containerd

Documentation

Overview

Package containerd implements the containerd EngineClient.

Notes

containerd's task states of pausing and paused are both mapped to a paused container from the perspective of the whalewatcher module.

Index

• Constants
• type ContainerdWatcher
  • func NewContainerdWatcher(client *containerd.Client, opts ...NewOption) *ContainerdWatcher
  • func (cw *ContainerdWatcher) API() string
  • func (cw *ContainerdWatcher) Client() interface{}
  • func (cw *ContainerdWatcher) Close()
  • func (cw *ContainerdWatcher) ID(ctx context.Context) string
  • func (cw *ContainerdWatcher) Inspect(ctx context.Context, nameorid string) (*whalewatcher.Container, error)
  • func (cw *ContainerdWatcher) LifecycleEvents(ctx context.Context) (<-chan engineclient.ContainerEvent, <-chan error)
  • func (cw *ContainerdWatcher) List(ctx context.Context) ([]*whalewatcher.Container, error)
  • func (cw *ContainerdWatcher) PID() int
  • func (cw *ContainerdWatcher) Type() string
• type NewOption
  • func WithPID(pid int) NewOption

Constants

const ComposerProjectLabel = "com.docker.compose.project"

ComposerProjectLabel is the name of an optional container label identifying the composer project a container is part of. We don't import the definition from the moby package in order to not having to rely on that dependency.

const DockerNamespace = "moby"

DockerNamespace is the name of the containerd namespace used by Docker for its own containers (and tasks). As the whalewatcher module has a dedicated Docker engine client, we need to skip this namespace -- the rationale is that especially the container name is missing at the containerd engine level, but only available via the docker/moby API.

const NerdctlLabelPrefix = "nerdctl/"

NerdctlLabelPrefix is the label key prefix used to namespace (oh no, not another "namespace") nertctl-related labels. On purpose, we don't import nerdctl's definitions in order to avoid even more dependencies.

const NerdctlNameLabel = NerdctlLabelPrefix + "name"

NerdctlNameLabel stores a container's name, as opposed to the ID.

const Type = "containerd.io"

Type specifies this container engine's type identifier.

Types

type ContainerdWatcher

type ContainerdWatcher struct {
	// contains filtered or unexported fields
}

ContainerdWatcher is a containerd EngineClient for interfacing the generic whale watching with containerd daemons.

func NewContainerdWatcher

func NewContainerdWatcher(client *containerd.Client, opts ...NewOption) *ContainerdWatcher

NewContainerdWatcher returns a new ontainerdWatcher using the specified containerd engine client; normally, you would want to use this lower-level constructor only in unit tests.

func (*ContainerdWatcher) API

func (cw *ContainerdWatcher) API() string

API returns the container engine API path.

func (*ContainerdWatcher) Client

func (cw *ContainerdWatcher) Client() interface{}

Client returns the underlying engine client (engine-specific).

func (*ContainerdWatcher) Close

func (cw *ContainerdWatcher) Close()

Close cleans up and release any engine client resources, if necessary.

func (*ContainerdWatcher) ID

func (cw *ContainerdWatcher) ID(ctx context.Context) string

ID returns the (more or less) unique engine identifier; the exact format is engine-specific.

func (*ContainerdWatcher) Inspect

func (cw *ContainerdWatcher) Inspect(ctx context.Context, nameorid string) (*whalewatcher.Container, error)

Inspect (only) those container details of interest to us, given the name or ID of a container.

func (*ContainerdWatcher) LifecycleEvents

func (cw *ContainerdWatcher) LifecycleEvents(ctx context.Context) (
	<-chan engineclient.ContainerEvent, <-chan error,
)

LifecycleEvents streams container engine events, limited just to those events in the lifecycle of containers getting born (=alive, as opposed to, say, "conceived") and die.

func (*ContainerdWatcher) List

func (cw *ContainerdWatcher) List(ctx context.Context) ([]*whalewatcher.Container, error)

List all the currently alive and kicking containers, but do not list any containers without any processes.

func (*ContainerdWatcher) PID

func (cw *ContainerdWatcher) PID() int

PID returns the container engine PID, when known.

func (*ContainerdWatcher) Type

func (cw *ContainerdWatcher) Type() string

Type returns the type identifier for this container engine.

type NewOption

type NewOption func(*ContainerdWatcher)

NewOption represents options to NewContainerdWatcher when creating new watchers keeping eyes on containerd engines.

func WithPID

func WithPID(pid int) NewOption

WithPID sets the engine's PID when known.