client.go

/*
Copyright 2014 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package libdocker

import (
	"strings"
	"time"

	dockerapi "github.com/docker/engine-api/client"
	dockertypes "github.com/docker/engine-api/types"
	"github.com/golang/glog"
)

const (
	// https://docs.docker.com/engine/reference/api/docker_remote_api/
	// docker version should be at least 1.10.x
	MinimumDockerAPIVersion = "1.22.0"

	// Status of a container returned by ListContainers.
	StatusRunningPrefix = "Up"
	StatusCreatedPrefix = "Created"
	StatusExitedPrefix  = "Exited"

	// This is only used by GetKubeletDockerContainers(), and should be removed
	// along with the function.
	containerNamePrefix = "k8s"
)

// Interface is an abstract interface for testability.  It abstracts the interface of docker client.
type Interface interface {
	ListContainers(options dockertypes.ContainerListOptions) ([]dockertypes.Container, error)
	InspectContainer(id string) (*dockertypes.ContainerJSON, error)
	CreateContainer(dockertypes.ContainerCreateConfig) (*dockertypes.ContainerCreateResponse, error)
	StartContainer(id string) error
	StopContainer(id string, timeout int) error
	RemoveContainer(id string, opts dockertypes.ContainerRemoveOptions) error
	InspectImageByRef(imageRef string) (*dockertypes.ImageInspect, error)
	InspectImageByID(imageID string) (*dockertypes.ImageInspect, error)
	ListImages(opts dockertypes.ImageListOptions) ([]dockertypes.Image, error)
	PullImage(image string, auth dockertypes.AuthConfig, opts dockertypes.ImagePullOptions) error
	RemoveImage(image string, opts dockertypes.ImageRemoveOptions) ([]dockertypes.ImageDelete, error)
	ImageHistory(id string) ([]dockertypes.ImageHistory, error)
	Logs(string, dockertypes.ContainerLogsOptions, StreamOptions) error
	Version() (*dockertypes.Version, error)
	Info() (*dockertypes.Info, error)
	CreateExec(string, dockertypes.ExecConfig) (*dockertypes.ContainerExecCreateResponse, error)
	StartExec(string, dockertypes.ExecStartCheck, StreamOptions) error
	InspectExec(id string) (*dockertypes.ContainerExecInspect, error)
	AttachToContainer(string, dockertypes.ContainerAttachOptions, StreamOptions) error
	ResizeContainerTTY(id string, height, width int) error
	ResizeExecTTY(id string, height, width int) error
}

// Get a *dockerapi.Client, either using the endpoint passed in, or using
// DOCKER_HOST, DOCKER_TLS_VERIFY, and DOCKER_CERT path per their spec
func getDockerClient(dockerEndpoint string) (*dockerapi.Client, error) {
	if len(dockerEndpoint) > 0 {
		glog.Infof("Connecting to docker on %s", dockerEndpoint)
		return dockerapi.NewClient(dockerEndpoint, "", nil, nil)
	}
	return dockerapi.NewEnvClient()
}

// ConnectToDockerOrDie creates docker client connecting to docker daemon.
// If the endpoint passed in is "fake://", a fake docker client
// will be returned. The program exits if error occurs. The requestTimeout
// is the timeout for docker requests. If timeout is exceeded, the request
// will be cancelled and throw out an error. If requestTimeout is 0, a default
// value will be applied.
func ConnectToDockerOrDie(dockerEndpoint string, requestTimeout, imagePullProgressDeadline time.Duration) Interface {
	if dockerEndpoint == "fake://" {
		return NewFakeDockerClient()
	}
	client, err := getDockerClient(dockerEndpoint)
	if err != nil {
		glog.Fatalf("Couldn't connect to docker: %v", err)
	}
	glog.Infof("Start docker client with request timeout=%v", requestTimeout)
	return newKubeDockerClient(client, requestTimeout, imagePullProgressDeadline)
}

// GetKubeletDockerContainers lists all container or just the running ones.
// Returns a list of docker containers that we manage
// TODO: This function should be deleted after migrating
// test/e2e_node/garbage_collector_test.go off of it.
func GetKubeletDockerContainers(client Interface, allContainers bool) ([]*dockertypes.Container, error) {
	result := []*dockertypes.Container{}
	containers, err := client.ListContainers(dockertypes.ContainerListOptions{All: allContainers})
	if err != nil {
		return nil, err
	}
	for i := range containers {
		container := &containers[i]
		if len(container.Names) == 0 {
			continue
		}
		// Skip containers that we didn't create to allow users to manually
		// spin up their own containers if they want.
		if !strings.HasPrefix(container.Names[0], "/"+containerNamePrefix+"_") {
			glog.V(5).Infof("Docker Container: %s is not managed by kubelet.", container.Names[0])
			continue
		}
		result = append(result, container)
	}
	return result, nil
}