refactor: run plugin system from main

cmd/aspect/BUILD.bazel

@@ -11,6 +11,8 @@ go_library(
     deps = [
         "//cmd/aspect/root",
         "//pkg/aspecterrors",
+        "//pkg/ioutils",
+        "//pkg/plugin/system",
     ],
 )
 

cmd/aspect/build/BUILD.bazel

@@ -8,11 +8,11 @@ go_library(
     deps = [
         "//cmd/aspect/root/flags",
         "//pkg/aspect/build",
-        "//pkg/aspect/build/bep",
+        "//pkg/aspecterrors",
         "//pkg/bazel",
-        "//pkg/hooks",
         "//pkg/ioutils",
         "//pkg/plugin/system",
+        "//pkg/plugin/system/bep",
         "@com_github_spf13_cobra//:cobra",
     ],
 )

cmd/aspect/build/build.go

@@ -7,59 +7,65 @@ Not licensed for re-use.
 package build
 
 import (
+	"errors"
+	"fmt"
+
 	"github.com/spf13/cobra"
 
 	rootFlags "aspect.build/cli/cmd/aspect/root/flags"
 	"aspect.build/cli/pkg/aspect/build"
-	"aspect.build/cli/pkg/aspect/build/bep"
+	"aspect.build/cli/pkg/aspecterrors"
 	"aspect.build/cli/pkg/bazel"
-	"aspect.build/cli/pkg/hooks"
 	"aspect.build/cli/pkg/ioutils"
 	"aspect.build/cli/pkg/plugin/system"
+	"aspect.build/cli/pkg/plugin/system/bep"
 )
 
 // NewDefaultBuildCmd creates a new build cobra command with the default
 // dependencies.
-func NewDefaultBuildCmd() *cobra.Command {
+func NewDefaultBuildCmd(pluginSystem system.PluginSystem) *cobra.Command {
 	return NewBuildCmd(
 		ioutils.DefaultStreams,
+		pluginSystem,
 		bazel.New(),
-		bep.NewBESBackend(),
-		hooks.New(),
 	)
 }
 
 // NewBuildCmd creates a new build cobra command.
 func NewBuildCmd(
 	streams ioutils.Streams,
+	pluginSystem system.PluginSystem,
 	bzl bazel.Spawner,
-	besBackend bep.BESBackend,
-	hooks *hooks.Hooks,
 ) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "build",
 		Short: "Builds the specified targets, using the options.",
 		Long: "Invokes bazel build on the specified targets. " +
 			"See 'bazel help target-syntax' for details and examples on how to specify targets to build.",
 		RunE: func(cmd *cobra.Command, args []string) (exitErr error) {
-			pluginSystem := system.NewPluginSystem()
-			if err := pluginSystem.Configure(streams); err != nil {
-				return err
-			}
-			defer pluginSystem.TearDown()
-
-			for node := pluginSystem.PluginList().Head; node != nil; node = node.Next {
-				besBackend.RegisterSubscriber(node.Plugin.BEPEventCallback)
-				hooks.RegisterPostBuild(node.Plugin.PostBuildHook)
-			}
-
 			isInteractiveMode, err := cmd.Root().PersistentFlags().GetBool(rootFlags.InteractiveFlagName)
 			if err != nil {
 				return err
 			}
 
-			b := build.New(streams, bzl, besBackend, hooks)
-			return b.Run(cmd.Context(), cmd, args, isInteractiveMode)
+			// TODO(f0rmiga): test this post-build hook.
+			defer func() {
+				errs := pluginSystem.ExecutePostBuild(isInteractiveMode).Errors()
+				if len(errs) > 0 {
+					for _, err := range errs {
+						fmt.Fprintf(streams.Stderr, "Error: failed to run build command: %v\n", err)
+					}
+					var err *aspecterrors.ExitError
+					if errors.As(exitErr, &err) {
+						err.ExitCode = 1
+					}
+				}
+			}()
+
+			b := build.New(streams, bzl)
+			return pluginSystem.WithBESBackend(cmd.Context(), func(besBackend bep.BESBackend) error {
+				return b.Run(args, besBackend)
+			})
 		},
 	}
 

cmd/aspect/main.go

@@ -14,6 +14,8 @@ import (
 
 	"aspect.build/cli/cmd/aspect/root"
 	"aspect.build/cli/pkg/aspecterrors"
+	"aspect.build/cli/pkg/ioutils"
+	"aspect.build/cli/pkg/plugin/system"
 )
 
 func main() {
@@ -34,7 +36,15 @@ func main() {
 	if wd, exists := os.LookupEnv("BUILD_WORKING_DIRECTORY"); exists {
 		_ = os.Chdir(wd)
 	}
-	cmd := root.NewDefaultRootCmd()
+
+	pluginSystem := system.NewPluginSystem()
+	if err := pluginSystem.Configure(ioutils.DefaultStreams); err != nil {
+		fmt.Fprintln(os.Stderr, "Error:", err)
+		os.Exit(1)
+	}
+	defer pluginSystem.TearDown()
+
+	cmd := root.NewDefaultRootCmd(pluginSystem)
 	if err := cmd.ExecuteContext(context.Background()); err != nil {
 		var exitErr *aspecterrors.ExitError
 		if errors.As(err, &exitErr) {

cmd/aspect/root/BUILD.bazel

@@ -18,6 +18,7 @@ go_library(
         "//cmd/aspect/version",
         "//docs/help/topics",
         "//pkg/ioutils",
+        "//pkg/plugin/system",
         "@com_github_fatih_color//:color",
         "@com_github_mattn_go_isatty//:go-isatty",
         "@com_github_mitchellh_go_homedir//:go-homedir",

cmd/aspect/root/root.go

@@ -24,19 +24,24 @@ import (
 	"aspect.build/cli/cmd/aspect/version"
 	"aspect.build/cli/docs/help/topics"
 	"aspect.build/cli/pkg/ioutils"
+	"aspect.build/cli/pkg/plugin/system"
 )
 
 var (
 	boldCyan = color.New(color.FgCyan, color.Bold)
 	faint    = color.New(color.Faint)
 )
 
-func NewDefaultRootCmd() *cobra.Command {
+func NewDefaultRootCmd(pluginSystem system.PluginSystem) *cobra.Command {
 	defaultInteractive := isatty.IsTerminal(os.Stdout.Fd()) || isatty.IsCygwinTerminal(os.Stdout.Fd())
-	return NewRootCmd(ioutils.DefaultStreams, defaultInteractive)
+	return NewRootCmd(ioutils.DefaultStreams, pluginSystem, defaultInteractive)
 }
 
-func NewRootCmd(streams ioutils.Streams, defaultInteractive bool) *cobra.Command {
+func NewRootCmd(
+	streams ioutils.Streams,
+	pluginSystem system.PluginSystem,
+	defaultInteractive bool,
+) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:           "aspect",
 		Short:         "Aspect.build bazel wrapper",
@@ -73,7 +78,7 @@ func NewRootCmd(streams ioutils.Streams, defaultInteractive bool) *cobra.Command
 
 	// ### Child commands
 	// IMPORTANT: when adding a new command, also update the _DOCS list in /docs/BUILD.bazel
-	cmd.AddCommand(build.NewDefaultBuildCmd())
+	cmd.AddCommand(build.NewDefaultBuildCmd(pluginSystem))
 	cmd.AddCommand(clean.NewDefaultCleanCmd())
 	cmd.AddCommand(version.NewDefaultVersionCmd())
 	cmd.AddCommand(docs.NewDefaultDocsCmd())

cmd/docgen/main.go

@@ -14,7 +14,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	err := doc.GenMarkdownTree(root.NewDefaultRootCmd(), os.Args[1])
+	err := doc.GenMarkdownTree(root.NewDefaultRootCmd(nil), os.Args[1])
 	if err != nil {
 		log.Fatal(err)
 	}

pkg/aspect/build/BUILD.bazel

@@ -6,12 +6,10 @@ go_library(
     importpath = "aspect.build/cli/pkg/aspect/build",
     visibility = ["//cmd/aspect/build:__pkg__"],
     deps = [
-        "//pkg/aspect/build/bep",
         "//pkg/aspecterrors",
         "//pkg/bazel",
-        "//pkg/hooks",
         "//pkg/ioutils",
-        "@com_github_spf13_cobra//:cobra",
+        "//pkg/plugin/system/bep",
     ],
 )
 
@@ -20,11 +18,10 @@ go_test(
     srcs = ["build_test.go"],
     deps = [
         ":build",
-        "//pkg/aspect/build/bep/mock",
         "//pkg/aspecterrors",
         "//pkg/bazel/mock",
-        "//pkg/hooks",
         "//pkg/ioutils",
+        "//pkg/plugin/system/bep/mock",
         "@com_github_golang_mock//gomock",
         "@com_github_onsi_gomega//:gomega",
     ],

pkg/aspect/build/build.go

@@ -7,81 +7,39 @@ Not licensed for re-use.
 package build
 
 import (
-	"context"
-	"errors"
 	"fmt"
-	"time"
 
-	"github.com/spf13/cobra"
-
-	"aspect.build/cli/pkg/aspect/build/bep"
 	"aspect.build/cli/pkg/aspecterrors"
 	"aspect.build/cli/pkg/bazel"
-	"aspect.build/cli/pkg/hooks"
 	"aspect.build/cli/pkg/ioutils"
+	"aspect.build/cli/pkg/plugin/system/bep"
 )
 
 // Build represents the aspect build command.
 type Build struct {
 	ioutils.Streams
-	bzl        bazel.Spawner
-	besBackend bep.BESBackend
-	hooks      *hooks.Hooks
+	bzl bazel.Spawner
 }
 
 // New creates a Build command.
 func New(
 	streams ioutils.Streams,
 	bzl bazel.Spawner,
-	besBackend bep.BESBackend,
-	hooks *hooks.Hooks,
 ) *Build {
 	return &Build{
-		Streams:    streams,
-		bzl:        bzl,
-		besBackend: besBackend,
-		hooks:      hooks,
+		Streams: streams,
+		bzl:     bzl,
 	}
 }
 
 // Run runs the aspect build command, calling `bazel build` with a local Build
 // Event Protocol backend used by Aspect plugins to subscribe to build events.
-func (b *Build) Run(
-	ctx context.Context,
-	cmd *cobra.Command,
-	args []string,
-	isInteractiveMode bool,
-) (exitErr error) {
-	// TODO(f0rmiga): this is a hook for the build command and should be discussed
-	// as part of the plugin design.
-	defer func() {
-		errs := b.hooks.ExecutePostBuild(isInteractiveMode).Errors()
-		if len(errs) > 0 {
-			for _, err := range errs {
-				fmt.Fprintf(b.Streams.Stderr, "Error: failed to run build command: %v\n", err)
-			}
-			var err *aspecterrors.ExitError
-			if errors.As(exitErr, &err) {
-				err.ExitCode = 1
-			}
-		}
-	}()
-
-	if err := b.besBackend.Setup(); err != nil {
-		return fmt.Errorf("failed to run build command: %w", err)
-	}
-	ctx, cancel := context.WithTimeout(ctx, time.Second)
-	defer cancel()
-	if err := b.besBackend.ServeWait(ctx); err != nil {
-		return fmt.Errorf("failed to run build command: %w", err)
-	}
-	defer b.besBackend.GracefulStop()
-
-	besBackendFlag := fmt.Sprintf("--bes_backend=grpc://%s", b.besBackend.Addr())
+func (b *Build) Run(args []string, besBackend bep.BESBackend) (exitErr error) {
+	besBackendFlag := fmt.Sprintf("--bes_backend=grpc://%s", besBackend.Addr())
 	exitCode, bazelErr := b.bzl.Spawn(append([]string{"build", besBackendFlag}, args...))
 
 	// Process the subscribers errors before the Bazel one.
-	subscriberErrors := b.besBackend.Errors()
+	subscriberErrors := besBackend.Errors()
 	if len(subscriberErrors) > 0 {
 		for _, err := range subscriberErrors {
 			fmt.Fprintf(b.Streams.Stderr, "Error: failed to run build command: %v\n", err)