Added utility on router to fetch mount entry using its ID

vault/router.go

@@ -14,9 +14,10 @@ import (
 
 // Router is used to do prefix based routing of a request to a logical backend
 type Router struct {
-	l              sync.RWMutex
-	root           *radix.Tree
-	tokenStoreSalt *salt.Salt
+	l               sync.RWMutex
+	root            *radix.Tree
+	mountEntryCache *radix.Tree
+	tokenStoreSalt  *salt.Salt
 
 	// storagePrefix maps the prefix used for storage (ala the BarrierView)
 	// to the backend. This is used to map a key back into the backend that owns it.
@@ -27,8 +28,9 @@ type Router struct {
 // NewRouter returns a new router
 func NewRouter() *Router {
 	r := &Router{
-		root:          radix.New(),
-		storagePrefix: radix.New(),
+		root:            radix.New(),
+		storagePrefix:   radix.New(),
+		mountEntryCache: radix.New(),
 	}
 	return r
 }
@@ -74,8 +76,10 @@ func (r *Router) Mount(backend logical.Backend, prefix string, mountEntry *Mount
 		rootPaths:   pathsToRadix(paths.Root),
 		loginPaths:  pathsToRadix(paths.Unauthenticated),
 	}
+
 	r.root.Insert(prefix, re)
 	r.storagePrefix.Insert(storageView.prefix, re)
+	r.mountEntryCache.Insert(re.mountEntry.UUID, re.mountEntry)
 
 	return nil
 }
@@ -98,6 +102,8 @@ func (r *Router) Unmount(prefix string) error {
 	// Purge from the radix trees
 	r.root.Delete(prefix)
 	r.storagePrefix.Delete(re.storageView.prefix)
+	r.mountEntryCache.Delete(re.mountEntry.UUID)
+
 	return nil
 }
 
@@ -141,6 +147,22 @@ func (r *Router) Untaint(path string) error {
 	return nil
 }
 
+func (r *Router) MatchingMountByID(mountID string) *MountEntry {
+	if mountID == "" {
+		return nil
+	}
+
+	r.l.RLock()
+	defer r.l.RUnlock()
+
+	_, raw, ok := r.mountEntryCache.LongestPrefix(mountID)
+	if !ok {
+		return nil
+	}
+
+	return raw.(*MountEntry)
+}
+
 // MatchingMount returns the mount prefix that would be used for a path
 func (r *Router) MatchingMount(path string) string {
 	r.l.RLock()

vault/router_test.go

@@ -2,6 +2,7 @@ package vault
 
 import (
 	"fmt"
+	"reflect"
 	"strings"
 	"sync"
 	"testing"
@@ -75,8 +76,14 @@ func TestRouter_Mount(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+
+	mountEntry := &MountEntry{
+		Path: "prod/aws/",
+		UUID: meUUID,
+	}
+
 	n := &NoopBackend{}
-	err = r.Mount(n, "prod/aws/", &MountEntry{Path: "prod/aws/", UUID: meUUID}, view)
+	err = r.Mount(n, "prod/aws/", mountEntry, view)
 	if err != nil {
 		t.Fatalf("err: %v", err)
 	}
@@ -85,6 +92,7 @@ func TestRouter_Mount(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+
 	err = r.Mount(n, "prod/aws/", &MountEntry{UUID: meUUID}, view)
 	if !strings.Contains(err.Error(), "cannot mount under existing mount") {
 		t.Fatalf("err: %v", err)
@@ -106,6 +114,11 @@ func TestRouter_Mount(t *testing.T) {
 		t.Fatalf("bad: %v", v)
 	}
 
+	mountEntryFetched := r.MatchingMountByID(mountEntry.UUID)
+	if mountEntryFetched == nil || !reflect.DeepEqual(mountEntry, mountEntryFetched) {
+		t.Fatalf("failed to fetch mount entry using its ID; mountEntry: %#v\n mountEntryFetched: %#v\n", mountEntry, mountEntryFetched)
+	}
+
 	mount, prefix, ok := r.MatchingStoragePrefix("logical/foo")
 	if !ok {
 		t.Fatalf("missing storage prefix")