lxc: return the GetImageAliasType error in dereferenceAlias to fa…

…il early if the remote index does not exist

Signed-off-by: Gabriel Mougard <gabriel.mougard@canonical.com>

lxc/image.go

@@ -109,17 +109,40 @@ hash or alias name (if one is set).`))
 	return cmd
 }
 
-func (c *cmdImage) dereferenceAlias(d lxd.ImageServer, imageType string, inName string) string {
+func (c *cmdImage) dereferenceAlias(d lxd.ImageServer, imageType string, inName string) (string, error) {
 	if inName == "" {
 		inName = "default"
 	}
 
-	result, _, _ := d.GetImageAliasType(imageType, inName)
-	if result == nil {
-		return inName
+	result, _, err := d.GetImageAliasType(imageType, inName)
+	if err != nil {
+		// Maybe that inName is a fingerprint and can't be found as an alias
+		fingerprints, errFingerprint := d.GetImageFingerprints()
+		if errFingerprint != nil {
+			return "", errFingerprint
+		}
+
+		fingerprintCount := 0
+		for _, fingerprint := range fingerprints {
+			// The string can be a 'full' fingerprint but also a 'partial' one
+			if strings.HasPrefix(fingerprint, inName) {
+				fingerprintCount++
+			}
+		}
+
+		// If we found only one full or partial fingerprint matching the input, return it
+		if fingerprintCount == 1 {
+			return inName, nil
+		} else if fingerprintCount > 1 {
+			return "", fmt.Errorf(i18n.G("Ambiguous fingerprint: %d matches found for %q prefix"), fingerprintCount, inName)
+		}
+
+		// If the input is not in the list of fingerprints, return the original error
+		return "", err
 	}
 
-	return result.Target
+	// If inName is an alias and could be resolved, return its fingerprint
+	return result.Target, nil
 }
 
 // Copy.
@@ -229,7 +252,11 @@ func (c *cmdImageCopy) Run(cmd *cobra.Command, args []string) error {
 		imgInfo.Public = true
 	} else {
 		// Resolve any alias and then grab the image information from the source
-		image := c.image.dereferenceAlias(sourceServer, imageType, name)
+		image, err := c.image.dereferenceAlias(sourceServer, imageType, name)
+		if err != nil {
+			return err
+		}
+
 		imgInfo, _, err = sourceServer.GetImage(image)
 		if err != nil {
 			return err
@@ -335,7 +362,11 @@ func (c *cmdImageDelete) Run(cmd *cobra.Command, args []string) error {
 			return fmt.Errorf(i18n.G("Image identifier missing"))
 		}
 
-		image := c.image.dereferenceAlias(resource.server, "", resource.name)
+		image, err := c.image.dereferenceAlias(resource.server, "", resource.name)
+		if err != nil {
+			return err
+		}
+
 		op, err := resource.server.DeleteImage(image)
 		if err != nil {
 			return err
@@ -404,7 +435,11 @@ func (c *cmdImageEdit) Run(cmd *cobra.Command, args []string) error {
 	}
 
 	// Resolve any aliases
-	image := c.image.dereferenceAlias(resource.server, "", resource.name)
+	image, err := c.image.dereferenceAlias(resource.server, "", resource.name)
+	if err != nil {
+		return err
+	}
+
 	if image == "" {
 		image = resource.name
 	}
@@ -522,7 +557,10 @@ func (c *cmdImageExport) Run(cmd *cobra.Command, args []string) error {
 		imageType = "virtual-machine"
 	}
 
-	fingerprint := c.image.dereferenceAlias(remoteServer, imageType, name)
+	fingerprint, err := c.image.dereferenceAlias(remoteServer, imageType, name)
+	if err != nil {
+		return err
+	}
 
 	// Default target is current directory
 	target := "."
@@ -914,7 +952,11 @@ func (c *cmdImageInfo) Run(cmd *cobra.Command, args []string) error {
 		imageType = "virtual-machine"
 	}
 
-	image := c.image.dereferenceAlias(remoteServer, imageType, name)
+	image, err := c.image.dereferenceAlias(remoteServer, imageType, name)
+	if err != nil {
+		return err
+	}
+
 	info, _, err := remoteServer.GetImage(image)
 	if err != nil {
 		return err
@@ -1361,7 +1403,11 @@ func (c *cmdImageRefresh) Run(cmd *cobra.Command, args []string) error {
 			return fmt.Errorf(i18n.G("Image identifier missing"))
 		}
 
-		image := c.image.dereferenceAlias(resource.server, "", resource.name)
+		image, err := c.image.dereferenceAlias(resource.server, "", resource.name)
+		if err != nil {
+			return err
+		}
+
 		progress := cli.ProgressRenderer{
 			Format: i18n.G("Refreshing the image: %s"),
 			Quiet:  c.global.flagQuiet,
@@ -1448,7 +1494,11 @@ func (c *cmdImageShow) Run(cmd *cobra.Command, args []string) error {
 		imageType = "virtual-machine"
 	}
 
-	image := c.image.dereferenceAlias(remoteServer, imageType, name)
+	image, err := c.image.dereferenceAlias(remoteServer, imageType, name)
+	if err != nil {
+		return err
+	}
+
 	info, _, err := remoteServer.GetImage(image)
 	if err != nil {
 		return err
@@ -1501,7 +1551,11 @@ func (c *cmdImageGetProp) Run(cmd *cobra.Command, args []string) error {
 	}
 
 	// Get the corresponding property
-	image := c.image.dereferenceAlias(remoteServer, "", name)
+	image, err := c.image.dereferenceAlias(remoteServer, "", name)
+	if err != nil {
+		return err
+	}
+
 	info, _, err := remoteServer.GetImage(image)
 	if err != nil {
 		return err
@@ -1554,7 +1608,11 @@ func (c *cmdImageSetProp) Run(cmd *cobra.Command, args []string) error {
 	}
 
 	// Show properties
-	image := c.image.dereferenceAlias(resource.server, "", resource.name)
+	image, err := c.image.dereferenceAlias(resource.server, "", resource.name)
+	if err != nil {
+		return err
+	}
+
 	info, etag, err := resource.server.GetImage(image)
 	if err != nil {
 		return err