feat(deploy): tail build logs from CloudWatch while waiting

README.ja.md

@@ -224,6 +224,7 @@ lamvms deploy [フラグ]
 | `--src` | zip アーカイブのソースディレクトリ | microvm 定義のディレクトリ |
 | `--skip-archive` | zip 作成・S3 アップロードをスキップ | `false` |
 | `--wait` / `--no-wait` | ビルド完了を待機 | `true` |
+| `--build-logs` / `--no-build-logs` | 待機中にビルドの CloudWatch Logs を tail する | `true` |
 | `--keep-versions N` | 最新 N 件のアクティブバージョンを保持 | `0`（無効） |
 | `--dry-run` | 実行内容を表示するのみ | `false` |
 | `--symlink` | 実体展開せずシンボリックリンクとしてアーカイブに格納する（`zip --symlink` と同等） | `false` |
@@ -239,6 +240,7 @@ lamvms wait [フラグ]
 | フラグ | 説明 | デフォルト |
 |--------|------|-----------|
 | `--image-version` | 待機する特定バージョン | 最新バージョン |
+| `--build-logs` / `--no-build-logs` | 待機中にビルドの CloudWatch Logs を tail する | `true` |
 | `--keep-versions N` | 待機後に古いバージョンを削除 | `0`（無効） |
 
 ### rollback

README.md

@@ -224,6 +224,7 @@ lamvms deploy [flags]
 | `--src` | Source directory for zip archive | Directory of microvm definition |
 | `--skip-archive` | Skip zip creation and S3 upload | `false` |
 | `--wait` / `--no-wait` | Wait for build completion | `true` |
+| `--build-logs` / `--no-build-logs` | Tail the build's CloudWatch Logs while waiting | `true` |
 | `--keep-versions N` | Keep N latest active versions, delete older | `0` (disabled) |
 | `--dry-run` | Show what would be done | `false` |
 | `--symlink` | Keep symlinks in the archive instead of following them (same as `zip --symlink`) | `false` |
@@ -239,6 +240,7 @@ lamvms wait [flags]
 | Flag | Description | Default |
 |------|-------------|---------|
 | `--image-version` | Specific version to wait for | Latest version |
+| `--build-logs` / `--no-build-logs` | Tail the build's CloudWatch Logs while waiting | `true` |
 | `--keep-versions N` | Delete old versions after wait | `0` (disabled) |
 
 ### rollback

cli.go

@@ -76,6 +76,7 @@ type DeployOption struct {
 	Src          string `help:"Source directory to archive and upload. Defaults to the directory of the microvm definition file." json:"src,omitempty"`
 	SkipArchive  bool   `help:"Skip creating and uploading zip archive." default:"false" json:"skip_archive,omitempty"`
 	Wait         bool   `help:"Wait for the image build to complete." default:"true" negatable:"" json:"wait,omitempty"`
+	BuildLogs    bool   `help:"Tail the build's CloudWatch Logs while waiting." default:"true" negatable:"" json:"build_logs,omitempty"`
 	KeepVersions int    `help:"Number of latest versions to keep. Older versions will be deleted." default:"0" json:"keep_versions,omitempty"`
 	DryRun       bool   `help:"Dry run." default:"false" json:"dry_run,omitempty"`
 	Symlink      bool   `help:"Keep symlinks in the archive instead of following them (same as zip --symlink,-y)." default:"false" json:"symlink,omitempty"`
@@ -84,6 +85,7 @@ type DeployOption struct {
 // WaitOption represents options for the wait subcommand.
 type WaitOption struct {
 	Version      string `help:"Image version to wait for. Defaults to the latest version." name:"image-version" json:"image_version,omitempty"`
+	BuildLogs    bool   `help:"Tail the build's CloudWatch Logs while waiting." default:"true" negatable:"" json:"build_logs,omitempty"`
 	KeepVersions int    `help:"Number of latest versions to keep. Older versions will be deleted." default:"0" json:"keep_versions,omitempty"`
 }
 

deploy.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log/slog"
 	"os"
+	"os/exec"
 	"path/filepath"
 	"strings"
 	"time"
@@ -64,7 +65,7 @@ func (app *App) Deploy(ctx context.Context, opt *DeployOption) error {
 		return nil
 	}
 
-	if err := app.waitForVersion(ctx, imageARN, imageVersion); err != nil {
+	if err := app.waitForVersion(ctx, imageARN, imageVersion, opt.BuildLogs); err != nil {
 		return err
 	}
 
@@ -198,8 +199,14 @@ func (app *App) updateMicrovmImage(ctx context.Context, existing *lambdamicrovms
 	return aws.ToString(out.ImageArn), aws.ToString(out.ImageVersion), nil
 }
 
-func (app *App) waitForVersion(ctx context.Context, imageARN, imageVersion string) error {
+func (app *App) waitForVersion(ctx context.Context, imageARN, imageVersion string, showBuildLogs bool) error {
 	slog.Info("waiting for version to be ready", "image", imageARN, "version", imageVersion)
+
+	if showBuildLogs {
+		stop := app.startBuildLogTail(ctx, imageVersion)
+		defer stop()
+	}
+
 	for {
 		select {
 		case <-ctx.Done():
@@ -265,5 +272,38 @@ func (app *App) getFailureReason(ctx context.Context, imageARN, imageVersion str
 	if len(reasons) > 0 {
 		return strings.Join(reasons, "; ")
 	}
-	return "(no reason found, check CloudWatch logs: /aws/lambda-microvms/)"
+	name := aws.ToString(app.microvmImage.Name)
+	return fmt.Sprintf("(no reason found, check CloudWatch logs: %s)", microvmLogGroupName(name))
+}
+
+func (app *App) startBuildLogTail(ctx context.Context, imageVersion string) (stop func()) {
+	name := aws.ToString(app.microvmImage.Name)
+	logGroup := microvmLogGroupName(name)
+	command := []string{"aws"}
+	if app.profile != "" {
+		command = append(command, "--profile", app.profile)
+	}
+	if app.awsConfig.Region != "" {
+		command = append(command, "--region", app.awsConfig.Region)
+	}
+	command = append(command, "logs", "tail", logGroup, "--follow", "--log-stream-name-prefix", imageVersion+"/")
+
+	tailCtx, cancel := context.WithCancel(ctx)
+	cmd := exec.CommandContext(tailCtx, command[0], command[1:]...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	if err := cmd.Start(); err != nil {
+		cancel()
+		slog.Warn("failed to start build log tail, continuing without it", "error", err)
+		return func() {}
+	}
+	slog.Debug("invoking command", "command", strings.Join(command, " "))
+
+	return func() {
+		cancel()
+		if err := cmd.Wait(); err != nil {
+			slog.Debug("build log tail process exited", "error", err)
+		}
+	}
 }

deploy_test.go

@@ -2,6 +2,10 @@ package lamvms
 
 import (
 	"context"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
 	"testing"
 	"time"
 
@@ -291,3 +295,104 @@ func TestDeploy_DryRun(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestDeploy_Create_BuildLogsBestEffortWhenAWSCLIMissing(t *testing.T) {
+	t.Setenv("PATH", t.TempDir())
+
+	ctrl := gomock.NewController(t)
+	mock := NewMockLambdaMicroVMsClient(ctrl)
+
+	expectListNotFound(mock)
+
+	mock.EXPECT().
+		CreateMicrovmImage(gomock.Any(), gomock.Any()).
+		Return(&lambdamicrovms.CreateMicrovmImageOutput{
+			Name:         aws.String("test-microvm"),
+			ImageArn:     aws.String(testImageARN),
+			ImageVersion: aws.String("1.0"),
+			State:        types.MicrovmImageStateCreating,
+		}, nil)
+
+	expectVersionSuccessful(mock, "1.0")
+
+	app := newTestApp(t, mock, "testdata/microvm.json")
+	if err := app.Deploy(context.Background(), &DeployOption{SkipArchive: true, Wait: true, BuildLogs: true}); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func newFakeAWS(t *testing.T) string {
+	t.Helper()
+	if runtime.GOOS == "windows" {
+		t.Skip("fake aws helper is a POSIX shell script")
+	}
+	dir := t.TempDir()
+	script := "#!/bin/sh\nprintf '%s\\n' \"$@\" > \"$FAKE_AWS_ARGS_FILE\"\nsleep 5\n"
+	if err := os.WriteFile(filepath.Join(dir, "aws"), []byte(script), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	t.Setenv("PATH", dir+string(os.PathListSeparator)+os.Getenv("PATH"))
+	return filepath.Join(t.TempDir(), "args.txt")
+}
+
+func TestStartBuildLogTail_NotFound(t *testing.T) {
+	t.Setenv("PATH", t.TempDir())
+
+	app := newTestApp(t, nil, "testdata/microvm.json")
+	stop := app.startBuildLogTail(context.Background(), "1.0")
+	stop()
+}
+
+func TestStartBuildLogTail_BuildsCommand(t *testing.T) {
+	argsFile := newFakeAWS(t)
+	t.Setenv("FAKE_AWS_ARGS_FILE", argsFile)
+
+	app := newTestApp(t, nil, "testdata/microvm.json")
+	app.profile = "test-profile"
+	app.awsConfig.Region = "ap-northeast-1"
+
+	stop := app.startBuildLogTail(context.Background(), "1.0")
+	defer stop()
+
+	deadline := time.Now().Add(3 * time.Second)
+	var got []byte
+	for {
+		var err error
+		got, err = os.ReadFile(argsFile)
+		if err == nil {
+			break
+		}
+		if time.Now().After(deadline) {
+			t.Fatalf("args file was not written in time: %v", err)
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	gotArgs := strings.Split(strings.TrimRight(string(got), "\n"), "\n")
+	want := []string{
+		"--profile", "test-profile",
+		"--region", "ap-northeast-1",
+		"logs", "tail", "/aws/lambda-microvms/test-microvm",
+		"--follow", "--log-stream-name-prefix", "1.0/",
+	}
+	if strings.Join(gotArgs, " ") != strings.Join(want, " ") {
+		t.Errorf("aws args = %v, want %v", gotArgs, want)
+	}
+}
+
+func TestStartBuildLogTail_StopDoesNotHang(t *testing.T) {
+	newFakeAWS(t)
+
+	app := newTestApp(t, nil, "testdata/microvm.json")
+	stop := app.startBuildLogTail(context.Background(), "1.0")
+
+	done := make(chan struct{})
+	go func() {
+		stop()
+		close(done)
+	}()
+	select {
+	case <-done:
+	case <-time.After(3 * time.Second):
+		t.Fatal("stop() did not return in time")
+	}
+}

logs.go

@@ -20,11 +20,15 @@ type LogsOption struct {
 	FilterPattern string `help:"The filter pattern to use." json:"filter_pattern,omitempty"`
 }
 
+func microvmLogGroupName(name string) string {
+	return fmt.Sprintf("/aws/lambda-microvms/%s", name)
+}
+
 // Logs tails CloudWatch logs for the MicroVM image.
 func (app *App) Logs(ctx context.Context, opt *LogsOption) error {
 	img := app.microvmImage
 	name := aws.ToString(img.Name)
-	logGroup := fmt.Sprintf("/aws/lambda-microvms/%s", name)
+	logGroup := microvmLogGroupName(name)
 
 	command := []string{"aws"}
 	if app.profile != "" {

wait.go

@@ -28,7 +28,7 @@ func (app *App) Wait(ctx context.Context, opt *WaitOption) error {
 
 	if opt.Version != "" {
 		slog.Info("waiting for version", "name", name, "version", opt.Version)
-		if err := app.waitForVersion(ctx, imageARN, opt.Version); err != nil {
+		if err := app.waitForVersion(ctx, imageARN, opt.Version, opt.BuildLogs); err != nil {
 			return err
 		}
 	} else {
@@ -43,7 +43,7 @@ func (app *App) Wait(ctx context.Context, opt *WaitOption) error {
 				return err
 			}
 			slog.Info("waiting for version", "name", name, "version", version)
-			if err := app.waitForVersion(ctx, imageARN, version); err != nil {
+			if err := app.waitForVersion(ctx, imageARN, version, opt.BuildLogs); err != nil {
 				return err
 			}
 		}