Add /v3/cluster/snapshot endpoint

cluster/api.go

@@ -242,7 +242,13 @@ func (a *api) RemoveServer(c echo.Context) error {
 // @Success 500 {array} Error
 // @Router /v1/snapshot [get]
 func (a *api) Snapshot(c echo.Context) error {
-	data, err := a.cluster.Snapshot()
+	origin := c.Request().Header.Get("X-Cluster-Origin")
+
+	if origin == a.id {
+		return Err(http.StatusLoopDetected, "", "breaking circuit")
+	}
+
+	data, err := a.cluster.Snapshot(origin)
 	if err != nil {
 		a.logger.Debug().WithError(err).Log("Unable to create snaphot")
 		return Err(http.StatusInternalServerError, "", "unable to create snapshot: %s", err.Error())

cluster/client/client.go

@@ -249,8 +249,8 @@ func (c *APIClient) UnsetKV(origin string, key string) error {
 	return err
 }
 
-func (c *APIClient) Snapshot() (io.ReadCloser, error) {
+func (c *APIClient) Snapshot(origin string) (io.ReadCloser, error) {
-	return c.stream(http.MethodGet, "/v1/snapshot", "", nil, "")
+	return c.stream(http.MethodGet, "/v1/snapshot", "", nil, origin)
 }
 
 func (c *APIClient) IsReady(origin string) error {

cluster/cluster.go

@@ -48,7 +48,7 @@ type Cluster interface {
 
 	Join(origin, id, raftAddress, peerAddress string) error
 	Leave(origin, id string) error // gracefully remove a node from the cluster
-	Snapshot() (io.ReadCloser, error)
+	Snapshot(origin string) (io.ReadCloser, error)
 
 	Shutdown() error
 
@@ -827,10 +827,10 @@ func (c *cluster) Join(origin, id, raftAddress, peerAddress string) error {
 	return nil
 }
 
-func (c *cluster) Snapshot() (io.ReadCloser, error) {
+func (c *cluster) Snapshot(origin string) (io.ReadCloser, error) {
 	if !c.IsRaftLeader() {
 		c.logger.Debug().Log("Not leader, forwarding to leader")
-		return c.forwarder.Snapshot()
+		return c.forwarder.Snapshot(origin)
 	}
 
 	return c.raft.Snapshot()

cluster/forwarder/forwarder.go

@@ -20,7 +20,7 @@ type Forwarder interface {
 
 	Join(origin, id, raftAddress, peerAddress string) error
 	Leave(origin, id string) error
-	Snapshot() (io.ReadCloser, error)
+	Snapshot(origin string) (io.ReadCloser, error)
 
 	AddProcess(origin string, config *app.Config) error
 	UpdateProcess(origin string, id app.ProcessID, config *app.Config) error
@@ -140,12 +140,12 @@ func (f *forwarder) Leave(origin, id string) error {
 	return client.Leave(origin, id)
 }
 
-func (f *forwarder) Snapshot() (io.ReadCloser, error) {
+func (f *forwarder) Snapshot(origin string) (io.ReadCloser, error) {
 	f.lock.RLock()
 	client := f.client
 	f.lock.RUnlock()
 
-	return client.Snapshot()
+	return client.Snapshot(origin)
 }
 
 func (f *forwarder) AddProcess(origin string, config *app.Config) error {

cluster/raft/raft.go

@@ -2,7 +2,8 @@ package raft
 
 import (
 	"bytes"
-	"encoding/gob"
+	"encoding/base64"
+	"encoding/json"
 	"fmt"
 	"io"
 	gonet "net"
@@ -287,7 +288,7 @@ func (rcw *readCloserWrapper) Close() error {
 
 type Snapshot struct {
 	Metadata *hcraft.SnapshotMeta
-	Data     []byte
+	Data     string
 }
 
 func (r *raft) Snapshot() (io.ReadCloser, error) {
@@ -311,11 +312,11 @@ func (r *raft) Snapshot() (io.ReadCloser, error) {
 
 	snapshot := Snapshot{
 		Metadata: metadata,
-		Data:     data,
+		Data:     base64.StdEncoding.EncodeToString(data),
 	}
 
 	buffer := bytes.Buffer{}
-	enc := gob.NewEncoder(&buffer)
+	enc := json.NewEncoder(&buffer)
 	err = enc.Encode(snapshot)
 	if err != nil {
 		return nil, err

docs/docs.go

@@ -1441,6 +1441,32 @@ const docTemplate = `{
                 }
             }
         },
+        "/api/v3/cluster/snapshot": {
+            "get": {
+                "security": [
+                    {
+                        "ApiKeyAuth": []
+                    }
+                ],
+                "description": "Retrieve snapshot of the cluster DB",
+                "produces": [
+                    "application/octet-stream"
+                ],
+                "tags": [
+                    "v16.?.?"
+                ],
+                "summary": "Retrieve snapshot of the cluster DB",
+                "operationId": "cluster-3-snapshot",
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "type": "file"
+                        }
+                    }
+                }
+            }
+        },
         "/api/v3/config": {
             "get": {
                 "security": [

docs/swagger.json

@@ -1433,6 +1433,32 @@
                 }
             }
         },
+        "/api/v3/cluster/snapshot": {
+            "get": {
+                "security": [
+                    {
+                        "ApiKeyAuth": []
+                    }
+                ],
+                "description": "Retrieve snapshot of the cluster DB",
+                "produces": [
+                    "application/octet-stream"
+                ],
+                "tags": [
+                    "v16.?.?"
+                ],
+                "summary": "Retrieve snapshot of the cluster DB",
+                "operationId": "cluster-3-snapshot",
+                "responses": {
+                    "200": {
+                        "description": "OK",
+                        "schema": {
+                            "type": "file"
+                        }
+                    }
+                }
+            }
+        },
         "/api/v3/config": {
             "get": {
                 "security": [

docs/swagger.yaml

@@ -3323,6 +3323,22 @@ paths:
       summary: Add JSON metadata with a process under the given key
       tags:
       - v16.?.?
+  /api/v3/cluster/snapshot:
+    get:
+      description: Retrieve snapshot of the cluster DB
+      operationId: cluster-3-snapshot
+      produces:
+      - application/octet-stream
+      responses:
+        "200":
+          description: OK
+          schema:
+            type: file
+      security:
+      - ApiKeyAuth: []
+      summary: Retrieve snapshot of the cluster DB
+      tags:
+      - v16.?.?
   /api/v3/config:
     get:
       description: Retrieve the currently active Restreamer configuration

http/handler/api/cluster.go

@@ -1291,3 +1291,23 @@ func (h *ClusterHandler) ListStoreKV(c echo.Context) error {
 
 	return c.JSON(http.StatusOK, kvs)
 }
+
+// GetSnapshot returns a current snapshot of the cluster DB
+// @Summary Retrieve snapshot of the cluster DB
+// @Description Retrieve snapshot of the cluster DB
+// @Tags v16.?.?
+// @ID cluster-3-snapshot
+// @Produce application/octet-stream
+// @Success 200 {file} byte
+// @Security ApiKeyAuth
+// @Router /api/v3/cluster/snapshot [get]
+func (h *ClusterHandler) GetSnapshot(c echo.Context) error {
+	r, err := h.cluster.Snapshot("")
+	if err != nil {
+		return api.Err(http.StatusInternalServerError, "", "failed to retrieve snapshot: %w", err)
+	}
+
+	defer r.Close()
+
+	return c.Stream(http.StatusOK, "application/octet-stream", r)
+}

http/server.go

@@ -675,6 +675,8 @@ func (s *server) setRoutesV3(v3 *echo.Group) {
 	if s.v3handler.cluster != nil {
 		v3.GET("/cluster", s.v3handler.cluster.About)
 
+		v3.GET("/cluster/snapshot", s.v3handler.cluster.GetSnapshot)
+
 		v3.GET("/cluster/db/process", s.v3handler.cluster.ListStoreProcesses)
 		v3.GET("/cluster/db/user", s.v3handler.cluster.ListStoreIdentities)
 		v3.GET("/cluster/db/user/:name", s.v3handler.cluster.ListStoreIdentity)