Move in code from netconf and docker-from-scratch

netconf/bridge.go

@@ -0,0 +1,48 @@
+package netconf
+
+import (
+	"fmt"
+
+	"github.com/vishvananda/netlink"
+)
+
+type Bridge struct {
+	name string
+}
+
+func NewBridge(name string) (*Bridge, error) {
+	b := &Bridge{name: name}
+	return b, b.init()
+}
+
+func (b *Bridge) init() error {
+	link, err := netlink.LinkByName(b.name)
+	if err == nil {
+		if _, ok := link.(*netlink.Bridge); !ok {
+			return fmt.Errorf("%s is not a bridge device", b.name)
+		}
+		return nil
+	}
+
+	bridge := netlink.Bridge{}
+	bridge.LinkAttrs.Name = b.name
+
+	return netlink.LinkAdd(&bridge)
+}
+
+func (b *Bridge) AddLink(link netlink.Link) error {
+	existing, err := netlink.LinkByName(b.name)
+	if err != nil {
+		return err
+	}
+
+	if bridge, ok := existing.(*netlink.Bridge); ok {
+		if link.Attrs().MasterIndex != bridge.Index {
+			return netlink.LinkSetMaster(link, bridge)
+		}
+	} else {
+		return fmt.Errorf("%s is not a bridge", b.name)
+	}
+
+	return nil
+}