Unit tests for the zone lookups and names updates

nameserver/zone_lookup_test.go

@@ -0,0 +1,114 @@
+package nameserver
+
+import (
+	"github.com/benbjohnson/clock"
+	. "github.com/weaveworks/weave/common"
+	wt "github.com/weaveworks/weave/testing"
+	"net"
+	"testing"
+	"time"
+)
+
+// Check that the refreshing mechanism works as expected
+func TestZoneRefresh(t *testing.T) {
+	const (
+		refreshInterval = 5
+		relevantTime    = 30
+	)
+	var (
+		name  = "mysql.weave.local."
+		addr1 = "10.2.8.4"
+		addr2 = "10.2.8.5"
+		addr3 = "10.2.8.6"
+		addr4 = "10.2.8.7"
+	)
+
+	InitDefaultLogging(testing.Verbose())
+	Info.Println("TestZoneRefresh starting")
+
+	clk := clock.NewMock()
+	forwardClock := func(secs int) {
+		Debug.Printf(">>>>>>> Moving clock forward %d seconds - Time traveling >>>>>>>", secs)
+		clk.Add(time.Duration(secs) * time.Second)
+		Debug.Printf("<<<<<<< Time travel finished! We are at %s <<<<<<<", clk.Now())
+	}
+
+	// Create multiple zone databases, linked through mocked mDNS connections
+	zc := ZoneConfig{
+		RefreshInterval: refreshInterval,
+		RelevantTime:    relevantTime,
+		Clock:           clk,
+	}
+	dbs := newZoneDbsWithMockedMDns(2, zc)
+	dbs.Start()
+	defer dbs.Stop()
+
+	time.Sleep(100 * time.Millisecond) // allow for server to get going
+
+	Debug.Printf("Adding '%s' to Db #1", name)
+	dbs[0].Zone.AddRecord("someident", name, net.ParseIP(addr1))
+
+	Debug.Printf("Checking that the name %s is relevant (as it has been locally inserted) and not remote", name)
+	wt.AssertTrue(t, dbs[0].Zone.IsNameRelevant(name), "name relevant")
+	wt.AssertTrue(t, dbs[0].Zone.HasNameLocalInfo(name), "local name info")
+	wt.AssertFalse(t, dbs[0].Zone.HasNameRemoteInfo(name), "remote name info")
+
+	Debug.Printf("Asking for '%s' to Db #1: should get 1 IP from the local database...", name)
+	res, err := dbs[0].Zone.DomainLookupName(name)
+	wt.AssertNoErr(t, err)
+	Debug.Printf("Got: %s", res)
+	t.Logf("Db #1 after the lookup:\n%s", dbs[0].Zone)
+	wt.AssertEqualInt(t, len(res), 1, "lookup result")
+
+	forwardClock(refreshInterval / 2)
+	Debug.Printf("A couple of seconds later, we should still have one IP for that name")
+	res, err = dbs[0].Zone.DomainLookupName(name)
+	wt.AssertNoErr(t, err)
+	wt.AssertEqualInt(t, len(res), 1, "lookup result")
+
+	Debug.Printf("And then we add 2 IPs for that name at ZoneDb 2")
+	forwardClock(1)
+	Debug.Printf("Adding 2 IPs to '%s' in Db #2", name)
+	dbs[1].Zone.AddRecord("someident", name, net.ParseIP(addr2))
+	dbs[1].Zone.AddRecord("someident", name, net.ParseIP(addr3))
+
+	Debug.Printf("Perform a lookup, to ensure the name will be updated in the background...")
+	dbs[0].Zone.DomainLookupName(name)
+
+	Debug.Printf("Wait for a while, until a refresh is performed...")
+	forwardClock(refreshInterval + 1)
+
+	Debug.Printf("A refresh should have been scheduled now: we should have 3 IPs:")
+	Debug.Printf("the first (local) IP and the others obtained from zone2 with a mDNS query")
+	Debug.Printf("Asking for '%s' again... we should have 3 IPs now", name)
+	res, err = dbs[0].Zone.DomainLookupName(name)
+	Debug.Printf("Got: %s", res)
+	t.Logf("Db #1 after the second lookup:\n%s", dbs[0].Zone)
+	wt.AssertEqualInt(t, len(res), 3, "lookup result length")
+
+	Debug.Printf("We will not ask for `name` for a while, so it will become irrelevant and will be removed...")
+	forwardClock(relevantTime + refreshInterval + 1)
+
+	// the name should be irrelevant now, and all remote info should have been
+	// removed from the zone database
+	Debug.Printf("Name '%s' should not be in the remote database in ZoneDb 1", name)
+	wt.AssertFalse(t, dbs[0].Zone.IsNameRelevant(name), "name still relevant after some inactivity time")
+	wt.AssertTrue(t, dbs[0].Zone.HasNameLocalInfo(name), "local name info")
+	wt.AssertFalse(t, dbs[0].Zone.HasNameRemoteInfo(name), "remote name info")
+
+	Debug.Printf("There is no remote info about this name at zone 1: a new IP appears remotely meanwhile...")
+	forwardClock(1)
+	Debug.Printf("Adding '%s' to Db #2", name)
+	dbs[1].Zone.AddRecord("someident", name, net.ParseIP(addr4))
+
+	Debug.Printf("When we ask about this name again, we get 4 IPs (1 local, 3 remote)")
+	forwardClock(1)
+	Debug.Printf("Asking for '%s' again... the first lookup will return only the local results", name)
+	res, err = dbs[0].Zone.DomainLookupName(name)
+	wt.AssertEqualInt(t, len(res), 1, "lookup result length")
+	Debug.Printf("... but a second lookup should return all the results in the network")
+	forwardClock(1)
+	res, err = dbs[0].Zone.DomainLookupName(name)
+	Debug.Printf("Got: %s", res)
+	wt.AssertEqualInt(t, len(res), 4, "lookup result length") // TODO: this fails 1% of the runs... !!??
+}