syncvolume

README

Volume Sync Controller

The Sync Volume controller is responsible for sending volumes to persistent layer by polling StorageOS API periodically.

Volume Sync Control Loop

The Volume sync controller periodically polls the StorageOS control plane API to retrieve a list of volumes. The poll interval defaults to 5s and is tunable via the -api-poll-interval flag.

All K8s volumes will be considered. Controller persists existing volumes and delete orpahn ones.

Prometheus Metrics

The following metrics are collected:

• storageos_api_request_duration_seconds A histogram of request latencies, partitioned by HTTP request method.
• storageos_api_requests_total A counter for requests from the api client, partitioned by HTTP request method and response code.
• storageos_sync_volume_duration_seconds Distribution of the length of time taken to sync all volumes.
• storageos_save_volume_duration_seconds Distribution of the length of time taken to save a volume.
• storageos_delete_volume_duration_seconds Distribution of the length of time taken to delete a volume.

Documentation

Index

• func RegisterMetrics()
• type LatencyMetric
• type Lister
• type Reconciler
  • func NewReconciler(k8s client.Client, api Lister, apiReset chan<- struct{}, ...) *Reconciler
  • func (r *Reconciler) SetupWithManager(mgr ctrl.Manager) error
  • func (r *Reconciler) Start(ctx context.Context) error

Functions

func RegisterMetrics

func RegisterMetrics()

RegisterMetrics ensures that the package metrics are registered.

Types

type LatencyMetric

type LatencyMetric interface {
	Observe(latency time.Duration)
}

LatencyMetric observes latency.

var (
	// SyncDuration is the latency metric that measures the duration of the
	// volume sync.
	SyncDuration LatencyMetric = &latencyAdapter{m: syncLatencyHistogram}

	// SaveDuration is the latency metric that measures the duration of the
	// volume save.
	SaveDuration LatencyMetric = &latencyAdapter{m: saveLatencyHistogram}

	// DeleteDuration is the latency metric that measures the duration of the
	// volume delete.
	DeleteDuration LatencyMetric = &latencyAdapter{m: saveLatencyHistogram}
)

type Lister

type Lister interface {
	ListVolumes(context.Context) ([]storageos.Object, error)
}

Lister provides access to StorageOS Volumes.

type Reconciler

type Reconciler struct {
	client.Client
	// contains filtered or unexported fields
}

Reconciler is syncing StorageOS volumes into K8s datastore, by polling it periodically.

func NewReconciler

func NewReconciler(
	k8s client.Client,
	api Lister,
	apiReset chan<- struct{},
	apiPollInterval time.Duration,
	recorder record.EventRecorder) *Reconciler

NewReconciler returns a new volume syncer.

func (*Reconciler) SetupWithManager

func (r *Reconciler) SetupWithManager(mgr ctrl.Manager) error

SetupWithManager registers with the controller manager.

Since this is an external controller, we don't need to register the controller, just add it as a Runnable so that the manager can control startup and shutdown.

func (*Reconciler) Start

func (r *Reconciler) Start(ctx context.Context) error

Start runs the main reconcile loop until the context is cancelled or there is a fatal error. It implements the controller-runtime Runnable interface so that it can be controlled by controller manager.

The reconcile loop spins up a separated routines for polling the API server and sync volumes into K8s datastore.