support for purging images list cache

cli/images.go

@@ -36,8 +36,8 @@ Use the image in creating a VM:
 $ vermin create <image>
 `,
 	Run: func(cmd *cobra.Command, args []string) {
-
-		i, err := images.Display()
+		purge, _ := cmd.Flags().GetBool("purge")
+		i, err := images.Display(purge)
 		if err != nil {
 			fmt.Println(err)
 			os.Exit(1)
@@ -57,5 +57,5 @@ func init() {
 
 	// Cobra supports local flags which will only run when this command
 	// is called directly, e.g.:
-	//imagesCmd.Flags().BoolP("all", "a", false, "List all VMs")
+	imagesCmd.Flags().BoolP("purge", "p", false, "Purge images list cache")
 }

images/images.go

@@ -23,7 +23,7 @@ func Create(image string) error {
 		}
 	}
 
-	remote, err := listRemoteImages()
+	remote, err := listRemoteImages(false)
 	if err != nil {
 		return err
 	}
@@ -39,9 +39,9 @@ func Create(image string) error {
 	}
 
 	if rimage == nil {
-		display, _ := List()
-		return errors.New(fmt.Sprintf("invalid image name: '%s'.", image) +
-			" Valid images are:\n" + strings.Join(display, "\n"))
+		l, _ := List()
+		return errors.New(fmt.Sprintf("invalid image name: '%s',", image) +
+			" valid images are:\n" + strings.Join(l, "\n"))
 	}
 
 	return download(rimage)
@@ -53,7 +53,7 @@ type image struct {
 }
 
 func List() ([]string, error) {
-	list, err := list()
+	list, err := list(false)
 	if err != nil {
 		return nil, err
 	}
@@ -64,9 +64,9 @@ func List() ([]string, error) {
 	return result, nil
 }
 
-func Display() (string, error) {
+func Display(purgeCache bool) (string, error) {
 
-	list, err := list()
+	list, err := list(purgeCache)
 	if err != nil {
 		return "", err
 	}
@@ -82,7 +82,7 @@ func Display() (string, error) {
 	return result, nil
 }
 
-func list() ([]image, error) {
+func list(purgeCache bool) ([]image, error) {
 	var result []image
 
 	cached, err := listCachedImages()
@@ -93,7 +93,7 @@ func list() ([]image, error) {
 		result = append(result, image{cached[i], true})
 	}
 
-	remote, err := listRemoteImagesNames()
+	remote, err := listRemoteImagesNames(purgeCache)
 	if err != nil {
 		return nil, err
 	}

images/remote.go

@@ -6,6 +6,7 @@ import (
 	"github.com/mhewedy/vermin/db"
 	"io/ioutil"
 	"os"
+	"path/filepath"
 	"strings"
 )
 
@@ -16,9 +17,8 @@ type rimage struct {
 	URL  string `csv:"url"`
 }
 
-func listRemoteImagesNames() ([]string, error) {
-
-	vms, err := listRemoteImages()
+func listRemoteImagesNames(purgeCache bool) ([]string, error) {
+	vms, err := listRemoteImages(purgeCache)
 	if err != nil {
 		return nil, err
 	}
@@ -32,17 +32,15 @@ func listRemoteImagesNames() ([]string, error) {
 	return images, nil
 }
 
-func listRemoteImages() ([]rimage, error) {
-	var tmp string
-	// read images csv from tmp cache
-	dir, err := ioutil.ReadDir(os.TempDir())
-	for i := range dir {
-		if strings.HasPrefix(dir[i].Name(), db.ImageFile) {
-			tmp = os.TempDir() + "/" + dir[i].Name()
-			break
+func listRemoteImages(purgeCache bool) ([]rimage, error) {
+	if purgeCache {
+		file, _ := getCSVTempFilePath()
+		if len(file) > 0 {
+			_ = os.Remove(file)
 		}
 	}
-
+	// read images csv from tmp cache
+	tmp, _ := getCSVTempFilePath()
 	// if not found, then download the file
 	if len(tmp) == 0 {
 		tmpFile, err := ioutil.TempFile("", db.ImageFile)
@@ -59,7 +57,7 @@ func listRemoteImages() ([]rimage, error) {
 
 	// parse the file as csv
 	var vms []rimage
-	err = csvtag.Load(csvtag.Config{
+	err := csvtag.Load(csvtag.Config{
 		Path: tmp,
 		Dest: &vms,
 	})
@@ -76,6 +74,17 @@ func listRemoteImages() ([]rimage, error) {
 	return vms, nil
 }
 
+func getCSVTempFilePath() (string, error) {
+	file, err := filepath.Glob(os.TempDir() + "/" + db.ImageFile + "*")
+	if err != nil {
+		return "", err
+	}
+	if len(file) == 0 {
+		return "", nil
+	}
+	return file[0], nil
+}
+
 // Check name follows <distro>/<version> name
 // Check Unique name
 func validate(vms []rimage) error {