containerd

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 Go to latest Published: Jan 2, 2020 License: Apache-2.0 Imports: 76 Imported by: 0

README ¶

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containerd is an industry-standard container runtime with an emphasis on simplicity, robustness and portability. It is available as a daemon for Linux and Windows, which can manage the complete container lifecycle of its host system: image transfer and storage, container execution and supervision, low-level storage and network attachments, etc.

containerd is designed to be embedded into a larger system, rather than being used directly by developers or end-users.

architecture

Getting Started

See our documentation on containerd.io:

See how to build containerd from source at BUILDING.

If you are interested in trying out containerd see our example at Getting Started.

Runtime Requirements

Runtime requirements for containerd are very minimal. Most interactions with the Linux and Windows container feature sets are handled via runc and/or OS-specific libraries (e.g. hcsshim for Microsoft). The current required version of runc is always listed in RUNC.md.

There are specific features used by containerd core code and snapshotters that will require a minimum kernel version on Linux. With the understood caveat of distro kernel versioning, a reasonable starting point for Linux is a minimum 4.x kernel version.

The overlay filesystem snapshotter, used by default, uses features that were finalized in the 4.x kernel series. If you choose to use btrfs, there may be more flexibility in kernel version (minimum recommended is 3.18), but will require the btrfs kernel module and btrfs tools to be installed on your Linux distribution.

To use Linux checkpoint and restore features, you will need criu installed on your system. See more details in Checkpoint and Restore.

Build requirements for developers are listed in BUILDING.

Features

Client

containerd offers a full client package to help you integrate containerd into your platform.


import (
  "github.com/containerd/containerd"
  "github.com/containerd/containerd/cio"
)


func main() {
	client, err := containerd.New("/run/containerd/containerd.sock")
	defer client.Close()
}

Namespaces

Namespaces allow multiple consumers to use the same containerd without conflicting with each other. It has the benefit of sharing content but still having separation with containers and images.

To set a namespace for requests to the API:

context = context.Background()
// create a context for docker
docker = namespaces.WithNamespace(context, "docker")

containerd, err := client.NewContainer(docker, "id")

To set a default namespace on the client:

client, err := containerd.New(address, containerd.WithDefaultNamespace("docker"))

Distribution

// pull an image
image, err := client.Pull(context, "docker.io/library/redis:latest")

// push an image
err := client.Push(context, "docker.io/library/redis:latest", image.Target())

Containers

In containerd, a container is a metadata object. Resources such as an OCI runtime specification, image, root filesystem, and other metadata can be attached to a container.

redis, err := client.NewContainer(context, "redis-master")
defer redis.Delete(context)

OCI Runtime Specification

containerd fully supports the OCI runtime specification for running containers. We have built in functions to help you generate runtime specifications based on images as well as custom parameters.

You can specify options when creating a container about how to modify the specification.

redis, err := client.NewContainer(context, "redis-master", containerd.WithNewSpec(oci.WithImageConfig(image)))

Root Filesystems

containerd allows you to use overlay or snapshot filesystems with your containers. It comes with builtin support for overlayfs and btrfs.

// pull an image and unpack it into the configured snapshotter
image, err := client.Pull(context, "docker.io/library/redis:latest", containerd.WithPullUnpack)

// allocate a new RW root filesystem for a container based on the image
redis, err := client.NewContainer(context, "redis-master",
	containerd.WithNewSnapshot("redis-rootfs", image),
	containerd.WithNewSpec(oci.WithImageConfig(image)),
)

// use a readonly filesystem with multiple containers
for i := 0; i < 10; i++ {
	id := fmt.Sprintf("id-%s", i)
	container, err := client.NewContainer(ctx, id,
		containerd.WithNewSnapshotView(id, image),
		containerd.WithNewSpec(oci.WithImageConfig(image)),
	)
}

Tasks

Taking a container object and turning it into a runnable process on a system is done by creating a new Task from the container. A task represents the runnable object within containerd.

// create a new task
task, err := redis.NewTask(context, cio.Stdio)
defer task.Delete(context)

// the task is now running and has a pid that can be use to setup networking
// or other runtime settings outside of containerd
pid := task.Pid()

// start the redis-server process inside the container
err := task.Start(context)

// wait for the task to exit and get the exit status
status, err := task.Wait(context)

Checkpoint and Restore

If you have criu installed on your machine you can checkpoint and restore containers and their tasks. This allow you to clone and/or live migrate containers to other machines.

// checkpoint the task then push it to a registry
checkpoint, err := task.Checkpoint(context)

err := client.Push(context, "myregistry/checkpoints/redis:master", checkpoint)

// on a new machine pull the checkpoint and restore the redis container
checkpoint, err := client.Pull(context, "myregistry/checkpoints/redis:master")

redis, err = client.NewContainer(context, "redis-master", containerd.WithNewSnapshot("redis-rootfs", checkpoint))
defer container.Delete(context)

task, err = redis.NewTask(context, cio.Stdio, containerd.WithTaskCheckpoint(checkpoint))
defer task.Delete(context)

err := task.Start(context)

Snapshot Plugins

In addition to the built-in Snapshot plugins in containerd, additional external plugins can be configured using GRPC. An external plugin is made available using the configured name and appears as a plugin alongside the built-in ones.

To add an external snapshot plugin, add the plugin to containerd's config file (by default at /etc/containerd/config.toml). The string following proxy_plugin. will be used as the name of the snapshotter and the address should refer to a socket with a GRPC listener serving containerd's Snapshot GRPC API. Remember to restart containerd for any configuration changes to take effect.

[proxy_plugins]
  [proxy_plugins.customsnapshot]
    type = "snapshot"
    address =  "/var/run/mysnapshotter.sock"

See PLUGINS.md for how to create plugins

Releases and API Stability

Please see RELEASES.md for details on versioning and stability of containerd components.

Communication

For async communication and long running discussions please use issues and pull requests on the github repo. This will be the best place to discuss design and implementation.

For sync communication we have a community slack with a #containerd channel that everyone is welcome to join and chat about development.

Slack: Catch us in the #containerd and #containerd-dev channels on dockercommunity.slack.com. Click here for an invite to docker community slack.

Security audit

A third party security audit was performed by Cure53 in 4Q2018; the full report is available in our docs/ directory.

Reporting security issues

If you are reporting a security issue, please reach out discreetly at security@containerd.io.

Licenses

The containerd codebase is released under the Apache 2.0 license. The README.md file, and files in the "docs" folder are licensed under the Creative Commons Attribution 4.0 International License. You may obtain a copy of the license, titled CC-BY-4.0, at http://creativecommons.org/licenses/by/4.0/.

Project details

containerd is the primary open source project within the broader containerd GitHub repository. However, all projects within the repo have common maintainership, governance, and contributing guidelines which are stored in a project repository commonly for all containerd projects.

Please find all these core project documents, including the:

information in our containerd/project repository.

Adoption

Interested to see who is using containerd? Are you using containerd in a project? Please add yourself via pull request to our ADOPTERS.md file.

Documentation ¶

Index ¶

Constants ¶

View Source 
const (
	// DefaultSnapshotter will set the default snapshotter for the platform.
	// This will be based on the client compilation target, so take that into
	// account when choosing this value.
	DefaultSnapshotter = "overlayfs"
)
View Source 
const StopSignalLabel = "io.containerd.image.config.stop-signal"

StopSignalLabel is a well-known containerd label for storing the stop signal specified in the OCI image config

View Source 
const UnknownExitStatus = 255

UnknownExitStatus is returned when containerd is unable to determine the exit status of a process. This can happen if the process never starts or if an error was encountered when obtaining the exit status, it is set to 255.

Variables ¶

View Source 
var (
	// ErrCheckpointRWUnsupported is returned if the container runtime does not support checkpoint
	ErrCheckpointRWUnsupported = errors.New("rw checkpoint is only supported on v2 runtimes")
	// ErrMediaTypeNotFound returns an error when a media type in the manifest is unknown
	ErrMediaTypeNotFound = errors.New("media type not found")
)
View Source 
var (
	// ErrImageNameNotFoundInIndex is returned when the image name is not found in the index
	ErrImageNameNotFoundInIndex = errors.New("image name not found in index")
	// ErrRuntimeNameNotFoundInIndex is returned when the runtime is not found in the index
	ErrRuntimeNameNotFoundInIndex = errors.New("runtime not found in index")
	// ErrSnapshotterNameNotFoundInIndex is returned when the snapshotter is not found in the index
	ErrSnapshotterNameNotFoundInIndex = errors.New("snapshotter not found in index")
)

Functions ¶

func CheckRuntime ¶ 

func CheckRuntime(current, expected string) bool

CheckRuntime returns true if the current runtime matches the expected runtime. Providing various parts of the runtime schema will match those parts of the expected runtime

func GetIndexByMediaType ¶ 

func GetIndexByMediaType(index *imagespec.Index, mt string) (*imagespec.Descriptor, error)

GetIndexByMediaType returns the index in a manifest for the specified media type

func GetOCIStopSignal ¶ 

func GetOCIStopSignal(ctx context.Context, image Image, defaultSignal string) (string, error)

GetOCIStopSignal retrieves the stop signal specified in the OCI image config

func GetStopSignal ¶ 

func GetStopSignal(ctx context.Context, container Container, defaultSignal syscall.Signal) (syscall.Signal, error)

GetStopSignal retrieves the container stop signal, specified by the well-known containerd label (StopSignalLabel)

func NewImageStoreFromClient ¶ 

func NewImageStoreFromClient(client imagesapi.ImagesClient) images.Store

NewImageStoreFromClient returns a new image store client

func NewNamespaceStoreFromClient ¶ 

func NewNamespaceStoreFromClient(client api.NamespacesClient) namespaces.Store

NewNamespaceStoreFromClient returns a new namespace store

func NewRemoteContainerStore ¶ 

func NewRemoteContainerStore(client containersapi.ContainersClient) containers.Store

NewRemoteContainerStore returns the container Store connected with the provided client

func ParseSignal ¶ 

func ParseSignal(rawSignal string) (syscall.Signal, error)

ParseSignal parses a given string into a syscall.Signal the rawSignal can be a string with "SIG" prefix, or a signal number in string format.

func WithCheckpointImage ¶ 

func WithCheckpointImage(ctx context.Context, client *Client, c *containers.Container, index *imagespec.Index, copts *options.CheckpointOptions) error

WithCheckpointImage includes the container image in the checkpoint

func WithCheckpointRW ¶ 

func WithCheckpointRW(ctx context.Context, client *Client, c *containers.Container, index *imagespec.Index, copts *options.CheckpointOptions) error

WithCheckpointRW includes the rw in the checkpoint

func WithCheckpointRuntime ¶ 

func WithCheckpointRuntime(ctx context.Context, client *Client, c *containers.Container, index *imagespec.Index, copts *options.CheckpointOptions) error

WithCheckpointRuntime includes the container runtime info

func WithCheckpointTask ¶ 

func WithCheckpointTask(ctx context.Context, client *Client, c *containers.Container, index *imagespec.Index, copts *options.CheckpointOptions) error

WithCheckpointTask includes the running task

func WithCheckpointTaskExit ¶ 

func WithCheckpointTaskExit(ctx context.Context, client *Client, c *containers.Container, index *imagespec.Index, copts *options.CheckpointOptions) error

WithCheckpointTaskExit causes the task to exit after checkpoint

func WithInstallLibs ¶ 

func WithInstallLibs(c *InstallConfig)

WithInstallLibs installs libs from the image

func WithInstallReplace ¶ 

func WithInstallReplace(c *InstallConfig)

WithInstallReplace will replace existing files

func WithKillAll ¶ 

func WithKillAll(ctx context.Context, i *KillInfo) error

WithKillAll kills all processes for a task

func WithNoNewKeyring ¶ 

func WithNoNewKeyring(ctx context.Context, c *Client, ti *TaskInfo) error

WithNoNewKeyring causes tasks not to be created with a new keyring for secret storage. There is an upper limit on the number of keyrings in a linux system

func WithNoPivotRoot ¶ 

func WithNoPivotRoot(_ context.Context, _ *Client, ti *TaskInfo) error

WithNoPivotRoot instructs the runtime not to you pivot_root

func WithProcessKill ¶ 

func WithProcessKill(ctx context.Context, p Process) error

WithProcessKill will forcefully kill and delete a process

func WithPullUnpack ¶ 

func WithPullUnpack(_ *Client, c *RemoteContext) error

WithPullUnpack is used to unpack an image after pull. This uses the snapshotter, content store, and diff service configured for the client.

func WithSchema1Conversion ¶ 

func WithSchema1Conversion(client *Client, c *RemoteContext) error

WithSchema1Conversion is used to convert Docker registry schema 1 manifests to oci manifests on pull. Without this option schema 1 manifests will return a not supported error.

func WithSnapshotCleanup ¶ 

func WithSnapshotCleanup(ctx context.Context, client *Client, c containers.Container) error

WithSnapshotCleanup deletes the rootfs snapshot allocated for the container

func WithStdinCloser ¶ 

func WithStdinCloser(r *IOCloseInfo)

WithStdinCloser closes the stdin of a process

func WithoutRefreshedMetadata ¶ 

func WithoutRefreshedMetadata(i *InfoConfig)

WithoutRefreshedMetadata will use the current metadata attached to the container object

Types ¶

type CheckpointOpts ¶ 

type CheckpointOpts func(context.Context, *Client, *containers.Container, *imagespec.Index, *options.CheckpointOptions) error

CheckpointOpts are options to manage the checkpoint operation

type CheckpointTaskInfo ¶ 

type CheckpointTaskInfo struct {
	Name string
	// ParentCheckpoint is the digest of a parent checkpoint
	ParentCheckpoint digest.Digest
	// Options hold runtime specific settings for checkpointing a task
	Options interface{}
	// contains filtered or unexported fields
}

CheckpointTaskInfo allows specific checkpoint information to be set for the task

func (*CheckpointTaskInfo) Runtime ¶ 

func (i *CheckpointTaskInfo) Runtime() string

Runtime name for the container

type CheckpointTaskOpts ¶ 

type CheckpointTaskOpts func(*CheckpointTaskInfo) error

CheckpointTaskOpts allows the caller to set checkpoint options

func WithCheckpointImagePath ¶ 

func WithCheckpointImagePath(path string) CheckpointTaskOpts

WithCheckpointImagePath sets image path for checkpoint option

func WithCheckpointName ¶ 

func WithCheckpointName(name string) CheckpointTaskOpts

WithCheckpointName sets the image name for the checkpoint

type Client ¶ 

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

Client is the client to interact with containerd and its various services using a uniform interface

func New ¶ 

func New(address string, opts ...ClientOpt) (*Client, error)

New returns a new containerd client that is connected to the containerd instance provided by address

func NewWithConn ¶ 

func NewWithConn(conn *grpc.ClientConn, opts ...ClientOpt) (*Client, error)

NewWithConn returns a new containerd client that is connected to the containerd instance provided by the connection

func (*Client) Close ¶ 

func (c *Client) Close() error

Close closes the clients connection to containerd

func (*Client) Conn ¶ 

func (c *Client) Conn() *grpc.ClientConn

Conn returns the underlying GRPC connection object

func (*Client) ContainerService ¶ 

func (c *Client) ContainerService() containers.Store

ContainerService returns the underlying container Store

func (*Client) Containers ¶ 

func (c *Client) Containers(ctx context.Context, filters ...string) ([]Container, error)

Containers returns all containers created in containerd

func (*Client) ContentStore ¶ 

func (c *Client) ContentStore() content.Store

ContentStore returns the underlying content Store

func (*Client) DiffService ¶ 

func (c *Client) DiffService() DiffService

DiffService returns the underlying Differ

func (*Client) EventService ¶ 

func (c *Client) EventService() EventService

EventService returns the underlying event service

func (*Client) Export ¶ 

func (c *Client) Export(ctx context.Context, w io.Writer, opts ...archive.ExportOpt) error

Export exports images to a Tar stream. The tar archive is in OCI format with a Docker compatible manifest when a single target platform is given.

func (*Client) Fetch ¶ 

func (c *Client) Fetch(ctx context.Context, ref string, opts ...RemoteOpt) (images.Image, error)

Fetch downloads the provided content into containerd's content store and returns a non-platform specific image reference

func (*Client) GetImage ¶ 

func (c *Client) GetImage(ctx context.Context, ref string) (Image, error)

GetImage returns an existing image

func (*Client) GetLabel ¶ 

func (c *Client) GetLabel(ctx context.Context, label string) (string, error)

GetLabel gets a label value from namespace store If there is no default label, an empty string returned with nil error

func (*Client) HealthService ¶ 

func (c *Client) HealthService() grpc_health_v1.HealthClient

HealthService returns the underlying GRPC HealthClient

func (*Client) ImageService ¶ 

func (c *Client) ImageService() images.Store

ImageService returns the underlying image Store

func (*Client) Import ¶ 

func (c *Client) Import(ctx context.Context, reader io.Reader, opts ...ImportOpt) ([]images.Image, error)

Import imports an image from a Tar stream using reader. Caller needs to specify importer. Future version may use oci.v1 as the default. Note that unreferenced blobs may be imported to the content store as well.

func (*Client) Install ¶ 

func (c *Client) Install(ctx context.Context, image Image, opts ...InstallOpts) error

Install a binary image into the opt service

func (*Client) IntrospectionService ¶ 

func (c *Client) IntrospectionService() introspectionapi.IntrospectionClient

IntrospectionService returns the underlying Introspection Client

func (*Client) IsServing ¶ 

func (c *Client) IsServing(ctx context.Context) (bool, error)

IsServing returns true if the client can successfully connect to the containerd daemon and the healthcheck service returns the SERVING response. This call will block if a transient error is encountered during connection. A timeout can be set in the context to ensure it returns early.

func (*Client) LeasesService ¶ 

func (c *Client) LeasesService() leases.Manager

LeasesService returns the underlying Leases Client

func (*Client) ListImages ¶ 

func (c *Client) ListImages(ctx context.Context, filters ...string) ([]Image, error)

ListImages returns all existing images

func (*Client) LoadContainer ¶ 

func (c *Client) LoadContainer(ctx context.Context, id string) (Container, error)

LoadContainer loads an existing container from metadata

func (*Client) NamespaceService ¶ 

func (c *Client) NamespaceService() namespaces.Store

NamespaceService returns the underlying Namespaces Store

func (*Client) NewContainer ¶ 

func (c *Client) NewContainer(ctx context.Context, id string, opts ...NewContainerOpts) (Container, error)

NewContainer will create a new container in container with the provided id the id must be unique within the namespace

func (*Client) Pull ¶ 

func (c *Client) Pull(ctx context.Context, ref string, opts ...RemoteOpt) (_ Image, retErr error)

Pull downloads the provided content into containerd's content store and returns a platform specific image object

func (*Client) Push ¶ 

func (c *Client) Push(ctx context.Context, ref string, desc ocispec.Descriptor, opts ...RemoteOpt) error

Push uploads the provided content to a remote resource

func (*Client) Reconnect ¶ 

func (c *Client) Reconnect() error

Reconnect re-establishes the GRPC connection to the containerd daemon

func (*Client) Restore ¶ 

func (c *Client) Restore(ctx context.Context, id string, checkpoint Image, opts ...RestoreOpts) (Container, error)

Restore restores a container from a checkpoint

func (*Client) Server ¶ 

func (c *Client) Server(ctx context.Context) (ServerInfo, error)

func (*Client) SnapshotService ¶ 

func (c *Client) SnapshotService(snapshotterName string) snapshots.Snapshotter

SnapshotService returns the underlying snapshotter for the provided snapshotter name

func (*Client) Subscribe ¶ 

func (c *Client) Subscribe(ctx context.Context, filters ...string) (ch <-chan *events.Envelope, errs <-chan error)

Subscribe to events that match one or more of the provided filters.

Callers should listen on both the envelope and errs channels. If the errs channel returns nil or an error, the subscriber should terminate.

The subscriber can stop receiving events by canceling the provided context. The errs channel will be closed and return a nil error.

func (*Client) TaskService ¶ 

func (c *Client) TaskService() tasks.TasksClient

TaskService returns the underlying TasksClient

func (*Client) Version ¶ 

func (c *Client) Version(ctx context.Context) (Version, error)

Version returns the version of containerd that the client is connected to

func (*Client) VersionService ¶ 

func (c *Client) VersionService() versionservice.VersionClient

VersionService returns the underlying VersionClient

func (*Client) WithLease ¶ 

func (c *Client) WithLease(ctx context.Context) (context.Context, func(context.Context) error, error)

WithLease attaches a lease on the context

type ClientOpt ¶ 

type ClientOpt func(c *clientOpts) error

ClientOpt allows callers to set options on the containerd client

func WithDefaultNamespace ¶ 

func WithDefaultNamespace(ns string) ClientOpt

WithDefaultNamespace sets the default namespace on the client

Any operation that does not have a namespace set on the context will be provided the default namespace

func WithDefaultPlatform ¶ 

func WithDefaultPlatform(platform platforms.MatchComparer) ClientOpt

WithDefaultPlatform sets the default platform matcher on the client

func WithDefaultRuntime ¶ 

func WithDefaultRuntime(rt string) ClientOpt

WithDefaultRuntime sets the default runtime on the client

func WithDialOpts ¶ 

func WithDialOpts(opts []grpc.DialOption) ClientOpt

WithDialOpts allows grpc.DialOptions to be set on the connection

func WithServices ¶ 

func WithServices(opts ...ServicesOpt) ClientOpt

WithServices sets services used by the client.

func WithTimeout ¶ 

func WithTimeout(d time.Duration) ClientOpt

WithTimeout sets the connection timeout for the client

type Container ¶ 

type Container interface {
	// ID identifies the container
	ID() string
	// Info returns the underlying container record type
	Info(context.Context, ...InfoOpts) (containers.Container, error)
	// Delete removes the container
	Delete(context.Context, ...DeleteOpts) error
	// NewTask creates a new task based on the container metadata
	NewTask(context.Context, cio.Creator, ...NewTaskOpts) (Task, error)
	// Spec returns the OCI runtime specification
	Spec(context.Context) (*oci.Spec, error)
	// Task returns the current task for the container
	//
	// If cio.Attach options are passed the client will reattach to the IO for the running
	// task. If no task exists for the container a NotFound error is returned
	//
	// Clients must make sure that only one reader is attached to the task and consuming
	// the output from the task's fifos
	Task(context.Context, cio.Attach) (Task, error)
	// Image returns the image that the container is based on
	Image(context.Context) (Image, error)
	// Labels returns the labels set on the container
	Labels(context.Context) (map[string]string, error)
	// SetLabels sets the provided labels for the container and returns the final label set
	SetLabels(context.Context, map[string]string) (map[string]string, error)
	// Extensions returns the extensions set on the container
	Extensions(context.Context) (map[string]prototypes.Any, error)
	// Update a container
	Update(context.Context, ...UpdateContainerOpts) error
	// Checkpoint creates a checkpoint image of the current container
	Checkpoint(context.Context, string, ...CheckpointOpts) (Image, error)
}

Container is a metadata object for container resources and task creation

type DeleteOpts ¶ 

type DeleteOpts func(ctx context.Context, client *Client, c containers.Container) error

DeleteOpts allows the caller to set options for the deletion of a container

type DiffService ¶ 

type DiffService interface {
	diff.Comparer
	diff.Applier
}

DiffService handles the computation and application of diffs

func NewDiffServiceFromClient ¶ 

func NewDiffServiceFromClient(client diffapi.DiffClient) DiffService

NewDiffServiceFromClient returns a new diff service which communicates over a GRPC connection.

type EventService ¶ 

type EventService interface {
	events.Publisher
	events.Forwarder
	events.Subscriber
}

EventService handles the publish, forward and subscribe of events.

func NewEventServiceFromClient ¶ 

func NewEventServiceFromClient(client eventsapi.EventsClient) EventService

NewEventServiceFromClient returns a new event service which communicates over a GRPC connection.

type ExitStatus ¶ 

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

ExitStatus encapsulates a process's exit status. It is used by `Wait()` to return either a process exit code or an error

func NewExitStatus ¶ 

func NewExitStatus(code uint32, t time.Time, err error) *ExitStatus

NewExitStatus populates an ExitStatus

func (ExitStatus) Error ¶ 

func (s ExitStatus) Error() error

Error returns the error, if any, that occurred while waiting for the process.

func (ExitStatus) ExitCode ¶ 

func (s ExitStatus) ExitCode() uint32

ExitCode returns the exit code of the process. This is only valid is Error() returns nil

func (ExitStatus) ExitTime ¶ 

func (s ExitStatus) ExitTime() time.Time

ExitTime returns the exit time of the process This is only valid is Error() returns nil

func (ExitStatus) Result ¶ 

func (s ExitStatus) Result() (uint32, time.Time, error)

Result returns the exit code and time of the exit status. An error may be returned here to which indicates there was an error 

at some point while waiting for the exit status. It does not signify
an error with the process itself.

If an error is returned, the process may still be running.

type IOCloseInfo ¶ 

type IOCloseInfo struct {
	Stdin bool
}

IOCloseInfo allows specific io pipes to be closed on a process

type IOCloserOpts ¶ 

type IOCloserOpts func(*IOCloseInfo)

IOCloserOpts allows the caller to set specific pipes as closed on a process

type Image ¶ 

type Image interface {
	// Name of the image
	Name() string
	// Target descriptor for the image content
	Target() ocispec.Descriptor
	// Labels of the image
	Labels() map[string]string
	// Unpack unpacks the image's content into a snapshot
	Unpack(context.Context, string, ...UnpackOpt) error
	// RootFS returns the unpacked diffids that make up images rootfs.
	RootFS(ctx context.Context) ([]digest.Digest, error)
	// Size returns the total size of the image's packed resources.
	Size(ctx context.Context) (int64, error)
	// Usage returns a usage calculation for the image.
	Usage(context.Context, ...UsageOpt) (int64, error)
	// Config descriptor for the image.
	Config(ctx context.Context) (ocispec.Descriptor, error)
	// IsUnpacked returns whether or not an image is unpacked.
	IsUnpacked(context.Context, string) (bool, error)
	// ContentStore provides a content store which contains image blob data
	ContentStore() content.Store
}

Image describes an image used by containers

func NewImage ¶ 

func NewImage(client *Client, i images.Image) Image

NewImage returns a client image object from the metadata image

func NewImageWithPlatform ¶ 

func NewImageWithPlatform(client *Client, i images.Image, platform platforms.MatchComparer) Image

NewImageWithPlatform returns a client image object from the metadata image

type ImportOpt ¶ 

type ImportOpt func(*importOpts) error

ImportOpt allows the caller to specify import specific options

func WithAllPlatforms ¶ 

func WithAllPlatforms(allPlatforms bool) ImportOpt

WithAllPlatforms is used to import content for all platforms.

func WithDigestRef ¶ 

func WithDigestRef(f func(digest.Digest) string) ImportOpt

WithDigestRef is used to create digest images for each manifest in the index.

func WithImageRefTranslator ¶ 

func WithImageRefTranslator(f func(string) string) ImportOpt

WithImageRefTranslator is used to translate the index reference to an image reference for the image store.

func WithImportCompression ¶ 

func WithImportCompression() ImportOpt

WithImportCompression compresses uncompressed layers on import. This is used for import formats which do not include the manifest.

func WithIndexName ¶ 

func WithIndexName(name string) ImportOpt

WithIndexName creates a tag pointing to the imported index

type InfoConfig ¶ 

type InfoConfig struct {
	// Refresh will to a fetch of the latest container metadata
	Refresh bool
}

InfoConfig specifies how container metadata is fetched

type InfoOpts ¶ 

type InfoOpts func(*InfoConfig)

InfoOpts controls how container metadata is fetched and returned

type InstallConfig ¶ 

type InstallConfig struct {
	// Libs installs libs from the image
	Libs bool
	// Replace will overwrite existing binaries or libs in the opt directory
	Replace bool
	// Path to install libs and binaries to
	Path string
}

InstallConfig sets the binary install configuration

type InstallOpts ¶ 

type InstallOpts func(*InstallConfig)

InstallOpts configures binary installs

func WithInstallPath ¶ 

func WithInstallPath(path string) InstallOpts

WithInstallPath sets the optional install path

type KillInfo ¶ 

type KillInfo struct {
	// All kills all processes inside the task
	// only valid on tasks, ignored on processes
	All bool
	// ExecID is the ID of a process to kill
	ExecID string
}

KillInfo contains information on how to process a Kill action

type KillOpts ¶ 

type KillOpts func(context.Context, *KillInfo) error

KillOpts allows options to be set for the killing of a process

func WithKillExecID ¶ 

func WithKillExecID(execID string) KillOpts

WithKillExecID specifies the process ID

type NewContainerOpts ¶ 

type NewContainerOpts func(ctx context.Context, client *Client, c *containers.Container) error

NewContainerOpts allows the caller to set additional options when creating a container

func WithContainerExtension ¶ 

func WithContainerExtension(name string, extension interface{}) NewContainerOpts

WithContainerExtension appends extension data to the container object. Use this to decorate the container object with additional data for the client integration.

Make sure to register the type of `extension` in the typeurl package via `typeurl.Register` or container creation may fail.

func WithContainerLabels ¶ 

func WithContainerLabels(labels map[string]string) NewContainerOpts

WithContainerLabels adds the provided labels to the container

func WithImage ¶ 

func WithImage(i Image) NewContainerOpts

WithImage sets the provided image as the base for the container

func WithImageName ¶ 

func WithImageName(n string) NewContainerOpts

WithImageName allows setting the image name as the base for the container

func WithImageStopSignal ¶ 

func WithImageStopSignal(image Image, defaultSignal string) NewContainerOpts

WithImageStopSignal sets a well-known containerd label (StopSignalLabel) on the container for storing the stop signal specified in the OCI image config

func WithNewSnapshot ¶ 

func WithNewSnapshot(id string, i Image, opts ...snapshots.Opt) NewContainerOpts

WithNewSnapshot allocates a new snapshot to be used by the container as the root filesystem in read-write mode

func WithNewSnapshotView ¶ 

func WithNewSnapshotView(id string, i Image, opts ...snapshots.Opt) NewContainerOpts

WithNewSnapshotView allocates a new snapshot to be used by the container as the root filesystem in read-only mode

func WithNewSpec ¶ 

func WithNewSpec(opts ...oci.SpecOpts) NewContainerOpts

WithNewSpec generates a new spec for a new container

func WithRemappedSnapshot ¶ 

func WithRemappedSnapshot(id string, i Image, uid, gid uint32) NewContainerOpts

WithRemappedSnapshot creates a new snapshot and remaps the uid/gid for the filesystem to be used by a container with user namespaces

func WithRemappedSnapshotView ¶ 

func WithRemappedSnapshotView(id string, i Image, uid, gid uint32) NewContainerOpts

WithRemappedSnapshotView is similar to WithRemappedSnapshot but rootfs is mounted as read-only.

func WithRestoreImage ¶ 

func WithRestoreImage(ctx context.Context, id string, client *Client, checkpoint Image, index *imagespec.Index) NewContainerOpts

WithRestoreImage restores the image for the container

func WithRestoreRW ¶ 

func WithRestoreRW(ctx context.Context, id string, client *Client, checkpoint Image, index *imagespec.Index) NewContainerOpts

WithRestoreRW restores the rw layer from the checkpoint for the container

func WithRestoreRuntime ¶ 

func WithRestoreRuntime(ctx context.Context, id string, client *Client, checkpoint Image, index *imagespec.Index) NewContainerOpts

WithRestoreRuntime restores the runtime for the container

func WithRestoreSpec ¶ 

func WithRestoreSpec(ctx context.Context, id string, client *Client, checkpoint Image, index *imagespec.Index) NewContainerOpts

WithRestoreSpec restores the spec from the checkpoint for the container

func WithRuntime ¶ 

func WithRuntime(name string, options interface{}) NewContainerOpts

WithRuntime allows a user to specify the runtime name and additional options that should be used to create tasks for the container

func WithSnapshot ¶ 

func WithSnapshot(id string) NewContainerOpts

WithSnapshot uses an existing root filesystem for the container

func WithSnapshotter ¶ 

func WithSnapshotter(name string) NewContainerOpts

WithSnapshotter sets the provided snapshotter for use by the container

This option must appear before other snapshotter options to have an effect.

func WithSpec ¶ 

func WithSpec(s *oci.Spec, opts ...oci.SpecOpts) NewContainerOpts

WithSpec sets the provided spec on the container

type NewTaskOpts ¶ 

type NewTaskOpts func(context.Context, *Client, *TaskInfo) error

NewTaskOpts allows the caller to set options on a new task

func WithRestoreImagePath ¶ 

func WithRestoreImagePath(path string) NewTaskOpts

WithRestoreImagePath sets image path for create option

func WithRootFS ¶ 

func WithRootFS(mounts []mount.Mount) NewTaskOpts

WithRootFS allows a task to be created without a snapshot being allocated to its container

func WithShimCgroup ¶ 

func WithShimCgroup(path string) NewTaskOpts

WithShimCgroup sets the existing cgroup for the shim

func WithTaskCheckpoint ¶ 

func WithTaskCheckpoint(im Image) NewTaskOpts

WithTaskCheckpoint allows a task to be created with live runtime and memory data from a previous checkpoint. Additional software such as CRIU may be required to restore a task from a checkpoint

type Process ¶ 

type Process interface {
	// ID of the process
	ID() string
	// Pid is the system specific process id
	Pid() uint32
	// Start starts the process executing the user's defined binary
	Start(context.Context) error
	// Delete removes the process and any resources allocated returning the exit status
	Delete(context.Context, ...ProcessDeleteOpts) (*ExitStatus, error)
	// Kill sends the provided signal to the process
	Kill(context.Context, syscall.Signal, ...KillOpts) error
	// Wait asynchronously waits for the process to exit, and sends the exit code to the returned channel
	Wait(context.Context) (<-chan ExitStatus, error)
	// CloseIO allows various pipes to be closed on the process
	CloseIO(context.Context, ...IOCloserOpts) error
	// Resize changes the width and height of the process's terminal
	Resize(ctx context.Context, w, h uint32) error
	// IO returns the io set for the process
	IO() cio.IO
	// Status returns the executing status of the process
	Status(context.Context) (Status, error)
}

Process represents a system process

type ProcessDeleteOpts ¶ 

type ProcessDeleteOpts func(context.Context, Process) error

ProcessDeleteOpts allows the caller to set options for the deletion of a task

type ProcessInfo ¶ 

type ProcessInfo struct {
	// Pid is the process ID
	Pid uint32
	// Info includes additional process information
	// Info varies by platform
	Info *google_protobuf.Any
}

ProcessInfo provides platform specific process information

type ProcessStatus ¶ 

type ProcessStatus string

ProcessStatus returns a human readable status for the Process representing its current status 

const (
	// Running indicates the process is currently executing
	Running ProcessStatus = "running"
	// Created indicates the process has been created within containerd but the
	// user's defined process has not started
	Created ProcessStatus = "created"
	// Stopped indicates that the process has ran and exited
	Stopped ProcessStatus = "stopped"
	// Paused indicates that the process is currently paused
	Paused ProcessStatus = "paused"
	// Pausing indicates that the process is currently switching from a
	// running state into a paused state
	Pausing ProcessStatus = "pausing"
	// Unknown indicates that we could not determine the status from the runtime
	Unknown ProcessStatus = "unknown"
)

type RemoteContext ¶ 

type RemoteContext struct {
	// Resolver is used to resolve names to objects, fetchers, and pushers.
	// If no resolver is provided, defaults to Docker registry resolver.
	Resolver remotes.Resolver

	// PlatformMatcher is used to match the platforms for an image
	// operation and define the preference when a single match is required
	// from multiple platforms.
	PlatformMatcher platforms.MatchComparer

	// Unpack is done after an image is pulled to extract into a snapshotter.
	// It is done simultaneously for schema 2 images when they are pulled.
	// If an image is not unpacked on pull, it can be unpacked any time
	// afterwards. Unpacking is required to run an image.
	Unpack bool

	// UnpackOpts handles options to the unpack call.
	UnpackOpts []UnpackOpt

	// Snapshotter used for unpacking
	Snapshotter string

	// Labels to be applied to the created image
	Labels map[string]string

	// BaseHandlers are a set of handlers which get are called on dispatch.
	// These handlers always get called before any operation specific
	// handlers.
	BaseHandlers []images.Handler

	// HandlerWrapper wraps the handler which gets sent to dispatch.
	// Unlike BaseHandlers, this can run before and after the built
	// in handlers, allowing operations to run on the descriptor
	// after it has completed transferring.
	HandlerWrapper func(images.Handler) images.Handler

	// ConvertSchema1 is whether to convert Docker registry schema 1
	// manifests. If this option is false then any image which resolves
	// to schema 1 will return an error since schema 1 is not supported.
	ConvertSchema1 bool

	// Platforms defines which platforms to handle when doing the image operation.
	// Platforms is ignored when a PlatformMatcher is set, otherwise the
	// platforms will be used to create a PlatformMatcher with no ordering
	// preference.
	Platforms []string

	// MaxConcurrentDownloads is the max concurrent content downloads for each pull.
	MaxConcurrentDownloads int

	// AllMetadata downloads all manifests and known-configuration files
	AllMetadata bool
}

RemoteContext is used to configure object resolutions and transfers with remote content stores and image providers.

type RemoteOpt ¶ 

type RemoteOpt func(*Client, *RemoteContext) error

RemoteOpt allows the caller to set distribution options for a remote

func WithAllMetadata ¶ 

func WithAllMetadata() RemoteOpt

WithAllMetadata downloads all manifests and known-configuration files

func WithImageHandler ¶ 

func WithImageHandler(h images.Handler) RemoteOpt

WithImageHandler adds a base handler to be called on dispatch.

func WithImageHandlerWrapper ¶ 

func WithImageHandlerWrapper(w func(images.Handler) images.Handler) RemoteOpt

WithImageHandlerWrapper wraps the handlers to be called on dispatch.

func WithMaxConcurrentDownloads ¶ 

func WithMaxConcurrentDownloads(max int) RemoteOpt

WithMaxConcurrentDownloads sets max concurrent download limit.

func WithPlatform ¶ 

func WithPlatform(platform string) RemoteOpt

WithPlatform allows the caller to specify a platform to retrieve content for

func WithPlatformMatcher ¶ 

func WithPlatformMatcher(m platforms.MatchComparer) RemoteOpt

WithPlatformMatcher specifies the matcher to use for determining which platforms to pull content for. This value supersedes anything set with `WithPlatform`.

func WithPullLabel ¶ 

func WithPullLabel(key, value string) RemoteOpt

WithPullLabel sets a label to be associated with a pulled reference

func WithPullLabels ¶ 

func WithPullLabels(labels map[string]string) RemoteOpt

WithPullLabels associates a set of labels to a pulled reference

func WithPullSnapshotter ¶ 

func WithPullSnapshotter(snapshotterName string) RemoteOpt

WithPullSnapshotter specifies snapshotter name used for unpacking

func WithResolver ¶ 

func WithResolver(resolver remotes.Resolver) RemoteOpt

WithResolver specifies the resolver to use.

type RestoreOpts ¶ 

type RestoreOpts func(context.Context, string, *Client, Image, *imagespec.Index) NewContainerOpts

RestoreOpts are options to manage the restore operation

type ServerInfo ¶ 

type ServerInfo struct {
	UUID string
}

type ServicesOpt ¶ 

type ServicesOpt func(c *services)

ServicesOpt allows callers to set options on the services

func WithContainerService ¶ 

func WithContainerService(containerService containersapi.ContainersClient) ServicesOpt

WithContainerService sets the container service.

func WithContentStore ¶ 

func WithContentStore(contentStore content.Store) ServicesOpt

WithContentStore sets the content store.

func WithDiffService ¶ 

func WithDiffService(diffService diff.DiffClient) ServicesOpt

WithDiffService sets the diff service.

func WithEventService ¶ 

func WithEventService(eventService EventService) ServicesOpt

WithEventService sets the event service.

func WithImageService ¶ 

func WithImageService(imageService imagesapi.ImagesClient) ServicesOpt

WithImageService sets the image service.

func WithLeasesService ¶ 

func WithLeasesService(leasesService leases.Manager) ServicesOpt

WithLeasesService sets the lease service.

func WithNamespaceService ¶ 

func WithNamespaceService(namespaceService namespacesapi.NamespacesClient) ServicesOpt

WithNamespaceService sets the namespace service.

func WithSnapshotters ¶ 

func WithSnapshotters(snapshotters map[string]snapshots.Snapshotter) ServicesOpt

WithSnapshotters sets the snapshotters.

func WithTaskService ¶ 

func WithTaskService(taskService tasks.TasksClient) ServicesOpt

WithTaskService sets the task service.

type Status ¶ 

type Status struct {
	// Status of the process
	Status ProcessStatus
	// ExitStatus returned by the process
	ExitStatus uint32
	// ExitedTime is the time at which the process died
	ExitTime time.Time
}

Status returns process status and exit information

type Task ¶ 

type Task interface {
	Process

	// Pause suspends the execution of the task
	Pause(context.Context) error
	// Resume the execution of the task
	Resume(context.Context) error
	// Exec creates a new process inside the task
	Exec(context.Context, string, *specs.Process, cio.Creator) (Process, error)
	// Pids returns a list of system specific process ids inside the task
	Pids(context.Context) ([]ProcessInfo, error)
	// Checkpoint serializes the runtime and memory information of a task into an
	// OCI Index that can be push and pulled from a remote resource.
	//
	// Additional software like CRIU maybe required to checkpoint and restore tasks
	// NOTE: Checkpoint supports to dump task information to a directory, in this way,
	// an empty OCI Index will be returned.
	Checkpoint(context.Context, ...CheckpointTaskOpts) (Image, error)
	// Update modifies executing tasks with updated settings
	Update(context.Context, ...UpdateTaskOpts) error
	// LoadProcess loads a previously created exec'd process
	LoadProcess(context.Context, string, cio.Attach) (Process, error)
	// Metrics returns task metrics for runtime specific metrics
	//
	// The metric types are generic to containerd and change depending on the runtime
	// For the built in Linux runtime, github.com/containerd/cgroups.Metrics
	// are returned in protobuf format
	Metrics(context.Context) (*types.Metric, error)
}

Task is the executable object within containerd

type TaskInfo ¶ 

type TaskInfo struct {
	// Checkpoint is the Descriptor for an existing checkpoint that can be used
	// to restore a task's runtime and memory state
	Checkpoint *types.Descriptor
	// RootFS is a list of mounts to use as the task's root filesystem
	RootFS []mount.Mount
	// Options hold runtime specific settings for task creation
	Options interface{}
	// contains filtered or unexported fields
}

TaskInfo sets options for task creation

func (*TaskInfo) Runtime ¶ 

func (i *TaskInfo) Runtime() string

Runtime name for the container

type UnpackConfig ¶ 

type UnpackConfig struct {
	// ApplyOpts for applying a diff to a snapshotter
	ApplyOpts []diff.ApplyOpt
	// SnapshotOpts for configuring a snapshotter
	SnapshotOpts []snapshots.Opt
}

UnpackConfig provides configuration for the unpack of an image

type UnpackOpt ¶ 

type UnpackOpt func(context.Context, *UnpackConfig) error

UnpackOpt provides configuration for unpack

type UpdateContainerOpts ¶ 

type UpdateContainerOpts func(ctx context.Context, client *Client, c *containers.Container) error

UpdateContainerOpts allows the caller to set additional options when updating a container

type UpdateTaskInfo ¶ 

type UpdateTaskInfo struct {
	// Resources updates a tasks resource constraints
	Resources interface{}
}

UpdateTaskInfo allows updated specific settings to be changed on a task

type UpdateTaskOpts ¶ 

type UpdateTaskOpts func(context.Context, *Client, *UpdateTaskInfo) error

UpdateTaskOpts allows a caller to update task settings

func WithResources ¶ 

func WithResources(resources interface{}) UpdateTaskOpts

WithResources sets the provided resources for task updates. Resources must be either a *specs.LinuxResources or a *specs.WindowsResources

type UsageOpt ¶ 

type UsageOpt func(*usageOptions) error

UsageOpt is used to configure the usage calculation

func WithManifestUsage ¶ 

func WithManifestUsage() UsageOpt

WithManifestUsage is used to get the usage for an image based on what is reported by the manifests rather than what exists in the content store. NOTE: This function is best used with the manifest limit set to get a consistent value, otherwise non-existent manifests will be excluded.

func WithSnapshotUsage ¶ 

func WithSnapshotUsage() UsageOpt

WithSnapshotUsage will check for referenced snapshots from the image objects and include the snapshot size in the total usage.

func WithUsageManifestLimit ¶ 

func WithUsageManifestLimit(i int) UsageOpt

WithUsageManifestLimit sets the limit to the number of manifests which will be walked for usage. Setting this value to 0 will require all manifests to be walked, returning ErrNotFound if manifests are missing. NOTE: By default all manifests which exist will be walked and any non-existent manifests and their subobjects will be ignored.

type Version ¶ 

type Version struct {
	// Version number
	Version string
	// Revision from git that was built
	Revision string
}

Version of containerd

Source Files ¶

View all Source files

Directories ¶

Path Synopsis
api
events
Package events has protobuf types for various events that are used in containerd.
 Package events has protobuf types for various events that are used in containerd.
services/containers/v1
services/content/v1
services/diff/v1
services/events/v1
Package events defines the event pushing and subscription service.
 Package events defines the event pushing and subscription service.
services/images/v1
services/introspection/v1
services/leases/v1
services/namespaces/v1
services/snapshots/v1
services/tasks/v1
services/ttrpc/events/v1
Package events defines the event pushing and subscription service.
 Package events defines the event pushing and subscription service.
services/version/v1
types
types/task
compression
tartest
cmd
containerd
containerd-shim
containerd-shim-runc-v1
containerd-shim-runc-v2
containerd-stress
containerd/command
ctr
ctr/app
ctr/commands
ctr/commands/containers
ctr/commands/content
ctr/commands/events
ctr/commands/images
ctr/commands/install
ctr/commands/leases
ctr/commands/namespaces
ctr/commands/plugins
ctr/commands/pprof
ctr/commands/run
ctr/commands/shim
ctr/commands/snapshots
ctr/commands/tasks
ctr/commands/version
gen-manpages
protoc-gen-gogoctrd
local
proxy
testsuite
contrib
apparmor
nvidia
seccomp
snapshotservice
Package defaults provides several common defaults for interacting with containerd.
 Package defaults provides several common defaults for interacting with containerd.
apply
lcow
walking
walking/plugin
windows
Package errdefs defines the common errors used throughout containerd packages.
 Package errdefs defines the common errors used throughout containerd packages.
exchange
Package filters defines a syntax and parser that can be used for the filtration of items across the containerd API.
 Package filters defines a syntax and parser that can be used for the filtration of items across the containerd API.
gc
Package gc experiments with providing central gc tooling to ensure deterministic resource removal within containerd.
 Package gc experiments with providing central gc tooling to ensure deterministic resource removal within containerd.
scheduler
Package identifiers provides common validation for identifiers and keys across containerd.
 Package identifiers provides common validation for identifiers and keys across containerd.
archive
Package archive provides a Docker and OCI compatible importer
 Package archive provides a Docker and OCI compatible importer
proxy
log
logtest
Package metadata stores all labels and object specific metadata by namespace.
 Package metadata stores all labels and object specific metadata by namespace.
boltutil
metrics
cgroups
types/v1
Package namespaces provides tools for working with namespaces across containerd.
 Package namespaces provides tools for working with namespaces across containerd.
pkg
dialer
oom
process
progress
Package progress assists in displaying human readable progress information.
 Package progress assists in displaying human readable progress information.
seed
stdio
testutil
timeout
ttrpcutil
Package platforms provides a toolkit for normalizing, matching and specifying container platforms.
 Package platforms provides a toolkit for normalizing, matching and specifying container platforms.
protobuf
plugin
plugin/fieldpath
docker
docker/schema1
linux/runctypes
opts
restart
Package restart enables containers to have labels added and monitored to keep the container's task running if it is killed.
 Package restart enables containers to have labels added and monitored to keep the container's task running if it is killed.
restart/monitor
v1
v1/linux
v1/shim
v1/shim/client
v1/shim/v1
v2
v2/example
v2/example/cmd
v2/logging
v2/runc
v2/runc/options
v2/runc/v1
v2/runc/v2
v2/shim
v2/task
containers
content
content/contentserver
diff
events
healthcheck
images
introspection
leases
namespaces
opt
server
server/config
snapshots
tasks
version
benchsuite
btrfs
devmapper
devmapper/dmsetup
devmapper/losetup
lcow
native
overlay
proxy
storage
Package storage provides a metadata storage implementation for snapshot drivers.
 Package storage provides a metadata storage implementation for snapshot drivers.
testsuite
windows
sys
reaper

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