Add "add-stack" command

WHEN I run pack add-stack my.custom.stack --run-image my-org/run --build-image my-org/build THEN a stack will be added to the config.toml file in the following format AND return the following message to the user "<stack ID> successfully added." [buildpacks#34]
quantumsheep · Oct 4, 2018 · 03ab0d3 · 03ab0d3
1 parent b1d0c29
commit 03ab0d3
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Showing 4 changed files with 148 additions and 8 deletions.
diff --git a/acceptance/acceptance_test.go b/acceptance/acceptance_test.go
@@ -14,6 +14,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/BurntSushi/toml"
 	"github.com/google/go-cmp/cmp"
 	"github.com/sclevine/spec"
 	"github.com/sclevine/spec/report"
@@ -246,6 +247,34 @@ func testPack(t *testing.T, when spec.G, it spec.S) {
 			}
 		})
 	}, spec.Parallel(), spec.Report(report.Terminal{}))
+
+	when("add-stack", func() {
+		it("adds a custom stack to ~/.pack/config.toml", func() {
+			cmd := exec.Command(pack, "add-stack", "my.custom.stack", "--run-image", "my-org/run", "--build-image", "my-org/build")
+			cmd.Env = append(os.Environ(), "HOME="+homeDir)
+			output, err := cmd.CombinedOutput()
+			if err != nil {
+				t.Fatalf("add-stack command failed: %s: %s", output, err)
+			}
+
+			assertEq(t, string(output), "my.custom.stack successfully added\n")
+
+			var config struct {
+				Stacks []struct {
+					ID          string   `toml:"id"`
+					BuildImages []string `toml:"build-images"`
+					RunImages   []string `toml:"run-images"`
+				} `toml:"stacks"`
+			}
+			_, err = toml.DecodeFile(filepath.Join(homeDir, ".pack", "config.toml"), &config)
+			assertNil(t, err)
+
+			stack := config.Stacks[len(config.Stacks)-1]
+			assertEq(t, stack.ID, "my.custom.stack")
+			assertEq(t, stack.BuildImages, []string{"my-org/build"})
+			assertEq(t, stack.RunImages, []string{"my-org/run"})
+		})
+	}, spec.Parallel(), spec.Report(report.Terminal{}))
 }
 
 func run(t *testing.T, cmd *exec.Cmd) string {

diff --git a/cmd/pack/main.go b/cmd/pack/main.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"log"
 	"os"
 	"path/filepath"
@@ -18,10 +19,12 @@ import (
 func main() {
 	buildCmd := buildCommand()
 	createBuilderCmd := createBuilderCommand()
+	addStackCmd := addStackCommand()
 
 	rootCmd := &cobra.Command{Use: "pack"}
 	rootCmd.AddCommand(buildCmd)
 	rootCmd.AddCommand(createBuilderCmd)
+	rootCmd.AddCommand(addStackCmd)
 	if err := rootCmd.Execute(); err != nil {
 		os.Exit(1)
 	}
@@ -90,3 +93,32 @@ func createBuilderCommand() *cobra.Command {
 	createBuilderCommand.Flags().StringVarP(&flags.StackID, "stack", "s", "", "stack ID")
 	return createBuilderCommand
 }
+
+func addStackCommand() *cobra.Command {
+	flags := struct {
+		BuildImage string
+		RunImage   string
+	}{}
+	addStackCommand := &cobra.Command{
+		Use:  "add-stack <stack-name> --run-image=<name> --build-image=<name>",
+		Args: cobra.MinimumNArgs(1),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			cfg, err := config.New(filepath.Join(os.Getenv("HOME"), ".pack"))
+			if err != nil {
+				return err
+			}
+			if err := cfg.Add(config.Stack{
+				ID:          args[0],
+				BuildImages: []string{flags.BuildImage},
+				RunImages:   []string{flags.RunImage},
+			}); err != nil {
+				return err
+			}
+			fmt.Printf("%s successfully added\n", args[0])
+			return nil
+		},
+	}
+	addStackCommand.Flags().StringVar(&flags.BuildImage, "build-image", "", "build image to be used for bulder images built with the stack")
+	addStackCommand.Flags().StringVar(&flags.RunImage, "run-image", "", "run image to be used for runnable images built with the stack")
+	return addStackCommand
+}
diff --git a/config/config.go b/config/config.go
@@ -13,6 +13,7 @@ import (
 type Config struct {
 	Stacks         []Stack `toml:"stacks"`
 	DefaultStackID string  `toml:"default-stack-id"`
+	configPath     string
 }
 
 type Stack struct {
@@ -37,20 +38,25 @@ func New(path string) (*Config, error) {
 		RunImages:   []string{"packs/run"},
 	})
 
-	if err := os.MkdirAll(filepath.Dir(configPath), 0777); err != nil {
+	config.configPath = configPath
+	if err := config.save(); err != nil {
 		return nil, err
 	}
-	w, err := os.OpenFile(configPath, os.O_CREATE|os.O_RDWR, 0644)
+
+	return config, nil
+}
+
+func (c *Config) save() error {
+	if err := os.MkdirAll(filepath.Dir(c.configPath), 0777); err != nil {
+		return err
+	}
+	w, err := os.OpenFile(c.configPath, os.O_CREATE|os.O_RDWR, 0644)
 	if err != nil {
-		return nil, err
+		return err
 	}
 	defer w.Close()
 
-	if err := toml.NewEncoder(w).Encode(config); err != nil {
-		return nil, err
-	}
-
-	return config, nil
+	return toml.NewEncoder(w).Encode(c)
 }
 
 func previousConfig(path string) (*Config, error) {
@@ -84,6 +90,14 @@ func (c *Config) Get(stackID string) (*Stack, error) {
 	return nil, fmt.Errorf(`Missing stack: stack with id "%s" not found in pack config.toml`, stackID)
 }
 
+func (c *Config) Add(stack Stack) error {
+	if _, err := c.Get(stack.ID); err == nil {
+		return fmt.Errorf(`stack "%s" already exists`, stack.ID)
+	}
+	c.Stacks = append(c.Stacks, stack)
+	return c.save()
+}
+
 func ImageByRegistry(registry string, images []string) (string, error) {
 	if len(images) == 0 {
 		return "", errors.New("empty images")

diff --git a/config/config_test.go b/config/config_test.go
@@ -201,6 +201,71 @@ default-stack-id = "my.stack"
 		})
 	})
 
+	when("Config#Add", func() {
+		var subject *config.Config
+		it.Before(func() {
+			assertNil(t, ioutil.WriteFile(filepath.Join(tmpDir, "config.toml"), []byte(`
+default-stack-id = "my.stack"
+[[stacks]]
+  id = "stack-1"
+[[stacks]]
+  id = "my.stack"
+[[stacks]]
+  id = "stack-3"
+`), 0666))
+			var err error
+			subject, err = config.New(tmpDir)
+			assertNil(t, err)
+		})
+
+		when("stack to be added is new", func() {
+			it("adds the stack and writes to file", func() {
+				err := subject.Add(config.Stack{
+					ID:          "new-stack",
+					BuildImages: []string{"neworg/build"},
+					RunImages:   []string{"neworg/run"},
+				})
+				assertNil(t, err)
+
+				stack, err := subject.Get("new-stack")
+				assertNil(t, err)
+				assertEq(t, stack.ID, "new-stack")
+				assertEq(t, stack.BuildImages, []string{"neworg/build"})
+				assertEq(t, stack.RunImages, []string{"neworg/run"})
+
+				b, err := ioutil.ReadFile(filepath.Join(tmpDir, "config.toml"))
+				assertNil(t, err)
+				assertContains(t, string(b), "new-stack")
+				assertContains(t, string(b), "neworg/build")
+				assertContains(t, string(b), "neworg/run")
+			})
+		})
+
+		when("stack to be added is already in file", func() {
+			it("errors and leaves file unchanged", func() {
+				stat, err := os.Stat(filepath.Join(tmpDir, "config.toml"))
+				assertNil(t, err)
+				origSize := stat.Size()
+
+				err = subject.Add(config.Stack{
+					ID:          "my.stack",
+					BuildImages: []string{"neworg/build"},
+					RunImages:   []string{"neworg/run"},
+				})
+				assertNotNil(t, err)
+				assertEq(t, err.Error(), `stack "my.stack" already exists`)
+
+				stack, err := subject.Get("my.stack")
+				assertNil(t, err)
+				assertEq(t, stack.BuildImages, []string(nil))
+
+				stat, err = os.Stat(filepath.Join(tmpDir, "config.toml"))
+				assertNil(t, err)
+				assertEq(t, stat.Size(), origSize)
+			})
+		})
+	})
+
 	when("ImageByRegistry", func() {
 		var images []string
 		it.Before(func() {