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etcd-druid CLI Flags
etcd-druid process can be started with the following command line flags.
Command line flags
Leader election
If you wish to setup etcd-druid in high-availability mode then leader election needs to be enabled to ensure that at a time only one replica services the incoming events and does the reconciliation.
| Flag | Description | Default |
|---|---|---|
| enable-leader-election | Leader election provides the capability to select one replica as a leader where active reconciliation will happen. The other replicas will keep waiting for leadership change and not do active reconciliations. | false |
| leader-election-id | Name of the k8s lease object that leader election will use for holding the leader lock. By default etcd-druid will use lease resource lock for leader election which is also a natural usecase for leases and is also recommended by k8s. | “druid-leader-election” |
| leader-election-resource-lock | Deprecated: This flag will be removed in later version of druid. By default lease.coordination.k8s.io resources will be used for leader election resource locking for the controller manager. | “leases” |
Metrics
etcd-druid exposes a /metrics endpoint which can be scrapped by tools like Prometheus. If the default metrics endpoint configuration is not suitable then consumers can change it via the following options.
| Flag | Description | Default |
|---|---|---|
| metrics-bind-address | The IP address that the metrics endpoint binds to | "" |
| metrics-port | The port used for the metrics endpoint | 8080 |
| metrics-addr | Duration to wait for after compaction job is completed, to allow Prometheus metrics to be scraped. Deprecated: Please use --metrics-bind-address and --metrics-port instead | “:8080” |
Metrics bind-address is computed by joining the host and port. By default its value is computed as :8080.
!!! tip
Ensure that the metrics-port is also reflected in the etcd-druid deployment specification.
Webhook Server
etcd-druid provides the following CLI flags to configure webhook server. These CLI flags are used to construct a new webhook.Server by configuring Options.
| Flag | Description | Default |
|---|---|---|
| webhook-server-bind-address | It is the address that the webhook server will listen on. | "" |
| webhook-server-port | Port is the port number that the webhook server will serve. | 9443 |
| webhook-server-tls-server-cert-dir | The path to a directory containing the server’s TLS certificate and key (the files must be named tls.crt and tls.key respectively). | /etc/webhook-server-tls |
Etcd-Components Webhook
etcd-druid provisions and manages several Kubernetes resources which we call Etcdcluster components. To ensure that there is no accidental changes done to these managed resources, a webhook is put in place to check manual changes done to any managed etcd-cluster Kubernetes resource. It rejects most of these changes except a few. The details on how to enable the etcd-components webhook, which resources are protected and in which scenarios is the change allowed is documented here.
Following CLI flags are provided to configure the etcd-components webhook:
| Flag | Description | Default |
|---|---|---|
| enable-etcd-components-webhook | Enable EtcdComponents Webhook to prevent unintended changes to resources managed by etcd-druid. | false |
| reconciler-service-account | The fully qualified name of the service account used by etcd-druid for reconciling etcd resources. If unspecified, the default service account mounted for etcd-druid will be used | etcd-druid-service-account |
| etcd-components-exempt-service-accounts | In case there is a need to allow changes to Etcd resources from external controllers like vertical-pod-autoscaler then one must list the ServiceAaccount that is used by each such controller. | "" |
Reconcilers
Following set of flags configures the reconcilers running within etcd-druid. To know more about different reconcilers read this document.
Etcd Reconciler
| Flag | Description | Default |
|---|---|---|
| etcd-workers | Number of workers spawned for concurrent reconciles of Etcd resources. | 3 |
| enable-etcd-spec-auto-reconcile | If true then automatically reconciles Etcd Spec. If false, waits for explicit annotation gardener.cloud/operation: reconcile to be placed on the Etcd resource to trigger reconcile. | false |
| disable-etcd-serviceaccount-automount | For each Etcd cluster a ServiceAccount is created which is used by the StatefulSet pods and tied to Role via RoleBinding. If false then pods running as this ServiceAccount will have the API token automatically mounted. You can consider disabling it if you wish to use Projected Volumes allowing one to set an expirationSeconds on the mounted token for better security. To use projected volumes ensure that you have set relevant kube-apiserver flags.Note: With Kubernetes version >=1.24 projected service account token is the default. This means that we no longer need this flag. Issue #872 has been raised to address this. | false |
| etcd-status-sync-period | Etcd.Status is periodically updated. This interval defines the status sync frequency. | 15s |
| etcd-member-notready-threshold | Threshold after which an etcd member is considered not ready if the status was unknown before. This is currently used to update EtcdMemberConditionStatus. | 5m |
| etcd-member-unknown-threshold | Threshold after which an etcd member is considered unknown. This is currently used to update EtcdMemberConditionStatus. | 1m |
| ignore-operation-annotation | Specifies whether to ignore or honour the annotation gardener.cloud/operation: reconcile on resources to be reconciled.Deprecated: please use --enable-etcd-spec-auto-reconcile instead. | false |
Compaction Reconciler
| Flag | Description | Default |
|---|---|---|
| enable-backup-compaction | Enable automatic compaction of etcd backups | false |
| compaction-workers | Number of workers that can be spawned for concurrent reconciles for compaction Jobs. The controller creates a backup compaction job if a certain etcd event threshold is reached. If compaction is enabled, the value for this flag must be greater than zero. | 3 |
| etcd-events-threshold | Defines the threshold in terms of total number of etcd events before a backup compaction job is triggered. | 1000000 |
| active-deadline-duration | Duration after which a running backup compaction job will be terminated. | 3h |
| metrics-scrape-wait-duration | Duration to wait for after compaction job is completed, to allow Prometheus metrics to be scraped. | 0s |
Etcd Copy-Backup Task & Secret Reconcilers
| Flag | Description | Default |
|---|---|---|
| etcd-copy-backups-task-workers | Number of workers spawned for concurrent reconciles for EtcdCopyBackupTask resources. | 3 |
| secret-workers | Number of workers spawned for concurrent reconciles for secrets. | 10 |
Miscellaneous
| Flag | Description | Default |
|---|---|---|
| feature-gates | A set of key=value pairs that describe feature gates for alpha/experimental features. Please check feature-gates for more information. | "" |
| disable-lease-cache | Disable cache for lease.coordination.k8s.io resources. | false |