chore(errors): review all errors in codebase

internal/routing/local.go

@@ -9,7 +9,6 @@ import (
 )
 
 var (
-	ErrLinkList              = errors.New("cannot list links")
 	ErrLinkLocalNotFound     = errors.New("local link not found")
 	ErrSubnetDefaultNotFound = errors.New("default subnet not found")
 	ErrSubnetLocalNotFound   = errors.New("local subnet not found")
@@ -28,7 +27,7 @@ type LocalSubnetGetter interface {
 func (r *Routing) LocalSubnet() (defaultSubnet net.IPNet, err error) {
 	routes, err := r.netLinker.RouteList(nil, netlink.FAMILY_ALL)
 	if err != nil {
-		return defaultSubnet, fmt.Errorf("%w: %s", ErrRoutesList, err)
+		return defaultSubnet, fmt.Errorf("cannot list routes: %w", err)
 	}
 
 	defaultLinkIndex := -1
@@ -61,7 +60,7 @@ type LocalNetworksGetter interface {
 func (r *Routing) LocalNetworks() (localNetworks []LocalNetwork, err error) {
 	links, err := r.netLinker.LinkList()
 	if err != nil {
-		return localNetworks, fmt.Errorf("%w: %s", ErrLinkList, err)
+		return localNetworks, fmt.Errorf("cannot list links: %w", err)
 	}
 
 	localLinks := make(map[int]struct{})
@@ -81,7 +80,7 @@ func (r *Routing) LocalNetworks() (localNetworks []LocalNetwork, err error) {
 
 	routes, err := r.netLinker.RouteList(nil, netlink.FAMILY_V4)
 	if err != nil {
-		return localNetworks, fmt.Errorf("%w: %s", ErrRoutesList, err)
+		return localNetworks, fmt.Errorf("cannot list routes: %w", err)
 	}
 
 	for _, route := range routes {
@@ -98,7 +97,7 @@ func (r *Routing) LocalNetworks() (localNetworks []LocalNetwork, err error) {
 
 		link, err := r.netLinker.LinkByIndex(route.LinkIndex)
 		if err != nil {
-			return localNetworks, fmt.Errorf("%w: at index %d: %s", ErrLinkByIndex, route.LinkIndex, err)
+			return localNetworks, fmt.Errorf("cannot find link at index %d: %w", route.LinkIndex, err)
 		}
 
 		localNet.InterfaceName = link.Attrs().Name