Add pack set-default-registry command

cmd/cmd.go

@@ -84,9 +84,10 @@ func NewPackCommand(logger ConfigurableLogger) (*cobra.Command, error) {
 	rootCmd.AddCommand(commands.Report(logger, pack.Version))
 
 	if cfg.Experimental {
-		rootCmd.AddCommand(commands.ListBuildpackRegistries(logger, cfg))
 		rootCmd.AddCommand(commands.AddBuildpackRegistry(logger, cfg, cfgPath))
+		rootCmd.AddCommand(commands.ListBuildpackRegistries(logger, cfg))
 		rootCmd.AddCommand(commands.RegisterBuildpack(logger, cfg, &packClient))
+		rootCmd.AddCommand(commands.SetDefaultRegistry(logger, cfg, cfgPath))
 		rootCmd.AddCommand(commands.RemoveRegistry(logger, cfg, cfgPath))
 		rootCmd.AddCommand(commands.YankBuildpack(logger, cfg, &packClient))
 	}

internal/commands/set_default_registry.go

@@ -0,0 +1,54 @@
+package commands
+
+import (
+	"github.com/pkg/errors"
+	"github.com/spf13/cobra"
+
+	"github.com/buildpacks/pack/internal/config"
+	"github.com/buildpacks/pack/internal/style"
+	"github.com/buildpacks/pack/logging"
+)
+
+func SetDefaultRegistry(logger logging.Logger, cfg config.Config, cfgPath string) *cobra.Command {
+	var (
+		registryName string
+	)
+
+	cmd := &cobra.Command{
+		Use:     "set-default-registry <name>",
+		Args:    cobra.ExactArgs(1),
+		Short:   "Set default registry",
+		Example: "pack set-default-registry myregistry",
+		RunE: logError(logger, func(cmd *cobra.Command, args []string) error {
+			registryName = args[0]
+			if !containsRegistry(config.GetRegistries(cfg), registryName) {
+				return errors.Errorf("no registry with the name %s exists", style.Symbol(registryName))
+			}
+
+			if cfg.DefaultRegistryName != registryName {
+				cfg.DefaultRegistryName = registryName
+				err := config.Write(cfg, cfgPath)
+				if err != nil {
+					return err
+				}
+			}
+
+			logger.Infof("Successfully set %s as the default registry", style.Symbol(registryName))
+
+			return nil
+		}),
+	}
+	AddHelpFlag(cmd, "set-default-registry")
+
+	return cmd
+}
+
+func containsRegistry(registries []config.Registry, registry string) bool {
+	for _, r := range registries {
+		if r.Name == registry {
+			return true
+		}
+	}
+
+	return false
+}

internal/commands/set_default_registry_test.go

@@ -0,0 +1,78 @@
+package commands_test
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/heroku/color"
+	"github.com/sclevine/spec"
+	"github.com/sclevine/spec/report"
+
+	"github.com/buildpacks/pack/internal/commands"
+	"github.com/buildpacks/pack/internal/config"
+	ilogging "github.com/buildpacks/pack/internal/logging"
+	h "github.com/buildpacks/pack/testhelpers"
+)
+
+func TestSetDefaultRegistry(t *testing.T) {
+	color.Disable(true)
+	defer color.Disable(false)
+
+	spec.Run(t, "SetDefaultRegistryCommand", testSetDefaultRegistryCommand, spec.Parallel(), spec.Report(report.Terminal{}))
+}
+
+func testSetDefaultRegistryCommand(t *testing.T, when spec.G, it spec.S) {
+	when("#SetDefaultRegistry", func() {
+		var (
+			outBuf     bytes.Buffer
+			logger     = ilogging.NewLogWithWriters(&outBuf, &outBuf)
+			tmpDir     string
+			configFile string
+			assert     = h.NewAssertionManager(t)
+		)
+
+		it.Before(func() {
+			var err error
+			tmpDir, err = ioutil.TempDir("", "pack-home-*")
+			assert.Nil(err)
+
+			configFile = filepath.Join(tmpDir, "config.toml")
+		})
+
+		it.After(func() {
+			_ = os.RemoveAll(tmpDir)
+		})
+
+		it("should set the default registry", func() {
+			cfg := config.Config{
+				Registries: []config.Registry{
+					{
+						Name: "myregistry",
+						URL:  "https://github.com/buildpacks/registry-index",
+						Type: "github",
+					},
+				},
+			}
+			command := commands.SetDefaultRegistry(logger, cfg, configFile)
+			command.SetArgs([]string{"myregistry"})
+			assert.Succeeds(command.Execute())
+
+			cfg, err := config.Read(configFile)
+			assert.Nil(err)
+
+			assert.Equal(cfg.DefaultRegistryName, "myregistry")
+		})
+
+		it("should fail if no corresponding registry exists", func() {
+			command := commands.SetDefaultRegistry(logger, config.Config{}, configFile)
+			command.SetArgs([]string{"myregistry"})
+			assert.Error(command.Execute())
+
+			output := outBuf.String()
+			h.AssertContains(t, output, "no registry with the name 'myregistry' exists")
+		})
+	})
+}