libct/cg/devices: stop using pkg/errors

Use Go native errors wrapping.

Introduce wrapErr helper to minimise the patch size.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

libcontainer/cgroups/devices/devices_emulator.go

@@ -22,14 +22,14 @@ package devices
 
 import (
 	"bufio"
+	"errors"
+	"fmt"
 	"io"
 	"regexp"
 	"sort"
 	"strconv"
 
 	"github.com/opencontainers/runc/libcontainer/devices"
-
-	"github.com/pkg/errors"
 )
 
 // deviceMeta is a Rule without the Allow or Permissions fields, and no
@@ -84,7 +84,7 @@ var devicesListRegexp = regexp.MustCompile(`^([abc])\s+(\d+|\*):(\d+|\*)\s+([rwm
 func parseLine(line string) (*deviceRule, error) {
 	matches := devicesListRegexp.FindStringSubmatch(line)
 	if matches == nil {
-		return nil, errors.Errorf("line doesn't match devices.list format")
+		return nil, errors.New("line doesn't match devices.list format")
 	}
 	var (
 		rule  deviceRule
@@ -108,7 +108,7 @@ func parseLine(line string) (*deviceRule, error) {
 		rule.meta.node = devices.CharDevice
 	default:
 		// Should never happen!
-		return nil, errors.Errorf("unknown device type %q", node)
+		return nil, fmt.Errorf("unknown device type %q", node)
 	}
 
 	// Parse the major number.
@@ -117,7 +117,7 @@ func parseLine(line string) (*deviceRule, error) {
 	} else {
 		val, err := strconv.ParseUint(major, 10, 32)
 		if err != nil {
-			return nil, errors.Wrap(err, "parse major number")
+			return nil, fmt.Errorf("invalid major number: %w", err)
 		}
 		rule.meta.major = int64(val)
 	}
@@ -128,7 +128,7 @@ func parseLine(line string) (*deviceRule, error) {
 	} else {
 		val, err := strconv.ParseUint(minor, 10, 32)
 		if err != nil {
-			return nil, errors.Wrap(err, "parse minor number")
+			return nil, fmt.Errorf("invalid minor number: %w", err)
 		}
 		rule.meta.minor = int64(val)
 	}
@@ -137,7 +137,7 @@ func parseLine(line string) (*deviceRule, error) {
 	rule.perms = devices.Permissions(perms)
 	if !rule.perms.IsValid() || rule.perms.IsEmpty() {
 		// Should never happen!
-		return nil, errors.Errorf("parse access mode: contained unknown modes or is empty: %q", perms)
+		return nil, fmt.Errorf("parse access mode: contained unknown modes or is empty: %q", perms)
 	}
 	return &rule, nil
 }
@@ -180,7 +180,7 @@ func (e *Emulator) rmRule(rule deviceRule) error {
 		// Only give an error if the set of permissions overlap.
 		partialPerms := e.rules[partialMeta]
 		if !partialPerms.Intersection(rule.perms).IsEmpty() {
-			return errors.Errorf("requested rule [%v %v] not supported by devices cgroupv1 (cannot punch hole in existing wildcard rule [%v %v])", rule.meta, rule.perms, partialMeta, partialPerms)
+			return fmt.Errorf("requested rule [%v %v] not supported by devices cgroupv1 (cannot punch hole in existing wildcard rule [%v %v])", rule.meta, rule.perms, partialMeta, partialPerms)
 		}
 	}
 
@@ -212,9 +212,9 @@ func (e *Emulator) allow(rule *deviceRule) error {
 
 	var err error
 	if e.defaultAllow {
-		err = errors.Wrap(e.rmRule(*rule), "remove 'deny' exception")
+		err = wrapErr(e.rmRule(*rule), "unable to remove 'deny' exception")
 	} else {
-		err = errors.Wrap(e.addRule(*rule), "add 'allow' exception")
+		err = wrapErr(e.addRule(*rule), "unable to add 'allow' exception")
 	}
 	return err
 }
@@ -232,16 +232,16 @@ func (e *Emulator) deny(rule *deviceRule) error {
 
 	var err error
 	if e.defaultAllow {
-		err = errors.Wrap(e.addRule(*rule), "add 'deny' exception")
+		err = wrapErr(e.addRule(*rule), "unable to add 'deny' exception")
 	} else {
-		err = errors.Wrap(e.rmRule(*rule), "remove 'allow' exception")
+		err = wrapErr(e.rmRule(*rule), "unable to remove 'allow' exception")
 	}
 	return err
 }
 
 func (e *Emulator) Apply(rule devices.Rule) error {
 	if !rule.Type.CanCgroup() {
-		return errors.Errorf("cannot add rule [%#v] with non-cgroup type %q", rule, rule.Type)
+		return fmt.Errorf("cannot add rule [%#v] with non-cgroup type %q", rule, rule.Type)
 	}
 
 	innerRule := &deviceRule{
@@ -283,17 +283,17 @@ func EmulatorFromList(list io.Reader) (*Emulator, error) {
 		line := s.Text()
 		deviceRule, err := parseLine(line)
 		if err != nil {
-			return nil, errors.Wrapf(err, "parsing line %q", line)
+			return nil, fmt.Errorf("error parsing line %q: %w", line, err)
 		}
 		// "devices.list" is an allow list. Note that this means that in
 		// black-list mode, we have no idea what rules are in play. As a
 		// result, we need to be very careful in Transition().
 		if err := e.allow(deviceRule); err != nil {
-			return nil, errors.Wrapf(err, "adding devices.list rule")
+			return nil, fmt.Errorf("error adding devices.list rule: %w", err)
 		}
 	}
 	if err := s.Err(); err != nil {
-		return nil, errors.Wrap(err, "reading devices.list lines")
+		return nil, fmt.Errorf("error reading devices.list lines: %w", err)
 	}
 	return e, nil
 }
@@ -380,3 +380,10 @@ func (e *Emulator) Rules() ([]*devices.Rule, error) {
 	defaultCgroup := &Emulator{defaultAllow: false}
 	return defaultCgroup.Transition(e)
 }
+
+func wrapErr(err error, text string) error {
+	if err == nil {
+		return nil
+	}
+	return fmt.Errorf(text+": %w", err)
+}