Modify tag handling

CHANGELOG.md

@@ -1,5 +1,19 @@
 # Changelog
 
+## [0.10.0] - 2026-04-26
+
+### Added
+
+- Enable passing custom tags to AMIs.
+
+### Changed
+
+- Rename default AMI tag key for the container image from `container_image` to `cloudboss.co/easyto/container-image`.
+
+### Fixed
+
+- Fix readlink wrapper to take an `aferofs.Fs` argument to fix broken `ctr2disk.TestNewBuilder` test. This aligns it with most functions in `ctr2disk` that access the filesystem.
+
 ## [0.9.0] - 2026-04-23
 
 ### Added
@@ -119,6 +133,7 @@
 
 Initial release
 
+[0.10.0]: https://github.com/cloudboss/easyto/releases/tag/v0.10.0
 [0.9.0]: https://github.com/cloudboss/easyto/releases/tag/v0.9.0
 [0.8.0]: https://github.com/cloudboss/easyto/releases/tag/v0.8.0
 [0.7.0]: https://github.com/cloudboss/easyto/releases/tag/v0.7.0

cmd/easyto/tree/ami.go

@@ -97,9 +97,16 @@ var (
 				return fmt.Errorf("unexpected value for services: %w", err)
 			}
 
+			quotedTags := bytes.NewBufferString("")
+			err = json.NewEncoder(quotedTags).Encode(parseTags(amiCfg.tags))
+			if err != nil {
+				return fmt.Errorf("unexpected value for tags: %w", err)
+			}
+
 			packerArgs := []string{
 				"build",
 				"-var", fmt.Sprintf("ami_name=%s", amiCfg.amiName),
+				"-var", fmt.Sprintf("ami_tags=%s", quotedTags.String()),
 				"-var", fmt.Sprintf("builder_instance_type=%s", amiCfg.builderInstanceType),
 				"-var", fmt.Sprintf("container_image=%s", amiCfg.containerImage),
 				"-var", fmt.Sprintf("debug=%t", amiCfg.debug),
@@ -164,6 +171,7 @@ type amiConfig struct {
 	size                  int
 	sshInterface          string
 	subnetID              string
+	tags                  []string
 }
 
 func init() {
@@ -240,6 +248,9 @@ func init() {
 	AMICmd.Flags().BoolVar(&amiCfg.debug, "debug", false, "Enable debug output.")
 
 	AMICmd.Flags().BoolVar(&amiCfg.public, "public", false, "Make the AMI and its snapshots public.")
+
+	AMICmd.Flags().StringArrayVar(&amiCfg.tags, "tag", []string{},
+		"Tag to apply to the AMI in the form key=value. May be specified multiple times. If no '=' is given, the tag has no value.")
 }
 
 func expandPath(pth string) (string, error) {
@@ -279,6 +290,19 @@ func validateSSHInterface(sshInterface string) error {
 	}
 }
 
+func parseTags(rawTags []string) map[string]string {
+	tags := map[string]string{}
+	for _, t := range rawTags {
+		parts := strings.SplitN(t, "=", 2)
+		if len(parts) == 1 {
+			tags[parts[0]] = ""
+			continue
+		}
+		tags[parts[0]] = parts[1]
+	}
+	return tags
+}
+
 func validateBuilderImageMode(mode, builderImage string) error {
 	if mode == "" {
 		return nil

packer/fast/build.pkr.hcl

@@ -11,6 +11,11 @@ variable "ami_name" {
   type    = string
 }
 
+variable "ami_tags" {
+  type    = map(string)
+  default = {}
+}
+
 variable "architecture" {
   type    = string
   default = "x86_64"
@@ -104,9 +109,9 @@ source "amazon-ebssurrogate" "builder_ami" {
   ssh_username                = var.ssh_username
   ssh_file_transfer_method    = "sftp"
   subnet_id                   = var.subnet_id
-  tags                        = {
-    "container_image"         = var.container_image
-  }
+  tags                        = merge(var.ami_tags, {
+    "cloudboss.co/easyto/container-image" = var.container_image
+  })
 
   ami_root_device {
     delete_on_termination     = true

packer/slow/build.pkr.hcl

@@ -11,6 +11,11 @@ variable "ami_name" {
   type    = string
 }
 
+variable "ami_tags" {
+  type    = map(string)
+  default = {}
+}
+
 variable "architecture" {
   type    = string
   default = "x86_64"
@@ -122,9 +127,9 @@ source "amazon-ebssurrogate" "builder_ami" {
   ssh_username                = var.ssh_username
   ssh_file_transfer_method    = "sftp"
   subnet_id                   = var.subnet_id
-  tags                        = {
-    "container_image"         = var.container_image
-  }
+  tags                        = merge(var.ami_tags, {
+    "cloudboss.co/easyto/container-image" = var.container_image
+  })
 
   ami_root_device {
     delete_on_termination     = true

pkg/ctr2disk/ctr2disk.go

@@ -186,7 +186,7 @@ func NewBuilder(fs afero.Fs, opts ...BuilderOpt) (*Builder, error) {
 	builder.pathInit = filepath.Join(builder.AssetDir, archiveInit)
 	builder.pathSSH = filepath.Join(builder.AssetDir, archiveSSH)
 
-	vmImageDevice, err := readlink(builder.VMImageDevice)
+	vmImageDevice, err := readlink(fs, builder.VMImageDevice)
 	if err != nil {
 		return nil, fmt.Errorf("unable to resolve path of VM image device: %w", err)
 	}
@@ -741,13 +741,17 @@ func partitionName(disk string, partition int) string {
 	return fmt.Sprintf("%s%d", disk, partition)
 }
 
-func readlink(path string) (string, error) {
+func readlink(fs afero.Fs, path string) (string, error) {
 	abs, err := filepath.Abs(path)
 	if err != nil {
 		return "", err
 	}
 
-	fi, err := os.Lstat(abs)
+	lst, ok := fs.(afero.Lstater)
+	if !ok {
+		return "", errors.New("filesystem does not support Lstat")
+	}
+	fi, _, err := lst.LstatIfPossible(abs)
 	if err != nil {
 		return "", err
 	}
@@ -756,7 +760,11 @@ func readlink(path string) (string, error) {
 		return abs, nil
 	}
 
-	target, err := os.Readlink(abs)
+	rdr, ok := fs.(afero.LinkReader)
+	if !ok {
+		return "", afero.ErrNoReadlink
+	}
+	target, err := rdr.ReadlinkIfPossible(abs)
 	if err != nil {
 		return "", err
 	}

pkg/ctr2disk/ctr2disk_test.go

@@ -331,7 +331,7 @@ func TestReadlink(t *testing.T) {
 
 	for _, tc := range testCases {
 		t.Run(tc.description, func(t *testing.T) {
-			result, err := readlink(tc.path)
+			result, err := readlink(afero.NewOsFs(), tc.path)
 			if tc.expectError {
 				assert.Error(t, err)
 			} else {
@@ -452,6 +452,10 @@ func TestNewBuilder(t *testing.T) {
 	err = testutil.WriteTarFile(testFS, kernelTar, kernelFiles)
 	require.NoError(t, err)
 
+	require.NoError(t, testFS.MkdirAll("/dev", 0755))
+	_, err = testFS.Create("/dev/loop0")
+	require.NoError(t, err)
+
 	testCases := []struct {
 		description   string
 		opts          []BuilderOpt