From dae67e6be654592c1d87f2d9a553f16a0fca8537 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adam=20=C5=A0trauch?= <cx@initd.cz>
Date: Sun, 31 Oct 2021 12:01:24 +0100
Subject: [PATCH] Get snapshot handler

It translates snapshot keys into metadata structure
---
 apps/snapshots.go      | 14 ++++++++++++++
 apps/snapshots_test.go |  6 ++++++
 handlers_nats.go       | 43 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 63 insertions(+)

diff --git a/apps/snapshots.go b/apps/snapshots.go
index 5414654..412d028 100644
--- a/apps/snapshots.go
+++ b/apps/snapshots.go
@@ -249,6 +249,20 @@ func (s *SnapshotProcessor) ListAppsSnapshotsByLabel(desiredLabel string) ([]Sna
 	return snapshots, nil
 }
 
+// GetSnapshot returns a single snapshot's metadata for given key.
+// In fact this is just key translation method. It parses the key and returns
+// what's inside. Doesn't check if the snapshot actually exist.
+func (s *SnapshotProcessor) GetSnapshot(key string) (Snapshot, error) {
+	snapshot := Snapshot{}
+
+	snapshot, err := DecodeKeyName(key)
+	if err != nil {
+		return snapshot, err
+	}
+
+	return snapshot, nil
+}
+
 // DeleteSnapshot delete's one snapshot
 func (s *SnapshotProcessor) DeleteSnapshot(key string) error {
 	err := s.Driver.Delete(key)
diff --git a/apps/snapshots_test.go b/apps/snapshots_test.go
index ca5ac38..fd8ce6c 100644
--- a/apps/snapshots_test.go
+++ b/apps/snapshots_test.go
@@ -154,6 +154,12 @@ func TestCreateRestoreListSnapshot(t *testing.T) {
 
 }
 
+func TestGetSnapshot(t *testing.T) {
+	snapshot, err := snapshotProcessor.GetSnapshot("app_0102:1634510035:eyJhcHBfbmFtZSI6ImFwcF8wMTAyIiwidHMiOjE2MzQ1MTAwMzUsImxhYmVscyI6WyJ1c2VyaWQ6MSJdfQ==")
+	assert.Nil(t, err)
+	assert.Equal(t, "app_0102", snapshot.AppName)
+}
+
 func TestListAppsSnapshotsByLabel(t *testing.T) {
 	appName := "app_0102"
 
diff --git a/handlers_nats.go b/handlers_nats.go
index bf1187a..0b00b0c 100644
--- a/handlers_nats.go
+++ b/handlers_nats.go
@@ -64,6 +64,7 @@ func _messageHandler(m *nats.Msg) error {
 		"list_snapshots":          listSnapshotsEventHandler,
 		"list_apps_snapshots":     listAppsSnapshotsEventHandler,
 		"list_snapshots_by_label": listSnapshotsByLabelEventHandler,
+		"get_snapshot":            getSnapshotEventHandler,
 		"delete_snapshot":         deleteSnapshotEventHandler,
 		"delete_app_snapshots":    deleteAppSnapshotsEventHandler,
 	}
@@ -1049,6 +1050,48 @@ func listSnapshotsByLabelEventHandler(m *nats.Msg, message *RequestMessage) erro
 	return nil
 }
 
+/*
+getSnapshotEventHandler returns a single snapshot for given key from the request payload.
+
+Payload: snapshot's key
+Response: snapshot metadata
+*/
+func getSnapshotEventHandler(m *nats.Msg, message *RequestMessage) error {
+	processor := apps.SnapshotProcessor{
+		AppsPath:        config.AppsPath,
+		TmpSnapshotPath: config.SnapshotsPath,
+
+		Driver: drivers.S3Driver{
+			S3AccessKey: config.SnapshotsS3AccessKey,
+			S3SecretKey: config.SnapshotsS3SecretKey,
+			S3Endpoint:  config.SnapshotsS3Endpoint,
+			S3SSL:       config.SnapshotsS3SSL,
+			Bucket:      config.SnapshotsS3Bucket,
+		},
+	}
+
+	snapshot, err := processor.GetSnapshot(message.Payload)
+	if err != nil {
+		return errorReplyFormater(m, "backend error", err)
+	}
+	output := SnapshotMetadata{
+		Key:      snapshot.KeyName(),
+		Metadata: snapshot,
+	}
+
+	data, err := json.Marshal(output)
+	if err != nil {
+		return errorReplyFormater(m, "reply formatter error", err)
+	}
+
+	err = m.Respond(data)
+	if err != nil {
+		log.Println("ERROR: get snapshot:", err.Error())
+	}
+
+	return nil
+}
+
 /*
 deleteSnapshotEventHandler delete a single snapshot. This is not bound to application name.