Add netlable. KeyValue() and ToMap()

Signed-off-by: Alessandro Boch <aboch@docker.com>

libnetwork/netlabel/labels.go

@@ -1,6 +1,9 @@
 package netlabel
 
-import "strings"
+import (
+	"fmt"
+	"strings"
+)
 
 const (
 	// Prefix constant marks the reserved label space for libnetwork
@@ -22,7 +25,7 @@ const (
 	// MacAddress constant represents Mac Address config of a Container
 	MacAddress = Prefix + ".endpoint.macaddress"
 
-	// ExposedPorts constant represents exposedports of a Container
+	// ExposedPorts constant represents the container's Exposed Ports
 	ExposedPorts = Prefix + ".endpoint.exposedports"
 
 	//EnableIPv6 constant represents enabling IPV6 at network level
@@ -86,3 +89,23 @@ func Value(label string) string {
 
 	return kv[1]
 }
+
+// KeyValue decomposes the label in the (key,value) pair
+func KeyValue(label string) (string, string, error) {
+	kv := strings.SplitN(label, "=", 2)
+	if len(kv) != 2 {
+		return "", "", fmt.Errorf("invalid label: %s", label)
+	}
+	return kv[0], kv[1], nil
+}
+
+// ToMap converts a list of labels in amap of (key,value) pairs
+func ToMap(labels []string) map[string]string {
+	m := make(map[string]string, len(labels))
+	for _, l := range labels {
+		if k, v, err := KeyValue(l); err == nil {
+			m[k] = v
+		}
+	}
+	return m
+}

libnetwork/netlabel/labels_test.go

@@ -0,0 +1,69 @@
+package netlabel
+
+import (
+	"testing"
+
+	_ "github.com/docker/libnetwork/testutils"
+)
+
+func TestKeyValue(t *testing.T) {
+	input := []struct {
+		label string
+		key   string
+		value string
+		good  bool
+	}{
+		{"name=joe", "name", "joe", true},
+		{"age=24", "age", "24", true},
+		{"address:1234 First st.", "", "", false},
+		{"girlfriend=", "girlfriend", "", true},
+		{"nickname=o=u=8", "nickname", "o=u=8", true},
+		{"", "", "", false},
+	}
+
+	for _, i := range input {
+		k, v, err := KeyValue(i.label)
+		if k != i.key || v != i.value || i.good != (err == nil) {
+			t.Fatalf("unexpected: %s, %s, %v", k, v, err)
+		}
+	}
+}
+
+func TestToMap(t *testing.T) {
+	input := []struct {
+		label string
+		key   string
+		value string
+		good  bool
+	}{
+		{"name=joe", "name", "joe", true},
+		{"age=24", "age", "24", true},
+		{"address:1234 First st.", "", "", false},
+		{"girlfriend=", "girlfriend", "", true},
+		{"nickname=o=u=8", "nickname", "o=u=8", true},
+		{"", "", "", false},
+	}
+
+	lista := make([]string, len(input))
+	for ind, i := range input {
+		lista[ind] = i.label
+	}
+
+	mappa := ToMap(lista)
+
+	if len(mappa) != len(lista)-2 {
+		t.Fatalf("Incorrect map length. Expected %d. Got %d", len(lista), len(mappa))
+	}
+
+	for _, i := range input {
+		if i.good {
+			if v, ok := mappa[i.key]; !ok || v != i.value {
+				t.Fatalf("Cannot find key or value for key: %s", i.key)
+			}
+		} else {
+			if _, ok := mappa[i.key]; ok {
+				t.Fatalf("Found invalid key in map: %s", i.key)
+			}
+		}
+	}
+}