CLUSTER SHARDS (#431)

* CLUSTER SHARDS

---------

Co-authored-by: Dimitrij Drus <dimitrij.drus@innoq.com>

Author: alicebob

cmd_cluster.go

@@ -31,6 +31,8 @@ func (m *Miniredis) cmdCluster(c *server.Peer, cmd string, args []string) {
 		m.cmdClusterKeySlot(c, cmd, args)
 	case "NODES":
 		m.cmdClusterNodes(c, cmd, args)
+	case "SHARDS":
+		m.cmdClusterShards(c, cmd, args)
 	default:
 		setDirty(c)
 		c.WriteError(fmt.Sprintf("ERR 'CLUSTER %s' not supported", strings.Join(args, " ")))
@@ -68,3 +70,53 @@ func (m *Miniredis) cmdClusterNodes(c *server.Peer, cmd string, args []string) {
 		c.WriteBulk(fmt.Sprintf("e7d1eecce10fd6bb5eb35b9f99a514335d9ba9ca %s@%d myself,master - 0 0 1 connected 0-16383", addr, port))
 	})
 }
+
+// CLUSTER SHARDS
+func (m *Miniredis) cmdClusterShards(c *server.Peer, cmd string, args []string) {
+	withTx(m, c, func(c *server.Peer, ctx *connCtx) {
+		addr := m.srv.Addr()
+		host := addr.IP.String()
+		port := addr.Port
+
+		// Array of shards (we return 1 shard)
+		c.WriteLen(1)
+
+		// Shard is a map with 2 keys: "slots" and "nodes"
+		c.WriteMapLen(2)
+
+		// "slots": flat list of start/end pairs (inclusive ranges)
+		c.WriteBulk("slots")
+		c.WriteLen(2)
+		c.WriteInt(0)
+		c.WriteInt(16383)
+
+		// "nodes": array of node maps
+		c.WriteBulk("nodes")
+		c.WriteLen(1)
+
+		// Node map.
+		// (id, endpoint, ip, port, role, replication-offset, health)
+		c.WriteMapLen(6)
+
+		c.WriteBulk("id")
+		c.WriteBulk("13f84e686106847b76671957dd348fde540a77bb")
+
+		//c.WriteBulk("endpoint")
+		//c.WriteBulk(host) // or host:port if your client expects that
+
+		c.WriteBulk("ip")
+		c.WriteBulk(host)
+
+		c.WriteBulk("port")
+		c.WriteInt(port)
+
+		c.WriteBulk("role")
+		c.WriteBulk("master")
+
+		c.WriteBulk("replication-offset")
+		c.WriteInt(0)
+
+		c.WriteBulk("health")
+		c.WriteBulk("online")
+	})
+}

cmd_cluster_test.go

@@ -38,6 +38,41 @@ func TestCluster(t *testing.T) {
 		)
 	})
 
+	t.Run("shards", func(t *testing.T) {
+		mustDo(t, c,
+			"CLUSTER", "SHARDS",
+			proto.Array(
+				proto.Array(
+					proto.String("slots"), proto.Array(
+						proto.Int(0),
+						proto.Int(16383),
+					),
+					proto.String("nodes"), proto.Array(
+						proto.Array(
+							proto.String("id"),
+							proto.String("13f84e686106847b76671957dd348fde540a77bb"),
+
+							proto.String("ip"),
+							proto.String(s.srv.Addr().IP.String()),
+
+							proto.String("port"),
+							proto.Int(s.srv.Addr().Port),
+
+							proto.String("role"),
+							proto.String("master"),
+
+							proto.String("replication-offset"),
+							proto.Int(0),
+
+							proto.String("health"),
+							proto.String("online"),
+						),
+					),
+				),
+			),
+		)
+	})
+
 	t.Run("keyslot", func(t *testing.T) {
 		mustDo(t, c,
 			"CLUSTER", "keyslot", "{test_key}",

integration/cluster_test.go

@@ -10,6 +10,7 @@ func TestCluster(t *testing.T) {
 			c.DoLoosely("CLUSTER", "KEYSLOT", "{test}")
 			c.DoLoosely("CLUSTER", "NODES")
 			c.Error("wrong number", "CLUSTER")
+			// c.DoLoosely("CLUSTER", "SHARDS")
 		},
 	)
 }