wait

Documentation

Overview

package wait provides functions to help with waiting for certain conditions to be true.

A `For` function is provided that can handle polling a given `WaitCondition` until it results in true or errors (either through a problem or a timeout condition).

A collection of conditions are also included that can be used with either the provided `For` function or or with the `Eventually` function from Gomega

Example using `For` with the `IsClusterReadyCondition` condition

err := wait.For(
	wait.IsClusterReadyCondition(ctx, f.MC(), clusterName, namespace, f.wcClients),
	wait.WithContext(ctx),
	wait.WithInterval(10*time.Second),
)
if err != nil {
	return nil, err
}

Example using Gomega's `Eventually` with the `IsNumNodesReady` condition

Eventually(
	wait.IsNumNodesReady(ctx, client, 3, &cr.MatchingLabels{"node-role.kubernetes.io/control-plane": ""}),
	20*time.Minute,
	30*time.Second,
).Should(BeTrue())

The WaitCondition functions return a success boolean and an error. The polling of the condition will continue until one of three things occurs:

1. The success boolean is returned as `true`
2. An error is returned from the WaitCondition function
3. A timeout occurs, resulting in an error being returned

Index

• Constants
• func For(fn WaitCondition, opts ...Option) error
• type Option
  • func WithContext(context context.Context) Option
  • func WithInterval(interval time.Duration) Option
  • func WithTimeout(timeout time.Duration) Option
• type Options
• type WaitCondition
  • func DoesResourceExist(ctx context.Context, kubeClient *client.Client, resource cr.Object) WaitCondition
  • func IsClusterReadyCondition(ctx context.Context, kubeClient *client.Client, clusterName string, ...) WaitCondition
  • func IsNumNodesReady(ctx context.Context, kubeClient *client.Client, expectedNodes int, ...) WaitCondition
  • func IsResourceDeleted(ctx context.Context, kubeClient *client.Client, resource cr.Object) WaitCondition

Constants

const (
	// DefaultTimeout is the default max time to wait before returning an error if a timeout is not provided
	DefaultTimeout = 1 * time.Hour
	// DefaultInterval is the polling interval to use if an interval is not provided
	DefaultInterval = 10 * time.Second
)

Functions

func For

func For(fn WaitCondition, opts ...Option) error

For continuously polls the provided WaitCondition function until either the timeout is reached or the function returns as done

Types

type Option

type Option func(*Options)

Option is a function that can be optionally provided to override default options of a wait condition

func WithContext

func WithContext(context context.Context) Option

WithContext overrides the context used when waiting. This allows for using a context with a timeout / deadline already set.

func WithInterval

func WithInterval(interval time.Duration) Option

WithInterval overrides the default polling interval when waiting

func WithTimeout

func WithTimeout(timeout time.Duration) Option

WithTimeout overrides the default timeout when waiting

type Options

type Options struct {
	Context  context.Context
	Interval time.Duration
	Timeout  time.Duration
}

Options are the options available when waiting

type WaitCondition

type WaitCondition func() (done bool, err error)

WaitCondition is a function performing a condition check for if we need to keep waiting

func DoesResourceExist

func DoesResourceExist(ctx context.Context, kubeClient *client.Client, resource cr.Object) WaitCondition

DoesResourceExist returns a WaitCondition that checks if the given resource exists in the cluster

func IsClusterReadyCondition

func IsClusterReadyCondition(ctx context.Context, kubeClient *client.Client, clusterName string, namespace string, clientMap map[string]*client.Client) WaitCondition

IsClusterReadyCondition returns a WaitCondition to check when a cluster is considered ready and accessible

func IsNumNodesReady

func IsNumNodesReady(ctx context.Context, kubeClient *client.Client, expectedNodes int, labels *cr.MatchingLabels) WaitCondition

IsNumNodesReady returns a WaitCondition that checks if the number of ready nodes matching the given labels equals or exceeds the expectedNodes value

func IsResourceDeleted

func IsResourceDeleted(ctx context.Context, kubeClient *client.Client, resource cr.Object) WaitCondition

IsResourceDeleted returns a WaitCondition that checks if the given resource has been deleted from the cluster yet