feat: Support manifestlist and multi-arch images (#341)

* feat: Support manifestlist and multi-arch images

Signed-off-by: jannfis <jann@mistrust.net>

* Add unit test

Signed-off-by: jannfis <jann@mistrust.net>

* Fix linter issue

Signed-off-by: jannfis <jann@mistrust.net>

2 files changed, 161 insertions, 0 deletions

diff --git a/pkg/options/options.go b/pkg/options/options.go
new file mode 100644
index 0000000..c1a6462
--- /dev/null
+++ b/pkg/options/options.go
@@ -0,0 +1,87 @@
+package options
+
+import (
+	"sort"
+	"sync"
+
+	"github.com/argoproj-labs/argocd-image-updater/pkg/log"
+)
+
+// ManifestOptions define some options when retrieving image manifests
+type ManifestOptions struct {
+	platforms map[string]bool
+	mutex     sync.RWMutex
+	metadata  bool
+}
+
+// NewManifestOptions returns an initialized ManifestOptions struct
+func NewManifestOptions() *ManifestOptions {
+	return &ManifestOptions{
+		platforms: make(map[string]bool),
+		metadata:  false,
+	}
+}
+
+// PlatformKey returns a string usable as platform key
+func PlatformKey(os string, arch string, variant string) string {
+	key := os + "/" + arch
+	if variant != "" {
+		key += "/" + variant
+	}
+	return key
+}
+
+// MatchesPlatform returns true if given OS name matches the OS set in options
+func (o *ManifestOptions) WantsPlatform(os string, arch string, variant string) bool {
+	o.mutex.RLock()
+	defer o.mutex.RUnlock()
+	if len(o.platforms) == 0 {
+		return true
+	}
+	_, ok := o.platforms[PlatformKey(os, arch, variant)]
+	return ok
+}
+
+// WithPlatform sets a platform filter for options o
+func (o *ManifestOptions) WithPlatform(os string, arch string, variant string) *ManifestOptions {
+	o.mutex.Lock()
+	defer o.mutex.Unlock()
+	if o.platforms == nil {
+		o.platforms = map[string]bool{}
+	}
+	log.Debugf("Adding platform " + PlatformKey(os, arch, variant))
+	o.platforms[PlatformKey(os, arch, variant)] = true
+	return o
+}
+
+func (o *ManifestOptions) Platforms() []string {
+	o.mutex.RLock()
+	defer o.mutex.RUnlock()
+	if len(o.platforms) == 0 {
+		return []string{}
+	}
+	keys := make([]string, 0, len(o.platforms))
+	for k := range o.platforms {
+		keys = append(keys, k)
+	}
+	// We sort the slice before returning it, to guarantee stable order
+	sort.Strings(keys)
+	return keys
+}
+
+// WantsMetdata returns true if metadata should be requested
+func (o *ManifestOptions) WantsMetdata() bool {
+	return o.metadata
+}
+
+// WithMetadata sets metadata to be requested
+func (o *ManifestOptions) WithMetadata() *ManifestOptions {
+	o.metadata = true
+	return o
+}
+
+// WithoutMetadata sets metadata not not be requested
+func (o *ManifestOptions) WithoutMetadata() *ManifestOptions {
+	o.metadata = false
+	return o
+}
diff --git a/pkg/options/options_test.go b/pkg/options/options_test.go
new file mode 100644
index 0000000..d0a7fdc
--- /dev/null
+++ b/pkg/options/options_test.go
@@ -0,0 +1,74 @@
+package options
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_PlatformKey(t *testing.T) {
+	t.Run("Without variant", func(t *testing.T) {
+		assert.Equal(t, PlatformKey("linux", "amd64", ""), "linux/amd64")
+	})
+	t.Run("With variant", func(t *testing.T) {
+		assert.Equal(t, PlatformKey("linux", "arm", "v6"), "linux/arm/v6")
+	})
+}
+
+func Test_WantsPlatform(t *testing.T) {
+	opts := NewManifestOptions()
+	t.Run("Empty options", func(t *testing.T) {
+		assert.True(t, opts.WantsPlatform("linux", "arm", "v7"))
+		assert.True(t, opts.WantsPlatform("linux", "amd64", ""))
+	})
+	t.Run("Single platform", func(t *testing.T) {
+		opts = opts.WithPlatform("linux", "arm", "v7")
+		assert.True(t, opts.WantsPlatform("linux", "arm", "v7"))
+	})
+	t.Run("Platform appended", func(t *testing.T) {
+		opts = opts.WithPlatform("linux", "arm", "v8")
+		assert.True(t, opts.WantsPlatform("linux", "arm", "v7"))
+		assert.True(t, opts.WantsPlatform("linux", "arm", "v8"))
+	})
+	t.Run("Uninitialized options", func(t *testing.T) {
+		opts := &ManifestOptions{}
+		assert.True(t, opts.WantsPlatform("linux", "amd64", ""))
+		opts = (&ManifestOptions{}).WithPlatform("linux", "amd64", "")
+		assert.True(t, opts.WantsPlatform("linux", "amd64", ""))
+	})
+}
+
+func Test_WantsMetadata(t *testing.T) {
+	opts := NewManifestOptions()
+	t.Run("Empty options", func(t *testing.T) {
+		assert.False(t, opts.WantsMetdata())
+	})
+	t.Run("Wants metadata", func(t *testing.T) {
+		opts = opts.WithMetadata()
+		assert.True(t, opts.WantsMetdata())
+	})
+	t.Run("Does not want metadata", func(t *testing.T) {
+		opts = opts.WithoutMetadata()
+		assert.False(t, opts.WantsMetdata())
+	})
+}
+
+func Test_Platforms(t *testing.T) {
+	opts := NewManifestOptions()
+	t.Run("Empty platforms returns empty array", func(t *testing.T) {
+		ps := opts.Platforms()
+		assert.Len(t, ps, 0)
+	})
+	t.Run("Single platform without variant", func(t *testing.T) {
+		ps := opts.WithPlatform("linux", "amd64", "").Platforms()
+		require.Len(t, ps, 1)
+		assert.Equal(t, ps[0], PlatformKey("linux", "amd64", ""))
+	})
+	t.Run("Single platform with variant", func(t *testing.T) {
+		ps := opts.WithPlatform("linux", "arm", "v8").Platforms()
+		require.Len(t, ps, 2)
+		assert.Equal(t, ps[0], PlatformKey("linux", "amd64", ""))
+		assert.Equal(t, ps[1], PlatformKey("linux", "arm", "v8"))
+	})
+}