Move address range helpers into address package

This means that users don't drag in a dependency on aws-sdk.

ipam/tracker/awsvpc.go

@@ -84,7 +84,7 @@ func NewAWSVPCTracker(bridgeName string) (*AWSVPCTracker, error) {
 func (t *AWSVPCTracker) HandleUpdate(prevRanges, currRanges []address.Range, local bool) error {
 	t.debugf("replacing %q by %q; local(%t)", prevRanges, currRanges, local)
 
-	prev, curr := RemoveCommon(address.NewCIDRs(Merge(prevRanges)), address.NewCIDRs(Merge(currRanges)))
+	prev, curr := address.RemoveCommon(address.NewCIDRs(address.Merge(prevRanges)), address.NewCIDRs(address.Merge(currRanges)))
 
 	// It might make sense to do the removal first and then add entries
 	// because of the 50 routes limit. However, in such case a container might

ipam/tracker/helpers.go → net/address/helpers.go

@@ -1,13 +1,9 @@
-package tracker
-
-import (
-	"github.com/weaveworks/weave/net/address"
-)
+package address
 
 // Merge merges adjacent range entries.
 // The given slice has to be sorted in increasing order.
-func Merge(r []address.Range) []address.Range {
-	var merged []address.Range
+func Merge(r []Range) []Range {
+	var merged []Range
 
 	for i := range r {
 		if prev := len(merged) - 1; prev >= 0 && merged[prev].End == r[i].Start {
@@ -22,7 +18,7 @@ func Merge(r []address.Range) []address.Range {
 
 // RemoveCommon filters out CIDR ranges which are contained in both a and b slices.
 // Both slices have to be sorted in increasing order.
-func RemoveCommon(a, b []address.CIDR) (newA, newB []address.CIDR) {
+func RemoveCommon(a, b []CIDR) (newA, newB []CIDR) {
 	i, j := 0, 0
 
 	for i < len(a) && j < len(b) {

net/address/helpers_test.go

@@ -0,0 +1,43 @@
+package address
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+var (
+	r0to127     = cidr2("10.0.0.0", "10.0.0.127")
+	r128to255   = cidr2("10.0.0.128", "10.0.0.255")
+	r0to255     = cidr2("10.0.0.0", "10.0.0.255")
+	r1dot0to255 = cidr2("10.0.1.0", "10.0.1.255")
+	r2dot0to255 = cidr2("10.0.2.0", "10.0.2.255")
+)
+
+func TestRemoveCommon(t *testing.T) {
+	a := []CIDR{r0to127, r1dot0to255}
+	b := []CIDR{r1dot0to255, r2dot0to255}
+	newA, newB := RemoveCommon(a, b)
+	require.Equal(t, []CIDR{r0to127}, newA)
+	require.Equal(t, []CIDR{r2dot0to255}, newB)
+}
+
+func TestMerge(t *testing.T) {
+	ranges := []Range{
+		r0to127.Range(),
+		r128to255.Range(),
+		r2dot0to255.Range(),
+	}
+	require.Equal(t, []Range{r0to255.Range(), r2dot0to255.Range()}, Merge(ranges))
+}
+
+// Helper
+
+// [start; end]
+func cidr2(start, end string) CIDR {
+	c := Range{Start: ip(start), End: ip(end) + 1}.CIDRs()
+	if len(c) != 1 {
+		panic("invalid cidr")
+	}
+	return c[0]
+}

net/bridge.go

@@ -15,7 +15,6 @@ import (
 	"github.com/weaveworks/weave/common"
 	"github.com/weaveworks/weave/common/chains"
 	"github.com/weaveworks/weave/common/odp"
-	"github.com/weaveworks/weave/ipam/tracker"
 	"github.com/weaveworks/weave/net/address"
 	"github.com/weaveworks/weave/net/ipset"
 )
@@ -565,9 +564,9 @@ func (t *NoMasqLocalTracker) HandleUpdate(prevRanges, currRanges []address.Range
 		return nil
 	}
 
-	prev, curr := tracker.RemoveCommon(
-		address.NewCIDRs(tracker.Merge(prevRanges)),
-		address.NewCIDRs(tracker.Merge(currRanges)))
+	prev, curr := address.RemoveCommon(
+		address.NewCIDRs(address.Merge(prevRanges)),
+		address.NewCIDRs(address.Merge(currRanges)))
 
 	for _, cidr := range curr {
 		if err := t.ips.AddEntry(t.owner, NoMasqLocalIpset, cidr.String(), ""); err != nil {