From 93de03fe8bf2f53fb2ca0452a387cf9cce86f105 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Fri, 2 Mar 2018 13:40:03 -0800
Subject: [PATCH] agent/consul: RPC endpoint for Intention.Match

---
 agent/consul/intention_endpoint.go      | 30 ++++++++++
 agent/consul/intention_endpoint_test.go | 76 +++++++++++++++++++++++++
 agent/structs/intention.go              | 15 +++--
 3 files changed, 116 insertions(+), 5 deletions(-)

diff --git a/agent/consul/intention_endpoint.go b/agent/consul/intention_endpoint.go
index fc552afd98..d130027227 100644
--- a/agent/consul/intention_endpoint.go
+++ b/agent/consul/intention_endpoint.go
@@ -142,3 +142,33 @@ func (s *Intention) List(
 		},
 	)
 }
+
+// Match returns the set of intentions that match the given source/destination.
+func (s *Intention) Match(
+	args *structs.IntentionQueryRequest,
+	reply *structs.IndexedIntentionMatches) error {
+	// Forward if necessary
+	if done, err := s.srv.forward("Intention.Match", args, args, reply); done {
+		return err
+	}
+
+	// TODO(mitchellh): validate
+
+	return s.srv.blockingQuery(
+		&args.QueryOptions,
+		&reply.QueryMeta,
+		func(ws memdb.WatchSet, state *state.Store) error {
+			index, matches, err := state.IntentionMatch(ws, args.Match)
+			if err != nil {
+				return err
+			}
+
+			reply.Index = index
+			reply.Matches = matches
+
+			// TODO(mitchellh): acl filtering
+
+			return nil
+		},
+	)
+}
diff --git a/agent/consul/intention_endpoint_test.go b/agent/consul/intention_endpoint_test.go
index 53aef35cdc..65170ff7ba 100644
--- a/agent/consul/intention_endpoint_test.go
+++ b/agent/consul/intention_endpoint_test.go
@@ -258,3 +258,79 @@ func TestIntentionList(t *testing.T) {
 		}
 	}
 }
+
+// Test basic matching. We don't need to exhaustively test inputs since this
+// is tested in the agent/consul/state package.
+func TestIntentionMatch_good(t *testing.T) {
+	t.Parallel()
+	dir1, s1 := testServer(t)
+	defer os.RemoveAll(dir1)
+	defer s1.Shutdown()
+	codec := rpcClient(t, s1)
+	defer codec.Close()
+
+	testrpc.WaitForLeader(t, s1.RPC, "dc1")
+
+	// Create some records
+	{
+		insert := [][]string{
+			{"foo", "*"},
+			{"foo", "bar"},
+			{"foo", "baz"}, // shouldn't match
+			{"bar", "bar"}, // shouldn't match
+			{"bar", "*"},   // shouldn't match
+			{"*", "*"},
+		}
+
+		for _, v := range insert {
+			ixn := structs.IntentionRequest{
+				Datacenter: "dc1",
+				Op:         structs.IntentionOpCreate,
+				Intention: &structs.Intention{
+					SourceNS:        "default",
+					SourceName:      "test",
+					DestinationNS:   v[0],
+					DestinationName: v[1],
+				},
+			}
+
+			// Create
+			var reply string
+			if err := msgpackrpc.CallWithCodec(codec, "Intention.Apply", &ixn, &reply); err != nil {
+				t.Fatalf("err: %v", err)
+			}
+		}
+	}
+
+	// Match
+	req := &structs.IntentionQueryRequest{
+		Datacenter: "dc1",
+		Match: &structs.IntentionQueryMatch{
+			Type: structs.IntentionMatchDestination,
+			Entries: []structs.IntentionMatchEntry{
+				{
+					Namespace: "foo",
+					Name:      "bar",
+				},
+			},
+		},
+	}
+	var resp structs.IndexedIntentionMatches
+	if err := msgpackrpc.CallWithCodec(codec, "Intention.Match", req, &resp); err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if len(resp.Matches) != 1 {
+		t.Fatalf("bad: %#v", resp.Matches)
+	}
+
+	expected := [][]string{{"foo", "bar"}, {"foo", "*"}, {"*", "*"}}
+	var actual [][]string
+	for _, ixn := range resp.Matches[0] {
+		actual = append(actual, []string{ixn.DestinationNS, ixn.DestinationName})
+	}
+
+	if !reflect.DeepEqual(actual, expected) {
+		t.Fatalf("bad (got, wanted):\n\n%#v\n\n%#v", actual, expected)
+	}
+}
diff --git a/agent/structs/intention.go b/agent/structs/intention.go
index 14b5e0b8e8..e2ad2fb92a 100644
--- a/agent/structs/intention.go
+++ b/agent/structs/intention.go
@@ -75,6 +75,12 @@ type IndexedIntentions struct {
 	QueryMeta
 }
 
+// IndexedIntentionMatches represents the list of matches for a match query.
+type IndexedIntentionMatches struct {
+	Matches []Intentions
+	QueryMeta
+}
+
 // IntentionOp is the operation for a request related to intentions.
 type IntentionOp string
 
@@ -123,11 +129,10 @@ type IntentionQueryRequest struct {
 	// IntentionID is the ID of a specific intention.
 	IntentionID string
 
-	// MatchBy and MatchNames are used to match a namespace/name pair
-	// to a set of intentions. The list of MatchNames is an OR list,
-	// all matching intentions are returned together.
-	MatchBy    IntentionMatchType
-	MatchNames []string
+	// Match is non-nil if we're performing a match query. A match will
+	// find intentions that "match" the given parameters. A match includes
+	// resolving wildcards.
+	Match *IntentionQueryMatch
 
 	// Options for queries
 	QueryOptions