manager

Documentation

Overview

Package manager is required to create Controllers and provides shared dependencies such as clients, caches, schemes, etc. Controllers must be started by calling Manager.Start.

Index

• type LeaderElectionRunnable
• type Manager
  • func New(config *rest.Config, options Options) (Manager, error)
• type NewClientFunc
• type Options
• type Runnable
• type RunnableFunc
  • func (r RunnableFunc) Start(s <-chan struct{}) error

Examples

• Manager (Add)
• Manager (Start)
• New
• New (MultinamespaceCache)

Types

type LeaderElectionRunnable

type LeaderElectionRunnable interface {
	// NeedLeaderElection returns true if the Runnable needs to be run in the leader election mode.
	// e.g. controllers need to be run in leader election mode, while webhook server doesn't.
	NeedLeaderElection() bool
}

LeaderElectionRunnable knows if a Runnable needs to be run in the leader election mode.

type Manager

type Manager interface {
	// Add will set requested dependencies on the component, and cause the component to be
	// started when Start is called.  Add will inject any dependencies for which the argument
	// implements the inject interface - e.g. inject.Client.
	// Depending on if a Runnable implements LeaderElectionRunnable interface, a Runnable can be run in either
	// non-leaderelection mode (always running) or leader election mode (managed by leader election if enabled).
	Add(Runnable) error

	// SetFields will set any dependencies on an object for which the object has implemented the inject
	// interface - e.g. inject.Client.
	SetFields(interface{}) error

	// Start starts all registered Controllers and blocks until the Stop channel is closed.
	// Returns an error if there is an error starting any controller.
	Start(<-chan struct{}) error

	// GetConfig returns an initialized Config
	GetConfig() *rest.Config

	// GetScheme returns an initialized Scheme
	GetScheme() *runtime.Scheme

	// GetClient returns a client configured with the Config. This client may
	// not be a fully "direct" client -- it may read from a cache, for
	// instance.  See Options.NewClient for more information on how the default
	// implementation works.
	GetClient() client.Client

	// GetFieldIndexer returns a client.FieldIndexer configured with the client
	GetFieldIndexer() client.FieldIndexer

	// GetCache returns a cache.Cache
	GetCache() cache.Cache

	// GetEventRecorderFor returns a new EventRecorder for the provided name
	GetEventRecorderFor(name string) record.EventRecorder

	// GetRESTMapper returns a RESTMapper
	GetRESTMapper() meta.RESTMapper

	// GetAPIReader returns a reader that will be configured to use the API server.
	// This should be used sparingly and only when the client does not fit your
	// use case.
	GetAPIReader() client.Reader

	// GetWebhookServer returns a webhook.Server
	GetWebhookServer() *webhook.Server
}

Manager initializes shared dependencies such as Caches and Clients, and provides them to Runnables. A Manager is required to create Controllers.

Example (Add)

This example adds a Runnable for the Manager to Start.

package main

import (
	"os"

	logf "sigs.k8s.io/controller-runtime/pkg/log"
	"sigs.k8s.io/controller-runtime/pkg/manager"
)

var (
	mgr manager.Manager

	log = logf.Log.WithName("manager-examples")
)

func main() {
	err := mgr.Add(manager.RunnableFunc(func(<-chan struct{}) error {
		// Do something
		return nil
	}))
	if err != nil {
		log.Error(err, "unable add a runnable to the manager")
		os.Exit(1)
	}
}

Example (Start)

This example starts a Manager that has had Runnables added.

package main

import (
	"os"

	logf "sigs.k8s.io/controller-runtime/pkg/log"
	"sigs.k8s.io/controller-runtime/pkg/manager"
	"sigs.k8s.io/controller-runtime/pkg/manager/signals"
)

var (
	mgr manager.Manager
	// NB: don't call SetLogger in init(), or else you'll mess up logging in the main suite.
	log = logf.Log.WithName("manager-examples")
)

func main() {
	err := mgr.Start(signals.SetupSignalHandler())
	if err != nil {
		log.Error(err, "unable start the manager")
		os.Exit(1)
	}
}

func New

func New(config *rest.Config, options Options) (Manager, error)

New returns a new Manager for creating Controllers.

Example

This example creates a new Manager that can be used with controller.New to create Controllers.

package main

import (
	"os"

	"sigs.k8s.io/controller-runtime/pkg/client/config"

	logf "sigs.k8s.io/controller-runtime/pkg/log"
	"sigs.k8s.io/controller-runtime/pkg/manager"
)

var

// NB: don't call SetLogger in init(), or else you'll mess up logging in the main suite.
log = logf.Log.WithName("manager-examples")

func main() {
	cfg, err := config.GetConfig()
	if err != nil {
		log.Error(err, "unable to get kubeconfig")
		os.Exit(1)
	}

	mgr, err := manager.New(cfg, manager.Options{})
	if err != nil {
		log.Error(err, "unable to set up manager")
		os.Exit(1)
	}
	log.Info("created manager", "manager", mgr)
}

Example (MultinamespaceCache)

This example creates a new Manager that has a cache scoped to a list of namespaces.

package main

import (
	"os"

	"sigs.k8s.io/controller-runtime/pkg/cache"
	"sigs.k8s.io/controller-runtime/pkg/client/config"

	logf "sigs.k8s.io/controller-runtime/pkg/log"
	"sigs.k8s.io/controller-runtime/pkg/manager"
)

var

// NB: don't call SetLogger in init(), or else you'll mess up logging in the main suite.
log = logf.Log.WithName("manager-examples")

func main() {
	cfg, err := config.GetConfig()
	if err != nil {
		log.Error(err, "unable to get kubeconfig")
		os.Exit(1)
	}

	mgr, err := manager.New(cfg, manager.Options{
		NewCache: cache.MultiNamespacedCacheBuilder([]string{"namespace1", "namespace2"}),
	})
	if err != nil {
		log.Error(err, "unable to set up manager")
		os.Exit(1)
	}
	log.Info("created manager", "manager", mgr)
}

type NewClientFunc

type NewClientFunc func(cache cache.Cache, config *rest.Config, options client.Options) (client.Client, error)

NewClientFunc allows a user to define how to create a client

type Options

type Options struct {
	// Scheme is the scheme used to resolve runtime.Objects to GroupVersionKinds / Resources
	// Defaults to the kubernetes/client-go scheme.Scheme, but it's almost always better
	// idea to pass your own scheme in.  See the documentation in pkg/scheme for more information.
	Scheme *runtime.Scheme

	// MapperProvider provides the rest mapper used to map go types to Kubernetes APIs
	MapperProvider func(c *rest.Config) (meta.RESTMapper, error)

	// SyncPeriod determines the minimum frequency at which watched resources are
	// reconciled. A lower period will correct entropy more quickly, but reduce
	// responsiveness to change if there are many watched resources. Change this
	// value only if you know what you are doing. Defaults to 10 hours if unset.
	SyncPeriod *time.Duration

	// LeaderElection determines whether or not to use leader election when
	// starting the manager.
	LeaderElection bool

	// LeaderElectionNamespace determines the namespace in which the leader
	// election configmap will be created.
	LeaderElectionNamespace string

	// LeaderElectionID determines the name of the configmap that leader election
	// will use for holding the leader lock.
	LeaderElectionID string

	// LeaseDuration is the duration that non-leader candidates will
	// wait to force acquire leadership. This is measured against time of
	// last observed ack. Default is 15 seconds.
	LeaseDuration *time.Duration
	// RenewDeadline is the duration that the acting master will retry
	// refreshing leadership before giving up. Default is 10 seconds.
	RenewDeadline *time.Duration
	// RetryPeriod is the duration the LeaderElector clients should wait
	// between tries of actions. Default is 2 seconds.
	RetryPeriod *time.Duration

	// Namespace if specified restricts the manager's cache to watch objects in
	// the desired namespace Defaults to all namespaces
	//
	// Note: If a namespace is specified, controllers can still Watch for a
	// cluster-scoped resource (e.g Node).  For namespaced resources the cache
	// will only hold objects from the desired namespace.
	Namespace string

	// MetricsBindAddress is the TCP address that the controller should bind to
	// for serving prometheus metrics.
	// It can be set to "0" to disable the metrics serving.
	MetricsBindAddress string

	// Port is the port that the webhook server serves at.
	// It is used to set webhook.Server.Port.
	Port int
	// Host is the hostname that the webhook server binds to.
	// It is used to set webhook.Server.Host.
	Host string

	// CertDir is the directory that contains the server key and certificate.
	// if not set, webhook server would look up the server key and certificate in
	// {TempDir}/k8s-webhook-server/serving-certs
	CertDir string

	// NewCache is the function that will create the cache to be used
	// by the manager. If not set this will use the default new cache function.
	NewCache cache.NewCacheFunc

	// NewClient will create the client to be used by the manager.
	// If not set this will create the default DelegatingClient that will
	// use the cache for reads and the client for writes.
	NewClient NewClientFunc

	// EventBroadcaster records Events emitted by the manager and sends them to the Kubernetes API
	// Use this to customize the event correlator and spam filter
	EventBroadcaster record.EventBroadcaster
	// contains filtered or unexported fields
}

Options are the arguments for creating a new Manager

type Runnable

type Runnable interface {
	// Start starts running the component.  The component will stop running
	// when the channel is closed.  Start blocks until the channel is closed or
	// an error occurs.
	Start(<-chan struct{}) error
}

Runnable allows a component to be started. It's very important that Start blocks until it's done running.

type RunnableFunc

type RunnableFunc func(<-chan struct{}) error

RunnableFunc implements Runnable using a function. It's very important that the given function block until it's done running.

func (RunnableFunc) Start

func (r RunnableFunc) Start(s <-chan struct{}) error

Start implements Runnable