New to KubeDB? Please start here.

Using Custom RBAC resources

KubeDB (version 0.13.0 and higher) supports finer user control over role based access permissions provided to a PerconaXtraDB instance. This tutorial will show you how to use KubeDB to run PerconaXtraDB instance with custom RBAC resources.

Before You Begin

At first, you need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using kind.

Now, install KubeDB cli on your workstation and KubeDB operator in your cluster following the steps here.

To keep things isolated, this tutorial uses a separate namespace called demo throughout this tutorial.

$ kubectl create ns demo
namespace/demo created

Note: YAML files used in this tutorial are stored in docs/examples/percona-xtradb folder in GitHub repository kubedb/docs.

Overview

KubeDB allows users to provide custom RBAC resources, namely, ServiceAccount, Role, and RoleBinding for PerconaXtraDB. This is provided via the .spec.podTemplate.spec.serviceAccountName field in PerconaXtraDB object. If this field is left empty, the KubeDB operator will create a service account name matching PerconaXtraDB object name. Role and RoleBinding that provide necessary access permissions will also be generated automatically for this service account.

If a service account name is given, but there’s no existing service account by that name, the KubeDB operator will create one, and Role and RoleBinding that provide necessary access permissions will also be generated for this service account.

If a service account name is given, and there’s an existing service account by that name, the KubeDB operator will use that existing service account. Since this service account is not managed by KubeDB, users are responsible for providing necessary access permissions manually.

This guide will show you how to create custom Service Account, Role, and RoleBinding for a PerconaXtraDB instance named px-custom-rbac to provide the bare minimum access permissions.

Custom RBAC for PerconaXtraDB

At first, let’s create a Service Account in demo namespace.

$ kubectl create serviceaccount -n demo px-custom-serviceaccount
serviceaccount/px-custom-serviceaccount created

It should create a service account.

$ kubectl get serviceaccount -n demo px-custom-serviceaccount -o yaml

Output:

apiVersion: v1
kind: ServiceAccount
metadata:
  creationTimestamp: "2020-01-09T09:05:05Z"
  name: px-custom-serviceaccount
  namespace: demo
  resourceVersion: "30521"
  selfLink: /api/v1/namespaces/demo/serviceaccounts/px-custom-serviceaccount
  uid: 06ff3050-bd49-41eb-9be5-ffdd69b174e7
secrets:
- name: px-custom-serviceaccount-token-wt4pm

Now, we need to create a role that has necessary access permissions for the PerconaXtraDB instance named px-custom-rbac.

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2021.04.16/docs/examples/percona-xtradb/px-custom-role.yaml
role.rbac.authorization.k8s.io/px-custom-role created

Below is the YAML for the Role we just created.

apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: px-custom-role
  namespace: demo
rules:
  - apiGroups:
      - policy
    resourceNames:
      - percona-xtradb-db
    resources:
      - podsecuritypolicies
    verbs:
      - use

This permission is required for PerconaXtraDB Pods running on PSP enabled clusters.

Now create a RoleBinding to bind this Role with the already created service account.

$ kubectl create rolebinding px-custom-rolebinding --role=px-custom-role --serviceaccount=demo:px-custom-serviceaccount --namespace=demo
rolebinding.rbac.authorization.k8s.io/px-custom-rolebinding created

It should bind px-custom-role and px-custom-serviceaccount successfully.

$ kubectl get rolebinding -n demo px-custom-rolebinding -o yaml

Output:

apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  creationTimestamp: "2020-01-09T10:09:26Z"
  name: px-custom-rolebinding
  namespace: demo
  resourceVersion: "38236"
  selfLink: /apis/rbac.authorization.k8s.io/v1/namespaces/demo/rolebindings/px-custom-rolebinding
  uid: eec78f30-2050-4d91-aff2-18df1779dfd5
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: px-custom-role
subjects:
- kind: ServiceAccount
  name: px-custom-serviceaccount
  namespace: demo

Now, create a PerconaXtraDB object specifying .spec.podTemplate.spec.serviceAccountName field to px-custom-serviceaccount.

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2021.04.16/docs/examples/percona-xtradb/px-custom-rbac.yaml
perconaxtradb.kubedb.com/px-custom-rbac created

Below is the YAML for the PerconaXtraDB object we just created.

apiVersion: kubedb.com/v1alpha2
kind: PerconaXtraDB
metadata:
  name: px-custom-rbac
  namespace: demo
spec:
  version: "5.7"
  replicas: 1
  storageType: Durable
  podTemplate:
    spec:
      serviceAccountName: px-custom-serviceaccount
  storage:
    storageClassName: "standard"
    accessModes:
      - ReadWriteOnce
    resources:
      requests:
        storage: 50Mi
  terminationPolicy: DoNotTerminate

Now, wait a few minutes. the KubeDB operator will create necessary PVC, statefulset, services, secret etc. If everything goes well, we should see that a Pod with the name px-custom-rbac-0 has been created.

Check that the StatefulSet’s Pod is running.

$ kubectl get px -n demo px-custom-rbac
NAME             VERSION   STATUS    AGE
px-custom-rbac   5.7       Running   2m11s

$ kubectl get pod -n demo px-custom-rbac-0
NAME               READY   STATUS    RESTARTS   AGE
px-custom-rbac-0   1/1     Running   0          29m

Check the Pod’s log to see if the database is ready.

$ kubectl logs -f -n demo px-custom-rbac-0
Initializing database
2020-01-09T10:20:17.263910Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2020-01-09T10:20:18.822906Z 0 [Warning] InnoDB: New log files created, LSN=45790
2020-01-09T10:20:19.045411Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2020-01-09T10:20:19.098009Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: a2e567b1-32c9-11ea-aefc-aa9dfb1ff340.
2020-01-09T10:20:19.101483Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2020-01-09T10:20:19.230258Z 0 [Warning] CA certificate ca.pem is self signed.
2020-01-09T10:20:19.299803Z 1 [Warning] [email protected] is created with an empty password ! Please consider switching off the --initialize-insecure option.
Database initialized
MySQL init process in progress...
2020-01-09T10:20:25.387944Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
...

MySQL init process done. Ready for start up.

2020-01-09T10:20:31.336569Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2020-01-09T10:20:31.337661Z 0 [Note] mysqld (mysqld 5.7.26-29) starting as process 1 ...
2020-01-09T10:20:31.339936Z 0 [Note] InnoDB: PUNCH HOLE support available
2020-01-09T10:20:31.339955Z 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2020-01-09T10:20:31.339959Z 0 [Note] InnoDB: Uses event mutexes
2020-01-09T10:20:31.339963Z 0 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
2020-01-09T10:20:31.339967Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.7
2020-01-09T10:20:31.339970Z 0 [Note] InnoDB: Using Linux native AIO
2020-01-09T10:20:31.340152Z 0 [Note] InnoDB: Number of pools: 1
2020-01-09T10:20:31.340238Z 0 [Note] InnoDB: Using CPU crc32 instructions
2020-01-09T10:20:31.341474Z 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2020-01-09T10:20:31.344542Z 0 [Note] InnoDB: Completed initialization of buffer pool
2020-01-09T10:20:31.346110Z 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2020-01-09T10:20:31.365087Z 0 [Note] InnoDB: Crash recovery did not find the parallel doublewrite buffer at /var/lib/mysql/xb_doublewrite
2020-01-09T10:20:31.365513Z 0 [Note] InnoDB: Highest supported file format is Barracuda.
2020-01-09T10:20:31.446986Z 0 [Note] InnoDB: Created parallel doublewrite buffer at /var/lib/mysql/xb_doublewrite, size 3932160 bytes
2020-01-09T10:20:31.459225Z 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2020-01-09T10:20:31.459318Z 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
2020-01-09T10:20:31.665372Z 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.
2020-01-09T10:20:31.666040Z 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active.
2020-01-09T10:20:31.666051Z 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active.
2020-01-09T10:20:31.666399Z 0 [Note] InnoDB: Waiting for purge to start
2020-01-09T10:20:31.716560Z 0 [Note] InnoDB: Percona XtraDB (http://www.percona.com) 5.7.26-29 started; log sequence number 11874994
2020-01-09T10:20:31.717099Z 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
2020-01-09T10:20:31.717713Z 0 [Note] Plugin 'FEDERATED' is disabled.
2020-01-09T10:20:31.724077Z 0 [Note] InnoDB: Buffer pool(s) load completed at 200109 10:20:31
2020-01-09T10:20:31.726495Z 0 [Note] Found ca.pem, server-cert.pem and server-key.pem in data directory. Trying to enable SSL support using them.
2020-01-09T10:20:31.726507Z 0 [Note] Skipping generation of SSL certificates as certificate files are present in data directory.
2020-01-09T10:20:31.726976Z 0 [Warning] CA certificate ca.pem is self signed.
2020-01-09T10:20:31.727004Z 0 [Note] Skipping generation of RSA key pair as key files are present in data directory.
2020-01-09T10:20:31.727333Z 0 [Note] Server hostname (bind-address): '*'; port: 3306
2020-01-09T10:20:31.727696Z 0 [Note] IPv6 is available.
2020-01-09T10:20:31.727705Z 0 [Note]   - '::' resolves to '::';
2020-01-09T10:20:31.727719Z 0 [Note] Server socket created on IP: '::'.
2020-01-09T10:20:31.738417Z 0 [Note] Event Scheduler: Loaded 0 events
2020-01-09T10:20:31.738597Z 0 [Note] mysqld: ready for connections.
Version: '5.7.26-29'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  Percona Server (GPL), Release 29, Revision 11ad961

Once we see MySQL init process done. Ready for start up. in the log, the database is ready.

Reusing Service Account

An existing service account can be reused in another PerconaXtraDB instance. No new access permission is required to run the new PerconaXtraDB instance.

Now, create another PerconaXtraDB object minute-mysql using the existing service account name px-custom-serviceaccount in the .spec.podTemplate.spec.serviceAccountName field.

$ kubectl apply -f https://github.com/kubedb/docs/raw/v2021.04.16/docs/examples/percona-xtradb/px-custom-rbac-two.yaml
perconaxtradb.kubedb.com/px-custom-rbac-two created

Below is the YAML for the PerconaXtraDB object we just created.

apiVersion: kubedb.com/v1alpha2
kind: PerconaXtraDB
metadata:
  name: px-custom-rbac-two
  namespace: demo
spec:
  version: "5.7"
  replicas: 1
  storageType: Durable
  podTemplate:
    spec:
      serviceAccountName: px-custom-serviceaccount
  storage:
    storageClassName: "standard"
    accessModes:
      - ReadWriteOnce
    resources:
      requests:
        storage: 50Mi
  terminationPolicy: DoNotTerminate

Now, wait a few minutes. the KubeDB operator will create necessary PVC, statefulset, services, secret etc. If everything goes well, we should see that a Pod with the name px-custom-rbac-two-0 has been created.

Check that the StatefulSet’s Pod is running

$ kubectl get px -n demo px-custom-rbac-two
NAME                 VERSION   STATUS    AGE
px-custom-rbac-two   5.7       Running   2m29s

$ kubectl get pod -n demo px-custom-rbac-two-0
NAME                   READY   STATUS    RESTARTS   AGE
px-custom-rbac-two-0   1/1     Running   0          3m7s

Check the Pod’s log to see if the database is ready

$ kubectl logs -f -n demo px-custom-rbac-two-0
Initializing database
2020-01-09T11:17:53.650798Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2020-01-09T11:17:54.644803Z 0 [Warning] InnoDB: New log files created, LSN=45790
2020-01-09T11:17:54.796314Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2020-01-09T11:17:54.830674Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: aeac5ce3-32d1-11ea-9c28-8641016787d1.
2020-01-09T11:17:54.838176Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2020-01-09T11:17:55.032258Z 0 [Warning] CA certificate ca.pem is self signed.
2020-01-09T11:17:55.099944Z 1 [Warning] [email protected] is created with an empty password ! Please consider switching off the --initialize-insecure option.
Database initialized
MySQL init process in progress...
2020-01-09T11:18:00.671870Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
...

MySQL init process done. Ready for start up.

2020-01-09T11:18:05.897577Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2020-01-09T11:18:05.898678Z 0 [Note] mysqld (mysqld 5.7.26-29) starting as process 1 ...
2020-01-09T11:18:05.901031Z 0 [Note] InnoDB: PUNCH HOLE support available
2020-01-09T11:18:05.901051Z 0 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2020-01-09T11:18:05.901055Z 0 [Note] InnoDB: Uses event mutexes
2020-01-09T11:18:05.901058Z 0 [Note] InnoDB: GCC builtin __atomic_thread_fence() is used for memory barrier
2020-01-09T11:18:05.901062Z 0 [Note] InnoDB: Compressed tables use zlib 1.2.7
2020-01-09T11:18:05.901065Z 0 [Note] InnoDB: Using Linux native AIO
2020-01-09T11:18:05.901255Z 0 [Note] InnoDB: Number of pools: 1
2020-01-09T11:18:05.901350Z 0 [Note] InnoDB: Using CPU crc32 instructions
2020-01-09T11:18:05.902544Z 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2020-01-09T11:18:05.905640Z 0 [Note] InnoDB: Completed initialization of buffer pool
2020-01-09T11:18:05.906981Z 0 [Note] InnoDB: If the mysqld execution user is authorized, page cleaner thread priority can be changed. See the man page of setpriority().
2020-01-09T11:18:05.925827Z 0 [Note] InnoDB: Crash recovery did not find the parallel doublewrite buffer at /var/lib/mysql/xb_doublewrite
2020-01-09T11:18:05.926491Z 0 [Note] InnoDB: Highest supported file format is Barracuda.
2020-01-09T11:18:05.970628Z 0 [Note] InnoDB: Created parallel doublewrite buffer at /var/lib/mysql/xb_doublewrite, size 3932160 bytes
2020-01-09T11:18:05.985063Z 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2020-01-09T11:18:05.985136Z 0 [Note] InnoDB: Setting file './ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
2020-01-09T11:18:06.079208Z 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.
2020-01-09T11:18:06.080463Z 0 [Note] InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active.
2020-01-09T11:18:06.080482Z 0 [Note] InnoDB: 32 non-redo rollback segment(s) are active.
2020-01-09T11:18:06.081247Z 0 [Note] InnoDB: Percona XtraDB (http://www.percona.com) 5.7.26-29 started; log sequence number 11875357
2020-01-09T11:18:06.081485Z 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
2020-01-09T11:18:06.081829Z 0 [Note] Plugin 'FEDERATED' is disabled.
2020-01-09T11:18:06.087193Z 0 [Note] InnoDB: Buffer pool(s) load completed at 200109 11:18:06
2020-01-09T11:18:06.089617Z 0 [Note] Found ca.pem, server-cert.pem and server-key.pem in data directory. Trying to enable SSL support using them.
2020-01-09T11:18:06.089632Z 0 [Note] Skipping generation of SSL certificates as certificate files are present in data directory.
2020-01-09T11:18:06.090088Z 0 [Warning] CA certificate ca.pem is self signed.
2020-01-09T11:18:06.090117Z 0 [Note] Skipping generation of RSA key pair as key files are present in data directory.
2020-01-09T11:18:06.090421Z 0 [Note] Server hostname (bind-address): '*'; port: 3306
2020-01-09T11:18:06.090446Z 0 [Note] IPv6 is available.
2020-01-09T11:18:06.090454Z 0 [Note]   - '::' resolves to '::';
2020-01-09T11:18:06.090467Z 0 [Note] Server socket created on IP: '::'.
2020-01-09T11:18:06.110254Z 0 [Note] Event Scheduler: Loaded 0 events
2020-01-09T11:18:06.110715Z 0 [Note] mysqld: ready for connections.
Version: '5.7.26-29'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  Percona Server (GPL), Release 29, Revision 11ad961

MySQL init process done. Ready for start up. in the log signifies that the database is running successfully.

Cleaning up

To cleanup the Kubernetes resources created by this tutorial, run:

kubectl patch -n demo px/px-custom-rbac-two -p '{"spec":{"terminationPolicy":"WipeOut"}}' --type="merge"
kubectl delete -n demo px/px-custom-rbac-two

kubectl patch -n demo px/px-custom-rbac -p '{"spec":{"terminationPolicy":"WipeOut"}}' --type="merge"
kubectl delete -n demo px/px-custom-rbac

kubectl delete -n demo role px-custom-role
kubectl delete -n demo rolebinding px-custom-rolebinding

kubectl delete sa -n demo px-custom-serviceaccount

kubectl delete ns demo

If you would like to uninstall the KubeDB operator, please follow the steps here.

Next Steps