suggest-builders command

acceptance/acceptance_test.go

@@ -642,6 +642,18 @@ func testAcceptance(t *testing.T, when spec.G, it spec.S) {
 		})
 	})
 
+	when("pack suggest-builders", func() {
+		it("displays suggested builders", func() {
+			cmd := packCmd("suggest-builders")
+			output, err := cmd.CombinedOutput()
+			if err != nil {
+				t.Fatalf("suggest-builders command failed: %s: %s", output, err)
+			}
+			h.AssertContains(t, string(output), "Suggested builders:")
+			h.AssertContains(t, string(output), "cloudfoundry/cnb:bionic")
+		})
+	})
+
 	when("pack set-default-builder", func() {
 		it("sets the default-stack-id in ~/.pack/config.toml", func() {
 			cmd := packCmd("set-default-builder", "some/builder")

cmd/pack/main.go

@@ -51,6 +51,7 @@ func main() {
 	rootCmd.AddCommand(commands.SetRunImagesMirrors(&logger))
 	rootCmd.AddCommand(commands.InspectBuilder(&logger, &cfg, &packClient))
 	rootCmd.AddCommand(commands.SetDefaultBuilder(&logger))
+	rootCmd.AddCommand(commands.SuggestBuilders(&logger))
 
 	rootCmd.AddCommand(commands.Version(&logger, Version))
 

commands/build.go

@@ -1,11 +1,6 @@
 package commands
 
 import (
-	"fmt"
-	"math/rand"
-	"text/tabwriter"
-	"time"
-
 	"github.com/spf13/cobra"
 
 	"github.com/buildpack/pack"
@@ -14,25 +9,6 @@ import (
 	"github.com/buildpack/pack/style"
 )
 
-type suggestedBuilder struct {
-	name  string
-	image string
-	info  string
-}
-
-var suggestedBuilders = [][]suggestedBuilder{
-	{
-		{"Cloud Foundry", "cloudfoundry/cnb:bionic", "small base image with Java & Node.js"},
-		{"Cloud Foundry", "cloudfoundry/cnb:cflinuxfs3", "larger base image with Java, Node.js & Python"},
-	},
-	{
-		{"Heroku", "heroku/buildpacks", "heroku-18 base image with official Heroku buildpacks"},
-	},
-}
-
-func init() {
-	rand.Seed(time.Now().UnixNano())
-}
 
 func Build(logger *logging.Logger, fetcher pack.ImageFetcher) *cobra.Command {
 	var buildFlags pack.BuildFlags
@@ -82,29 +58,6 @@ func Build(logger *logging.Logger, fetcher pack.ImageFetcher) *cobra.Command {
 	return cmd
 }
 
-func suggestSettingBuilder(logger *logging.Logger) {
-	logger.Info("Please select a default builder with:\n")
-	logger.Info("\tpack set-default-builder <builder image>\n")
-	suggestBuilders(logger)
-}
-
-func suggestBuilders(logger *logging.Logger) {
-	logger.Info("Suggested builders:\n")
-	tw := tabwriter.NewWriter(logger.RawWriter(), 10, 10, 5, ' ', tabwriter.TabIndent)
-	for len(suggestedBuilders) > 0 {
-		n := rand.Intn(len(suggestedBuilders))
-		builders := suggestedBuilders[n]
-		for _, builder := range builders {
-			tw.Write([]byte(fmt.Sprintf("\t%s:\t%s\t%s\t\n", builder.name, style.Symbol(builder.image), builder.info)))
-		}
-		suggestedBuilders = append(suggestedBuilders[:n], suggestedBuilders[n+1:]...)
-	}
-	tw.Flush()
-	logger.Info("")
-	logger.Tip("Learn more about a specific builder with:\n")
-	logger.Info("\tpack inspect-builder [builder image]")
-}
-
 func buildCommandFlags(cmd *cobra.Command, buildFlags *pack.BuildFlags) {
 	cmd.Flags().StringVarP(&buildFlags.AppDir, "path", "p", "", "Path to app dir (defaults to current working directory)")
 	cmd.Flags().StringVar(&buildFlags.Builder, "builder", "", "Builder (defaults to builder configured by 'set-default-builder')")

commands/commands.go

@@ -3,9 +3,12 @@ package commands
 import (
 	"context"
 	"fmt"
+	"github.com/buildpack/pack/style"
+	"math/rand"
 	"os"
 	"os/signal"
 	"syscall"
+	"text/tabwriter"
 
 	"github.com/docker/docker/client"
 	"github.com/spf13/cobra"
@@ -20,6 +23,23 @@ type PackClient interface {
 	Rebase(context.Context, pack.RebaseOptions) error
 }
 
+
+type suggestedBuilder struct {
+	name  string
+	image string
+	info string
+}
+
+var suggestedBuilders = [][]suggestedBuilder{
+	{
+		{"Cloud Foundry", "cloudfoundry/cnb:bionic", "small base image with Java & Node.js"},
+		{"Cloud Foundry", "cloudfoundry/cnb:cflinuxfs3", "larger base image with Java, Node.js & Python"},
+	},
+	{
+		{"Heroku", "heroku/buildpacks", "heroku-18 base image with official Heroku buildpacks"},
+	},
+}
+
 func AddHelpFlag(cmd *cobra.Command, commandName string) {
 	cmd.Flags().BoolP("help", "h", false, fmt.Sprintf("Help for '%s'", commandName))
 }
@@ -59,3 +79,28 @@ func createCancellableContext() context.Context {
 func dockerClient() (*client.Client, error){
 	return client.NewClientWithOpts(client.FromEnv, client.WithVersion("1.38"))
 }
+
+
+
+func suggestSettingBuilder(logger *logging.Logger) {
+	logger.Info("Please select a default builder with:\n")
+	logger.Info("\tpack set-default-builder <builder image>\n")
+	suggestBuilders(logger)
+}
+
+func suggestBuilders(logger *logging.Logger) {
+	logger.Info("Suggested builders:\n")
+
+	tw := tabwriter.NewWriter(logger.RawWriter(), 10, 10, 5, ' ', tabwriter.TabIndent)
+	for _, i := range rand.Perm(len(suggestedBuilders)) {
+		builders := suggestedBuilders[i]
+		for _, builder := range builders {
+			_, _ = tw.Write([]byte(fmt.Sprintf("\t%s:\t%s\t%s\t\n", builder.name, style.Symbol(builder.image), builder.info)))
+		}
+	}
+	_ = tw.Flush()
+
+	logger.Info("")
+	logger.Tip("Learn more about a specific builder with:\n")
+	logger.Info("\tpack inspect-builder [builder image]")
+}

commands/suggest_builders.go

@@ -0,0 +1,22 @@
+package commands
+
+import (
+	"github.com/buildpack/pack/logging"
+	"github.com/spf13/cobra"
+)
+
+func SuggestBuilders(logger *logging.Logger) *cobra.Command {
+	cmd := &cobra.Command{
+		Use:   "suggest-builders",
+		Short: "Display list of recommended builders",
+		Args:  cobra.NoArgs,
+		RunE: logError(logger, func(cmd *cobra.Command, args []string) error {
+			suggestBuilders(logger)
+
+			return nil
+		}),
+	}
+
+	AddHelpFlag(cmd, "suggest-builders")
+	return cmd
+}

commands/suggest_builders_test.go

@@ -0,0 +1,41 @@
+package commands_test
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/sclevine/spec"
+	"github.com/sclevine/spec/report"
+	"github.com/spf13/cobra"
+
+	"github.com/buildpack/pack/commands"
+	"github.com/buildpack/pack/logging"
+	h "github.com/buildpack/pack/testhelpers"
+)
+
+func TestSuggestBuilders(t *testing.T) {
+	spec.Run(t, "Commands", testSuggestBuildersCommand, spec.Parallel(), spec.Report(report.Terminal{}))
+}
+
+func testSuggestBuildersCommand(t *testing.T, when spec.G, it spec.S) {
+
+	var (
+		command *cobra.Command
+		logger  *logging.Logger
+		outBuf  bytes.Buffer
+	)
+
+	it.Before(func() {
+		logger = logging.NewLogger(&outBuf, &outBuf, false, false)
+		command = commands.SuggestBuilders(logger)
+	})
+
+	when("#SuggestBuilders", func() {
+		it("display suggested builders", func() {
+			command.SetArgs([]string{})
+			h.AssertNil(t, command.Execute())
+			h.AssertContains(t, outBuf.String(), "Suggested builders:")
+			h.AssertContains(t, outBuf.String(), "cloudfoundry/cnb:bionic")
+		})
+	})
+}