feat(sync): add tag rejectRegex filter

pkg/cli/server/root.go

@@ -1148,6 +1148,16 @@
 						}
 					}
 
+					if content.Tags != nil && content.Tags.RejectRegex != nil {
+						_, err := regexp.Compile(*content.Tags.RejectRegex)
+						if err != nil {
+							msg := "sync content reject_regex could not be compiled"
+							log.Error().Err(glob.ErrBadPattern).Str("reject_regex", *content.Tags.RejectRegex).Msg(msg)
+
+							return fmt.Errorf("%w: %s: %s", zerr.ErrBadConfig, msg, *content.Tags.RejectRegex)
+						}
+					}
+
 					if content.StripPrefix && !strings.Contains(content.Prefix, "/*") && content.Destination == "/" {
 						msg := "can not use stripPrefix true and destination '/' without using glob patterns in prefix"
 						log.Error().Err(zerr.ErrBadConfig).

pkg/extensions/config/sync/config.go

@@ -42,6 +42,7 @@ type Content struct {
 }
 
 type Tags struct {
-	Regex  *string
-	Semver *bool
+	Regex       *string
+	RejectRegex *string
+	Semver      *bool
 }

pkg/extensions/sync/content.go

@@ -63,6 +63,13 @@
 			}
 		}
 
+		if content.Tags.RejectRegex != nil {
+			tags, err = rejectTagsByRegex(tags, *content.Tags.RejectRegex, cm.log)
+			if err != nil {
+				return []string{}, err
+			}
+		}
+
 		if content.Tags.Semver != nil && *content.Tags.Semver {
 			tags = filterTagsBySemver(tags, cm.log)
 		}
@@ -240,6 +247,32 @@
 	return filteredTags, nil
 }
 
+// rejectTagsByRegex filter-out images by tag regex given in the config.
+func rejectTagsByRegex(tags []string, regex string, log log.Logger) ([]string, error) {
+	if len(tags) == 0 || regex == "" {
+		return tags, nil
+	}
+
+	filteredTags := make([]string, 0, len(tags))
+
+	log.Info().Str("reject_regex", regex).Msg("filtering out tags using regex")
+
+	tagReg, err := regexp.Compile(regex)
+	if err != nil {
+		log.Error().Err(err).Str("reject_regex", regex).Msg("failed to compile regex")
+
+		return filteredTags, err
+	}
+
+	for _, tag := range tags {
+		if !tagReg.MatchString(tag) {
+			filteredTags = append(filteredTags, tag)
+		}
+	}
+
+	return filteredTags, nil
+}
+
 // filterTagsBySemver filters tags by checking if they are semver compliant.
 func filterTagsBySemver(tags []string, log log.Logger) []string {
 	filteredTags := []string{}

pkg/extensions/sync/content_internal_test.go

@@ -170,6 +170,7 @@ func TestGetContentByLocalRepo(t *testing.T) {
 func TestFilterTags(t *testing.T) {
 	allTagsRegex := ".*"
 	badRegex := "[*"
+	rejectArchRegex := ".*(x86_64|aarch64|amd64|arm64)$"
 	semverFalse := false
 	semverTrue := true
 	testCases := []struct {
@@ -234,6 +235,24 @@ func TestFilterTags(t *testing.T) {
 			filteredTags: []string{},
 			err:          false,
 		},
+		{
+			repo: "alpine",
+			content: []syncconf.Content{
+				{Prefix: "**", Tags: &syncconf.Tags{RejectRegex: &allTagsRegex}},
+			},
+			tags:         []string{"v1", "v2", "v3"},
+			filteredTags: []string{},
+			err:          false,
+		},
+		{
+			repo: "alpine",
+			content: []syncconf.Content{
+				{Prefix: "**", Tags: &syncconf.Tags{RejectRegex: &rejectArchRegex}},
+			},
+			tags:         []string{"v1", "v2-x86_64", "v3-aarch64"},
+			filteredTags: []string{"v1"},
+			err:          false,
+		},
 	}
 
 	Convey("Test FilterTags()", t, func() {