When you decide to write your bike to catch hooks from the docker hub or from the registry to automatically update/start containers on the server, you may find the Docker Cli useful to help manage the Docker daemon on your system.
To work, you need Go version at least 1.9.4
If you still haven't switched to modules, install Cli with the following command:
go get github.com/docker/docker/client
Running a container
The following example shows how to run a container using the Docker API. On the command line, you would use the command docker run
, but we can easily cope with this task in our service.
This example is equivalent to running the command docker run alpine echo hello world
package main {
ctx := context.Background()
cli, err := client.NewEnvClient()
if err != nil {
panic(err)
}
// ΠΠ΅Π»Π°Π΅ΠΌ docker pull
reader, err := cli.ImagePull(ctx, "docker.io/library/alpine", types.ImagePullOptions{})
if err != nil {
panic(err)
}
io.Copy(os.Stdout, reader)
hostBinding := nat.PortBinding{
HostIP: "0.0.0.0",
HostPort: "8000",
}
containerPort, err := nat.NewPort("tcp", "80")
if err != nil {
panic("Unable to get the port")
}
portBinding := nat.PortMap{containerPort: []nat.PortBinding{hostBinding}}
// Π‘ΠΎΠ·Π΄Π°Π΅ΠΌ ΠΊΠΎΠ½ΡΠ΅ΠΉΠ½Π΅Ρ Ρ Π·Π°Π΄Π°Π½Π½ΠΎΠΉ ΠΊΠΎΠ½ΡΠΈΠ³ΡΡΠ°ΡΠΈΠ΅ΠΉ
resp, err := cli.ContainerCreate(ctx, &container.Config{
Image: "alpine",
Cmd: []string{"echo", "hello world"},
Tty: true,
}, &container.HostConfig{
PortBindings: portBinding,
}, nil, "")
if err != nil {
panic(err)
}
// ΠΠ°ΠΏΡΡΠΊΠ°Π΅ΠΌ ΠΊΠΎΠ½ΡΠ΅ΠΉΠ½Π΅Ρ
if err := cli.ContainerStart(ctx, resp.ID, types.ContainerStartOptions{}); err != nil {
panic(err)
}
// ΠΠΎΠ»ΡΡΠ°Π΅ΠΌ Π»ΠΎΠ³ΠΈ ΠΊΠΎΠ½ΡΠ΅ΠΉΠ½Π΅ΡΠ°
out, err := cli.ContainerLogs(ctx, resp.ID, types.ContainerLogsOptions{ShowStdout: true})
if err != nil {
panic(err)
}
io.Copy(os.Stdout, out)
}
Getting a list of running containers
This example is equivalent to running the command docker ps
package main
import (
"context"
"fmt"
"github.com/docker/docker/api/types"
"github.com/docker/docker/client"
)
func main() {
cli, err := client.NewEnvClient()
if err != nil {
panic(err)
}
// ΠΠΎΠ»ΡΡΠ΅Π½ΠΈΠ΅ ΡΠΏΠΈΡΠΊΠ° Π·Π°ΠΏΡΡΡΠ΅Π½Π½ΡΡ
ΠΊΠΎΠ½ΡΠ΅ΠΉΠ½Π΅ΡΠΎΠ²(docker ps)
containers, err := cli.ContainerList(context.Background(), types.ContainerListOptions{})
if err != nil {
panic(err)
}
// ΠΡΠ²ΠΎΠ΄ Π²ΡΠ΅Ρ
ΠΈΠ΄Π΅Π½ΡΠΈΡΠΈΠΊΠ°ΡΠΎΡΠΎΠ² ΠΊΠΎΠ½ΡΠ΅ΠΉΠ½Π΅ΡΠΎΠ²
for _, container := range containers {
fmt.Println(container.ID)
}
}
Stop all running containers
Once you've learned how to create and run containers, it's time to learn how to manage them. The following example will stop all running containers.
Don't run this code on a production server!
package main
import (
"context"
"fmt"
"github.com/docker/docker/api/types"
"github.com/docker/docker/client"
)
func main() {
ctx := context.Background()
cli, err := client.NewEnvClient()
if err != nil {
panic(err)
}
// ΠΠΎΠ»ΡΡΠ΅Π½ΠΈΠ΅ ΡΠΏΠΈΡΠΊΠ° Π·Π°ΠΏΡΡΡΠ΅Π½Π½ΡΡ
ΠΊΠΎΠ½ΡΠ΅ΠΉΠ½Π΅ΡΠΎΠ²(docker ps)
containers, err := cli.ContainerList(ctx, types.ContainerListOptions{})
if err != nil {
panic(err)
}
for _, c := range containers {
fmt.Print("Stopping container ", c.ID[:10], "... ")
if err := cli.ContainerStop(ctx, c.ID, nil); err != nil {
panic(err)
}
fmt.Println("Success")
}
}
Output logs of a single container
You can work with individual containers. The following example prints the logs of the container with the specified ID. Before launching, you need to change the ID of the container whose logs you want to get.
package main
import (
"context"
"io"
"os"
"github.com/docker/docker/api/types"
"github.com/docker/docker/client"
)
func main() {
ctx := context.Background()
cli, err := client.NewEnvClient()
if err != nil {
panic(err)
}
options := types.ContainerLogsOptions{ShowStdout: true}
// ΠΠ·ΠΌΠ΅Π½ΠΈΡΠ΅ id ΠΊΠΎΠ½ΡΠ΅ΠΉΠ½Π΅ΡΠ° Π·Π΄Π΅ΡΡ
out, err := cli.ContainerLogs(ctx, "f1064a8a4c82", options)
if err != nil {
panic(err)
}
io.Copy(os.Stdout, out)
}
Getting a list of images
This example is equivalent to running the command docker image ls
package main
import (
"context"
"fmt"
"github.com/docker/docker/api/types"
"github.com/docker/docker/client"
)
func main() {
cli, err := client.NewEnvClient()
if err != nil {
panic(err)
}
// ΠΠΎΠ»ΡΡΠ΅Π½ΠΈΠ΅ ΡΠΏΠΈΡΠΊΠ° ΠΎΠ±ΡΠ°Π·ΠΎΠ²
images, err := cli.ImageList(context.Background(), types.ImageListOptions{})
if err != nil {
panic(err)
}
for _, image := range images {
fmt.Println(image.ID)
}
}
Pullover
This example is equivalent to running the command docker pull
package main
import (
"context"
"io"
"os"
"github.com/docker/docker/api/types"
"github.com/docker/docker/client"
)
func main() {
ctx := context.Background()
cli, err := client.NewEnvClient()
if err != nil {
panic(err)
}
// docker pull alpine
out, err := cli.ImagePull(ctx, "docker.io/library/alpine", types.ImagePullOptions{})
if err != nil {
panic(err)
}
defer out.Close()
io.Copy(os.Stdout, out)
}
Downloading an image with user authentication
This example is equivalent to running the command docker pull
, with authentication.
Authentication data is sent in clear text. The official docker registries use HTTPS,
private registries must also be configured to communicate using HTTPS.
package main
import (
"context"
"encoding/base64"
"encoding/json"
"io"
"os"
"github.com/docker/docker/api/types"
"github.com/docker/docker/client"
)
func main() {
ctx := context.Background()
cli, err := client.NewEnvClient()
if err != nil {
panic(err)
}
// Π‘ΠΎΠ·Π΄Π°Π½ΠΈΠ΅ ΠΊΠΎΠ½ΡΠΈΠ³Π° Ρ Π΄Π°Π½Π½ΡΠΌΠΈ Π΄Π»Ρ Π°ΡΡΠ΅Π½ΡΠΈΡΠΈΠΊΠ°ΡΠΈΠΈ
authConfig := types.AuthConfig{
Username: "username",
Password: "password",
}
encodedJSON, err := json.Marshal(authConfig)
if err != nil {
panic(err)
}
authStr := base64.URLEncoding.EncodeToString(encodedJSON)
out, err := cli.ImagePull(ctx, "docker.io/library/alpine", types.ImagePullOptions{RegistryAuth: authStr})
if err != nil {
panic(err)
}
defer out.Close()
io.Copy(os.Stdout, out)
}
Source: habr.com