Chapter 3. Configuring the internal OAuth server 3.1. OpenShift Container Platform OAuth server The OpenShift Container Platform master includes a built-in OAuth server. Users obtain OAuth access tokens to authenticate themselves to the API. When a person requests a new OAuth token, the OAuth server uses the configured identity provider to determine the identity of the person making the request. It then determines what user that identity maps to, creates an access token for that user, and returns the token for use. 3.2. OAuth token request flows and responses The OAuth server supports standard authorization code grant and the implicit grant OAuth authorization flows. When requesting an OAuth token using the implicit grant flow ( response_type=token ) with a client_id configured to request WWW-Authenticate challenges (like openshift-challenging-client ), these are the possible server responses from /oauth/authorize , and how they should be handled: Status Content Client response 302 Location header containing an access_token parameter in the URL fragment ( RFC 6749 section 4.2.2 ) Use the access_token value as the OAuth token. 302 Location header containing an error query parameter ( RFC 6749 section 4.1.2.1 ) Fail, optionally surfacing the error (and optional error_description ) query values to the user. 302 Other Location header Follow the redirect, and process the result using these rules. 401 WWW-Authenticate header present Respond to challenge if type is recognized (e.g. Basic , Negotiate , etc), resubmit request, and process the result using these rules. 401 WWW-Authenticate header missing No challenge authentication is possible. Fail and show response body (which might contain links or details on alternate methods to obtain an OAuth token). Other Other Fail, optionally surfacing response body to the user. 3.3. Options for the internal OAuth server Several configuration options are available for the internal OAuth server. 3.3.1. OAuth token duration options The internal OAuth server generates two kinds of tokens: Token Description Access tokens Longer-lived tokens that grant access to the API. Authorize codes Short-lived tokens whose only use is to be exchanged for an access token. You can configure the default duration for both types of token. If necessary, you can override the duration of the access token by using an OAuthClient object definition. 3.3.2. OAuth grant options When the OAuth server receives token requests for a client to which the user has not previously granted permission, the action that the OAuth server takes is dependent on the OAuth client's grant strategy. The OAuth client requesting token must provide its own grant strategy. You can apply the following default methods: Grant option Description auto Auto-approve the grant and retry the request. prompt Prompt the user to approve or deny the grant. 3.4. Configuring the internal OAuth server's token duration You can configure default options for the internal OAuth server's token duration. Important By default, tokens are only valid for 24 hours. Existing sessions expire after this time elapses. If the default time is insufficient, then this can be modified using the following procedure. Procedure Create a configuration file that contains the token duration options. The following file sets this to 48 hours, twice the default. apiVersion: config.openshift.io/v1 kind: OAuth metadata: name: cluster spec: tokenConfig: accessTokenMaxAgeSeconds: 172800 1 1 Set accessTokenMaxAgeSeconds to control the lifetime of access tokens. The default lifetime is 24 hours, or 86400 seconds. This attribute cannot be negative. If set to zero, the default lifetime is used. Apply the new configuration file: Note Because you update the existing OAuth server, you must use the oc apply command to apply the change. USD oc apply -f </path/to/file.yaml> Confirm that the changes are in effect: USD oc describe oauth.config.openshift.io/cluster Example output ... Spec: Token Config: Access Token Max Age Seconds: 172800 ... 3.5. Configuring token inactivity timeout for the internal OAuth server You can configure OAuth tokens to expire after a set period of inactivity. By default, no token inactivity timeout is set. Note If the token inactivity timeout is also configured in your OAuth client, that value overrides the timeout that is set in the internal OAuth server configuration. Prerequisites You have access to the cluster as a user with the cluster-admin role. You have configured an identity provider (IDP). Procedure Update the OAuth configuration to set a token inactivity timeout. Edit the OAuth object: USD oc edit oauth cluster Add the spec.tokenConfig.accessTokenInactivityTimeout field and set your timeout value: apiVersion: config.openshift.io/v1 kind: OAuth metadata: ... spec: tokenConfig: accessTokenInactivityTimeout: 400s 1 1 Set a value with the appropriate units, for example 400s for 400 seconds, or 30m for 30 minutes. The minimum allowed timeout value is 300s . Save the file to apply the changes. Check that the OAuth server pods have restarted: USD oc get clusteroperators authentication Do not continue to the step until PROGRESSING is listed as False , as shown in the following output: Example output NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE authentication 4.18.0 True False False 145m Check that a new revision of the Kubernetes API server pods has rolled out. This will take several minutes. USD oc get clusteroperators kube-apiserver Do not continue to the step until PROGRESSING is listed as False , as shown in the following output: Example output NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE kube-apiserver 4.18.0 True False False 145m If PROGRESSING is showing True , wait a few minutes and try again. Verification Log in to the cluster with an identity from your IDP. Execute a command and verify that it was successful. Wait longer than the configured timeout without using the identity. In this procedure's example, wait longer than 400 seconds. Try to execute a command from the same identity's session. This command should fail because the token should have expired due to inactivity longer than the configured timeout. Example output error: You must be logged in to the server (Unauthorized) 3.6. Customizing the internal OAuth server URL You can customize the internal OAuth server URL by setting the custom hostname and TLS certificate in the spec.componentRoutes field of the cluster Ingress configuration. Warning If you update the internal OAuth server URL, you might break trust from components in the cluster that need to communicate with the OpenShift OAuth server to retrieve OAuth access tokens. Components that need to trust the OAuth server will need to include the proper CA bundle when calling OAuth endpoints. For example: USD oc login -u <username> -p <password> --certificate-authority=<path_to_ca.crt> 1 1 For self-signed certificates, the ca.crt file must contain the custom CA certificate, otherwise the login will not succeed. The Cluster Authentication Operator publishes the OAuth server's serving certificate in the oauth-serving-cert config map in the openshift-config-managed namespace. You can find the certificate in the data.ca-bundle.crt key of the config map. Prerequisites You have logged in to the cluster as a user with administrative privileges. You have created a secret in the openshift-config namespace containing the TLS certificate and key. This is required if the domain for the custom hostname suffix does not match the cluster domain suffix. The secret is optional if the suffix matches. Tip You can create a TLS secret by using the oc create secret tls command. Procedure Edit the cluster Ingress configuration: USD oc edit ingress.config.openshift.io cluster Set the custom hostname and optionally the serving certificate and key: apiVersion: config.openshift.io/v1 kind: Ingress metadata: name: cluster spec: componentRoutes: - name: oauth-openshift namespace: openshift-authentication hostname: <custom_hostname> 1 servingCertKeyPairSecret: name: <secret_name> 2 1 The custom hostname. 2 Reference to a secret in the openshift-config namespace that contains a TLS certificate ( tls.crt ) and key ( tls.key ). This is required if the domain for the custom hostname suffix does not match the cluster domain suffix. The secret is optional if the suffix matches. Save the file to apply the changes. 3.7. OAuth server metadata Applications running in OpenShift Container Platform might have to discover information about the built-in OAuth server. For example, they might have to discover what the address of the <namespace_route> is without manual configuration. To aid in this, OpenShift Container Platform implements the IETF OAuth 2.0 Authorization Server Metadata draft specification. Thus, any application running inside the cluster can issue a GET request to https://openshift.default.svc/.well-known/oauth-authorization-server to fetch the following information: 1 The authorization server's issuer identifier, which is a URL that uses the https scheme and has no query or fragment components. This is the location where .well-known RFC 5785 resources containing information about the authorization server are published. 2 URL of the authorization server's authorization endpoint. See RFC 6749 . 3 URL of the authorization server's token endpoint. See RFC 6749 . 4 JSON array containing a list of the OAuth 2.0 RFC 6749 scope values that this authorization server supports. Note that not all supported scope values are advertised. 5 JSON array containing a list of the OAuth 2.0 response_type values that this authorization server supports. The array values used are the same as those used with the response_types parameter defined by "OAuth 2.0 Dynamic Client Registration Protocol" in RFC 7591 . 6 JSON array containing a list of the OAuth 2.0 grant type values that this authorization server supports. The array values used are the same as those used with the grant_types parameter defined by OAuth 2.0 Dynamic Client Registration Protocol in RFC 7591 . 7 JSON array containing a list of PKCE RFC 7636 code challenge methods supported by this authorization server. Code challenge method values are used in the code_challenge_method parameter defined in Section 4.3 of RFC 7636 . The valid code challenge method values are those registered in the IANA PKCE Code Challenge Methods registry. See IANA OAuth Parameters . 3.8. Troubleshooting OAuth API events In some cases the API server returns an unexpected condition error message that is difficult to debug without direct access to the API master log. The underlying reason for the error is purposely obscured in order to avoid providing an unauthenticated user with information about the server's state. A subset of these errors is related to service account OAuth configuration issues. These issues are captured in events that can be viewed by non-administrator users. When encountering an unexpected condition server error during OAuth, run oc get events to view these events under ServiceAccount . The following example warns of a service account that is missing a proper OAuth redirect URI: USD oc get events | grep ServiceAccount Example output 1m 1m 1 proxy ServiceAccount Warning NoSAOAuthRedirectURIs service-account-oauth-client-getter system:serviceaccount:myproject:proxy has no redirectURIs; set serviceaccounts.openshift.io/oauth-redirecturi.<some-value>=<redirect> or create a dynamic URI using serviceaccounts.openshift.io/oauth-redirectreference.<some-value>=<reference> Running oc describe sa/<service_account_name> reports any OAuth events associated with the given service account name. USD oc describe sa/proxy | grep -A5 Events Example output Events: FirstSeen LastSeen Count From SubObjectPath Type Reason Message --------- -------- ----- ---- ------------- -------- ------ ------- 3m 3m 1 service-account-oauth-client-getter Warning NoSAOAuthRedirectURIs system:serviceaccount:myproject:proxy has no redirectURIs; set serviceaccounts.openshift.io/oauth-redirecturi.<some-value>=<redirect> or create a dynamic URI using serviceaccounts.openshift.io/oauth-redirectreference.<some-value>=<reference> The following is a list of the possible event errors: No redirect URI annotations or an invalid URI is specified Reason Message NoSAOAuthRedirectURIs system:serviceaccount:myproject:proxy has no redirectURIs; set serviceaccounts.openshift.io/oauth-redirecturi.<some-value>=<redirect> or create a dynamic URI using serviceaccounts.openshift.io/oauth-redirectreference.<some-value>=<reference> Invalid route specified Reason Message NoSAOAuthRedirectURIs [routes.route.openshift.io "<name>" not found, system:serviceaccount:myproject:proxy has no redirectURIs; set serviceaccounts.openshift.io/oauth-redirecturi.<some-value>=<redirect> or create a dynamic URI using serviceaccounts.openshift.io/oauth-redirectreference.<some-value>=<reference>] Invalid reference type specified Reason Message NoSAOAuthRedirectURIs [no kind "<name>" is registered for version "v1", system:serviceaccount:myproject:proxy has no redirectURIs; set serviceaccounts.openshift.io/oauth-redirecturi.<some-value>=<redirect> or create a dynamic URI using serviceaccounts.openshift.io/oauth-redirectreference.<some-value>=<reference>] Missing SA tokens Reason Message NoSAOAuthTokens system:serviceaccount:myproject:proxy has no tokens

Commands:
apiVersion: config.openshift.io/v1 kind: OAuth metadata: name: cluster spec: tokenConfig: accessTokenMaxAgeSeconds: 172800 1
oc apply -f </path/to/file.yaml>
oc describe oauth.config.openshift.io/cluster
Spec: Token Config: Access Token Max Age Seconds: 172800
oc edit oauth cluster
apiVersion: config.openshift.io/v1 kind: OAuth metadata: spec: tokenConfig: accessTokenInactivityTimeout: 400s 1
oc get clusteroperators authentication
NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE authentication 4.18.0 True False False 145m
oc get clusteroperators kube-apiserver
NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE kube-apiserver 4.18.0 True False False 145m
error: You must be logged in to the server (Unauthorized)
oc login -u <username> -p <password> --certificate-authority=<path_to_ca.crt> 1
oc edit ingress.config.openshift.io cluster
apiVersion: config.openshift.io/v1 kind: Ingress metadata: name: cluster spec: componentRoutes: - name: oauth-openshift namespace: openshift-authentication hostname: <custom_hostname> 1 servingCertKeyPairSecret: name: <secret_name> 2
{ "issuer": "https://<namespace_route>", 1 "authorization_endpoint": "https://<namespace_route>/oauth/authorize", 2 "token_endpoint": "https://<namespace_route>/oauth/token", 3 "scopes_supported": [ 4 "user:full", "user:info", "user:check-access", "user:list-scoped-projects", "user:list-projects" ], "response_types_supported": [ 5 "code", "token" ], "grant_types_supported": [ 6 "authorization_code", "implicit" ], "code_challenge_methods_supported": [ 7 "plain", "S256" ] }
oc get events | grep ServiceAccount
1m 1m 1 proxy ServiceAccount Warning NoSAOAuthRedirectURIs service-account-oauth-client-getter system:serviceaccount:myproject:proxy has no redirectURIs; set serviceaccounts.openshift.io/oauth-redirecturi.<some-value>=<redirect> or create a dynamic URI using serviceaccounts.openshift.io/oauth-redirectreference.<some-value>=<reference>
oc describe sa/proxy | grep -A5 Events
Events: FirstSeen LastSeen Count From SubObjectPath Type Reason Message --------- -------- ----- ---- ------------- -------- ------ ------- 3m 3m 1 service-account-oauth-client-getter Warning NoSAOAuthRedirectURIs system:serviceaccount:myproject:proxy has no redirectURIs; set serviceaccounts.openshift.io/oauth-redirecturi.<some-value>=<redirect> or create a dynamic URI using serviceaccounts.openshift.io/oauth-redirectreference.<some-value>=<reference>
Reason Message NoSAOAuthRedirectURIs system:serviceaccount:myproject:proxy has no redirectURIs; set serviceaccounts.openshift.io/oauth-redirecturi.<some-value>=<redirect> or create a dynamic URI using serviceaccounts.openshift.io/oauth-redirectreference.<some-value>=<reference>
Reason Message NoSAOAuthRedirectURIs [routes.route.openshift.io "<name>" not found, system:serviceaccount:myproject:proxy has no redirectURIs; set serviceaccounts.openshift.io/oauth-redirecturi.<some-value>=<redirect> or create a dynamic URI using serviceaccounts.openshift.io/oauth-redirectreference.<some-value>=<reference>]
Reason Message NoSAOAuthRedirectURIs [no kind "<name>" is registered for version "v1", system:serviceaccount:myproject:proxy has no redirectURIs; set serviceaccounts.openshift.io/oauth-redirecturi.<some-value>=<redirect> or create a dynamic URI using serviceaccounts.openshift.io/oauth-redirectreference.<some-value>=<reference>]
Reason Message NoSAOAuthTokens system:serviceaccount:myproject:proxy has no tokens