Report count of active IP addresses in status

ipam/space/space.go

@@ -88,6 +88,14 @@ func (s *Space) Claim(addr address.Address) error {
 	return nil
 }
 
+func (s *Space) NumOwnedAddresses() address.Count {
+	res := address.Count(0)
+	for i := 0; i < len(s.ours); i += 2 {
+		res += address.Length(s.ours[i+1], s.ours[i])
+	}
+	return res
+}
+
 func (s *Space) NumFreeAddresses() address.Count {
 	res := address.Count(0)
 	for i := 0; i < len(s.free); i += 2 {

ipam/space/space_test.go

@@ -98,16 +98,19 @@ func TestSpaceAllocate(t *testing.T) {
 
 	space1 := makeSpace(start, size)
 	require.Equal(t, address.Count(20), space1.NumFreeAddresses())
+	require.Equal(t, address.Count(0), space1.NumOwnedAddresses())
 	space1.assertInvariants()
 
 	_, addr1 := space1.Allocate(address.NewRange(start, size))
 	require.Equal(t, testAddr1, addr1.String(), "address")
 	require.Equal(t, address.Count(19), space1.NumFreeAddresses())
+	require.Equal(t, address.Count(1), space1.NumOwnedAddresses())
 	space1.assertInvariants()
 
 	_, addr2 := space1.Allocate(address.NewRange(start, size))
 	require.False(t, addr2.String() == testAddr1, "address")
 	require.Equal(t, address.Count(18), space1.NumFreeAddresses())
+	require.Equal(t, address.Count(2), space1.NumOwnedAddresses())
 	require.Equal(t, address.Count(13), space1.NumFreeAddressesInRange(address.Range{Start: ip(testAddr1), End: ip(testAddrx)}))
 	require.Equal(t, address.Count(18), space1.NumFreeAddressesInRange(address.Range{Start: ip(testAddr1), End: ip(testAddry)}))
 	space1.assertInvariants()

ipam/status.go

@@ -10,6 +10,7 @@ type Status struct {
 	Paxos            *paxos.Status
 	Range            string
 	RangeNumIPs      int
+	ActiveIPs        int
 	DefaultSubnet    string
 	Entries          []EntryStatus
 	PendingClaims    []ClaimStatus
@@ -52,6 +53,7 @@ func NewStatus(allocator *Allocator, defaultSubnet address.CIDR) *Status {
 			paxosStatus,
 			allocator.universe.String(),
 			int(allocator.universe.Size()),
+			int(allocator.space.NumOwnedAddresses()),
 			defaultSubnet.String(),
 			newEntryStatusSlice(allocator),
 			newClaimStatusSlice(allocator),

prog/weaver/http.go

@@ -57,7 +57,8 @@ var rootTemplate = template.New("root").Funcs(map[string]interface{}{
 
 		// print the local info first
 		if ourStats := peerStats[router.Name]; ourStats != nil {
-			printOwned(router.Name, ourStats.nickname, "", ourStats.ips)
+			activeStr := fmt.Sprintf("(%d active)", status.ActiveIPs)
+			printOwned(router.Name, ourStats.nickname, activeStr, ourStats.ips)
 		}
 
 		// and then the rest