Merge pull request #15 from koudaiii/koudiaii/specify-output-dir

[aztfy enhancement proposal] `-o` option for specified output dir

internal/config/config.go

@@ -7,13 +7,15 @@ type Config struct {
 	Logfile           string `env:"AZTFY_LOGFILE" default:""`
 	Debug             bool   `env:"AZTFY_DEBUG" default:"false"`
 	MockClient        bool   `env:"AZTFY_MOCK_CLIENT" default:"false"`
+	OutputDir         string // specified via CLI option
 }
 
-func NewConfig(rg string) (*Config, error) {
+func NewConfig(rg string, outputDir string) (*Config, error) {
 	var cfg Config
 	if err := babyenv.Parse(&cfg); err != nil {
 		return nil, err
 	}
 	cfg.ResourceGroupName = rg
+	cfg.OutputDir = outputDir
 	return &cfg, nil
 }

internal/meta/meta.go

@@ -16,5 +16,5 @@ func NewMeta(cfg config.Config) (Meta, error) {
 	if cfg.MockClient {
 		return newMetaDummy(cfg.ResourceGroupName)
 	}
-	return newMetaImpl(cfg.ResourceGroupName)
+	return newMetaImpl(cfg.ResourceGroupName, cfg.OutputDir)
 }

internal/meta/meta_impl.go

@@ -5,6 +5,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
 	"os"
 	"path"
 	"path/filepath"
@@ -32,7 +33,7 @@ type MetaImpl struct {
 	armTemplate    armtemplate.Template
 }
 
-func newMetaImpl(rg string) (Meta, error) {
+func newMetaImpl(rg string, outputDir string) (Meta, error) {
 	ctx := context.TODO()
 
 	// Initialize the workspace
@@ -53,11 +54,35 @@ func newMetaImpl(rg string) (Meta, error) {
 	}
 
 	wsp := filepath.Join(rootDir, rg)
-	if err := os.RemoveAll(wsp); err != nil {
-		return nil, fmt.Errorf("removing existing workspace %q: %w", wsp, err)
-	}
-	if err := os.MkdirAll(wsp, 0755); err != nil {
-		return nil, fmt.Errorf("creating workspace %q: %w", wsp, err)
+
+	if outputDir != "" {
+		wsp = outputDir
+
+		// Ensure wsp is an empty directory
+		stat, err := os.Stat(wsp)
+		if os.IsNotExist(err) {
+			return nil, fmt.Errorf("the output directory %q doesn't exist", wsp)
+		}
+		if !stat.IsDir() {
+			return nil, fmt.Errorf("the output path %q is not a directory", wsp)
+		}
+
+		f, err := os.Open(wsp)
+		if err != nil {
+			return nil, err
+		}
+		_, err = f.Readdirnames(1) // Or f.Readdir(1)
+		f.Close()
+		if err != io.EOF {
+			return nil, fmt.Errorf("the output directory %q is not empty", wsp)
+		}
+	} else {
+		if err := os.RemoveAll(wsp); err != nil {
+			return nil, fmt.Errorf("removing existing workspace %q: %w", wsp, err)
+		}
+		if err := os.MkdirAll(wsp, 0755); err != nil {
+			return nil, fmt.Errorf("creating workspace %q: %w", wsp, err)
+		}
 	}
 
 	// Authentication

main.go

@@ -12,11 +12,13 @@ import (
 )
 
 var (
-	flagVersion *bool
+	flagVersion   *bool
+	flagOutputDir *string
 )
 
 func init() {
 	flagVersion = flag.Bool("v", false, "Print version")
+	flagOutputDir = flag.String("o", "", "Specify output dir. Default is a dir under the user cache dir, which is named after the resource group name")
 }
 
 const usage = `aztfy [option] <resource group name>
@@ -39,7 +41,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	cfg, err := config.NewConfig(flag.Args()[0])
+	cfg, err := config.NewConfig(flag.Args()[0], *flagOutputDir)
 	if err != nil {
 		log.Fatal(err)
 	}