Add Chef package registry (#22554)

This PR implements a [Chef registry](https://chef.io/) to manage
cookbooks. This package type was a bit complicated because Chef uses RSA
signed requests as authentication with the registry.


![grafik](https://user-images.githubusercontent.com/1666336/213747995-46819fd8-c3d6-45a2-afd4-a4c3c8505a4a.png)


![grafik](https://user-images.githubusercontent.com/1666336/213748145-d01c9e81-d4dd-41e3-a3cc-8241862c3166.png)

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

modules/packages/chef/metadata_test.go

@@ -0,0 +1,92 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package chef
+
+import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	packageName          = "gitea"
+	packageVersion       = "1.0.1"
+	packageAuthor        = "KN4CK3R"
+	packageDescription   = "Package Description"
+	packageRepositoryURL = "https://gitea.io/gitea/gitea"
+)
+
+func TestParsePackage(t *testing.T) {
+	t.Run("MissingMetadataFile", func(t *testing.T) {
+		var buf bytes.Buffer
+		zw := gzip.NewWriter(&buf)
+		tw := tar.NewWriter(zw)
+		tw.Close()
+		zw.Close()
+
+		p, err := ParsePackage(&buf)
+		assert.Nil(t, p)
+		assert.ErrorIs(t, err, ErrMissingMetadataFile)
+	})
+
+	t.Run("Valid", func(t *testing.T) {
+		var buf bytes.Buffer
+		zw := gzip.NewWriter(&buf)
+		tw := tar.NewWriter(zw)
+
+		content := `{"name":"` + packageName + `","version":"` + packageVersion + `"}`
+
+		hdr := &tar.Header{
+			Name: packageName + "/metadata.json",
+			Mode: 0o600,
+			Size: int64(len(content)),
+		}
+		tw.WriteHeader(hdr)
+		tw.Write([]byte(content))
+
+		tw.Close()
+		zw.Close()
+
+		p, err := ParsePackage(&buf)
+		assert.NoError(t, err)
+		assert.NotNil(t, p)
+		assert.Equal(t, packageName, p.Name)
+		assert.Equal(t, packageVersion, p.Version)
+		assert.NotNil(t, p.Metadata)
+	})
+}
+
+func TestParseChefMetadata(t *testing.T) {
+	t.Run("InvalidName", func(t *testing.T) {
+		for _, name := range []string{" test", "test "} {
+			p, err := ParseChefMetadata(strings.NewReader(`{"name":"` + name + `","version":"1.0.0"}`))
+			assert.Nil(t, p)
+			assert.ErrorIs(t, err, ErrInvalidName)
+		}
+	})
+
+	t.Run("InvalidVersion", func(t *testing.T) {
+		for _, version := range []string{"1", "1.2.3.4", "1.0.0 "} {
+			p, err := ParseChefMetadata(strings.NewReader(`{"name":"test","version":"` + version + `"}`))
+			assert.Nil(t, p)
+			assert.ErrorIs(t, err, ErrInvalidVersion)
+		}
+	})
+
+	t.Run("Valid", func(t *testing.T) {
+		p, err := ParseChefMetadata(strings.NewReader(`{"name":"` + packageName + `","version":"` + packageVersion + `","description":"` + packageDescription + `","maintainer":"` + packageAuthor + `","source_url":"` + packageRepositoryURL + `"}`))
+		assert.NotNil(t, p)
+		assert.NoError(t, err)
+
+		assert.Equal(t, packageName, p.Name)
+		assert.Equal(t, packageVersion, p.Version)
+		assert.Equal(t, packageDescription, p.Metadata.Description)
+		assert.Equal(t, packageAuthor, p.Metadata.Author)
+		assert.Equal(t, packageRepositoryURL, p.Metadata.RepositoryURL)
+	})
+}