Allow multiple routes to be added for the same prefix.

Enables ECMP

Signed-off-by: Michael Cambria <[email protected]>

go.sum

@@ -515,8 +515,6 @@ github.com/urfave/cli v1.22.1/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtX
 github.com/urfave/cli v1.22.2/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtXRu0=
 github.com/vishvananda/netlink v0.0.0-20181108222139-023a6dafdcdf/go.mod h1:+SR5DhBJrl6ZM7CoCKvpw5BKroDKQ+PJqOg65H/2ktk=
 github.com/vishvananda/netlink v1.1.0/go.mod h1:cTgwzPIzzgDAYoQrMm0EdrjRUBkTqKYppBueQtXaqoE=
-github.com/vishvananda/netlink v1.1.1-0.20201029203352-d40f9887b852 h1:cPXZWzzG0NllBLdjWoD1nDfaqu98YMv+OneaKc8sPOA=
-github.com/vishvananda/netlink v1.1.1-0.20201029203352-d40f9887b852/go.mod h1:twkDnbuQxJYemMlGd4JFIcuhgX83tXhKS2B/PRMpOho=
 github.com/vishvananda/netlink v1.1.1-0.20210330154013-f5de75959ad5 h1:+UB2BJA852UkGH42H+Oee69djmxS3ANzl2b/JtT1YiA=
 github.com/vishvananda/netlink v1.1.1-0.20210330154013-f5de75959ad5/go.mod h1:twkDnbuQxJYemMlGd4JFIcuhgX83tXhKS2B/PRMpOho=
 github.com/vishvananda/netns v0.0.0-20180720170159-13995c7128cc/go.mod h1:ZjcWmFBXmLKZu9Nxj3WKYEafiSqer2rnvPr0en9UNpI=

pkg/ipam/ipam_linux.go

@@ -113,11 +113,14 @@ func ConfigureIface(ifName string, res *current.Result) error {
 				gw = v6gw
 			}
 		}
-		if err = ip.AddRoute(&r.Dst, gw, link); err != nil {
-			// we skip over duplicate routes as we assume the first one wins
-			if !os.IsExist(err) {
-				return fmt.Errorf("failed to add route '%v via %v dev %v': %v", r.Dst, gw, ifName, err)
-			}
+		route := netlink.Route{
+			Dst:       &r.Dst,
+			LinkIndex: link.Attrs().Index,
+			Gw:        gw,
+		}
+
+		if err = netlink.RouteAddEcmp(&route); err != nil {
+			return fmt.Errorf("failed to add route '%v via %v dev %v': %v", r.Dst, gw, ifName, err)
 		}
 	}