| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | package dockerhost |
| 4 | |
| 5 | import ( |
| 6 | "bytes" |
| 7 | "context" |
| 8 | "fmt" |
| 9 | "os" |
| 10 | "strings" |
| 11 | "time" |
| 12 | |
| 13 | typesContainer "github.com/docker/docker/api/types/container" |
| 14 | docker "github.com/docker/docker/client" |
| 15 | "github.com/docker/docker/pkg/stdcopy" |
| 16 | ) |
| 17 | |
| 18 | func FromEnv() string { |
| 19 | addr := os.Getenv("DOCKER_HOST") |
| 20 | if addr == "" { |
| 21 | return "" |
| 22 | } |
| 23 | if strings.HasPrefix(addr, "tcp://") || strings.HasPrefix(addr, "unix://") { |
| 24 | return addr |
| 25 | } |
| 26 | if strings.HasPrefix(addr, "/") { |
| 27 | return fmt.Sprintf("unix://%s", addr) |
| 28 | } |
| 29 | return fmt.Sprintf("tcp://%s", addr) |
| 30 | } |
| 31 | |
| 32 | func Exec(ctx context.Context, container string, cmd string, args ...string) ([]byte, error) { |
| 33 | // based on https://github.com/moby/moby/blob/8e610b2b55bfd1bfa9436ab110d311f5e8a74dcb/integration/internal/container/exec.go#L38 |
| 34 | addr := docker.DefaultDockerHost |
| 35 | if v := FromEnv(); v != "" { |
| 36 | addr = v |
| 37 | } |
| 38 | |
| 39 | cli, err := docker.NewClientWithOpts(docker.WithHost(addr)) |
| 40 | if err != nil { |
| 41 | return nil, fmt.Errorf("failed to create docker client: %w", err) |
| 42 | } |
| 43 | defer func() { _ = cli.Close() }() |
| 44 | |
| 45 | cli.NegotiateAPIVersion(ctx) |
| 46 | |
| 47 | execCreateConfig := typesContainer.ExecOptions{ |
| 48 | AttachStderr: true, |
| 49 | AttachStdout: true, |
| 50 | Cmd: append([]string{cmd}, args...), |
| 51 | } |
| 52 | |
| 53 | createResp, err := cli.ContainerExecCreate(ctx, container, execCreateConfig) |
| 54 | if err != nil { |
| 55 | return nil, fmt.Errorf("failed to container exec create (%s): %w", container, err) |
| 56 | } |
| 57 | |
| 58 | attachResp, err := cli.ContainerExecAttach(ctx, createResp.ID, typesContainer.ExecAttachOptions{}) |
| 59 | if err != nil { |
| 60 | return nil, fmt.Errorf("failed to container exec attach (%s): %w", container, err) |
| 61 | } |
| 62 | defer attachResp.Close() |
| 63 | |
| 64 | var outBuf, errBuf bytes.Buffer |
| 65 | done := make(chan error, 1) |
| 66 | |
| 67 | go func() { |
| 68 | _, err := stdcopy.StdCopy(&outBuf, &errBuf, attachResp.Reader) |
| 69 | done <- err |
| 70 | }() |
| 71 | |
| 72 | select { |
| 73 | case err := <-done: |
| 74 | if err != nil { |
| 75 | return nil, fmt.Errorf("failed to read response from container (%s): %w", container, err) |
| 76 | } |
| 77 | case <-ctx.Done(): |
| 78 | // Close connection to interrupt StdCopy |
| 79 | attachResp.Close() |
| 80 | |
| 81 | select { |
| 82 | case <-done: |
| 83 | case <-time.After(150 * time.Millisecond): |
| 84 | // Don't wait too long, let it clean up in background |
| 85 | } |
| 86 | |
| 87 | return nil, fmt.Errorf("timed out reading response: %w", ctx.Err()) |
| 88 | } |
| 89 | |
| 90 | inspResp, err := cli.ContainerExecInspect(ctx, createResp.ID) |
| 91 | if err != nil { |
| 92 | return nil, fmt.Errorf("failed to container exec inspect (%s): %w", container, err) |
| 93 | } |
| 94 | |
| 95 | if inspResp.ExitCode != 0 { |
| 96 | msg := strings.ReplaceAll(errBuf.String(), "\n", " ") |
| 97 | return nil, fmt.Errorf("command returned non-zero exit code (%d), error: %q", inspResp.ExitCode, msg) |
| 98 | } |
| 99 | |
| 100 | return outBuf.Bytes(), nil |
| 101 | } |