[#306] netmap: Allow to select empty set of nodes

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

netmap/selector.go

@@ -114,7 +114,7 @@ func (c *context) getSelection(s netmap.Selector) ([]nodes, error) {
 	}
 
 	if len(res) < bucketCount {
-		if len(res) == 0 {
+		if c.strict && len(res) == 0 {
 			return nil, errNotEnoughNodes
 		}
 		bucketCount = len(res)

netmap/selector_test.go

@@ -254,6 +254,39 @@ func TestPlacementPolicy_ProcessSelectors(t *testing.T) {
 	}
 }
 
+func TestPlacementPolicy_PartiallyMissingContainer(t *testing.T) {
+	s := `REP 2 IN D1OBJ
+REP 2 IN D2OBJ
+CBF 2
+SELECT 2 FROM PRIMARY AS D1OBJ
+SELECT 2 FROM SECONDARY AS D2OBJ
+FILTER ClusterName EQ D1OBJ AS PRIMARY
+FILTER ClusterName EQ D2OBJ AS SECONDARY`
+
+	var p PlacementPolicy
+	require.NoError(t, p.DecodeString(s))
+
+	nodes := []NodeInfo{
+		nodeInfoFromAttributes("ClusterName", "D1OBJ", "ID", "1"),
+		nodeInfoFromAttributes("ClusterName", "D1OBJ", "ID", "2"),
+		nodeInfoFromAttributes("ClusterName", "D1OBJ", "ID", "3"),
+		nodeInfoFromAttributes("ClusterName", "D1OBJ", "ID", "4"),
+		nodeInfoFromAttributes("ClusterName", "D1OBJ", "ID", "5"),
+		nodeInfoFromAttributes("ClusterName", "D1OBJ", "ID", "6"),
+		nodeInfoFromAttributes("ClusterName", "D1OBJ", "ID", "7"),
+		nodeInfoFromAttributes("ClusterName", "D1OBJ", "ID", "8"),
+	}
+
+	var nm NetMap
+	nm.SetNodes(nodes)
+
+	res, err := nm.ContainerNodes(p, nil)
+	require.NoError(t, err)
+	require.Len(t, res, 2)
+	require.Len(t, res[0], 4)
+	require.Len(t, res[1], 0)
+}
+
 func TestPlacementPolicy_Like(t *testing.T) {
 	nodes := []NodeInfo{
 		nodeInfoFromAttributes("Country", "Russia"),

netmap/yml_test.go

@@ -84,8 +84,15 @@ func TestPlacementPolicy_Interopability(t *testing.T) {
 				t.Run(name, func(t *testing.T) {
 					v, err := nm.ContainerNodes(tt.Policy, tt.Pivot)
 					if tt.Result == nil {
-						require.Error(t, err)
-						require.Contains(t, err.Error(), tt.Error)
+						if tt.Error != "" {
+							require.Error(t, err)
+							require.Contains(t, err.Error(), tt.Error)
+						} else {
+							require.Len(t, v, tt.Policy.NumberOfReplicas())
+							for i := range v {
+								require.Len(t, v[i], 0)
+							}
+						}
 					} else {
 						require.NoError(t, err)
 						require.Equal(t, srcNodes, tc.Nodes)

netmap/yml_tests/filter_complex.yml

@@ -107,7 +107,6 @@ tests:
                   op: EQ
                   value: Value2
                   filters: []
-    error: not enough nodes
   bad rating:
     policy:
       replicas:
@@ -157,7 +156,6 @@ tests:
                   op: EQ
                   value: Value2
                   filters: []
-    error: not enough nodes
   bad param:
     policy:
       replicas:
@@ -207,4 +205,3 @@ tests:
                   op: EQ
                   value: Value2
                   filters: []
-    error: not enough nodes

netmap/yml_tests/filter_invalid_integer.yml

@@ -24,7 +24,6 @@ tests:
           op: LE
           value: '8'
           filters: []
-    error: not enough nodes
   non-empty string is not casted to a number:
     policy:
       replicas:
@@ -42,4 +41,3 @@ tests:
           op: GE
           value: '0'
           filters: []
-    error: not enough nodes

netmap/yml_tests/filter_simple.yml

@@ -42,7 +42,6 @@ tests:
           op: GE
           value: '5'
           filters: []
-    error: not enough nodes
   GT true:
     policy:
       replicas:
@@ -79,7 +78,6 @@ tests:
           op: GT
           value: '4'
           filters: []
-    error: not enough nodes
   LE true:
     policy:
       replicas:
@@ -116,7 +114,6 @@ tests:
           op: LE
           value: '3'
           filters: []
-    error: not enough nodes
   LT true:
     policy:
       replicas:
@@ -153,7 +150,6 @@ tests:
           op: LT
           value: '4'
           filters: []
-    error: not enough nodes
   EQ true:
     policy:
       replicas:
@@ -190,7 +186,6 @@ tests:
           op: EQ
           value: China
           filters: []
-    error: not enough nodes
   NE true:
     policy:
       replicas:
@@ -227,4 +222,3 @@ tests:
           op: NE
           value: Germany
           filters: []
-    error: not enough nodes

netmap/yml_tests/selector_invalid.yml

@@ -45,4 +45,3 @@ tests:
           op: EQ
           value: Moon
           filters: []
-    error: not enough nodes