Tags sorting support (#645)

Co-authored-by: CrazyMax <crazy-max@users.noreply.github.com>

docs/faq.md

@@ -55,7 +55,7 @@ The title and body of a notification message can be customized for each notifier
 Templating is supported with the following fields:
 
 | Key                             | Description                                                                           |
-|----------------------------------|-------------|
+|---------------------------------|---------------------------------------------------------------------------------------|
 | `.Meta.ID`                      | App ID: `diun`                                                                        |
 | `.Meta.Name`                    | App Name: `Diun`                                                                      |
 | `.Meta.Desc`                    | App description: `Docker image update notifier`                                       |
@@ -205,6 +205,97 @@ Or you can tweak the [`schedule` setting](config/watch.md#schedule) with somethi
 !!! warning
     Also be careful with the `watch_repo` setting as it will fetch manifest for **ALL** tags available for the image.
 
+## Tags sorting when using `watch_repo`
+
+When you use the `watch_repo` setting, Diun will fetch all tags available for
+the image. Depending on the registry, order of the tags list can change.
+
+You can use the `sort_tags` setting available for each provider to use a
+specific sorting method for the tags list.
+
+* `default`: do not sort and use the expected tags list from the registry
+* `reverse`: reverse order for the tags list from the registry
+* `lexicographical`: sort the tags list lexicographically
+* `semver`: sort the tags list using semantic versioning
+
+Given the following list of tags received from the registry:
+
+```json
+[
+  "0.1.0",
+  "0.4.0",
+  "3.0.0-beta.1",
+  "3.0.0-beta.4",
+  "4",
+  "4.0.0",
+  "4.0.0-beta.1",
+  "4.1.0",
+  "4.1.1",
+  "4.10.0",
+  "4.11.0",
+  "4.20",
+  "4.20.0",
+  "4.20.1",
+  "4.3.0",
+  "4.3.1",
+  "4.9.0",
+  "edge",
+  "latest"
+]
+```
+
+Here is the result for `reverse`:
+
+```json
+[
+  "latest",
+  "edge",
+  "4.9.0",
+  "4.3.1",
+  "4.3.0",
+  "4.20.1",
+  "4.20.0",
+  "4.20",
+  "4.11.0",
+  "4.10.0",
+  "4.1.1",
+  "4.1.0",
+  "4.0.0-beta.1",
+  "4.0.0",
+  "4",
+  "3.0.0-beta.4",
+  "3.0.0-beta.1",
+  "0.4.0",
+  "0.1.0"
+]
+```
+
+And for `semver`:
+
+```json
+[
+  "4.20.1",
+  "4.20.0",
+  "4.20",
+  "4.11.0",
+  "4.10.0",
+  "4.9.0",
+  "4.3.1",
+  "4.3.0",
+  "4.1.1",
+  "4.1.0",
+  "4.0.0",
+  "4",
+  "4.0.0-beta.1",
+  "3.0.0-beta.4",
+  "3.0.0-beta.1",
+  "0.4.0",
+  "0.1.0",
+  "edge",
+  "latest"
+]
+```
+
 ## Profiling
 
 Diun provides a simple way to manage runtime/pprof profiling through the

docs/providers/docker.md

@@ -173,11 +173,12 @@ Include created and exited containers too (default `false`).
 You can configure more finely the way to analyze the image of your container through Docker labels:
 
 | Name                | Default      | Description                                                                                                                                                |
-|-------------------------------|---------------|---------------|
+|---------------------|--------------|------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `diun.enable`       |              | Set to true to enable image analysis of this container                                                                                                     |
 | `diun.regopt`       |              | [Registry options](../config/regopts.md) name to use                                                                                                       |
 | `diun.watch_repo`   | `false`      | Watch all tags of this container image ([be careful](../faq.md#docker-hub-rate-limits) with this setting)                                                  |
-| `diun.notify_on`              | `new;update`  | Semicolon separated list of status to be notified: `new`, `update`. |
+| `diun.notify_on`    | `new;update` | Semicolon separated list of status to be notified: `new`, `update`                                                                                         |
+| `diun.sort_tags`    | `reverse`    | [Sort tags method](../faq.md#tags-sorting-when-using-watch_repo) if `diun.watch_repo` enabled. One of `default`, `reverse`, `numerical`, `lexicographical` |
 | `diun.max_tags`     | `0`          | Maximum number of tags to watch if `diun.watch_repo` enabled. `0` means all of them                                                                        |
 | `diun.include_tags` |              | Semicolon separated list of regular expressions to include tags. Can be useful if you enable `diun.watch_repo`                                             |
 | `diun.exclude_tags` |              | Semicolon separated list of regular expressions to exclude tags. Can be useful if you enable `diun.watch_repo`                                             |

docs/providers/dockerfile.md

@@ -107,10 +107,11 @@ List of path patterns with [matching and globbing supporting patterns](https://g
 The following annotations can be added as comments before the target instruction to customize the image analysis:
 
 | Name                | Default      | Description                                                                                                                                                |
-|-------------------------------|---------------|---------------|
+|---------------------|--------------|------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `diun.regopt`       |              | [Registry options](../config/regopts.md) name to use                                                                                                       |
 | `diun.watch_repo`   | `false`      | Watch all tags of this image                                                                                                                               |
-| `diun.notify_on`              | `new;update`  | Semicolon separated list of status to be notified: `new`, `update`. |
+| `diun.notify_on`    | `new;update` | Semicolon separated list of status to be notified: `new`, `update`                                                                                         |
+| `diun.sort_tags`    | `reverse`    | [Sort tags method](../faq.md#tags-sorting-when-using-watch_repo) if `diun.watch_repo` enabled. One of `default`, `reverse`, `numerical`, `lexicographical` |
 | `diun.max_tags`     | `0`          | Maximum number of tags to watch if `watch_repo` enabled. `0` means all of them                                                                             |
 | `diun.include_tags` |              | Semicolon separated list of regular expressions to include tags. Can be useful if you enable `diun.watch_repo`                                             |
 | `diun.exclude_tags` |              | Semicolon separated list of regular expressions to exclude tags. Can be useful if you enable `diun.watch_repo`                                             |

docs/providers/file.md

@@ -173,11 +173,12 @@ Defines the path to the directory that contains the [configuration files](#yaml-
 The configuration file(s) defines a slice of images to analyze with the following fields:
 
 | Name               | Default      | Description                                                                                                                                                |
-|-------------------------------|----------------------------------|---------------|
+|--------------------|--------------|------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `name`             | `latest`     | Docker image name to watch using `registry/path:tag` format. If registry omitted, `docker.io` will be used and if tag omitted, `latest` will be used       |
 | `regopt`           |              | [Registry options](../config/regopts.md) name to use                                                                                                       |
 | `watch_repo`       | `false`      | Watch all tags of this image ([be careful](../faq.md#docker-hub-rate-limits) with this setting)                                                            |
-| `notify_on`                   | `new;update`                     | Semicolon separated list of status to be notified: `new`, `update`. |
+| `notify_on`        | `new;update` | Semicolon separated list of status to be notified: `new`, `update`                                                                                         |
+| `sort_tags`        | `reverse`    | [Sort tags method](../faq.md#tags-sorting-when-using-watch_repo) if `diun.watch_repo` enabled. One of `default`, `reverse`, `numerical`, `lexicographical` |
 | `max_tags`         | `0`          | Maximum number of tags to watch if `watch_repo` enabled. `0` means all of them                                                                             |
 | `include_tags`     |              | List of regular expressions to include tags. Can be useful if you enable `watch_repo`                                                                      |
 | `exclude_tags`     |              | List of regular expressions to exclude tags. Can be useful if you enable `watch_repo`                                                                      |

docs/providers/kubernetes.md

@@ -281,11 +281,12 @@ Enable watch by default. If false, pods that don't have `diun.enable: "true"` an
 You can configure more finely the way to analyze the image of your pods through Kubernetes annotations:
 
 | Name                | Default      | Description                                                                                                                                                |
-|-------------------------------|---------------|---------------|
+|---------------------|--------------|------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `diun.enable`       |              | Set to true to enable image analysis of this pod                                                                                                           |
 | `diun.regopt`       |              | [Registry options](../config/regopts.md) name to use                                                                                                       |
 | `diun.watch_repo`   | `false`      | Watch all tags of this pod image ([be careful](../faq.md#docker-hub-rate-limits) with this setting)                                                        |
 | `diun.notify_on`    | `new;update` | Semicolon separated list of status to be notified: `new`, `update`.                                                                                        |
+| `diun.sort_tags`    | `reverse`    | [Sort tags method](../faq.md#tags-sorting-when-using-watch_repo) if `diun.watch_repo` enabled. One of `default`, `reverse`, `numerical`, `lexicographical` |
 | `diun.max_tags`     | `0`          | Maximum number of tags to watch if `diun.watch_repo` enabled. `0` means all of them                                                                        |
 | `diun.include_tags` |              | Semicolon separated list of regular expressions to include tags. Can be useful if you enable `diun.watch_repo`                                             |
 | `diun.exclude_tags` |              | Semicolon separated list of regular expressions to exclude tags. Can be useful if you enable `diun.watch_repo`                                             |

docs/providers/swarm.md

@@ -175,11 +175,12 @@ Enable watch by default. If false, services that don't have `diun.enable=true` l
 You can configure more finely the way to analyze the image of your service through Docker labels:
 
 | Name                | Default      | Description                                                                                                                                                |
-|-------------------------------|---------------|---------------|
+|---------------------|--------------|------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `diun.enable`       |              | Set to true to enable image analysis of this service                                                                                                       |
 | `diun.regopt`       |              | [Registry options](../config/regopts.md) name to use                                                                                                       |
 | `diun.watch_repo`   | `false`      | Watch all tags of this service image ([be careful](../faq.md#docker-hub-rate-limits) with this setting)                                                    |
 | `diun.notify_on`    | `new;update` | Semicolon separated list of status to be notified: `new`, `update`.                                                                                        |
+| `diun.sort_tags`    | `reverse`    | [Sort tags method](../faq.md#tags-sorting-when-using-watch_repo) if `diun.watch_repo` enabled. One of `default`, `reverse`, `numerical`, `lexicographical` |
 | `diun.max_tags`     | `0`          | Maximum number of tags to watch if `diun.watch_repo` enabled. `0` means all of them                                                                        |
 | `diun.include_tags` |              | Semicolon separated list of regular expressions to include tags. Can be useful if you enable `diun.watch_repo`                                             |
 | `diun.exclude_tags` |              | Semicolon separated list of regular expressions to exclude tags. Can be useful if you enable `diun.watch_repo`                                             |

go.mod

@@ -39,6 +39,7 @@ require (
 	github.com/stretchr/testify v1.8.0
 	github.com/tidwall/pretty v1.2.0
 	go.etcd.io/bbolt v1.3.6
+	golang.org/x/mod v0.5.1
 	golang.org/x/sys v0.0.0-20220422013727-9388b58f7150
 	google.golang.org/grpc v1.48.0
 	google.golang.org/grpc/cmd/protoc-gen-go-grpc v1.2.0

go.sum

@@ -1144,6 +1144,8 @@ golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.1/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/mod v0.4.2/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
+golang.org/x/mod v0.5.1 h1:OJxoQ/rynoF0dcCdI7cLPktw/hR2cueqYfjm43oqK38=
+golang.org/x/mod v0.5.1/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
 golang.org/x/net v0.0.0-20180218175443-cbe0f9307d01/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=

internal/app/job.go

@@ -124,6 +124,7 @@ func (di *Diun) createJob(job model.Job) {
 	tags, err := job.Registry.Tags(registry.TagsOptions{
 		Image:   job.RegImage,
 		Max:     job.Image.MaxTags,
+		Sort:    job.Image.SortTags,
 		Include: job.Image.IncludeTags,
 		Exclude: job.Image.ExcludeTags,
 	})

internal/config/config_test.go

@@ -360,6 +360,7 @@ func TestLoadEnv(t *testing.T) {
 	}
 
 	for _, tt := range testCases {
+		tt := tt
 		t.Run(tt.desc, func(t *testing.T) {
 			UnsetEnv("DIUN_")
 
@@ -484,6 +485,7 @@ for <code>{{ .Entry.Manifest.Platform }}</code> platform.
 	}
 
 	for _, tt := range testCases {
+		tt := tt
 		t.Run(tt.desc, func(t *testing.T) {
 			UnsetEnv("DIUN_")
 

internal/model/image.go

@@ -1,5 +1,7 @@
 package model
 
+import "github.com/crazy-max/diun/v4/pkg/registry"
+
 // Image holds image configuration
 type Image struct {
 	Name        string           `yaml:"name,omitempty" json:",omitempty"`
@@ -8,6 +10,7 @@ type Image struct {
 	WatchRepo   bool             `yaml:"watch_repo,omitempty" json:",omitempty"`
 	NotifyOn    []NotifyOn       `yaml:"notify_on,omitempty" json:",omitempty"`
 	MaxTags     int              `yaml:"max_tags,omitempty" json:",omitempty"`
+	SortTags    registry.SortTag `yaml:"sort_tags,omitempty" json:",omitempty"`
 	IncludeTags []string         `yaml:"include_tags,omitempty" json:",omitempty"`
 	ExcludeTags []string         `yaml:"exclude_tags,omitempty" json:",omitempty"`
 	HubTpl      string           `yaml:"hub_tpl,omitempty" json:",omitempty"`

internal/provider/common.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/containerd/containerd/platforms"
 	"github.com/crazy-max/diun/v4/internal/model"
+	"github.com/crazy-max/diun/v4/pkg/registry"
 )
 
 // ValidateImage returns a standard image through Docker labels
@@ -17,6 +18,7 @@ func ValidateImage(image string, labels map[string]string, watchByDef bool) (img
 	img = model.Image{
 		Name:     image,
 		NotifyOn: model.NotifyOnDefaults,
+		SortTags: registry.SortTagReverse,
 	}
 
 	if enableStr, ok := labels["diun.enable"]; ok {
@@ -51,6 +53,15 @@ func ValidateImage(image string, labels map[string]string, watchByDef bool) (img
 				}
 				img.NotifyOn = append(img.NotifyOn, notifyOn)
 			}
+		case "diun.sort_tags":
+			if value == "" {
+				break
+			}
+			sortTags := registry.SortTag(value)
+			if !sortTags.Valid() {
+				return img, fmt.Errorf("unknown sort tags type %q", value)
+			}
+			img.SortTags = sortTags
 		case "diun.max_tags":
 			if img.MaxTags, err = strconv.Atoi(value); err != nil {
 				return img, fmt.Errorf("cannot parse %s value of label %s", value, key)

internal/provider/file/file_test.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/crazy-max/diun/v4/internal/model"
 	"github.com/crazy-max/diun/v4/internal/provider/file"
+	"github.com/crazy-max/diun/v4/pkg/registry"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -16,6 +17,7 @@ var (
 				Name:     "jfrog-docker-reg2.bintray.io/jfrog/artifactory-oss:4.0.0",
 				RegOpt:   "bintrayoptions",
 				NotifyOn: model.NotifyOnDefaults,
+				SortTags: registry.SortTagReverse,
 			},
 		},
 		{
@@ -26,6 +28,7 @@ var (
 				NotifyOn: []model.NotifyOn{
 					model.NotifyOnNew,
 				},
+				SortTags: registry.SortTagLexicographical,
 				MaxTags:  50,
 			},
 		},
@@ -37,6 +40,7 @@ var (
 				Name:     "docker.io/crazymax/nextcloud:latest",
 				RegOpt:   "myregistry",
 				NotifyOn: model.NotifyOnDefaults,
+				SortTags: registry.SortTagReverse,
 			},
 		},
 		{
@@ -45,6 +49,7 @@ var (
 				Name:      "crazymax/swarm-cronjob",
 				WatchRepo: true,
 				NotifyOn:  model.NotifyOnDefaults,
+				SortTags:  registry.SortTagSemver,
 				IncludeTags: []string{
 					`^1\.2\..*`,
 				},
@@ -57,6 +62,7 @@ var (
 				WatchRepo: true,
 				NotifyOn:  model.NotifyOnDefaults,
 				MaxTags:   10,
+				SortTags:  registry.SortTagReverse,
 				IncludeTags: []string{
 					`^(0|[1-9]\d*)\..*`,
 				},
@@ -68,6 +74,7 @@ var (
 				Name:      "traefik",
 				WatchRepo: true,
 				NotifyOn:  model.NotifyOnDefaults,
+				SortTags:  registry.SortTagDefault,
 			},
 		},
 		{
@@ -75,6 +82,7 @@ var (
 			Image: model.Image{
 				Name:     "alpine",
 				NotifyOn: model.NotifyOnDefaults,
+				SortTags: registry.SortTagReverse,
 				Platform: model.ImagePlatform{
 					OS:      "linux",
 					Arch:    "arm64",
@@ -87,6 +95,7 @@ var (
 			Image: model.Image{
 				Name:     "docker.io/graylog/graylog:3.2.0",
 				NotifyOn: model.NotifyOnDefaults,
+				SortTags: registry.SortTagReverse,
 			},
 		},
 		{
@@ -94,6 +103,7 @@ var (
 			Image: model.Image{
 				Name:     "jacobalberty/unifi:5.9",
 				NotifyOn: model.NotifyOnDefaults,
+				SortTags: registry.SortTagReverse,
 			},
 		},
 		{
@@ -102,6 +112,7 @@ var (
 				Name:      "crazymax/ddns-route53",
 				WatchRepo: true,
 				NotifyOn:  model.NotifyOnDefaults,
+				SortTags:  registry.SortTagReverse,
 				IncludeTags: []string{
 					`^1\..*`,
 				},
@@ -114,6 +125,7 @@ var (
 			Image: model.Image{
 				Name:     "quay.io/coreos/hyperkube",
 				NotifyOn: model.NotifyOnDefaults,
+				SortTags: registry.SortTagReverse,
 			},
 		},
 		{
@@ -121,6 +133,7 @@ var (
 			Image: model.Image{
 				Name:     "quay.io/coreos/hyperkube:v1.1.7-coreos.1",
 				NotifyOn: model.NotifyOnDefaults,
+				SortTags: registry.SortTagReverse,
 			},
 		},
 	}

internal/provider/file/fixtures/bintray.yml

@@ -4,4 +4,5 @@
   watch_repo: true
   notify_on:
     - new
+  sort_tags: lexicographical
   max_tags: 50

internal/provider/file/fixtures/dockerhub.yml

@@ -2,15 +2,18 @@
   regopt: myregistry
 - name: crazymax/swarm-cronjob
   watch_repo: true
+  sort_tags: semver
   include_tags:
     - ^1\.2\..*
 - name: docker.io/portainer/portainer
   watch_repo: true
   max_tags: 10
+  sort_tags: reverse
   include_tags:
     - ^(0|[1-9]\d*)\..*
 - name: traefik
   watch_repo: true
+  sort_tags: default
 - name: alpine
   platform:
     os: linux

internal/provider/file/image.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/containerd/containerd/platforms"
 	"github.com/crazy-max/diun/v4/internal/model"
+	"github.com/crazy-max/diun/v4/pkg/registry"
 	ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
 	"gopkg.in/yaml.v2"
 )
@@ -45,6 +46,17 @@ func (c *Client) listFileImage() []model.Image {
 				}
 			}
 
+			// Check SortType
+			if item.SortTags == "" {
+				item.SortTags = registry.SortTagReverse
+			}
+			if !item.SortTags.Valid() {
+				c.logger.Error().
+					Str("file", file).
+					Str("img_name", item.Name).
+					Msgf("unknown sort tags type %q", item.SortTags)
+			}
+
 			// Check Platform
 			if item.Platform != (model.ImagePlatform{}) {
 				_, err = platforms.Parse(platforms.Format(ocispecs.Platform{

pkg/registry/image_test.go

@@ -126,6 +126,7 @@ func TestParseImage(t *testing.T) {
 	}
 
 	for _, tt := range testCases {
+		tt := tt
 		t.Run(tt.desc, func(t *testing.T) {
 			img, err := registry.ParseImage(tt.parseOpts)
 			if err != nil {
@@ -239,6 +240,7 @@ func TestHubLink(t *testing.T) {
 	}
 
 	for _, tt := range testCases {
+		tt := tt
 		t.Run(tt.desc, func(t *testing.T) {
 			img, err := registry.ParseImage(tt.parseOpts)
 			if err != nil {

pkg/registry/ref_test.go

@@ -52,6 +52,7 @@ func TestParseReference(t *testing.T) {
 	}
 
 	for _, tt := range testCases {
+		tt := tt
 		t.Run(tt.input, func(t *testing.T) {
 			ref, err := registry.ParseReference(tt.input)
 			if tt.wantErr {

pkg/registry/tags.go

@@ -18,6 +18,7 @@ type Tags struct {
 type TagsOptions struct {
 	Image   Image
 	Max     int
+	Sort    SortTag
 	Include []string
 	Exclude []string
 }
@@ -43,6 +44,9 @@ func (c *Client) Tags(opts TagsOptions) (*Tags, error) {
 		Total:       len(tags),
 	}
 
+	// Sort tags
+	tags = SortTags(tags, opts.Sort)
+
 	// Filter
 	for _, tag := range tags {
 		if !utl.IsIncluded(tag, opts.Include) {
@@ -55,12 +59,6 @@ func (c *Client) Tags(opts TagsOptions) (*Tags, error) {
 		res.List = append(res.List, tag)
 	}
 
-	// Reverse order (latest tags first)
-	for i := len(res.List)/2 - 1; i >= 0; i-- {
-		opp := len(res.List) - 1 - i
-		res.List[i], res.List[opp] = res.List[opp], res.List[i]
-	}
-
 	if opts.Max > 0 && len(res.List) >= opts.Max {
 		res.List = res.List[:opts.Max]
 	}

pkg/registry/tags_sort.go

@@ -0,0 +1,79 @@
+package registry
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	"golang.org/x/mod/semver"
+)
+
+// SortTags sorts tags list
+func SortTags(tags []string, sortTag SortTag) []string {
+	switch sortTag {
+	case SortTagReverse:
+		for i := len(tags)/2 - 1; i >= 0; i-- {
+			opp := len(tags) - 1 - i
+			tags[i], tags[opp] = tags[opp], tags[i]
+		}
+		return tags
+	case SortTagLexicographical:
+		sort.Strings(tags)
+		return tags
+	case SortTagSemver:
+		semverIsh := func(s string) string {
+			if semver.IsValid(s) {
+				return s
+			}
+			if vt := fmt.Sprintf("v%s", s); semver.IsValid(vt) {
+				return vt
+			}
+			return ""
+		}
+		sort.Slice(tags, func(i, j int) bool {
+			if c := semver.Compare(semverIsh(tags[i]), semverIsh(tags[j])); c > 0 {
+				return true
+			} else if c < 0 {
+				return false
+			}
+			return strings.Count(tags[i], ".") > strings.Count(tags[j], ".")
+		})
+		return tags
+	default:
+		return tags
+	}
+}
+
+// SortTag holds sort tag type
+type SortTag string
+
+// SortTag constants
+const (
+	SortTagDefault         = SortTag("default")
+	SortTagReverse         = SortTag("reverse")
+	SortTagLexicographical = SortTag("lexicographical")
+	SortTagSemver          = SortTag("semver")
+)
+
+// SortTagTypes is the list of available sort tag types
+var SortTagTypes = []SortTag{
+	SortTagDefault,
+	SortTagReverse,
+	SortTagLexicographical,
+	SortTagSemver,
+}
+
+// Valid checks sort tag type is valid
+func (st *SortTag) Valid() bool {
+	return st.OneOf(SortTagTypes)
+}
+
+// OneOf checks if sort type is one of the values in the list
+func (st *SortTag) OneOf(stl []SortTag) bool {
+	for _, n := range stl {
+		if n == *st {
+			return true
+		}
+	}
+	return false
+}

pkg/registry/tags_test.go

@@ -27,3 +27,207 @@ func TestTags(t *testing.T) {
 	assert.True(t, tags.Total > 0)
 	assert.True(t, len(tags.List) > 0)
 }
+
+func TestTagsSort(t *testing.T) {
+	repotags := []string{
+		"0.1.0",
+		"0.4.0",
+		"3.0.0-beta.1",
+		"3.0.0-beta.3",
+		"3.0.0-beta.4",
+		"4",
+		"4.0.0",
+		"4.0.0-beta.1",
+		"4.1.0",
+		"4.1.1",
+		"4.10.0",
+		"4.11.0",
+		"4.12.0",
+		"4.13.0",
+		"4.14.0",
+		"4.19.0",
+		"4.2.0",
+		"4.20",
+		"4.20.0",
+		"4.20.1",
+		"4.21",
+		"4.21.0",
+		"4.3.0",
+		"4.3.1",
+		"4.4.0",
+		"4.6.1",
+		"4.7.0",
+		"4.8.0",
+		"4.8.1",
+		"4.9.0",
+		"edge",
+		"latest",
+	}
+
+	testCases := []struct {
+		name     string
+		sortTag  registry.SortTag
+		expected []string
+	}{
+		{
+			name:    "sort default",
+			sortTag: registry.SortTagDefault,
+			expected: []string{
+				"0.1.0",
+				"0.4.0",
+				"3.0.0-beta.1",
+				"3.0.0-beta.3",
+				"3.0.0-beta.4",
+				"4",
+				"4.0.0",
+				"4.0.0-beta.1",
+				"4.1.0",
+				"4.1.1",
+				"4.10.0",
+				"4.11.0",
+				"4.12.0",
+				"4.13.0",
+				"4.14.0",
+				"4.19.0",
+				"4.2.0",
+				"4.20",
+				"4.20.0",
+				"4.20.1",
+				"4.21",
+				"4.21.0",
+				"4.3.0",
+				"4.3.1",
+				"4.4.0",
+				"4.6.1",
+				"4.7.0",
+				"4.8.0",
+				"4.8.1",
+				"4.9.0",
+				"edge",
+				"latest",
+			},
+		},
+		{
+			name:    "sort lexicographical",
+			sortTag: registry.SortTagLexicographical,
+			expected: []string{
+				"0.1.0",
+				"0.4.0",
+				"3.0.0-beta.1",
+				"3.0.0-beta.3",
+				"3.0.0-beta.4",
+				"4",
+				"4.0.0",
+				"4.0.0-beta.1",
+				"4.1.0",
+				"4.1.1",
+				"4.10.0",
+				"4.11.0",
+				"4.12.0",
+				"4.13.0",
+				"4.14.0",
+				"4.19.0",
+				"4.2.0",
+				"4.20",
+				"4.20.0",
+				"4.20.1",
+				"4.21",
+				"4.21.0",
+				"4.3.0",
+				"4.3.1",
+				"4.4.0",
+				"4.6.1",
+				"4.7.0",
+				"4.8.0",
+				"4.8.1",
+				"4.9.0",
+				"edge",
+				"latest",
+			},
+		},
+		{
+			name:    "sort reverse",
+			sortTag: registry.SortTagReverse,
+			expected: []string{
+				"latest",
+				"edge",
+				"4.9.0",
+				"4.8.1",
+				"4.8.0",
+				"4.7.0",
+				"4.6.1",
+				"4.4.0",
+				"4.3.1",
+				"4.3.0",
+				"4.21.0",
+				"4.21",
+				"4.20.1",
+				"4.20.0",
+				"4.20",
+				"4.2.0",
+				"4.19.0",
+				"4.14.0",
+				"4.13.0",
+				"4.12.0",
+				"4.11.0",
+				"4.10.0",
+				"4.1.1",
+				"4.1.0",
+				"4.0.0-beta.1",
+				"4.0.0",
+				"4",
+				"3.0.0-beta.4",
+				"3.0.0-beta.3",
+				"3.0.0-beta.1",
+				"0.4.0",
+				"0.1.0",
+			},
+		},
+		{
+			name:    "sort semver",
+			sortTag: registry.SortTagSemver,
+			expected: []string{
+				"4.21.0",
+				"4.21",
+				"4.20.1",
+				"4.20.0",
+				"4.20",
+				"4.19.0",
+				"4.14.0",
+				"4.13.0",
+				"4.12.0",
+				"4.11.0",
+				"4.10.0",
+				"4.9.0",
+				"4.8.1",
+				"4.8.0",
+				"4.7.0",
+				"4.6.1",
+				"4.4.0",
+				"4.3.1",
+				"4.3.0",
+				"4.2.0",
+				"4.1.1",
+				"4.1.0",
+				"4.0.0",
+				"4",
+				"4.0.0-beta.1",
+				"3.0.0-beta.4",
+				"3.0.0-beta.3",
+				"3.0.0-beta.1",
+				"0.4.0",
+				"0.1.0",
+				"edge",
+				"latest",
+			},
+		},
+	}
+
+	for _, tt := range testCases {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			tags := registry.SortTags(repotags, tt.sortTag)
+			assert.Equal(t, tt.expected, tags)
+		})
+	}
+}