See xref:../../admin_guide/custom_resource_definitions.adoc#admin-guide-custom-resources[Extend the Kubernetes API with Custom Resources].
A limit range provides a mechanism to enforce min/max limits placed on resources in a Kubernetes namespace.
By adding a limit range to your namespace, you can enforce the minimum and maximum amount of CPU and Memory consumed by an individual pod or container.
For CPU and Memory limits, if you specify a max
value, but do not specify a
min
limit in the LimitRange object, the resource can consume CPU/memory
resources greater than max
value`.
Kubernetes can limit both the number of objects created in a namespace, and the total amount of resources requested across objects in a namespace. This facilitates sharing of a single Kubernetes cluster by several teams, each in a namespace, as a mechanism of preventing one team from starving another team of cluster resources.
See Cluster Administrationfor more information on ResourceQuota
.
A Kubernetes Resource
is something that can be requested by, allocated to,
or consumed by a pod or container. Examples include memory (RAM), CPU,
disk-time, and network bandwidth.
See the Developer Guidefor more information.
Secrets are storage for sensitive information, such as keys, passwords, and certificates. They are accessible by the intended pod(s), but held separately from their definitions.
A persistent volume is an object
(PersistentVolume
) in the infrastructure provisioned by the cluster
administrator. Persistent volumes provide durable storage for stateful
applications.
A PersistentVolumeClaim
object is a
request for storage by a pod
author. Kubernetes matches the claim against the pool of available volumes and
binds them together. The claim is then used as a volume by a pod. Kubernetes
makes sure the volume is available on the same node as the pod that requires it.
A custom resource is an extension of the Kubernetes API that extends the API or allows you to introduce your own API into a project or a cluster.
See xref:../../admin_guide/custom_resource_definitions.adoc#admin-guide-custom-resources[Extend the Kubernetes API with Custom Resources].
An OAuthClient
represents an OAuth client, as described in
RFC 6749, section 2.
The following OAuthClient
objects are automatically created:
openshift-web-console
|
Client used to request tokens for the web console |
openshift-browser-client
|
Client used to request tokens at /oauth/token/request with a user-agent that can handle interactive logins |
openshift-challenging-client
|
Client used to request tokens with a user-agent that can handle WWW-Authenticate challenges |
OAuthClient
Object Definitionkind: "OAuthClient"
accessTokenMaxAgeSeconds: null (1)
apiVersion: "oauth.openshift.io/v1"
metadata:
name: "openshift-web-console" (2)
selflink: "/oapi/v1/oAuthClients/openshift-web-console"
resourceVersion: "1"
creationTimestamp: "2015-01-01T01:01:01Z"
respondWithChallenges: false (3)
secret: "45e27750-a8aa-11e4-b2ea-3c970e4b7ffe" (4)
redirectURIs:
- "https://localhost:8443" (5)
1 | The lifetime of access tokens in seconds (see the description below). |
2 | The name is used as the client_id parameter in OAuth requests. |
3 | When respondWithChallenges is set to true , unauthenticated requests to
/oauth/authorize will result in WWW-Authenticate challenges, if supported by
the configured authentication methods. |
4 | The value in the secret parameter is used as the client_secret parameter
in an authorization code flow. |
5 | One or more absolute URIs can be placed in the redirectURIs section. The
redirect_uri parameter sent with authorization requests must be prefixed by
one of the specified redirectURIs . |
The accessTokenMaxAgeSeconds
value overrides the default accessTokenMaxAgeSeconds
value in the master configuration file
for individual OAuth clients. Setting this value for a client allows long-lived access tokens for that client
without affecting the lifetime of other clients.
If null
, the default value in the master configuration file is used.
If set to 0
, the token will not expire.
If set to a value greater than 0
, tokens issued for that client are given the specified expiration time. For example, accessTokenMaxAgeSeconds: 172800
would cause the token to expire 48 hours after being issued.
An OAuthClientAuthorization
represents an approval by a user
for a
particular OAuthClient
to be given an OAuthAccessToken
with particular
scopes.
Creation of OAuthClientAuthorization
objects is done during an
authorization request to the OAuth
server.
OAuthClientAuthorization
Object Definitionkind: "OAuthClientAuthorization"
apiVersion: "oauth.openshift.io/v1"
metadata:
name: "bob:openshift-web-console"
resourceVersion: "1"
creationTimestamp: "2015-01-01T01:01:01-00:00"
clientName: "openshift-web-console"
userName: "bob"
userUID: "9311ac33-0fde-11e5-97a1-3c970e4b7ffe"
scopes: []
An OAuthAuthorizeToken
represents an OAuth
authorization code, as
described in RFC 6749, section
1.3.1.
An OAuthAuthorizeToken
is created by a request to the /oauth/authorize endpoint,
as described in RFC 6749,
section 4.1.1.
An OAuthAuthorizeToken
can then be used to obtain an OAuthAccessToken
with a request to the /oauth/token endpoint, as described in
RFC 6749, section 4.1.3.
OAuthAuthorizeToken
Object Definitionkind: "OAuthAuthorizeToken"
apiVersion: "oauth.openshift.io/v1"
metadata:
name: "MDAwYjM5YjMtMzM1MC00NDY4LTkxODItOTA2OTE2YzE0M2Fj" (1)
resourceVersion: "1"
creationTimestamp: "2015-01-01T01:01:01-00:00"
clientName: "openshift-web-console" (2)
expiresIn: 300 (3)
scopes: []
redirectURI: "https://localhost:8443/console/oauth" (4)
userName: "bob" (5)
userUID: "9311ac33-0fde-11e5-97a1-3c970e4b7ffe" (6)
1 | name represents the token name, used as an authorization code to exchange
for an OAuthAccessToken. |
2 | The clientName value is the OAuthClient that requested this token. |
3 | The expiresIn value is the expiration in seconds from the
creationTimestamp. |
4 | The redirectURI value is the location where the user was redirected to
during the authorization flow that resulted in this token. |
5 | userName represents the name of the user this token allows obtaining an
OAuthAccessToken for. |
6 | userUID represents the UID of the user this token allows obtaining an
OAuthAccessToken for. |
An OAuthAccessToken
represents an OAuth
access token, as described in
RFC 6749, section 1.4.
An OAuthAccessToken
is created by a request to the /oauth/token endpoint,
as described in RFC 6749,
section 4.1.3.
Access tokens are used as bearer tokens to authenticate to the API.
OAuthAccessToken
Object Definitionkind: "OAuthAccessToken"
apiVersion: "oauth.openshift.io/v1"
metadata:
name: "ODliOGE5ZmMtYzczYi00Nzk1LTg4MGEtNzQyZmUxZmUwY2Vh" (1)
resourceVersion: "1"
creationTimestamp: "2015-01-01T01:01:02-00:00"
clientName: "openshift-web-console" (2)
expiresIn: 86400 (3)
scopes: []
redirectURI: "https://localhost:8443/console/oauth" (4)
userName: "bob" (5)
userUID: "9311ac33-0fde-11e5-97a1-3c970e4b7ffe" (6)
authorizeToken: "MDAwYjM5YjMtMzM1MC00NDY4LTkxODItOTA2OTE2YzE0M2Fj" (7)
1 | name is the token name, which is used as a bearer token to authenticate to
the API. |
2 | The clientName value is the OAuthClient that requested this token. |
3 | The expiresIn value is the expiration in seconds from the
creationTimestamp. |
4 | The redirectURI is where the user was redirected to during the
authorization flow that resulted in this token. |
5 | userName represents the user this token allows authentication as. |
6 | userUID represents the user this token allows authentication as. |
7 | authorizeToken is the name of the OAuthAuthorizationToken used to obtain
this token, if any. |
When a user logs into OpenShift Container Platform, they do so using a configured identity provider. This determines the user’s identity, and provides that information to OpenShift Container Platform.
OpenShift Container Platform then looks for a userIdentityMapping
for that Identity
:
If the identity provider is configured with the |
If the Identity
already exists, but is not mapped to a user
, login
fails.
If the Identity
already exists, and is mapped to a user
, the user is
given an OAuthAccessToken
for the mapped user
.
If the Identity
does not exist, an Identity
, user
, and
userIdentityMapping
are created, and the user is given an
OAuthAccessToken
for the mapped user
.
Identity
Object Definitionkind: "Identity"
apiVersion: "user.openshift.io/v1"
metadata:
name: "anypassword:bob" (1)
uid: "9316ebad-0fde-11e5-97a1-3c970e4b7ffe"
resourceVersion: "1"
creationTimestamp: "2015-01-01T01:01:01-00:00"
providerName: "anypassword" (2)
provideruserName: "bob" (3)
user:
name: "bob" (4)
uid: "9311ac33-0fde-11e5-97a1-3c970e4b7ffe" (5)
1 | The identity name must be in the form providerName:provideruserName. |
2 | providerName is the name of the identity provider. |
3 | provideruserName is the name that uniquely represents this identity in the scope of the identity provider. |
4 | The name in the user parameter is the name of the user this identity maps to. |
5 | The uid represents the UID of the user this identity maps to. |
A user
represents an actor in the system. users are granted permissions by
adding
roles to users or to their groups.
user objects are created automatically on first login, or can be created via the API.
OpenShift Container Platform user names containing |
user
Object Definitionkind: "user"
apiVersion: "user.openshift.io/v1"
metadata:
name: "bob" (1)
uid: "9311ac33-0fde-11e5-97a1-3c970e4b7ffe"
resourceVersion: "1"
creationTimestamp: "2015-01-01T01:01:01-00:00"
identities:
- "anypassword:bob" (2)
fullName: "Bob user" (3)
1 | name is the user name used when adding roles to a user. |
2 | The values in identities are Identity objects that map to this user. May be null or empty for users that cannot log in. |
3 | The fullName value is an optional display name of user. |
A userIdentityMapping
maps an Identity
to a user
.
Creating, updating, or deleting a userIdentityMapping
modifies the
corresponding fields in the Identity
and user
objects.
An Identity
can only map to a single user
, so logging in as a particular
identity unambiguously determines the user
.
A user
can have multiple identities mapped to it. This allows multiple login
methods to identify the same user
.
userIdentityMapping
Object Definitionkind: "userIdentityMapping"
apiVersion: "user.openshift.io/v1"
metadata:
name: "anypassword:bob" (1)
uid: "9316ebad-0fde-11e5-97a1-3c970e4b7ffe"
resourceVersion: "1"
identity:
name: "anypassword:bob"
uid: "9316ebad-0fde-11e5-97a1-3c970e4b7ffe"
user:
name: "bob"
uid: "9311ac33-0fde-11e5-97a1-3c970e4b7ffe"
1 | userIdentityMapping name matches the mapped Identity name |
A Group
represents a list of users in the system. Groups are granted permissions by
adding
roles to users or to their groups.
Group
Object Definitionkind: "Group"
apiVersion: "user.openshift.io/v1"
metadata:
name: "developers" (1)
creationTimestamp: "2015-01-01T01:01:01-00:00"
users:
- "bob" (2)
1 | name is the group name used when adding roles to a group. |
2 | The values in users are the names of user objects that are members of this group. |