ArangoDeployment Custom Resource

The ArangoDB Deployment Operator creates and maintains ArangoDB deployments in a Kubernetes cluster, given a deployment specification. This deployment specification is a CustomResource following a CustomResourceDefinition created by the operator.

Example minimal deployment definition of an ArangoDB database cluster:

apiVersion: "database.arangodb.com/v1alpha"
kind: "ArangoDeployment"
metadata:
  name: "example-arangodb-cluster"
spec:
  mode: Cluster

Example more elaborate deployment definition:

apiVersion: "database.arangodb.com/v1alpha"
kind: "ArangoDeployment"
metadata:
  name: "example-arangodb-cluster"
spec:
  mode: Cluster
  environment: Production
  agents:
    count: 3
    args:
      - --log.level=debug
    resources:
      requests:
        storage: 8Gi
    storageClassName: ssd
  dbservers:
    count: 5
    resources:
      requests:
        storage: 80Gi
    storageClassName: ssd
  coordinators:
    count: 3
  image: "arangodb/arangodb:3.3.4"

Specification reference

Below you’ll find all settings of the ArangoDeployment custom resource. Several settings are for various groups of servers. These are indicated with <group> where <group> can be any of:

  • agents for all agents of a Cluster or ActiveFailover pair.
  • dbservers for all dbservers of a Cluster.
  • coordinators for all coordinators of a Cluster.
  • single for all single servers of a Single instance or ActiveFailover pair.
  • syncmasters for all syncmasters of a Cluster.
  • syncworkers for all syncworkers of a Cluster.

spec.mode: string

This setting specifies the type of deployment you want to create. Possible values are:

  • Cluster (default) Full cluster. Defaults to 3 agents, 3 dbservers & 3 coordinators.
  • ActiveFailover Active-failover single pair. Defaults to 3 agents and 2 single servers.
  • Single Single server only (note this does not provide high availability or reliability).

This setting cannot be changed after the deployment has been created.

spec.environment: string

This setting specifies the type of environment in which the deployment is created. Possible values are:

  • Development (default) This value optimizes the deployment for development use. It is possible to run a deployment on a small number of nodes (e.g. minikube).
  • Production This value optimizes the deployment for production use. It puts required affinity constraints on all pods to avoid agents & dbservers from running on the same machine.

spec.image: string

This setting specifies the docker image to use for all ArangoDB servers. In a development environment this setting defaults to arangodb/arangodb:latest. For production environments this is a required setting without a default value. It is highly recommend to use explicit version (not latest) for production environments.

spec.imagePullPolicy: string

This setting specifies the pull policy for the docker image to use for all ArangoDB servers. Possible values are:

  • IfNotPresent (default) to pull only when the image is not found on the node.
  • Always to always pull the image before using it.

spec.imagePullSecrets: []string

This setting specifies the list of image pull secrets for the docker image to use for all ArangoDB servers.

spec.storageEngine: string

This setting specifies the type of storage engine used for all servers in the cluster. Possible values are:

  • MMFiles To use the MMFiles storage engine.
  • RocksDB (default) To use the RocksDB storage engine.

This setting cannot be changed after the cluster has been created.

spec.downtimeAllowed: bool

This setting is used to allow automatic reconciliation actions that yield some downtime of the ArangoDB deployment. When this setting is set to false (the default), no automatic action that may result in downtime is allowed. If the need for such an action is detected, an event is added to the ArangoDeployment.

Once this setting is set to true, the automatic action is executed.

Operations that may result in downtime are:

  • Rotating TLS CA certificate

Note: It is still possible that there is some downtime when the Kubernetes cluster is down, or in a bad state, irrespective of the value of this setting.

spec.rocksdb.encryption.keySecretName

This setting specifies the name of a Kubernetes Secret that contains an encryption key used for encrypting all data stored by ArangoDB servers. When an encryption key is used, encryption of the data in the cluster is enabled, without it encryption is disabled. The default value is empty.

This requires the Enterprise version.

The encryption key cannot be changed after the cluster has been created.

The secret specified by this setting, must have a data field named ‘key’ containing an encryption key that is exactly 32 bytes long.

spec.networkAttachedVolumes: bool

The default of this option is false. If set to true, and the deployed ArangoDB version is new enough (>= 3.4.8 for 3.4 and >= 3.5.1 for 3.5), a ResignLeaderShip operation will be triggered when a dbserver pod is evicted (rather than a CleanOutServer operation). Furthermore, the pod will simply be redeployed on a different node, rather than cleaned and retired and replaced by a new member. You must only set this option to true if your persistent volumes are “movable” in the sense that they can be mounted from a different k8s node, like in the case of network attached volumes. If your persistent volumes are tied to a specific pod, you must leave this option on false.

spec.externalAccess.type: string

This setting specifies the type of Service that will be created to provide access to the ArangoDB deployment from outside the Kubernetes cluster. Possible values are:

  • None To limit access to application running inside the Kubernetes cluster.
  • LoadBalancer To create a Service of type LoadBalancer for the ArangoDB deployment.
  • NodePort To create a Service of type NodePort for the ArangoDB deployment.
  • Auto (default) To create a Service of type LoadBalancer and fallback to a Service or type NodePort when the LoadBalancer is not assigned an IP address.

spec.externalAccess.loadBalancerIP: string

This setting specifies the IP used to for the LoadBalancer to expose the ArangoDB deployment on. This setting is used when spec.externalAccess.type is set to LoadBalancer or Auto.

If you do not specify this setting, an IP will be chosen automatically by the load-balancer provisioner.

spec.externalAccess.loadBalancerSourceRanges: []string

If specified and supported by the platform (cloud provider), this will restrict traffic through the cloud-provider load-balancer will be restricted to the specified client IPs. This field will be ignored if the cloud-provider does not support the feature.

More info: https://kubernetes.io/docs/tasks/access-application-cluster/configure-cloud-provider-firewall/

spec.externalAccess.nodePort: int

This setting specifies the port used to expose the ArangoDB deployment on. This setting is used when spec.externalAccess.type is set to NodePort or Auto.

If you do not specify this setting, a random port will be chosen automatically.

spec.externalAccess.advertisedEndpoint: string

This setting specifies the advertised endpoint for all coordinators.

spec.auth.jwtSecretName: string

This setting specifies the name of a kubernetes Secret that contains the JWT token used for accessing all ArangoDB servers. When no name is specified, it defaults to <deployment-name>-jwt. To disable authentication, set this value to None.

If you specify a name of a Secret, that secret must have the token in a data field named token.

If you specify a name of a Secret that does not exist, a random token is created and stored in a Secret with given name.

Changing a JWT token results in stopping the entire cluster and restarting it.

spec.tls.caSecretName: string

This setting specifies the name of a kubernetes Secret that contains a standard CA certificate + private key used to sign certificates for individual ArangoDB servers. When no name is specified, it defaults to <deployment-name>-ca. To disable authentication, set this value to None.

If you specify a name of a Secret that does not exist, a self-signed CA certificate + key is created and stored in a Secret with given name.

The specified Secret, must contain the following data fields:

  • ca.crt PEM encoded public key of the CA certificate
  • ca.key PEM encoded private key of the CA certificate

spec.tls.altNames: []string

This setting specifies a list of alternate names that will be added to all generated certificates. These names can be DNS names or email addresses. The default value is empty.

spec.tls.ttl: duration

This setting specifies the time to live of all generated server certificates. The default value is 2160h (about 3 month).

When the server certificate is about to expire, it will be automatically replaced by a new one and the affected server will be restarted.

Note: The time to live of the CA certificate (when created automatically) will be set to 10 years.

spec.sync.enabled: bool

This setting enables/disables support for data center 2 data center replication in the cluster. When enabled, the cluster will contain a number of syncmaster & syncworker servers. The default value is false.

spec.sync.externalAccess.type: string

This setting specifies the type of Service that will be created to provide access to the ArangoSync syncMasters from outside the Kubernetes cluster. Possible values are:

  • None To limit access to applications running inside the Kubernetes cluster.
  • LoadBalancer To create a Service of type LoadBalancer for the ArangoSync SyncMasters.
  • NodePort To create a Service of type NodePort for the ArangoSync SyncMasters.
  • Auto (default) To create a Service of type LoadBalancer and fallback to a Service or type NodePort when the LoadBalancer is not assigned an IP address.

Note that when you specify a value of None, a Service will still be created, but of type ClusterIP.

spec.sync.externalAccess.loadBalancerIP: string

This setting specifies the IP used for the LoadBalancer to expose the ArangoSync SyncMasters on. This setting is used when spec.sync.externalAccess.type is set to LoadBalancer or Auto.

If you do not specify this setting, an IP will be chosen automatically by the load-balancer provisioner.

spec.sync.externalAccess.nodePort: int

This setting specifies the port used to expose the ArangoSync SyncMasters on. This setting is used when spec.sync.externalAccess.type is set to NodePort or Auto.

If you do not specify this setting, a random port will be chosen automatically.

spec.sync.externalAccess.loadBalancerSourceRanges: []string

If specified and supported by the platform (cloud provider), this will restrict traffic through the cloud-provider load-balancer will be restricted to the specified client IPs. This field will be ignored if the cloud-provider does not support the feature.

More info: https://kubernetes.io/docs/tasks/access-application-cluster/configure-cloud-provider-firewall/

spec.sync.externalAccess.masterEndpoint: []string

This setting specifies the master endpoint(s) advertised by the ArangoSync SyncMasters. If not set, this setting defaults to:

  • If spec.sync.externalAccess.loadBalancerIP is set, it defaults to https://<load-balancer-ip>:<8629>.
  • Otherwise it defaults to https://<sync-service-dns-name>:<8629>.

spec.sync.externalAccess.accessPackageSecretNames: []string

This setting specifies the names of zero of more Secrets that will be created by the deployment operator containing “access packages”. An access package contains those Secrets that are needed to access the SyncMasters of this ArangoDeployment.

By removing a name from this setting, the corresponding Secret is also deleted. Note that to remove all access packages, leave an empty array in place ([]). Completely removing the setting results in not modifying the list.

See the ArangoDeploymentReplication specification for more information on access packages.

spec.sync.auth.jwtSecretName: string

This setting specifies the name of a kubernetes Secret that contains the JWT token used for accessing all ArangoSync master servers. When not specified, the spec.auth.jwtSecretName value is used.

If you specify a name of a Secret that does not exist, a random token is created and stored in a Secret with given name.

spec.sync.auth.clientCASecretName: string

This setting specifies the name of a kubernetes Secret that contains a PEM encoded CA certificate used for client certificate verification in all ArangoSync master servers. This is a required setting when spec.sync.enabled is true. The default value is empty.

spec.sync.mq.type: string

This setting sets the type of message queue used by ArangoSync. Possible values are:

  • Direct (default) for direct HTTP connections between the 2 data centers.

spec.sync.tls.caSecretName: string

This setting specifies the name of a kubernetes Secret that contains a standard CA certificate + private key used to sign certificates for individual ArangoSync master servers.

When no name is specified, it defaults to <deployment-name>-sync-ca.

If you specify a name of a Secret that does not exist, a self-signed CA certificate + key is created and stored in a Secret with given name.

The specified Secret, must contain the following data fields:

  • ca.crt PEM encoded public key of the CA certificate
  • ca.key PEM encoded private key of the CA certificate

spec.sync.tls.altNames: []string

This setting specifies a list of alternate names that will be added to all generated certificates. These names can be DNS names or email addresses. The default value is empty.

spec.sync.monitoring.tokenSecretName: string

This setting specifies the name of a kubernetes Secret that contains the bearer token used for accessing all monitoring endpoints of all ArangoSync servers. When not specified, no monitoring token is used. The default value is empty.

spec.disableIPv6: bool

This setting prevents the use of IPv6 addresses by ArangoDB servers. The default is false.

This setting cannot be changed after the deployment has been created.

spec.restoreFrom: string

This setting specifies a ArangoBackup resource name the cluster should be restored from.

After a restore or failure to do so, the status of the deployment contains information about the restore operation in the restore key.

It will contain some of the following fields:

  • requestedFrom: name of the ArangoBackup used to restore from.
  • message: optional message explaining why the restore failed.
  • state: state indicating if the restore was successful or not. Possible values: Restoring, Restored, RestoreFailed

If the restoreFrom key is removed from the spec, the restore key is deleted as well.

A new restore attempt is made if and only if either in the status restore is not set or if spec.restoreFrom and status.requestedFrom are different.

spec.license.secretName: string

This setting specifies the name of a kubernetes Secret that contains the license key token used for enterprise images. This value is not used for the community edition.

spec.bootstrap.passwordSecretNames.root: string

This setting specifies a secret name for the credentials of the root user.

When a deployment is created the operator will setup the root user account according to the credentials given by the secret. If the secret doesn’t exist the operator creates a secret with a random password.

There are two magic values for the secret name:

  • None specifies no action. This disables root password randomization. This is the default value. (Thus the root password is empty - not recommended)
  • Auto specifies automatic name generation, which is <deploymentname>-root-password.

spec.metrics.enabled: bool

If this is set to true, the operator runs a sidecar container for every DBserver pod and every coordinator pod. The sidecar container runs the ArangoDB-exporter and exposes metrics of the corresponding arangod instance in Prometheus format on port 9101 under path /metrics. You also have to specify a string for spec.metrics.image, which is the Docker image name of the arangodb-exporter. At the time of this writing you should use arangodb/arangodb-exporter:0.1.6. See this repository for the latest version. If the image name is left empty, the same image as for the main deployment is used. Note however, that current ArangoDB releases (<= 3.4.5) do not ship the exporter in their image. This is going to change in the future.

In addition to the sidecar containers the operator will deploy a service to access the exporter ports (from within the k8s cluster), and a resource of type ServiceMonitor, provided the corresponding custom resource definition is deployed in the k8s cluster. If you are running Prometheus in the same k8s cluster with the Prometheus operator, this will be the case. The ServiceMonitor will have the following labels set:

  • app: arangodb
  • arango_deployment: YOUR_DEPLOYMENT_NAME
  • context: metrics
  • metrics: prometheus

This makes it possible that you configure your Prometheus deployment to automatically start monitoring on the available Prometheus feeds. To this end, you must configure the serviceMonitorSelector in the specs of your Prometheus deployment to match these labels. For example:

  serviceMonitorSelector:
    matchLabels:
      metrics: prometheus

would automatically select all pods of all ArangoDB cluster deployments which have metrics enabled.

spec.metrics.image: string

See above, this is the name of the Docker image for the ArangoDB exporter to expose metrics. If empty, the same image as for the main deployment is used.

spec.<group>.count: number

This setting specifies the number of servers to start for the given group. For the agent group, this value must be a positive, odd number. The default value is 3 for all groups except single (there the default is 1 for spec.mode: Single and 2 for spec.mode: ActiveFailover).

For the syncworkers group, it is highly recommended to use the same number as for the dbservers group.

spec.<group>.minCount: number

Specifies a minimum for the count of servers. If set, a specification is invalid if count < minCount.

spec.<group>.maxCount: number

Specifies a maximum for the count of servers. If set, a specification is invalid if count > maxCount.

spec.<group>.args: []string

This setting specifies additional commandline arguments passed to all servers of this group. The default value is an empty array.

spec.<group>.resources: ResourceRequirements

This setting specifies the resources required by pods of this group. This includes requests and limits.

See https://kubernetes.io/docs/concepts/configuration/manage-compute-resources-container/ for details.

spec.<group>.volumeClaimTemplate.Spec: PersistentVolumeClaimSpec

Specifies a volumeClaimTemplate used by operator to create to volume claims for pods of this group. This setting is not available for group coordinators, syncmasters & syncworkers.

The default value describes a volume with 8Gi storage, ReadWriteOnce access mode and volume mode set to PersistentVolumeFilesystem.

If this field is not set and spec.<group>.resources.requests.storage is set, then a default volume claim with size as specified by spec.<group>.resources.requests.storage will be created. In that case storage and iops is not forwarded to the pods resource requirements.

spec.<group>.serviceAccountName: string

This setting specifies the serviceAccountName for the Pods created for each server of this group. If empty, it defaults to using the default service account.

Using an alternative ServiceAccount is typically used to separate access rights. The ArangoDB deployments need some very minimal access rights. With the deployment of the operator, we grant the following rights for the default service account:

rules:
- apiGroups:
  - ""
  resources:
  - pods
  verbs:
  - get

If you are using a different service account, please grant these rights to that service account.

spec.<group>.priorityClassName: string

Priority class name for pods of this group. Will be forwarded to the pod spec. Kubernetes documentation

spec.<group>.probes.livenessProbeDisabled: bool

If set to true, the operator does not generate a liveness probe for new pods belonging to this group.

spec.<group>.probes.readinessProbeDisabled: bool

If set to true, the operator does not generate a readiness probe for new pods belonging to this group.

spec.<group>.tolerations: []Toleration

This setting specifies the tolerations for the Pods created for each server of this group.

By default, suitable tolerations are set for the following keys with the NoExecute effect:

  • node.kubernetes.io/not-ready
  • node.kubernetes.io/unreachable
  • node.alpha.kubernetes.io/unreachable (will be removed in future version)

For more information on tolerations, consult the Kubernetes documentation.

spec.<group>.nodeSelector: map[string]string

This setting specifies a set of labels to be used as nodeSelector for Pods of this node.

For more information on node selectors, consult the Kubernetes documentation.

Deprecated Fields

spec.<group>.resources.requests.storage: storageUnit

This setting specifies the amount of storage required for each server of this group. The default value is 8Gi.

This setting is not available for group coordinators, syncmasters & syncworkers because servers in these groups do not need persistent storage.

Please use VolumeClaimTemplate from now on. This field is not considered if VolumeClaimTemplate is set. Note however, that the information in requests is completely handed over to the pod in this case.

spec.<group>.storageClassName: string

This setting specifies the storageClass for the PersistentVolumes created for each server of this group.

This setting is not available for group coordinators, syncmasters & syncworkers because servers in these groups do not need persistent storage.

Please use VolumeClaimTemplate from now on. This field is not considered if VolumeClaimTemplate is set. Note however, that the information in requests is completely handed over to the pod in this case.