Merge pull request #1195 from weaveworks/1177-dns-disappear

Don't periodically delete all non-tombstone entries.

Fixes #1177.

nameserver/entry.go

@@ -131,6 +131,7 @@ func (es *Entries) merge(incoming Entries) Entries {
 	return newEntries
 }
 
+// f returning true means keep the entry.
 func (es *Entries) tombstone(ourname router.PeerName, f func(*Entry) bool) Entries {
 	es.checkAndPanic()
 	defer es.checkAndPanic()

nameserver/http.go

@@ -1,6 +1,7 @@
 package nameserver
 
 import (
+	"encoding/json"
 	"fmt"
 	"net/http"
 
@@ -82,4 +83,12 @@ func (n *Nameserver) HandleHTTP(router *mux.Router) {
 	router.Methods("DELETE").Path("/name/{container}/{ip}").HandlerFunc(deleteHandler)
 	router.Methods("DELETE").Path("/name/{container}").HandlerFunc(deleteHandler)
 	router.Methods("DELETE").Path("/name").HandlerFunc(deleteHandler)
+
+	router.Methods("GET").Path("/name").Headers("Accept", "application/json").HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		n.RLock()
+		defer n.RUnlock()
+		if err := json.NewEncoder(w).Encode(n.entries); err != nil {
+			badRequest(w, fmt.Errorf("Error marshalling response: %v", err))
+		}
+	})
 }

nameserver/nameserver.go

@@ -176,7 +176,7 @@ func (n *Nameserver) deleteTombstones() {
 	defer n.Unlock()
 	now := time.Now().Unix()
 	n.entries.filter(func(e *Entry) bool {
-		return now-e.Tombstone <= int64(tombstoneTimeout/time.Second)
+		return e.Tombstone == 0 || now-e.Tombstone <= int64(tombstoneTimeout/time.Second)
 	})
 }
 

nameserver/nameserver_test.go

@@ -230,6 +230,9 @@ func TestTombstoneDeletion(t *testing.T) {
 	require.Nil(t, err)
 	require.Equal(t, []address.Address{0}, nameserver.Lookup("hostname"))
 
+	nameserver.deleteTombstones()
+	require.Equal(t, []address.Address{0}, nameserver.Lookup("hostname"))
+
 	err = nameserver.Delete("hostname", "containerid", "", address.Address(0))
 	require.Nil(t, err)
 	require.Equal(t, []address.Address{}, nameserver.Lookup("hostname"))

net/address/address.go

@@ -90,6 +90,10 @@ func (addr Address) IP4() (r net.IP) {
 	return
 }
 
+func (addr Address) MarshalJSON() ([]byte, error) {
+	return []byte(fmt.Sprintf("%q", addr.String())), nil
+}
+
 func (addr Address) String() string {
 	return addr.IP4().String()
 }