Add Context to root Cobra command

 - Bump cobra to 0.0.6 to get context support
 - Creates root command context and threads through subcommands

Signed-off-by: Zander Mackie <[email protected]>

cmd/pack/main.go

@@ -79,7 +79,8 @@ func main() {
 	rootCmd.Version = cmd.Version
 	rootCmd.SetVersionTemplate(`{{.Version}}{{"\n"}}`)
 
-	if err := rootCmd.Execute(); err != nil {
+	ctx := commands.CreateCancellableContext()
+	if err := rootCmd.ExecuteContext(ctx); err != nil {
 		if commands.IsSoftError(err) {
 			os.Exit(2)
 		}

go.mod

@@ -27,7 +27,7 @@ require (
 	github.com/opencontainers/selinux v1.3.3 // indirect
 	github.com/pkg/errors v0.9.1
 	github.com/sclevine/spec v1.4.0
-	github.com/spf13/cobra v0.0.5
+	github.com/spf13/cobra v0.0.6
 	golang.org/x/crypto v0.0.0-20200302210943-78000ba7a073
 	golang.org/x/net v0.0.0-20200301022130-244492dfa37a // indirect
 	golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e // indirect

internal/commands/build.go

@@ -35,7 +35,6 @@ type BuildFlags struct {
 
 func Build(logger logging.Logger, cfg config.Config, packClient PackClient) *cobra.Command {
 	var flags BuildFlags
-	ctx := createCancellableContext()
 
 	cmd := &cobra.Command{
 		Use:   "build <image-name>",
@@ -80,7 +79,7 @@ func Build(logger logging.Logger, cfg config.Config, packClient PackClient) *cob
 				}
 			}
 
-			if err := packClient.Build(ctx, pack.BuildOptions{
+			if err := packClient.Build(cmd.Context(), pack.BuildOptions{
 				AppPath:           flags.AppPath,
 				Builder:           flags.Builder,
 				AdditionalMirrors: getMirrors(cfg),

internal/commands/commands.go

@@ -28,6 +28,19 @@ func AddHelpFlag(cmd *cobra.Command, commandName string) {
 	cmd.Flags().BoolP("help", "h", false, fmt.Sprintf("Help for '%s'", commandName))
 }
 
+func CreateCancellableContext() context.Context {
+	signals := make(chan os.Signal)
+	signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM)
+	ctx, cancel := context.WithCancel(context.Background())
+
+	go func() {
+		<-signals
+		cancel()
+	}()
+
+	return ctx
+}
+
 func logError(logger logging.Logger, f func(cmd *cobra.Command, args []string) error) func(*cobra.Command, []string) error {
 	return func(cmd *cobra.Command, args []string) error {
 		cmd.SilenceErrors = true
@@ -47,19 +60,6 @@ func multiValueHelp(name string) string {
 	return fmt.Sprintf("\nRepeat for each %s in order,\n  or supply once by comma-separated list", name)
 }
 
-func createCancellableContext() context.Context {
-	signals := make(chan os.Signal)
-	signal.Notify(signals, syscall.SIGINT, syscall.SIGTERM)
-	ctx, cancel := context.WithCancel(context.Background())
-
-	go func() {
-		<-signals
-		cancel()
-	}()
-
-	return ctx
-}
-
 func getMirrors(config config.Config) map[string][]string {
 	mirrors := map[string][]string{}
 	for _, ri := range config.RunImages {

internal/commands/create_builder.go

@@ -20,7 +20,6 @@ type CreateBuilderFlags struct {
 
 func CreateBuilder(logger logging.Logger, client PackClient) *cobra.Command {
 	var flags CreateBuilderFlags
-	ctx := createCancellableContext()
 	cmd := &cobra.Command{
 		Use:   "create-builder <image-name> --builder-config <builder-config-path>",
 		Args:  cobra.ExactArgs(1),
@@ -35,7 +34,7 @@ func CreateBuilder(logger logging.Logger, client PackClient) *cobra.Command {
 			}
 
 			imageName := args[0]
-			if err := client.CreateBuilder(ctx, pack.CreateBuilderOptions{
+			if err := client.CreateBuilder(cmd.Context(), pack.CreateBuilderOptions{
 				BuilderName: imageName,
 				Config:      builderConfig,
 				Publish:     flags.Publish,

internal/commands/package_buildpack.go

@@ -28,7 +28,6 @@ type BuildpackPackager interface {
 
 func PackageBuildpack(logger logging.Logger, client BuildpackPackager, packageConfigReader PackageConfigReader) *cobra.Command {
 	var flags PackageBuildpackFlags
-	ctx := createCancellableContext()
 	cmd := &cobra.Command{
 		Use:   "package-buildpack <image-name> --package-config <package-config-path>",
 		Args:  cobra.ExactArgs(1),
@@ -40,7 +39,7 @@ func PackageBuildpack(logger logging.Logger, client BuildpackPackager, packageCo
 			}
 
 			imageName := args[0]
-			if err := client.PackageBuildpack(ctx, pack.PackageBuildpackOptions{
+			if err := client.PackageBuildpack(cmd.Context(), pack.PackageBuildpackOptions{
 				Name:    imageName,
 				Config:  config,
 				Publish: flags.Publish,

internal/commands/rebase.go

@@ -11,7 +11,6 @@ import (
 
 func Rebase(logger logging.Logger, cfg config.Config, client PackClient) *cobra.Command {
 	var opts pack.RebaseOptions
-	ctx := createCancellableContext()
 
 	cmd := &cobra.Command{
 		Use:   "rebase <image-name>",
@@ -20,7 +19,7 @@ func Rebase(logger logging.Logger, cfg config.Config, client PackClient) *cobra.
 		RunE: logError(logger, func(cmd *cobra.Command, args []string) error {
 			opts.RepoName = args[0]
 			opts.AdditionalMirrors = getMirrors(cfg)
-			if err := client.Rebase(ctx, opts); err != nil {
+			if err := client.Rebase(cmd.Context(), opts); err != nil {
 				return err
 			}
 			logger.Infof("Successfully rebased image %s", style.Symbol(opts.RepoName))

internal/commands/suggest_builders.go

@@ -46,7 +46,7 @@ func SuggestBuilders(logger logging.Logger, client PackClient) *cobra.Command {
 		Use:   "suggest-builders",
 		Short: "Display list of recommended builders",
 		Args:  cobra.NoArgs,
-		Run: func(*cobra.Command, []string) {
+		Run: func(cmd *cobra.Command, s []string) {
 			suggestBuilders(logger, client)
 		},
 	}