New to KubeVault? Please start here.
Manage Azure service principals using the KubeVault operator
The Azure secrets engine dynamically generates Azure service principals and role assignments. Vault roles can be mapped to one or more Azure roles, providing a simple, flexible way to manage the permissions granted to generated service principals. You can easily manage the Azure secret engine using the KubeVault operator.
You need to be familiar with the following CRDs:
Before you begin
- Install KubeVault operator in your cluster from here.
To keep things isolated, we are going to use a separate namespace called demo throughout this tutorial.
$ kubectl create ns demo
namespace/demo created
In this tutorial, we are going to create a role using AzureRole and issue credential using SecretAccessRequest.
Vault Server
If you don’t have a Vault Server, you can deploy it by using the KubeVault operator.
The KubeVault operator can manage policies and secret engines of Vault servers which are not provisioned by the KubeVault operator. You need to configure both the Vault server and the cluster so that the KubeVault operator can communicate with your Vault server.
Now, we have the AppBinding that contains connection and authentication information about the Vault server.
$ kubectl get appbinding -n demo
NAME AGE
vault 50m
$ kubectl get appbinding -n demo vault -o yaml
apiVersion: appcatalog.appscode.com/v1alpha1
kind: AppBinding
metadata:
creationTimestamp: "2021-08-16T08:23:38Z"
generation: 1
labels:
app.kubernetes.io/instance: vault
app.kubernetes.io/managed-by: kubevault.com
app.kubernetes.io/name: vaultservers.kubevault.com
name: vault
namespace: demo
ownerReferences:
- apiVersion: kubevault.com/v1alpha1
blockOwnerDeletion: true
controller: true
kind: VaultServer
name: vault
uid: 6b405147-93da-41ff-aad3-29ae9f415d0a
resourceVersion: "602898"
uid: b54873fd-0f34-42f7-bdf3-4e667edb4659
spec:
clientConfig:
service:
name: vault
port: 8200
scheme: http
parameters:
apiVersion: config.kubevault.com/v1alpha1
kind: VaultServerConfiguration
kubernetes:
serviceAccountName: vault
tokenReviewerServiceAccountName: vault-k8s-token-reviewer
usePodServiceAccountForCSIDriver: true
path: kubernetes
vaultRole: vault-policy-controller
Enable and Configure Azure Secret Engine
When a SecretEngine crd object is created, the KubeVault operator will enable a secret engine on specified path and configure the secret engine with given configurations.
A sample SecretEngine object for Azure secret engine:
apiVersion: engine.kubevault.com/v1alpha1
kind: SecretEngine
metadata:
name: azure-engine
namespace: demo
spec:
vaultRef:
name: vault
azure:
credentialSecret: azure-cred
To configure the Azure secret engine, you need to provide azure credentials through a Kubernetes secret.
apiVersion: v1
kind: Secret
metadata:
name: azure-cred
namespace: demo
data:
client-secret: eyJtc2ciOiJleGFtcGxlIn0=
subscription-id: eyJtc2ciOiJleGFtcGxlIn0=
client-id: eyJtc2ciOiJleGFtcGxlIn0=
tenant-id: eyJtc2ciOiJleGFtcGxlIn0=
Let’s deploy SecretEngine:
$ kubectl apply -f docs/examples/guides/secret-engines/azure/secret.yaml
secret/azure-cred created
$ kubectl apply -f docs/examples/guides/secret-engines/azure/secretengine.yaml
secretengine.engine.kubevault.com/azure-engine created
Wait till the status become Success:
$ kubectl get secretengines -n demo
NAME STATUS
azure-engine Success
Since the status is Success, the Azure secret engine is enabled and successfully configured. You can use kubectl describe secretengine -n <namepsace> <name> to check for error events, if any.
Create Azure Role
By using AzureRole, you can create a role on the Vault server in Kubernetes native way.
A sample AzureRole object is given below:
apiVersion: engine.kubevault.com/v1alpha1
kind: AzureRole
metadata:
name: azure-role
namespace: demo
spec:
secretEngineRef:
name: vault
applicationObjectID: e211afbc-cc4a-462f-ad6f-59e26eb5406f
ttl: 1h
Let’s deploy AzureRole:
$ kubectl apply -f docs/examples/guides/secret-engines/azure/secretenginerole.yaml
azurerole.engine.kubevault.com/azure-role created
$ kubectl get azureroles -n demo
NAME STATUS
azure-role Success
You can also check from Vault that the role is created.
To resolve the naming conflict, name of the role in Vault will follow this format: k8s.{clusterName}.{metadata.namespace}.{metadata.name}.
Don’t have Vault CLI? Download and configure it as described here
$ vault list azure/roles
Keys
----
k8s.-.demo.azure-role
$ vault read azure/roles/k8s.-.demo.azure-role
Key Value
--- -----
application_object_id c1cb042d-96d7-423a-8dba-243c2e5010d3
azure_roles <nil>
max_ttl 0s
ttl 1h
If we delete the AzureRole, then the respective role will be deleted from the Vault.
$ kubectl delete -f docs/examples/guides/secret-engines/azure/secretenginerole.yaml
azurerole.engine.kubevault.com "azure-role" deleted
Check from Vault whether the role exists:
$ vault read azure/roles/k8s.-.demo.azure-role
No value found at azure/roles/k8s.-.demo.azure-role
$ vault list azure/roles
No value found at azure/roles/
Generate Azure credentials
Here, we are going to make a request to Vault for Azure credentials by creating azure-cred-rqst SecretAccessRequest in demo namespace.
apiVersion: engine.kubevault.com/v1alpha1
kind: SecretAccessRequest
metadata:
name: azure-cred-rqst
namespace: demo
spec:
roleRef:
kind: AzureRole
name: azure-role
subjects:
- kind: ServiceAccount
name: demo-sa
namespace: demo
Here, spec.roleRef is the reference of AzureRole against which credentials will be issued. spec.subjects is the reference to the object or user identities a role binding applies to and it will have read access of the credential secret.
Now, we are going to create SecretAccessRequest.
$ kubectl apply -f docs/examples/guides/secret-engines/azure/azureaccessrequest.yaml
secretaccessrequest.engine.kubevault.com/azure-cred-rqst created
$ kubectl get secretaccessrequests -n demo
NAME AGE
azure-cred-rqst 3s
Azure credentials will not be issued until it is approved. The KubeVault operator will watch for the approval in the status.conditions[].type field of the request object. You can use KubeVault CLI, a kubectl plugin, to approve or deny SecretAccessRequest.
# using KubeVault CLI as kubectl plugin to approve request
$ kubectl vault approve secretaccessrequest azure-cred-rqst -n demo
approved
$ kubectl get secretaccessrequests -n demo azure-cred-rqst -o yaml
apiVersion: engine.kubevault.com/v1alpha1
kind: SecretAccessRequest
metadata:
name: azure-cred-rqst
namespace: demo
spec:
roleRef:
name: azure-role
namespace: demo
subjects:
- kind: ServiceAccount
name: demo-sa
namespace: demo
status:
conditions:
- lastUpdateTime: "2019-11-14T09:21:49Z"
message: This was approved by kubectl vault approve secretaccessrequest
reason: KubectlApprove
type: Approved
lease:
duration: 1h0m0s
id: azure/creds/k8s.-.demo.azure-role/FJVEWUW9NpGlFOdIIMd900Zr
renewable: true
secret:
name: azure-cred-rqst-luc5p4
Once SecretAccessRequest is approved, the KubeVault operator will issue credentials from Vault and create a secret containing the credential. It will also create a role and rolebinding so that spec.subjects can access secret. You can view the information in the status field.
$ kubectl get secretaccessrequest azure-cred-rqst -n demo -o json | jq '.status'
{
"conditions": [
{
"lastUpdateTime": "2019-11-14T09:21:49Z",
"message": "This was approved by kubectl vault approve secretaccessrequest",
"reason": "KubectlApprove",
"type": "Approved"
}
],
"lease": {
"duration": "1h0m0s",
"id": "azure/creds/k8s.-.demo.azure-role/FJVEWUW9NpGlFOdIIMd900Zr",
"renewable": true
},
"secret": {
"name": "azure-cred-rqst-luc5p4"
}
}
$ kubectl get secret -n demo azure-cred-rqst-luc5p4 -o yaml
apiVersion: v1
data:
client_id: MmI4NzFkNGEtN...
client_secret: ZjJlMjA3N...
kind: Secret
metadata:
name: azure-cred-rqst-luc5p4
namespace: demo
ownerReferences:
- apiVersion: engine.kubevault.com/v1alpha1
controller: true
kind: SecretAccessRequest
name: azure-cred-rqst
uid: d944491b-a22c-4777-bc8f-2e2c94b47b7b
type: Opaque
If SecretAccessRequest is deleted, then credential lease (if any) will be revoked.
$ kubectl delete secretaccessrequest -n demo azure-cred-rqst
secretaccessrequest.engine.kubevault.com "azure-cred-rqst" deleted
If SecretAccessRequest is Denied, then the KubeVault operator will not issue any credentials.
$ kubectl vault deny secretaccessrequest azure-cred-rqst -n demo
Denied
$ kubectl get secretaccessrequest azure-cred-rqst -n demo -o json | jq '.status'
{
"conditions": [
{
"lastUpdateTime": "2019-11-14T09:21:49Z",
"message": "This was denied by kubectl vault deny secretaccessrequest",
"reason": "KubectlDeny",
"type": "Denied"
}
]
}
Note: Once SecretAccessRequest is
ApprovedorDenied, you cannot changespec.roleRefandspec.subjectsfield.