From 0f3f3d13cacf9da01164d5af6e9913a6be7bcfb9 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Tue, 17 Apr 2018 18:18:16 -0500
Subject: [PATCH] agent/cache-types: support intention match queries

---
 agent/cache-types/intention_match.go      | 41 ++++++++++++++++
 agent/cache-types/intention_match_test.go | 57 +++++++++++++++++++++++
 agent/structs/intention.go                | 33 +++++++++++++
 3 files changed, 131 insertions(+)
 create mode 100644 agent/cache-types/intention_match.go
 create mode 100644 agent/cache-types/intention_match_test.go

diff --git a/agent/cache-types/intention_match.go b/agent/cache-types/intention_match.go
new file mode 100644
index 0000000000..4c42725a1a
--- /dev/null
+++ b/agent/cache-types/intention_match.go
@@ -0,0 +1,41 @@
+package cachetype
+
+import (
+	"fmt"
+
+	"github.com/hashicorp/consul/agent/cache"
+	"github.com/hashicorp/consul/agent/structs"
+)
+
+// Recommended name for registration.
+const IntentionMatchName = "intention-match"
+
+// IntentionMatch supports fetching the intentions via match queries.
+type IntentionMatch struct {
+	RPC RPC
+}
+
+func (c *IntentionMatch) Fetch(opts cache.FetchOptions, req cache.Request) (cache.FetchResult, error) {
+	var result cache.FetchResult
+
+	// The request should be an IntentionQueryRequest.
+	reqReal, ok := req.(*structs.IntentionQueryRequest)
+	if !ok {
+		return result, fmt.Errorf(
+			"Internal cache failure: request wrong type: %T", req)
+	}
+
+	// Set the minimum query index to our current index so we block
+	reqReal.MinQueryIndex = opts.MinIndex
+	reqReal.MaxQueryTime = opts.Timeout
+
+	// Fetch
+	var reply structs.IndexedIntentionMatches
+	if err := c.RPC.RPC("Intention.Match", reqReal, &reply); err != nil {
+		return result, err
+	}
+
+	result.Value = &reply
+	result.Index = reply.Index
+	return result, nil
+}
diff --git a/agent/cache-types/intention_match_test.go b/agent/cache-types/intention_match_test.go
new file mode 100644
index 0000000000..97b2951b36
--- /dev/null
+++ b/agent/cache-types/intention_match_test.go
@@ -0,0 +1,57 @@
+package cachetype
+
+import (
+	"testing"
+	"time"
+
+	"github.com/hashicorp/consul/agent/cache"
+	"github.com/hashicorp/consul/agent/structs"
+	"github.com/stretchr/testify/mock"
+	"github.com/stretchr/testify/require"
+)
+
+func TestIntentionMatch(t *testing.T) {
+	require := require.New(t)
+	rpc := TestRPC(t)
+	defer rpc.AssertExpectations(t)
+	typ := &IntentionMatch{RPC: rpc}
+
+	// Expect the proper RPC call. This also sets the expected value
+	// since that is return-by-pointer in the arguments.
+	var resp *structs.IndexedIntentionMatches
+	rpc.On("RPC", "Intention.Match", mock.Anything, mock.Anything).Return(nil).
+		Run(func(args mock.Arguments) {
+			req := args.Get(1).(*structs.IntentionQueryRequest)
+			require.Equal(uint64(24), req.MinQueryIndex)
+			require.Equal(1*time.Second, req.MaxQueryTime)
+
+			reply := args.Get(2).(*structs.IndexedIntentionMatches)
+			reply.Index = 48
+			resp = reply
+		})
+
+	// Fetch
+	result, err := typ.Fetch(cache.FetchOptions{
+		MinIndex: 24,
+		Timeout:  1 * time.Second,
+	}, &structs.IntentionQueryRequest{Datacenter: "dc1"})
+	require.Nil(err)
+	require.Equal(cache.FetchResult{
+		Value: resp,
+		Index: 48,
+	}, result)
+}
+
+func TestIntentionMatch_badReqType(t *testing.T) {
+	require := require.New(t)
+	rpc := TestRPC(t)
+	defer rpc.AssertExpectations(t)
+	typ := &IntentionMatch{RPC: rpc}
+
+	// Fetch
+	_, err := typ.Fetch(cache.FetchOptions{}, cache.TestRequest(
+		t, cache.RequestInfo{Key: "foo", MinIndex: 64}))
+	require.NotNil(err)
+	require.Contains(err.Error(), "wrong type")
+
+}
diff --git a/agent/structs/intention.go b/agent/structs/intention.go
index 316c9632b0..6ad1a98359 100644
--- a/agent/structs/intention.go
+++ b/agent/structs/intention.go
@@ -2,10 +2,13 @@ package structs
 
 import (
 	"fmt"
+	"strconv"
 	"strings"
 	"time"
 
+	"github.com/hashicorp/consul/agent/cache"
 	"github.com/hashicorp/go-multierror"
+	"github.com/mitchellh/hashstructure"
 )
 
 const (
@@ -267,6 +270,36 @@ func (q *IntentionQueryRequest) RequestDatacenter() string {
 	return q.Datacenter
 }
 
+// cache.Request impl.
+func (q *IntentionQueryRequest) CacheInfo() cache.RequestInfo {
+	// We only support caching Match queries, so if Match isn't set,
+	// then return an empty info object which will cause a pass-through
+	// (and likely fail).
+	if q.Match == nil {
+		return cache.RequestInfo{}
+	}
+
+	info := cache.RequestInfo{
+		Token:      q.Token,
+		Datacenter: q.Datacenter,
+		MinIndex:   q.MinQueryIndex,
+		Timeout:    q.MaxQueryTime,
+	}
+
+	// Calculate the cache key via just hashing the Match struct. This
+	// has been configured so things like ordering of entries has no
+	// effect (via struct tags).
+	v, err := hashstructure.Hash(q.Match, nil)
+	if err == nil {
+		// If there is an error, we don't set the key. A blank key forces
+		// no cache for this request so the request is forwarded directly
+		// to the server.
+		info.Key = strconv.FormatUint(v, 10)
+	}
+
+	return info
+}
+
 // IntentionQueryMatch are the parameters for performing a match request
 // against the state store.
 type IntentionQueryMatch struct {