add support for specifying container image platforms to search for

.goreleaser.yml

@@ -23,6 +23,7 @@ changelog:
   use: github-native
 source:
   enabled: true
+  rlcp: true
 sboms:
 - id: archive
   artifacts: archive

README.md

@@ -14,10 +14,32 @@ go install github.com/Hsn723/container-tag-exists@latest
 ## Usage
 
 ```sh
-container-tag-exists IMAGE TAG
+Usage:
+  container-tag-exists IMAGE TAG [flags]
+  container-tag-exists [command]
+
+Available Commands:
+  completion  Generate the autocompletion script for the specified shell
+  help        Help about any command
+  version     show version
+
+Flags:
+  -h, --help               help for container-tag-exists
+  -p, --platform strings   specify platforms in the format os/arch to look for in container images. Default behavior is to look for any platform.
 ```
 
-If `IMAGE:TAG` exists, this simply outputs `found`. This is intended to be used in CI environments to automate checking for existing container images before pushing.
+If `IMAGE:TAG` exists, this simply outputs `found`. This is intended to be used in CI environments to automate checking for existing container images before pushing. By default, `container-tag-exists` looks for any existing container image with the given tag.
+
+```sh
+container-tag-exists ghcr.io/example 0.0.0
+```
+
+If you additionally need to check for specific platforms, specify platform strings, in the format `os/arch`, to check for.
+
+```sh
+container-tag-exists ghcr.io/example 0.0.0 -p linux/amd64,linux/arm64
+container-tag-exists ghcr.io/example 0.0.0 -p linux/amd64 -p linux/arm64
+```
 
 ## Configuration
 

cmd/root.go

@@ -17,12 +17,15 @@ var (
 		Args:  cobra.ExactArgs(2),
 		RunE:  runRoot,
 	}
+
+	platforms []string
 )
 
 func init() {
 	_ = rootCmd.LocalFlags().MarkHidden("logfile")
 	_ = rootCmd.LocalFlags().MarkHidden("loglevel")
 	_ = rootCmd.LocalFlags().MarkHidden("logformat")
+	rootCmd.Flags().StringSliceVarP(&platforms, "platform", "p", nil, "specify platforms in the format os/arch to look for in container images. Default behavior is to look for any platform.")
 }
 
 func runRoot(cmd *cobra.Command, args []string) error {
@@ -45,6 +48,7 @@ func runRoot(cmd *cobra.Command, args []string) error {
 				TLSHandshakeTimeout: 10 * time.Second,
 			},
 		},
+		Platforms: platforms,
 	}
 	hasTag, err := registryClient.IsTagExist(args[1])
 	if err != nil {

pkg/registry.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"net/http"
 	"os"
+	"strings"
 )
 
 var (
@@ -24,12 +25,26 @@ type RegistryClient struct {
 	RegistryURL  string
 	ImagePath    string
 	HttpClient   *http.Client
+	Platforms    []string
 }
 
 type tokenResponse struct {
 	Token string `json:"token"`
 }
 
+type manifestResponse struct {
+	Manifests []manifest `json:"manifests"`
+}
+
+type manifest struct {
+	Platform platform `json:"platform"`
+}
+
+type platform struct {
+	Architecture string `json:"architecture"`
+	Os           string `json:"os"`
+}
+
 func (r RegistryClient) retrieve(method, endpoint, auth string) (int, []byte, error) {
 	req, err := http.NewRequest(method, endpoint, nil)
 	if err != nil {
@@ -69,22 +84,52 @@ func (r RegistryClient) retrieveBearerToken(auth string) (string, error) {
 	return token.Token, nil
 }
 
+func (r RegistryClient) hasPlatform(platform string, manifests []manifest) bool {
+	for _, m := range manifests {
+		p := fmt.Sprintf("%s/%s", m.Platform.Os, m.Platform.Architecture)
+		if strings.EqualFold(p, platform) {
+			return true
+		}
+	}
+	return false
+}
+
+func (r RegistryClient) hasPlatforms(res []byte) (bool, error) {
+	var manifests manifestResponse
+	if err := json.Unmarshal(res, &manifests); err != nil {
+		return false, err
+	}
+	for _, p := range r.Platforms {
+		if !r.hasPlatform(p, manifests.Manifests) {
+			return false, nil
+		}
+	}
+	return true, nil
+}
+
 func (r RegistryClient) checkManifestForTag(bearer, tag string) (bool, error) {
 	endpoint := fmt.Sprintf(manifestAPI, r.RegistryURL, r.ImagePath, tag)
 	auth := ""
 	if bearer != "" {
 		auth = fmt.Sprintf("Bearer %s", bearer)
 	}
-	status, _, err := r.retrieve(http.MethodHead, endpoint, auth)
+	method := http.MethodHead
+	if r.Platforms != nil {
+		method = http.MethodGet
+	}
+	status, res, err := r.retrieve(method, endpoint, auth)
 	if err != nil {
 		return false, err
 	}
-	if status == http.StatusOK {
-		return true, nil
-	}
 	if status == http.StatusNotFound {
 		return false, nil
 	}
+	if status == http.StatusOK {
+		if r.Platforms == nil {
+			return true, nil
+		}
+		return r.hasPlatforms(res)
+	}
 	return false, fmt.Errorf("unexpected response registry API: %d", status)
 }
 

pkg/registry_test.go

@@ -1,6 +1,7 @@
 package pkg
 
 import (
+	_ "embed"
 	"encoding/json"
 	"fmt"
 	"net/http"
@@ -12,6 +13,11 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
+var (
+	//go:embed t/sample.json
+	sampleManifest []byte
+)
+
 type mockRegistry struct {
 	t      *testing.T
 	tags   []string
@@ -496,3 +502,48 @@ func TestIsTagExist(t *testing.T) {
 		})
 	}
 }
+
+func TestHasPlatforms(t *testing.T) {
+	t.Parallel()
+	cases := []struct {
+		title     string
+		platforms []string
+		response  []byte
+		expected  bool
+		isErr     bool
+	}{
+		{
+			title:     "SinglePlatform",
+			platforms: []string{"linux/amd64"},
+			response:  sampleManifest,
+			expected:  true,
+		},
+		{
+			title:     "MultiPlatform",
+			platforms: []string{"linux/amd64", "linux/arm64"},
+			response:  sampleManifest,
+			expected:  true,
+		},
+		{
+			title:     "MissingPlatform",
+			platforms: []string{"linux/amd64", "darwin/arm64"},
+			response:  sampleManifest,
+		},
+		{
+			title:     "UnmarshalError",
+			platforms: []string{"linux/amd64"},
+			response:  []byte("{hoge}"),
+			isErr:     true,
+		},
+	}
+	for _, tc := range cases {
+		tc := tc
+		t.Run(tc.title, func(t *testing.T) {
+			t.Helper()
+			client := RegistryClient{Platforms: tc.platforms}
+			actual, err := client.hasPlatforms(tc.response)
+			assertExpectedErr(t, err, tc.isErr)
+			assert.Equal(t, tc.expected, actual)
+		})
+	}
+}

pkg/t/sample.json

@@ -0,0 +1,24 @@
+{
+    "mediaType": "application/vnd.docker.distribution.manifest.list.v2+json",
+    "schemaVersion": 2,
+    "manifests": [
+       {
+          "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
+          "digest": "sha256:232479a01040fd2b02f10c568eb3860b52843f6a0c23a96e843ee80f22f3fdc7",
+          "size": 1786,
+          "platform": {
+             "architecture": "amd64",
+             "os": "linux"
+          }
+       },
+       {
+          "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
+          "digest": "sha256:9b6ce0b6aac841b356d19ebaad2860a849cf4b69b35a564f523eb1c3d07b3dea",
+          "size": 1786,
+          "platform": {
+             "architecture": "arm64",
+             "os": "linux"
+          }
+       }
+    ]
+}