这是一个使用github.com/fsouza/go-dockerclient来访问docker API的例子程序；主要包括：

1. 列出images
2. 列出containers
3. 列出swarm services
4. 列出swarm tasks
5. 列出swarm nodes
6. 取出swarm service的输出log日志
7. 取出container的输出log日志

package main

import (
    "fmt"
    "bytes"
    "strings"
    "regexp"

    docker "github.com/fsouza/go-dockerclient"
)

func main() {
    var endpoint string = "unix:///var/run/docker.sock"
    var client *docker.Client
    var err error

    client, err = docker.NewClient(endpoint)
    if err != nil {
        panic(err)
    }

    listImages(client)
    listContainers(client)
    listServices(client)
    listTasks(client)
    listNodes(client)
    getServiceLogs(client)
    getContainerLogs(client)
}


func listImages(client * docker.Client) {
    opts := docker.ListImagesOptions{All: false}

    images, err := client.ListImages(opts)
    if err != nil {
        panic(err)
    }
    for _, image := range images {
        fmt.Println("Image  ID      : ", image.ID)
        fmt.Println("Imager RepoTags: ", image.RepoTags)
    }
}

func listContainers(client * docker.Client) {
    opts := docker.ListContainersOptions{}

    containers, err := client.ListContainers(opts)
    if err != nil {
        panic(err)
    }
    for _, container := range containers {
        fmt.Println("Container ID   : ", container.ID)
        fmt.Println("Container Names: ", container.Names)
    }
}

func listServices(client * docker.Client) {
    //opts := docker.ListServicesOptions{Filters: map[string][]string {"name":{"<servicename>"}}}
    opts := docker.ListServicesOptions{}

    services, err := client.ListServices(opts)
    if err != nil {
        panic(err)
    }
    for _, service := range services {
        fmt.Println("Service ID      : ", service.ID)
        fmt.Println("Service Name    : ", service.Spec.Name)
        fmt.Println("Service Replicas: ", *(service.Spec.Mode.Replicated.Replicas))
    }
}

func listTasks(client * docker.Client) {
    opts := docker.ListTasksOptions{Filters: map[string][]string {"service":{"<servicename>"}}}

    tasks, err := client.ListTasks(opts)
    if err != nil {
        panic(err)
    }
    for _, task := range tasks {
        fmt.Println("Task ID         : ", task.ID)
        fmt.Println("Task Name       : ", task.Name)
        fmt.Println("Task ServiceID  : ", task.ServiceID)
        fmt.Println("Task Slot       : ", task.Slot)
        fmt.Println("Task NodeID     : ", task.NodeID)
        fmt.Println("Task Message    : ", task.Status.Message)
        fmt.Println("Task Error      : ", task.Status.Err)
        fmt.Println("Task ContainerID: ", task.Status.ContainerStatus.ContainerID)
        fmt.Println("Task PID        : ", task.Status.ContainerStatus.PID)
        fmt.Println("Task ExitCode   : ", task.Status.ContainerStatus.ExitCode)
    }
}

func listNodes(client * docker.Client) {
    opts := docker.ListNodesOptions{}

    nodes, err := client.ListNodes(opts)
    if err != nil {
        panic(err)
    }
    for _, node := range nodes {
        fmt.Println("Node ID           : ", node.ID)
        fmt.Println("Node Hostname     : ", node.Description.Hostname)
        fmt.Println("Node State        : ", node.Status.State)
        fmt.Println("Node Message      : ", node.Status.Message)
        fmt.Println("Node Addr         : ", node.Status.Addr)
        fmt.Println("Node ManagerStatus: ", node.ManagerStatus)
    }
}

func getServiceLogs(client * docker.Client) {
    var buf bytes.Buffer
    opts := docker.LogsServiceOptions{
        Service:      "<servicename>",
        OutputStream: &buf,
        ErrorStream:  &buf,
        Follow:       false,
        Stdout:       true,
        Stderr:       true,
        Timestamps:   true,
        Tail:         "10",      // get the last 10 lines log
    }

    err := client.GetServiceLogs(opts)
    if err != nil {
        panic(err)
    }

    fmt.Println(buf.String())
}


func getContainerLogs(client * docker.Client) {
    var buf bytes.Buffer
    opts := docker.LogsOptions {
        Container:      "<containername>",
        OutputStream: &buf,
        ErrorStream:  &buf,
        Follow:       false,
        Stdout:       true,
        Stderr:       true,
//      Timestamps:   true,
        Tail:         "10",
    }

    err := client.Logs(opts)
    if err != nil {
        panic(err)
    }

    lines := strings.Split(buf.String(), "\n")
    for _, line := range lines {
        if matched, _ := regexp.MatchString(`: ERROR  : `, line); matched {
            fmt.Println(line)
        }
    }
}

这里需要定义docker的endpoint，在这里我们使用"unix:///var/run/docker.sock"，当然也可以使用远程的地址。

参考资料：
github.com/fsouza/go-dockerclient的github地址是：https://github.com/fsouza/go-dockerclient

github.com/fsouza/go-dockerclient的API文档：https://godoc.org/github.com/fsouza/go-dockerclient

docker的API文档：https://docs.docker.com/develop/sdk/