least one identity provider.
You must have added the cluster-admin
role to a user.
You must be logged in as an administrator.
Remove the kubeadmin
secrets:
$ oc delete secrets kubeadmin -n kube-system
Understand and configure image registry settings.
The image.config.openshift.io/cluster
resource holds cluster-wide information about how to handle images. The canonical, and only valid name is cluster
. Its spec
offers the following configuration parameters.
Parameters such as |
Parameter | Description |
---|---|
|
Limits the container image registries from which normal users can import images. Set this list to the registries that you trust to contain valid images, and that you want applications to be able to import from. users with permission to create images or Every element of this list contains a location of the registry specified by the registry domain name.
|
|
A reference to a config map containing additional CAs that should be trusted during The namespace for this config map is |
|
Provides the hostnames for the default external image registry. The external hostname should be set only when the image registry is exposed externally. The first value is used in |
|
Contains configuration that determines how the container runtime should treat individual registries when accessing images for builds and pods. For instance, whether or not to allow insecure access. It does not contain configuration for the internal cluster registry.
Either |
When the |
The status
field of the image.config.openshift.io/cluster
resource holds observed values from the cluster.
Parameter | Description |
---|---|
|
Set by the Image Registry Operator, which controls the |
|
Set by the Image Registry Operator, provides the external hostnames for the image registry when it is exposed externally. The first value is used in |
You can configure image registry settings by editing the image.config.openshift.io/cluster
custom resource (CR). The Machine Config Operator (MCO) watches the image.config.openshift.io/cluster
CR for any changes to the registries and reboots the nodes when it detects changes.
Edit the image.config.openshift.io/cluster
custom resource:
$ oc edit image.config.openshift.io/cluster
The following is an example image.config.openshift.io/cluster
CR:
apiVersion: config.openshift.io/v1
kind: Image (1)
metadata:
annotations:
release.openshift.io/create-only: "true"
creationTimestamp: "2019-05-17T13:44:26Z"
generation: 1
name: cluster
resourceVersion: "8302"
selfLink: /apis/config.openshift.io/v1/images/cluster
uid: e34555da-78a9-11e9-b92b-06d6c7da38dc
spec:
allowedRegistriesForImport: (2)
- domainName: quay.io
insecure: false
additionalTrustedCA: (3)
name: myconfigmap
registrySources: (4)
allowedRegistries:
- example.com
- quay.io
- registry.redhat.io
- image-registry.openshift-image-registry.svc:5000
- reg1.io/myrepo/myapp:latest
insecureRegistries:
- insecure.com
status:
internalRegistryHostname: image-registry.openshift-image-registry.svc:5000
1 | Image : Holds cluster-wide information about how to handle images. The canonical, and only valid name is cluster . |
2 | allowedRegistriesForImport : Limits the container image registries from which normal users may import images. Set this list to the registries that you trust to contain valid images, and that you want applications to be able to import from. users with permission to create images or ImageStreamMappings from the API are not affected by this policy. Typically only cluster administrators have the appropriate permissions. |
3 | additionalTrustedCA : A reference to a config map containing additional certificate authorities (CA) that are trusted during image stream import, pod image pull, openshift-image-registry pullthrough, and builds. The namespace for this config map is openshift-config . The format of the config map is to use the registry hostname as the key, and the PEM certificate as the value, for each additional registry CA to trust. |
4 | registrySources : Contains configuration that determines whether the container runtime allows or blocks individual registries when accessing images for builds and pods. Either the allowedRegistries parameter or the blockedRegistries parameter can be set, but not both. You can also define whether or not to allow access to insecure registries or registries that allow registries that use image short names. This example uses the allowedRegistries parameter, which defines the registries that are allowed to be used. The insecure registry insecure.com is also allowed. The registrySources paramter does not contain configuration for the internal cluster registry. |
When the When using the Insecure external registries should be avoided to reduce possible security risks. |
To check that the changes are applied, list your nodes:
$ oc get nodes
NAME STATUS ROLES AGE VERSION
ci-ln-j5cd0qt-f76d1-vfj5x-master-0 Ready master 98m v1.19.0+7070803
ci-ln-j5cd0qt-f76d1-vfj5x-master-1 Ready,SchedulingDisabled master 99m v1.19.0+7070803
ci-ln-j5cd0qt-f76d1-vfj5x-master-2 Ready master 98m v1.19.0+7070803
ci-ln-j5cd0qt-f76d1-vfj5x-worker-b-nsnd4 Ready worker 90m v1.19.0+7070803
ci-ln-j5cd0qt-f76d1-vfj5x-worker-c-5z2gz NotReady,SchedulingDisabled worker 90m v1.19.0+7070803
ci-ln-j5cd0qt-f76d1-vfj5x-worker-d-stsjv Ready worker 90m v1.19.0+7070803
For more information on the allowed, blocked, and insecure registry parameters, see Configuring image registry settings.
The image.config.openshift.io/cluster
custom resource can contain a reference to a config map that contains additional certificate authorities to be trusted during image registry access.
The certificate authorities (CA) must be PEM-encoded.
You can create a config map in the openshift-config
namespace and use its name in AdditionalTrustedCA
in the image.config.openshift.io
custom resource to provide additional CAs that should be trusted when contacting external registries.
The config map key is the hostname of a registry with the port for which this CA is to be trusted, and the base64-encoded certificate is the value, for each additional registry CA to trust.
apiVersion: v1
kind: ConfigMap
metadata:
name: my-registry-ca
data:
registry.example.com: |
-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----
registry-with-port.example.com..5000: | (1)
-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----
1 | If the registry has the port, such as registry-with-port.example.com:5000 , : should be replaced with .. . |
You can configure additional CAs with the following procedure.
To configure an additional CA:
$ oc create configmap registry-config --from-file=<external_registry_address>=ca.crt -n openshift-config
$ oc edit image.config.openshift.io cluster
spec:
additionalTrustedCA:
name: registry-config
Setting up container registry repository mirroring enables you to do the following:
Configure your OpenShift Container Platform cluster to redirect requests to pull images from a repository on a source image registry and have it resolved by a repository on a mirrored image registry.
Identify multiple mirrored repositories for each target repository, to make sure that if one mirror is down, another can be used.
The attributes of repository mirroring in OpenShift Container Platform include:
Image pulls are resilient to registry downtimes.
Clusters in disconnected environments can pull images from critical locations, such as quay.io, and have registries behind a company firewall provide the requested images.
A particular order of registries is tried when an image pull request is made, with the permanent registry typically being the last one tried.
The mirror information you enter is added to the /etc/containers/registries.conf
file on every node in the OpenShift Container Platform cluster.
When a node makes a request for an image from the source repository, it tries each mirrored repository in turn until it finds the requested content. If all mirrors fail, the cluster tries the source repository. If successful, the image is pulled to the node.
Setting up repository mirroring can be done in the following ways:
At OpenShift Container Platform installation:
By pulling container images needed by OpenShift Container Platform and then bringing those images behind your company’s firewall, you can install OpenShift Container Platform into a datacenter that is in a disconnected environment.
After OpenShift Container Platform installation:
Even if you don’t configure mirroring during OpenShift Container Platform installation, you can do so later using the ImageContentSourcePolicy
object.
The following procedure provides a post-installation mirror configuration, where you create an ImageContentSourcePolicy
object that identifies:
The source of the container image repository you want to mirror.
A separate entry for each mirror repository you want to offer the content requested from the source repository.
You can only configure global pull secrets for clusters that have an |
Access to the cluster as a user with the cluster-admin
role.
Configure mirrored repositories, by either:
Setting up a mirrored repository with Red Hat Quay, as described in Red Hat Quay Repository Mirroring. Using Red Hat Quay allows you to copy images from one repository to another and also automatically sync those repositories repeatedly over time.
Using a tool such as skopeo
to copy images manually from the source directory to the mirrored repository.
For example, after installing the skopeo RPM package on a Red Hat Enterprise Linux (RHEL) 7 or RHEL 8 system, use the skopeo
command as shown in this example:
$ skopeo copy \
docker://registry.access.redhat.com/ubi8/ubi-minimal@sha256:5cfbaf45ca96806917830c183e9f37df2e913b187adb32e89fd83fa455ebaa6 \
docker://example.io/example/ubi-minimal
In this example, you have a container image registry that is named example.io
with an image repository named example
to which you want to copy the ubi8/ubi-minimal
image from registry.access.redhat.com
. After you create the registry, you can configure your OpenShift Container Platform cluster to redirect requests made of the source repository to the mirrored repository.
Log in to your OpenShift Container Platform cluster.
Create an ImageContentSourcePolicy
file (for example, registryrepomirror.yaml
), replacing the source and mirrors with your own registry and repository pairs and images:
apiVersion: operator.openshift.io/v1alpha1
kind: ImageContentSourcePolicy
metadata:
name: ubi8repo
spec:
repositoryDigestMirrors:
- mirrors:
- example.io/example/ubi-minimal (1)
source: registry.access.redhat.com/ubi8/ubi-minimal (2)
- mirrors:
- example.com/example/ubi-minimal
source: registry.access.redhat.com/ubi8/ubi-minimal
- mirrors:
- mirror.example.com/redhat
source: registry.redhat.io/openshift4 (3)
1 | Indicates the name of the image registry and repository. |
2 | Indicates the registry and repository containing the content that is mirrored. |
3 | You can configure a namespace inside a registry to use any image in that namespace. If you use a registry domain as a source, the ImageContentSourcePolicy resource is applied to all repositories from the registry. |
Create the new ImageContentSourcePolicy
object:
$ oc create -f registryrepomirror.yaml
After the ImageContentSourcePolicy
object is created, the new settings are deployed to each node and the cluster starts using the mirrored repository for requests to the source repository.
To check that the mirrored configuration settings, are applied, do the following on one of the nodes.
List your nodes:
$ oc get node
NAME STATUS ROLES AGE VERSION
ip-10-0-137-44.ec2.internal Ready worker 7m v1.21.0
ip-10-0-138-148.ec2.internal Ready master 11m v1.21.0
ip-10-0-139-122.ec2.internal Ready master 11m v1.21.0
ip-10-0-147-35.ec2.internal Ready,SchedulingDisabled worker 7m v1.21.0
ip-10-0-153-12.ec2.internal Ready worker 7m v1.21.0
ip-10-0-154-10.ec2.internal Ready master 11m v1.21.0
You can see that scheduling on each worker node is disabled as the change is being applied.
Start the debugging process to access the node:
$ oc debug node/ip-10-0-147-35.ec2.internal
Starting pod/ip-10-0-147-35ec2internal-debug ...
To use host binaries, run `chroot /host`
Change your root directory to /host
:
sh-4.2# chroot /host
Check the /etc/containers/registries.conf
file to make sure
the changes were made:
sh-4.2# cat /etc/containers/registries.conf
unqualified-search-registries = ["registry.access.redhat.com", "docker.io"]
[[registry]]
location = "registry.access.redhat.com/ubi8/"
insecure = false
blocked = false
mirror-by-digest-only = true
prefix = ""
[[registry.mirror]]
location = "example.io/example/ubi8-minimal"
insecure = false
[[registry.mirror]]
location = "example.com/example/ubi8-minimal"
insecure = false
Pull an image digest to the node from the source and check if it is resolved by the mirror. ImageContentSourcePolicy
objects support image digests only, not image tags.
sh-4.2# podman pull --log-level=debug registry.access.redhat.com/ubi8/ubi-minimal@sha256:5cfbaf45ca96806917830c183e9f37df2e913b187adb32e89fd83fa455ebaa6
If the repository mirroring procedure does not work as described, use the following information about how repository mirroring works to help troubleshoot the problem.
The first working mirror is used to supply the pulled image.
The main registry is only used if no other mirror works.
From the system context, the Insecure
flags are used as fallback.
The format of the /etc/containers/registries.conf
file has changed recently. It is now version 2 and in TOML format.
OperatorHub is a user interface for discovering Operators; it works in conjunction with Operator Lifecycle Manager (OLM), which installs and manages Operators on a cluster.
As a cluster administrator, you can install an Operator from OperatorHub using the OpenShift Container Platform web console or CLI. Subscribing an Operator to one or more namespaces makes the Operator available to developers on your cluster.
During installation, you must determine the following initial settings for the Operator:
Choose All namespaces on the cluster (default) to have the Operator installed on all namespaces or choose individual namespaces, if available, to only install the Operator on selected namespaces. This example chooses All namespaces… to make the Operator available to all users and projects.
If an Operator is available through multiple channels, you can choose which channel you want to subscribe to. For example, to deploy from the stable channel, if available, select it from the list.
You can choose automatic or manual updates.
If you choose automatic updates for an installed Operator, when a new version of that Operator is available in the selected channel, Operator Lifecycle Manager (OLM) automatically upgrades the running instance of your Operator without human intervention.
If you select manual updates, when a newer version of an Operator is available, OLM creates an update request. As a cluster administrator, you must then manually approve that update request to have the Operator updated to the new version.
You can install and subscribe to an Operator from OperatorHub using the OpenShift Container Platform web console.
Access to an OpenShift Container Platform cluster using an account with
cluster-admin
permissions.
Navigate in the web console to the Operators → OperatorHub page.
Scroll or type a keyword into the Filter by keyword box to find the Operator you want. For example, type jaeger
to find the Jaeger Operator.
You can also filter options by Infrastructure Features. For example, select Disconnected if you want to see Operators that work in disconnected environments, also known as restricted network environments.
Select the Operator to display additional information.
Choosing a Community Operator warns that Red Hat does not certify Community Operators; you must acknowledge the warning before continuing. |
Read the information about the Operator and click Install.
On the Install Operator page:
Select one of the following:
All namespaces on the cluster (default) installs the Operator in the default openshift-operators
namespace to watch and be made available to all namespaces in the cluster. This option is not always available.
A specific namespace on the cluster allows you to choose a specific, single namespace in which to install the Operator. The Operator will only watch and be made available for use in this single namespace.
Select an Update Channel (if more than one is available).
Select Automatic or Manual approval strategy, as described earlier.
Click Install to make the Operator available to the selected namespaces on this OpenShift Container Platform cluster.
If you selected a Manual approval strategy, the upgrade status of the subscription remains Upgrading until you review and approve the 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.
After the upgrade status of the subscription is Up to date, select Operators → Installed Operators to verify that the cluster service version (CSV) of the installed Operator eventually shows up. The Status should ultimately resolve to InstallSucceeded in the relevant namespace.
For the All namespaces… installation mode, the status resolves to InstallSucceeded in the |
If it does not:
Check the logs in any pods in the openshift-operators
project (or other relevant namespace if A specific namespace… installation mode was selected) on the Workloads → Pods page that are reporting issues to troubleshoot further.
Instead of using the OpenShift Container Platform web console, you can install an Operator from OperatorHub using the CLI. Use the oc
command to create or update a Subscription
object.
Access to an OpenShift Container Platform cluster using an account with
cluster-admin
permissions.
Install the oc
command to your local system.
View the list of Operators available to the cluster from OperatorHub:
$ oc get packagemanifests -n openshift-marketplace
NAME CATALOG AGE
3scale-operator Red Hat Operators 91m
advanced-cluster-management Red Hat Operators 91m
amq7-cert-manager Red Hat Operators 91m
...
couchbase-enterprise-certified Certified Operators 91m
crunchy-postgres-operator Certified Operators 91m
mongodb-enterprise Certified Operators 91m
...
etcd Community Operators 91m
jaeger Community Operators 91m
kubefed Community Operators 91m
...
Note the catalog for your desired Operator.
Inspect your desired Operator to verify its supported install modes and available channels:
$ oc describe packagemanifests <operator_name> -n openshift-marketplace
An Operator group, defined by an OperatorGroup
object, selects target namespaces in which to generate required RBAC access for all Operators in the same namespace as the Operator group.
The namespace to which you subscribe the Operator must have an Operator group that matches the install mode of the Operator, either the AllNamespaces
or SingleNamespace
mode. If the Operator you intend to install uses the AllNamespaces
, then the openshift-operators
namespace already has an appropriate Operator group in place.
However, if the Operator uses the SingleNamespace
mode and you do not already have an appropriate Operator group in place, you must create one.
The web console version of this procedure handles the creation of the |
Create an OperatorGroup
object YAML file, for example operatorgroup.yaml
:
OperatorGroup
objectapiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
name: <operatorgroup_name>
namespace: <namespace>
spec:
targetNamespaces:
- <namespace>
Create the OperatorGroup
object:
$ oc apply -f operatorgroup.yaml
Create a Subscription
object YAML file to subscribe a namespace to an Operator, for example sub.yaml
:
Subscription
objectapiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
name: <subscription_name>
namespace: openshift-operators (1)
spec:
channel: <channel_name> (2)
name: <operator_name> (3)
source: redhat-operators (4)
sourceNamespace: openshift-marketplace (5)
config:
env: (6)
- name: ARGS
value: "-v=10"
envFrom: (7)
- secretRef:
name: license-secret
volumes: (8)
- name: <volume_name>
configMap:
name: <configmap_name>
volumeMounts: (9)
- mountPath: <directory_name>
name: <volume_name>
tolerations: (10)
- operator: "Exists"
resources: (11)
requests:
memory: "64Mi"
cpu: "250m"
limits:
memory: "128Mi"
cpu: "500m"
nodeSelector: (12)
foo: bar
1 | For AllNamespaces install mode usage, specify the openshift-operators namespace. Otherwise, specify the relevant single namespace for SingleNamespace install mode usage. |
2 | Name of the channel to subscribe to. |
3 | Name of the Operator to subscribe to. |
4 | Name of the catalog source that provides the Operator. |
5 | Namespace of the catalog source. Use openshift-marketplace for the default OperatorHub catalog sources. |
6 | The env parameter defines a list of Environment Variables that must exist in all containers in the pod created by OLM. |
7 | The envFrom parameter defines a list of sources to populate Environment Variables in the container. |
8 | The volumes parameter defines a list of Volumes that must exist on the pod created by OLM. |
9 | The volumeMounts parameter defines a list of VolumeMounts that must exist in all containers in the pod created by OLM. If a volumeMount references a volume that does not exist, OLM fails to deploy the Operator. |
10 | The tolerations parameter defines a list of Tolerations for the pod created by OLM. |
11 | The resources parameter defines resource constraints for all the containers in the pod created by OLM. |
12 | The nodeSelector parameter defines a NodeSelector for the pod created by OLM. |
Create the Subscription
object:
$ oc apply -f sub.yaml
At this point, OLM is now aware of the selected Operator. A cluster service version (CSV) for the Operator should appear in the target namespace, and APIs provided by the Operator should be available for creation.