Set up OIDC Auth Applications

The oidc-auth-apps application is a system application that enables the use of a remote Windows Active Directory server or an LDAP server to authenticate users of the Kubernetes API.

In this document, the LDAP server presented is the one present in the StarlingX deploy, called Local LDAP server. This LDAP server runs in the controllers except for DC environments, where it runs only in the SystemController’s controllers.

The oidc-auth-apps is packaged in the ISO and uploaded by default.

Configure OIDC Auth Applications

Prerequisites

• You must have configured the Kubernetes kube-apiserver to use the oidc-auth-apps OIDC identity provider for validation of tokens in Kubernetes API requests, which use OIDC authentication. For more information on configuring the Kubernetes kube-apiserver, see Configure Kubernetes for OIDC Token Validation while Bootstrapping the System or Configure Kubernetes for OIDC Token Validation after Bootstrapping the System.

Procedure

1. Create certificates using one of the following options.

   1. Create certificates using cert-manager (recommended):

      Certificates used by oidc-auth-apps can be managed by Cert-Manager. Doing so will automatically renew the certificates before they expire. The system-local-ca ClusterIssuer (see System Local CA Issuer) will be used to issue this certificate.

      Note

      If a signing CA is not a well-known trusted CA, you must ensure the system trusts the CA by specifying it either during the bootstrap phase of system installation, by specifying ssl_ca_cert: <certificate_file> in the ansible bootstrap overrides localhost.yml file, or by using the system certificate-install -m ssl_ca <certificate_file> command.

      Also refer to Add a Trusted CA for installing a root CA, which includes instruction to lock/unlock controller nodes when using system certificate-install command.

      Important

      The namespace for oidc-auth-apps must be kube-system.

      1. Create the OIDC client and identity provider server certificate and private key pair.

         ~(keystone_admin)]$ cat <<EOF > oidc-auth-apps-certificate.yaml
         ---
         apiVersion: cert-manager.io/v1
         kind: Certificate
         metadata:
           name: oidc-auth-apps-certificate
           namespace: kube-system
         spec:
           secretName: oidc-auth-apps-certificate
           duration: 2160h # 90 days
           renewBefore: 360h # 15 days
           issuerRef:
             name: system-local-ca
             kind: ClusterIssuer
           commonName: <OAM_floating_IP_address>
           subject:
             organizations:
               - ABC-Company
             organizationalUnits:
               - StarlingX-system-oidc-auth-apps
           ipAddresses:
           - <OAM_floating_IP_address>
         
         EOF
         

         Note

         The Certificate usage of Cert-manager Documentation (https://cert-manager.io/docs/usage/certificate/) states that one should “Take care when setting the renewBefore field to be very close to the duration as this can lead to a renewal loop, where the Certificate is always in the renewal period.”

         In the light of the statement above, you must not set renewBefore to a value very close to the “duration” value, such as a renewBefore of 29 days and a duration of 30 days. Instead, you could set values such as renewBefore=15 days and duration=30 days to avoid renewal loops.

      2. Apply the configuration.

         ~(keystone_admin)]$ kubectl apply -f oidc-auth-apps-certificate.yaml
         

      3. Verify the configuration.

         ~(keystone_admin)]$ kubectl get certificate oidc-auth-apps-certificate –n kube-system
         

      4. Configure the OIDC-client with both the OIDC Client and Identity Server Certificate and the OIDC Client and Identity Trusted CA certificate.

         Create a secret with the certificate of the root CA that signed the OIDC client and identity provider’s server certificate. In this example, it will be the ca.crt of the system-local-ca (ClusterIssuer).

         ~(keystone_admin)]$ mkdir /home/sysadmin/ssl
         ~(keystone_admin)]$ kubectl get secret system-local-ca -n cert-manager -o=jsonpath='{.data.ca\.crt}' | base64 --decode > /home/sysadmin/ssl/dex-ca-cert.crt
         
         ~(keystone_admin)]$ kubectl create secret generic dex-ca-cert --from-file=/home/sysadmin/ssl/dex-ca-cert.crt  -n kube-system
         
         ~(keystone_admin)]$ cat <<EOF > stx-oidc-client.yaml
         tlsName: oidc-auth-apps-certificate
         config:
            # The OIDC-client container mounts the dex-ca-cert secret at /home, therefore
            # issuer_root_ca: /home/<filename-only-of-generic-secret>
            issuer_root_ca: /home/dex-ca-cert.crt
            issuer_root_ca_secret: dex-ca-cert
         EOF
         
         ~(keystone_admin)]$ system helm-override-update oidc-auth-apps oidc-client kube-system --values stx-oidc-client.yaml
         

      5. Create a secret with the certificate of the CA that signed the certificate of the Identity Providers (IdPs) that you will be using.

         If you will use a WAD server, create the secret wad-ca-cert with the CA’s certificate that signed the Active Directory’s certificate using the command below.

         ~(keystone_admin)]$ kubectl create secret generic wad-ca-cert --from-file=wad-ca-cert.crt -n kube-system
         

         If you will use the Local LDAP server, create the secret local-ldap-ca-cert with the CA’s certificate that signed the Local LDAP’s certificate using the command below. This CA’s certificate, presented below as file local-ldap-ca-cert.crt, can be extracted from the controller where the Local LDAP server is running (the SystemController in DC environments) using the command kubectl get secret system-local-ca -n cert-manager -o=jsonpath='{.data.ca\.crt}' | base64 --decode > local-ldap-ca-cert.crt.

         ~(keystone_admin)]$ kubectl create secret generic local-ldap-ca-cert --from-file=local-ldap-ca-cert.crt -n kube-system
         

         The secrets wad-ca-cert and/or local-ldap-ca-cert will be used later in the application overrides.

      6. Configure the secret observer to track changes.

         Change the cronSchedule according to your needs. The cronSchedule controls how often the application checks to see if the certificate mounted on the dex and oidc-client pods had changed.

         Create a YAML configuration to modify the cronSchedule according to your needs.

         The cronSchedule controls how often the application checks to see if the certificate mounted on the dex and oidc-client pods changed. The following example sets the schedule to every 15 minutes.

         ~(keystone_admin)]$ cat <<EOF > secret-observer-overrides.yaml
         cronSchedule: "*/15 * * * *"
         observedSecrets:
           - secretName: "dex-ca-cert"
             filename: "dex-ca-cert.crt"
             deploymentToRestart: "stx-oidc-client"
           - secretName: "oidc-auth-apps-certificate"
             filename: "tls.crt"
             deploymentToRestart: "stx-oidc-client"
           - secretName: "oidc-auth-apps-certificate"
             filename: "tls.crt"
             deploymentToRestart: "oidc-dex"
         EOF
         

      Execute the following command to update the overrides:

      ~(keystone_admin)]$ system helm-override-update oidc-auth-apps secret-observer kube-system --values secret-observer-overrides.yaml
      

   2. Use certificates generated and signed by an external CA.

      Although it is recommended to use cert-manager to manage certificates, as described above in item “Create certificates using cert-manager (recommended)”, one can instead use certificates generated by an external CA.

      For backwards compatibility reasons, the default helm chart overrides of dex, oidc-client and secret-observer in oidc-auth-apps application are set for this example of using externally generated certificates. The default override values of helm charts in oidc-auth-apps application include the use of kubernetes secrets named local-dex.tls, and dex-client-secret for declaring the dex server certificate and the CA which signed it, respectively. These secrets are created in this example.

      In addition, one can indicate the certificates for a WAD server and/or a Local LDAP server that have https enabled by using the secrets wad-ca-cert and/or local-ldap-ca-cert as in this example.

      Prerequisites

      • You must have a CA signed certificate (dex-cert.pem file), and private key (dex-key.pem file) for the dex OIDC Identity Provider of oidc-auth-apps.

        This certificate must have the StarlingX’s floating OAM IP Address in the SAN list. If you are planning on defining and using a DNS name for the StarlingX’s floating OAM IP Address, then this DNS name must also be in the SAN list. Refer to the documentation for the external CA that you are using, in order to create a signed certificate and key.

        If you are using an intermediate CA to sign the dex certificate, include both the dex certificate (signed by the intermediate CA), and the intermediate CA’s certificate (signed by the Root CA) in that order, in dex-cert.pem.

      • You must have the certificate of the CA (dex-ca.pem file) that signed the above certificate for the dex OIDC Identity Provider of oidc-auth-apps.

        If an intermediate CA was used to sign the dex certificate and both the dex certificate and the intermediate CA certificate was included in dex-cert.pem, then the dex-ca.pem file should contain the root CA’s certificate.

        If the signing CA (dex-ca.pem) is not a well-known trusted CA, you must ensure the system trusts the CA by specifying it either during the bootstrap phase of system installation, by specifying ssl_ca_cert: dex-ca.pem in the ansible bootstrap overrides localhost.yml file, or by using the system certificate-install -m ssl_ca dex-ca.pem command.

        Also refer to Add a Trusted CA for installing a root CA, which includes instruction to lock/unlock controller nodes when using system certificate-install command.

      • Create the secret, local-dex.tls, with the certificate and key, to be used by the oidc-auth-apps, as well as the secret, dex-client-secret, with the CA’s certificate that signed the local-dex.tls certificate.

        For example, assuming the cert and key pem files for creating these secrets are in /home/sysadmin/ssl/, run the following commands to create the secrets:

        Note

        oidc-auth-apps looks specifically for secrets of these names in the kube-system namespace.

        For the generic secret dex-client-secret, the filename must be dex-ca.pem.

        ~(keystone_admin)]$ kubectl create secret tls local-dex.tls --cert=ssl/dex-cert.pem --key=ssl/dex-key.pem -n kube-system
        
        ~(keystone_admin)]$ kubectl create secret generic dex-client-secret --from-file=/home/sysadmin/ssl/dex-ca.pem -n kube-system
        

        If you will use a WAD server, create the secret wad-ca-cert with the CA’s certificate that signed the Active Directory’s certificate using the command below.

        ~(keystone_admin)]$ kubectl create secret generic wad-ca-cert --from-file=wad-ca-cert.crt -n kube-system
        

        If you will use the Local LDAP server, create the secret local-ldap-ca-cert with the CA’s certificate that signed the Local LDAP’s certificate using the command below. This CA’s certificate, presented below as file local-ldap-ca-cert.crt, can be extracted from the controller where the Local LDAP server is running (the SystemController in DC environments) using the command kubectl get secret system-local-ca -n cert-manager -o=jsonpath='{.data.ca\.crt}' | base64 --decode > local-ldap-ca-cert.crt.

        ~(keystone_admin)]$ kubectl create secret generic local-ldap-ca-cert --from-file=local-ldap-ca-cert.crt -n kube-system
        

2. Specify user overrides for oidc-auth-apps application, by using the following command:

   ~(keystone_admin)]$ system helm-override-update oidc-auth-apps dex kube-system --values /home/sysadmin/dex-overrides.yaml
   

   The dex-overrides.yaml file contains the desired dex helm chart overrides (that is, the LDAP connector configuration for the Active Directory service, optional token expiry, and so on), and volume mounts for providing access to the wad-ca-cert secret and/or to the local-ldap-ca-cert, described in this section.

   For the complete list of dex helm chart values supported, see Dex Helm Chart Values. For the complete list of parameters of the dex LDAP connector configuration, see Authentication Through LDAP.

   The overall Dex documentation is available on dexidp.io. The configuration of dex server version v2.37.0 is described on github (https://github.com/dexidp/dex/blob/v2.37.0/config.yaml.dist) with example config.dev.yaml (https://github.com/dexidp/dex/blob/v2.37.0/config.dev.yaml).

   The examples below configure a token expiry of ten hours, the LDAP connectors to the remote servers using HTTPS (LDAPS) using the servers CA secrets, the required remote servers login information (that is, bindDN, and bindPW), and example userSearch, and groupSearch clauses.

   (Optional) There is a default secret in the dex configuration for staticClients. You can change this using helm overrides. For example, to change the secret, first run the following command to see the default settings. In this example, 10.10.10.2 is the StarlingX OAM floating IP address.

   ~(keystone_admin)]$ system helm-override-show oidc-auth-apps dex kube-system
   
   config:
     staticClients:
     - id: stx-oidc-client-app
       name: STX OIDC Client app
       redirectURIs: ['https://10.10.10.2:30555/callback']
       secret: St8rlingX
   

   Change the secret from the output and copy the entire configuration section shown above in to your dex overrides file shown in the example below.

   Warning

   Do not forget to include the id, name, and redirectURIs parameters.

   Note

   There is an internal password (called secret in dex overrides and client_secret in oidc-client overrides) that is used between the oidc-client container and the dex container. It is recommended that you configure a unique, more secure password by specifying the value in the dex overrides file, as shown in the example below.

   For only a WAD server, the configuration is shown below.

   config:
     staticClients:
     - id: stx-oidc-client-app
       name: STX OIDC Client app
       redirectURIs: ['https://<OAM floating IP address>:30555/callback']
       secret: BetterSecret
     expiry:
       idTokens: "10h"
     connectors:
     - type: ldap
       name: WAD
       id: wad-1
       config:
         host: pv-windows-acti.windows-activedir.example.com:636
         rootCA: /etc/ssl/certs/adcert/wad-ca-cert.crt
         insecureNoSSL: false
         insecureSkipVerify: false
         bindDN: cn=Administrator,cn=Users,dc=windows-activedir,dc=example,dc=com
         bindPW: [<password>]
         usernamePrompt: Username
         userSearch:
           baseDN: ou=Users,ou=Titanium,dc=windows-activedir,dc=example,dc=com
           filter: "(objectClass=user)"
           username: sAMAccountName
           idAttr: sAMAccountName
           emailAttr: sAMAccountName
           nameAttr: displayName
         groupSearch:
           baseDN: ou=Groups,ou=Titanium,dc=windows-activedir,dc=example,dc=com
           filter: "(objectClass=group)"
           userMatchers:
           - userAttr: DN
             groupAttr: member
           nameAttr: cn
   volumeMounts:
   - mountPath: /etc/ssl/certs/adcert
     name: certdir
   - mountPath: /etc/dex/tls
     name: https-tls
   volumes:
   - name: certdir
     secret:
       secretName: wad-ca-cert
   - name: https-tls
     secret:
       defaultMode: 420
       secretName: oidc-auth-apps-certificate
   

   For only the Local LDAP server, the configuration is shown below. The value of bindPW can be retrieved through command keyring get ldap ldapadmin executed in the controller where the Local LDAP server is running. In DC environments, the MGMT floating IP address to be used is the one from the SystemController.

   config:
     staticClients:
     - id: stx-oidc-client-app
       name: STX OIDC Client app
       redirectURIs: ['https://<OAM floating IP address>:30555/callback']
       secret: BetterSecret
     expiry:
       idTokens: "10h"
     connectors:
     - type: ldap
       name: LocalLDAP
       id: localldap-1
       config:
         host: <MGMT floating IP address>:636
         rootCA: /etc/ssl/certs/adcert/local-ldap-ca-cert.crt
         insecureNoSSL: false
         insecureSkipVerify: false
         bindDN: CN=ldapadmin,DC=cgcs,DC=local
         bindPW: [<password>]
         usernamePrompt: Username
         userSearch:
           baseDN: ou=People,dc=cgcs,dc=local
           filter: "(objectClass=posixAccount)"
           username: uid
           idAttr: DN
           emailAttr: uid
           nameAttr: gecos
         groupSearch:
           baseDN: ou=Group,dc=cgcs,dc=local
           filter: "(objectClass=posixGroup)"
           userMatchers:
           - userAttr: uid
             groupAttr: memberUid
           nameAttr: cn
   volumeMounts:
   - mountPath: /etc/ssl/certs/adcert
     name: certdir
   - mountPath: /etc/dex/tls
     name: https-tls
   volumes:
   - name: certdir
     secret:
       secretName: local-ldap-ca-cert
   - name: https-tls
     secret:
       defaultMode: 420
       secretName: oidc-auth-apps-certificate
   

   If both WAD and Local LDAP servers are used at same time, use the examples above with the connectors from WAD and Local LDAP in the same connectors list while the volumes to be used is the one written below.

   volumes:
   - name: certdir
     projected:
       sources:
       - secret:
           name: wad-ca-cert
       - secret:
           name: local-ldap-ca-cert
   - name: https-tls
     secret:
       defaultMode: 420
       secretName: oidc-auth-apps-certificate
   

   If more than one Windows Active Directory service is required for authenticating the different users of the StarlingX, multiple ldap type connectors can be configured; one for each Windows Active Directory service.

   If more than one userSearch plus groupSearch clauses are required for the same Windows Active Directory service, multiple ldap type connectors, with the same host information but different userSearch plus groupSearch clauses, should be used.

   Whenever you use multiple ldap type connectors, ensure you use unique name: and id: parameters for each connector.

3. An override in the secrets in the dex helm chart must be accompanied by an override in the oidc-client helm chart.

   The following override is sufficient for changing the secret in the /home/sysadmin/oidc-client-overrides.yaml file.

   config:
     client_secret: BetterSecret
   

   Apply the oidc-client overrides using the following command:

   ~(keystone_admin)]$ system helm-override-update oidc-auth-apps oidc-client kube-system --values /home/sysadmin/oidc-client-overrides.yaml --reuse-values
   

   Note

   If you need to manually override the secrets, the client_secret in the oidc-client overrides must match the staticClients secret in the dex overrides, otherwise the oidc-auth CLI client will not function.

4. Use the system application-apply command to apply the configuration:

   ~(keystone_admin)]$ system application-apply oidc-auth-apps
   

Default helm overrides for oidc-auth-apps application

For backwards compatibility reasons, the default helm overrides for dex helm are:

Note

It is NOT recommended to use these; it is recommended to create certificates using cert-manager and explicitly refer to the resulting certificate secrets in user-specified helm overrides, as described on the procedure above.

image:
  repository: ghcr.io/dexidp/dex
  pullPolicy: IfNotPresent
  tag: v2.37.0
imagePullSecrets:
  - name: default-registry-key
env:
  name: KUBERNETES_POD_NAMESPACE
  value: kube-system
config:
  issuer: https://<OAM_IP>:30556/dex
  staticClients:
  - id: stx-oidc-client-app
    name: STX OIDC Client app
    secret: St8rlingX
    redirectURIs:
    - https://<OAM_IP>:30555/callback
  enablePasswordDB: false
  web:
    tlsCert: /etc/dex/tls/tls.crt
    tlsKey: /etc/dex/tls/tls.key
  storage:
    type: kubernetes
    config:
      inCluster: true
  oauth2:
    skipApprovalScreen: true
  logger:
    level: debug
service:
  type: NodePort
  ports:
    https:
      nodePort: 30556
https:
  enabled: true
grpc:
  enabled: false
nodeSelector:
  node-role.kubernetes.io/control-plane: ""
volumeMounts:
- mountPath: /etc/dex/tls/
  name: https-tls
volumes:
- name: https-tls
  secret:
    defaultMode: 420
    secretName: local-dex.tls
tolerations:
- key: "node-role.kubernetes.io/master"
  operator: "Exists"
  effect: "NoSchedule"
- key: "node-role.kubernetes.io/control-plane"
  operator: "Exists"
  effect: "NoSchedule"
affinity:
  podAntiAffinity:
    requiredDuringSchedulingIgnoredDuringExecution:
    - labelSelector:
        matchExpressions:
        - key: app
          operator: In
          values:
          - dex
      topologyKey: kubernetes.io/hostname

The default helm overrides for oidc-client are:

config:
  client_id: stx-oidc-client-app
  client_secret: St8rlingX
  issuer: https://<OAM_IP>:30556/dex
  issuer_root_ca: /home/dex-ca.pem
  issuer_root_ca_secret: dex-client-secret
  listen: https://0.0.0.0:5555
  redirect_uri: https://<OAM_IP>:30555/callback
  tlsCert: /etc/dex/tls/https/server/tls.crt
  tlsKey: /etc/dex/tls/https/server/tls.key
nodeSelector:
  node-role.kubernetes.io/control-plane: ""
service:
  type: NodePort
  port: 5555
  nodePort: 30555
replicas: <replicate count>
tolerations:
- key: "node-role.kubernetes.io/master"
  operator: "Exists"
  effect: "NoSchedule"
- key: "node-role.kubernetes.io/control-plane"
  operator: "Exists"
  effect: "NoSchedule"
affinity:
  podAntiAffinity:
    requiredDuringSchedulingIgnoredDuringExecution:
    - labelSelector:
        matchExpressions:
        - key: app
          operator: In
          values:
          - stx-oidc-client
      topologyKey: kubernetes.io/hostname
helmv3Compatible: true

The default helm overrides for secret-observer are:

namespace: "kube-system"
observedSecrets:
  - secretName: "dex-client-secret"
    filename: "dex-ca.pem"
    deploymentToRestart: "stx-oidc-client"
  - secretName: "local-dex.tls"
    filename: "tls.crt"
    deploymentToRestart: "stx-oidc-client"
  - secretName: "local-dex.tls"
    filename: "tls.crt"
    deploymentToRestart: "oidc-dex"
tolerations:
  - key: "node-role.kubernetes.io/master"
    operator: "Exists"
    effect: "NoSchedule"
  - key: "node-role.kubernetes.io/control-plane"
    operator: "Exists"
    effect: "NoSchedule"