victoriametrics.com

Access control #

Roles #

To run in a cluster the operator needs certain permissions, you can see them in this directory:

  • role.yaml file - basic set of cluster roles for launching an operator.
  • leader_election_role.yaml file - set of roles with permissions to do leader election (is necessary to run the operator in several replicas for high availability).

Also, you can use single-namespace mode with minimal permissions, see this section for details.

Also in the same directory are files with a set of separate permissions to view or edit operator resources to organize fine-grained access:

  • file <RESOURCE_NAME>_viewer_role.yaml - permissions for viewing (get, list and watch) some resource of vmoperator.
  • file <RESOURCE_NAME>_editor_role.yaml - permissions for editing (create, delete, patch, update and deletecollection) some resource of vmoperator (also includes viewing permissions).

For instance, vmalert_editor_role.yaml file contain permission for editing vmagent custom resources.

Security policies #

VictoriaMetrics operator provides several security features, such as PodSecurityPolicies, PodSecurityContext.

PodSecurityPolicy #

PodSecurityPolicy was deprecated in Kubernetes v1.21, and removed from Kubernetes in v1.25.

If your Kubernetes version is under v1.25 and want to use PodSecurityPolicy, you can set env VM_PSPAUTOCREATEENABLED: "true" in operator, it will create serviceAccount for each cluster resource and binds default PodSecurityPolicy to it.

Default psp:

apiVersion: policy/v1beta1
kind: PodSecurityPolicy
metadata:
  name: vmagent-example-vmagent
spec:
  allowPrivilegeEscalation: false
  fsGroup:
    rule: RunAsAny
  hostNetwork: true
  requiredDropCapabilities:
  - ALL
  runAsUser:
    rule: RunAsAny
  seLinux:
    rule: RunAsAny
  supplementalGroups:
    rule: RunAsAny
  volumes:
  - persistentVolumeClaim
  - secret
  - emptyDir
  - configMap
  - projected
  - downwardAPI
  - nfs

User may also override default pod security policy with setting: spec.podSecurityPolicyName: "psp-name".

PodSecurityContext #

VictoriaMetrics operator will add default Security Context to managed pods and containers if env EnableStrictSecurity: "true" is set. The following SecurityContext will be applied:

Pod SecurityContext #

  1. RunAsNonRoot: true

  2. RunAsUser/RunAsGroup/FSGroup: 65534

    ‘65534’ refers to ’nobody’ in all the used default images like alpine, busybox.

    If you’re using customize image, please make sure ‘65534’ is a valid uid in there or specify SecurityContext.

  3. FSGroupChangePolicy: &onRootMismatch

    If KubeVersion>=1.20, use FSGroupChangePolicy="onRootMismatch" to skip the recursive permission change when the root of the volume already has the correct permissions

  4. SeccompProfile: {type: RuntimeDefault}

    Use RuntimeDefault seccomp profile by default, which is defined by the container runtime, instead of using the Unconfined (seccomp disabled) mode.

Container SecurityContext #

  1. AllowPrivilegeEscalation: false
  2. ReadOnlyRootFilesystem: true
  3. Capabilities: {drop: [all]}

Also SecurityContext can be configured with spec setting. It may be useful for mounted volumes, with VMSingle for example:

apiVersion: operator.victoriametrics.com/v1beta1
kind: VMSingle
metadata:
  name: vmsingle-f
  namespace: monitoring-system
spec:
  retentionPeriod: "2"
  removePvcAfterDelete: true
  securityContext:
      runAsUser: 1000
      fsGroup: 1000
      runAsGroup: 1000
  extraArgs:
    dedup.minScrapeInterval: 10s
  storage:
    accessModes:
      - ReadWriteOnce
    resources:
      requests:
        storage: 25Gi
  resources:
    requests:
      cpu: "0.5"
      memory: "512Mi"
    limits:
      cpu: "1"
      memory: "1512Mi"

Kubernetes API Access #

By default, operator configures Kubernetes API Access for all managed components with own ServiceAccount. This behaviour can be altered with object configuration - spec.disableAutomountServiceAccountToken: true Available from v0.54.0 . See the following Kubernetes doc for details.

Consider the following example for VMAgent:

apiVersion: operator.victoriametrics.com/v1beta1
kind: VMAgent
metadata:
  name: example-vmagent
  namespace: default
spec:
  remoteWrite:
  - url: http://vmsingle-vms-victoria-metrics-k8s-stack.default.svc:8429/api/v1/write
  replicaCount: 1
  selectAllByDefault: true
  statefulMode: true

Kubernetes controller-manager creates the following Pod definition and attaches volumes and volumeMounts with serviceAccount token:

apiVersion: v1
kind: Pod
metadata:
  name: vmagent-example-vmagent-0
  namespace: default
spec:
  containers:
  - args:
...
    name: config-reloader
    volumeMounts:
...
    - mountPath: /var/run/secrets/kubernetes.io/serviceaccount
      name: kube-api-access-q44gh
      readOnly: true
  - args:
...
    name: vmagent
    volumeMounts:
...
    - mountPath: /var/run/secrets/kubernetes.io/serviceaccount
      name: kube-api-access-q44gh
      readOnly: true
  dnsPolicy: ClusterFirst
  enableServiceLinks: true
  hostname: vmagent-example-vmagent-0
  initContainers:
  - args:
...
    name: config-init
    volumeMounts:
...
    - mountPath: /var/run/secrets/kubernetes.io/serviceaccount
      name: kube-api-access-q44gh
      readOnly: true

  serviceAccount: vmagent-example-vmagent
  serviceAccountName: vmagent-example-vmagent
  volumes:
...
  - emptyDir: {}
    name: persistent-queue-data
  - name: kube-api-access-q44gh
    projected:
      defaultMode: 420
      sources:
      - serviceAccountToken:
          expirationSeconds: 3607
          path: token
      - configMap:
          items:
          - key: ca.crt
            path: ca.crt
          name: kube-root-ca.crt
      - downwardAPI:
          items:
          - fieldRef:
              apiVersion: v1
              fieldPath: metadata.namespace
            path: namespace

If disableAutomountServiceAccountToken: true is set. Operator adds volumes and volumeMounts only if application explicitly requires access to Kubernetes API:

apiVersion: operator.victoriametrics.com/v1beta1
kind: VMAgent
metadata:
  name: example-vmagent
  namespace: default
spec:
  disableAutomountServiceAccountToken: true
  remoteWrite:
  - url: http://vmsingle-vms-victoria-metrics-k8s-stack.default.svc:8429/api/v1/write
  replicaCount: 1
  selectAllByDefault: true
  statefulMode: true

And Pod definition no longer has volumeMounts with serviceAccountToken for config-reloader container:

apiVersion: v1
kind: Pod
metadata:
  name: vmagent-example-vmagent-0
  namespace: default
spec:
  automountServiceAccountToken: false
  containers:
  - args:
    name: config-reloader
    volumeMounts:
    - mountPath: /etc/vmagent/config_out
      name: config-out
    - mountPath: /etc/vmagent/config
      name: config
  - args:
    name: vmagent
    terminationMessagePath: /dev/termination-log
    terminationMessagePolicy: FallbackToLogsOnError
    volumeMounts:
    - mountPath: /vmagent_pq/vmagent-remotewrite-data
      name: persistent-queue-data
...
    - mountPath: /var/run/secrets/kubernetes.io/serviceaccount
      name: kube-api-access
      readOnly: true
  dnsPolicy: ClusterFirst
  enableServiceLinks: true
  hostname: vmagent-example-vmagent-0
  initContainers:
  - args:
    name: config-init
    volumeMounts:
    - mountPath: /etc/vmagent/config
      name: config
    - mountPath: /etc/vmagent/config_out
      name: config-out
  serviceAccount: vmagent-example-vmagent
  serviceAccountName: vmagent-example-vmagent
  volumes:
...
  - name: kube-api-access
    projected:
      defaultMode: 420
      sources:
      - serviceAccountToken:
          expirationSeconds: 3600
          path: token
      - configMap:
          name: kube-root-ca.crt
      - downwardAPI:
          items:
          - fieldRef:
              apiVersion: v1
              fieldPath: metadata.namespace
            path: namespace
  - emptyDir: {}
    name: persistent-queue-data

The following containers needs access to Kubernetes API server:

  • vmagent uses Kubernetes service-discovery for scrapping target metrics.
  • config-reloader watches configuration secret and triggers application state config reload on change. Note, it’s only true for useVMConfigReloader: true. This option can be used with VMAgent, VMAuth and VMAlertmanager.

It’s also possible to mount serviceAccountToken manually to any component. Consider the following example:

# add Role and Rolebinding for `vmsingle-with-sidecar` ServiceAccount
# or provide specific serviceAccount via: `spec.serviceAccountName`
apiVersion: operator.victoriametrics.com/v1beta1
kind: VMSingle
metadata:
  name: with-sidecar
  namespace: default
spec:
  retentionPeriod: 1
  disableAutomountServiceAccountToken: true
  containers:
  - name: side-car-with-api-access
    image: busybox
    command: ["/bin/sh"] 
    args: ["-c", "tail -f /dev/stdout"] 
    volumeMounts:
    - name: kube-api-access
      mountPath: /var/run/secrets/kubernetes.io/serviceaccount
  volumes:
  - name: kube-api-access
    projected:
      defaultMode: 420
      sources:
      - serviceAccountToken:
          expirationSeconds: 3600
          path: token
      - configMap:
          name: kube-root-ca.crt
      - downwardAPI:
          items:
          - fieldRef:
              apiVersion: v1
              fieldPath: metadata.namespace
            path: namespace

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