*: use errors.Is/errors.As to handle wrapped error checking

Enable golangci-lint errorlint linter to check proper use of errors.Is
and error.As instead of direct comparison or error type casting.

.golangci.yml

@@ -0,0 +1,2 @@
+linters:
+  enable: errorlint

cmd/agola/cmd/directrunstart.go

@@ -97,7 +97,7 @@ func directRunStart(cmd *cobra.Command, args []string) error {
 
 	for _, res := range directRunStartOpts.prRefRegexes {
 		if _, err := regexp.Compile(res); err != nil {
-			return fmt.Errorf("wrong regular expression %q: %v", res, err)
+			return fmt.Errorf("wrong regular expression %q: %w", res, err)
 		}
 	}
 
@@ -145,7 +145,7 @@ func directRunStart(cmd *cobra.Command, args []string) error {
 		}
 
 		if err := yaml.Unmarshal(data, &variables); err != nil {
-			return errors.Errorf("failed to unmarshal values: %v", err)
+			return errors.Errorf("failed to unmarshal values: %w", err)
 		}
 
 		// TODO(sgotti) validate variable name
@@ -165,7 +165,7 @@ func directRunStart(cmd *cobra.Command, args []string) error {
 	if repoUUID == "" {
 		repoUUID = uuid.Must(uuid.NewV4()).String()
 		if _, err := git.ConfigSet(context.Background(), "agola.repouuid", repoUUID); err != nil {
-			return fmt.Errorf("failed to set agola repo uid in git config: %v", err)
+			return fmt.Errorf("failed to set agola repo uid in git config: %w", err)
 		}
 	}
 

cmd/toolbox/cmd/sleeper.go

@@ -15,6 +15,7 @@
 package cmd
 
 import (
+	"errors"
 	"os"
 	"os/signal"
 	"syscall"
@@ -41,7 +42,7 @@ func childsReaper() {
 		for range sigs {
 			for {
 				var wstatus syscall.WaitStatus
-				if _, err := syscall.Wait4(-1, &wstatus, syscall.WNOHANG|syscall.WUNTRACED|syscall.WCONTINUED, nil); err == syscall.EINTR {
+				if _, err := syscall.Wait4(-1, &wstatus, syscall.WNOHANG|syscall.WUNTRACED|syscall.WCONTINUED, nil); errors.Is(err, syscall.EINTR) {
 					continue
 				}
 				break

internal/config/config_test.go

@@ -207,7 +207,8 @@ func TestParseConfig(t *testing.T) {
 				if tt.err == nil {
 					t.Fatalf("got error: %v, expected no error", err)
 				}
-				if errs, ok := err.(*util.Errors); ok {
+				var errs *util.Errors
+				if errors.As(err, &errs) {
 					if !errs.Equal(tt.err) {
 						t.Fatalf("got error: %v, want error: %v", err, tt.err)
 					}

internal/datamanager/changes.go

@@ -143,7 +143,7 @@ func (d *DataManager) applyWalChanges(ctx context.Context, walData *WalData, rev
 		var action *Action
 
 		err := dec.Decode(&action)
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			// all done
 			break
 		}
@@ -261,7 +261,7 @@ func (d *DataManager) watcher(ctx context.Context) error {
 	for wresp := range wch {
 		if wresp.Canceled {
 			err := wresp.Err()
-			if err == etcdclientv3rpc.ErrCompacted {
+			if errors.Is(err, etcdclientv3rpc.ErrCompacted) {
 				d.log.Errorf("required events already compacted, reinitializing watcher changes")
 				d.changes.Lock()
 				d.changes.initialized = false

internal/datamanager/data.go

@@ -111,7 +111,7 @@ func (d *DataManager) walIndex(ctx context.Context, wals []*WalData) (walIndex,
 			var action *Action
 
 			err := dec.Decode(&action)
-			if err == io.EOF {
+			if errors.Is(err, io.EOF) {
 				// all done
 				break
 			}
@@ -349,7 +349,7 @@ func (d *DataManager) writeDataType(ctx context.Context, wi walIndex, dataType s
 					var de *DataEntry
 
 					err := dec.Decode(&de)
-					if err == io.EOF {
+					if errors.Is(err, io.EOF) {
 						// all done
 						break
 					}
@@ -743,7 +743,7 @@ func (d *DataManager) Import(ctx context.Context, r io.Reader) error {
 		var de *DataEntry
 
 		err := dec.Decode(&de)
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			dataFileID := d.dataFileID(dataSequence, uuid.Must(uuid.NewV4()).String())
 			if err := d.writeDataFile(ctx, &buf, int64(buf.Len()), dataFileIndex, dataFileID, curDataType); err != nil {
 				return err

internal/datamanager/datamanager_test.go

@@ -371,7 +371,7 @@ func TestConcurrentUpdate(t *testing.T) {
 
 	// this must fail since we are using the old cgt
 	_, err = dm.WriteWal(ctx, actions, oldcgt)
-	if err != ErrConcurrency {
+	if !errors.Is(err, ErrConcurrency) {
 		t.Fatalf("expected err: %v, got %v", ErrConcurrency, err)
 	}
 
@@ -384,7 +384,7 @@ func TestConcurrentUpdate(t *testing.T) {
 
 	// this must fail since we are using the old cgt
 	_, err = dm.WriteWal(ctx, actions, oldcgt)
-	if err != ErrConcurrency {
+	if !errors.Is(err, ErrConcurrency) {
 		t.Fatalf("expected err: %v, got %v", ErrConcurrency, err)
 	}
 }
@@ -670,7 +670,7 @@ func checkDataFiles(ctx context.Context, t *testing.T, dm *DataManager, expected
 				var de *DataEntry
 
 				err := dec.Decode(&de)
-				if err == io.EOF {
+				if errors.Is(err, io.EOF) {
 					// all done
 					break
 				}

internal/datamanager/wal.go

@@ -296,10 +296,10 @@ func (d *DataManager) FirstAvailableWalData(ctx context.Context) (*WalData, int6
 
 func (d *DataManager) LastCommittedStorageWal(ctx context.Context) (string, int64, error) {
 	resp, err := d.e.Get(ctx, etcdLastCommittedStorageWalSeqKey, 0)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return "", 0, err
 	}
-	if err == etcd.ErrKeyNotFound {
+	if errors.Is(err, etcd.ErrKeyNotFound) {
 		return "", 0, errors.Errorf("no last committedstorage wal on etcd")
 	}
 	lastCommittedStorageWal := string(resp.Kvs[0].Value)
@@ -334,10 +334,9 @@ func (d *DataManager) Watch(ctx context.Context, revision int64) <-chan *WatchEl
 
 			if wresp.Canceled {
 				err := wresp.Err()
-				switch err {
+				if errors.Is(err, etcdclientv3rpc.ErrCompacted) {
-				case etcdclientv3rpc.ErrCompacted:
 					we.Err = ErrCompacted
-				default:
+				} else {
 					we.Err = err
 				}
 
@@ -1054,7 +1053,7 @@ func (d *DataManager) InitEtcd(ctx context.Context, dataStatus *DataStatus) erro
 		}
 		dec := json.NewDecoder(walFile)
 		var header *WalHeader
-		if err = dec.Decode(&header); err != nil && err != io.EOF {
+		if err = dec.Decode(&header); err != nil && !errors.Is(err, io.EOF) {
 			walFile.Close()
 			return err
 		}
@@ -1113,7 +1112,7 @@ func (d *DataManager) InitEtcd(ctx context.Context, dataStatus *DataStatus) erro
 
 	_, err = d.e.Get(ctx, etcdWalsDataKey, 0)
 	if err != nil {
-		if err != etcd.ErrKeyNotFound {
+		if !errors.Is(err, etcd.ErrKeyNotFound) {
 			return err
 		}
 		mustInit = true

internal/etcd/etcd.go

@@ -62,8 +62,7 @@ type Config struct {
 }
 
 func FromEtcdError(err error) error {
-	switch err {
+	if errors.Is(err, rpctypes.ErrKeyNotFound) {
-	case rpctypes.ErrKeyNotFound:
 		return ErrKeyNotFound
 	}
 	return err

internal/git-handler/handler.go

@@ -166,7 +166,7 @@ func (h *GitSmartHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 	repoAbsPath, exists, err := h.repoAbsPathFunc(h.reposDir, repoPath)
 	if err != nil {
-		if err == ErrWrongRepoPath {
+		if errors.Is(err, ErrWrongRepoPath) {
 			http.Error(w, err.Error(), http.StatusBadRequest)
 			return
 		}
@@ -257,7 +257,7 @@ func (h *FetchFileHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 	repoAbsPath, _, err := h.repoAbsPathFunc(h.reposDir, fetchData.RepoPath)
 	if err != nil {
-		if err == ErrWrongRepoPath {
+		if errors.Is(err, ErrWrongRepoPath) {
 			http.Error(w, err.Error(), http.StatusBadRequest)
 			return
 		}

internal/log/log.go

@@ -36,7 +36,7 @@ func New(level zap.AtomicLevel) *zap.Logger {
 
 	logger, err := config.Build()
 	if err != nil {
-		panic(fmt.Errorf("failed to initialize logger: %v", err))
+		panic(fmt.Errorf("failed to initialize logger: %w", err))
 	}
 
 	return logger

internal/objectstorage/objectstorage.go

@@ -46,13 +46,13 @@ func (e *ErrNotExist) Error() string {
 	return e.err.Error()
 }
 
-func (*ErrNotExist) Is(err error) bool {
+func (e *ErrNotExist) Unwrap() error {
-	_, ok := err.(*ErrNotExist)
+	return e.err
-	return ok
 }
 
 func IsNotExist(err error) bool {
-	return errors.Is(err, &ErrNotExist{})
+	var e *ErrNotExist
+	return errors.As(err, &e)
 }
 
 type ReadSeekCloser interface {

internal/objectstorage/posix.go

@@ -133,7 +133,7 @@ func (s *PosixStorage) DeleteObject(p string) error {
 		}
 
 		_, err = f.Readdirnames(1)
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			f.Close()
 			if err := os.Remove(pdir); err != nil {
 				return nil
@@ -221,7 +221,7 @@ func (s *PosixStorage) List(prefix, startWith, delimiter string, doneCh <-chan s
 
 			return nil
 		})
-		if err != nil && err != io.EOF {
+		if err != nil && !errors.Is(err, io.EOF) {
 			objectCh <- ObjectInfo{
 				Err: err,
 			}

internal/objectstorage/posixflat.go

@@ -307,7 +307,7 @@ func (s *PosixFlatStorage) DeleteObject(p string) error {
 		}
 
 		_, err = f.Readdirnames(1)
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			f.Close()
 			if err := os.Remove(pdir); err != nil {
 				return nil
@@ -418,7 +418,7 @@ func (s *PosixFlatStorage) List(prefix, startWith, delimiter string, doneCh <-ch
 
 			return nil
 		})
-		if err != nil && err != io.EOF {
+		if err != nil && !errors.Is(err, io.EOF) {
 			objectCh <- ObjectInfo{
 				Err: err,
 			}

internal/objectstorage/posixflat_test.go

@@ -20,6 +20,8 @@ import (
 	"os"
 	"path/filepath"
 	"testing"
+
+	errors "golang.org/x/xerrors"
 )
 
 func TestEscapeUnescape(t *testing.T) {
@@ -64,7 +66,7 @@ func TestEscapeUnescape(t *testing.T) {
 		if err != nil {
 			if tt.err == nil {
 				t.Errorf("%d: unescape: expected no error got %v", i, err)
-			} else if tt.err != err {
+			} else if !errors.Is(tt.err, err) {
 				t.Errorf("%d: unescape: expected error %v got %v", i, tt.err, err)
 			}
 		} else {

internal/runconfig/runconfig_test.go

@@ -663,7 +663,8 @@ func TestCheckRunConfig(t *testing.T) {
 			}
 
 			if err := CheckRunConfigTasks(inRcts); err != nil {
-				if errs, ok := err.(*util.Errors); ok {
+				var errs *util.Errors
+				if errors.As(err, &errs) {
 					if !errs.Equal(tt.err) {
 						t.Fatalf("got error: %v, want error: %v", err, tt.err)
 					}

internal/sequence/sequence.go

@@ -73,15 +73,15 @@ func (s *Sequence) EqualEpoch(s2 *Sequence) bool {
 
 func CurSequence(ctx context.Context, e *etcd.Store, key string) (*Sequence, bool, error) {
 	resp, err := e.Get(ctx, key, 0)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return nil, false, err
 	}
-	if err == etcd.ErrKeyNotFound {
+	if errors.Is(err, etcd.ErrKeyNotFound) {
 		return nil, false, nil
 	}
 
 	seq := &Sequence{}
-	if err != etcd.ErrKeyNotFound {
+	if !errors.Is(err, etcd.ErrKeyNotFound) {
 		kv := resp.Kvs[0]
 		if err := json.Unmarshal(kv.Value, &seq); err != nil {
 			return nil, false, err
@@ -92,13 +92,13 @@ func CurSequence(ctx context.Context, e *etcd.Store, key string) (*Sequence, boo
 
 func IncSequence(ctx context.Context, e *etcd.Store, key string) (*Sequence, error) {
 	resp, err := e.Get(ctx, key, 0)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return nil, err
 	}
 
 	var revision int64
 	seq := &Sequence{}
-	if err != etcd.ErrKeyNotFound {
+	if !errors.Is(err, etcd.ErrKeyNotFound) {
 		kv := resp.Kvs[0]
 		if err := json.Unmarshal(kv.Value, &seq); err != nil {
 			return nil, err

internal/services/configstore/action/maintenance.go

@@ -27,7 +27,7 @@ import (
 
 func (h *ActionHandler) MaintenanceMode(ctx context.Context, enable bool) error {
 	resp, err := h.e.Get(ctx, common.EtcdMaintenanceKey, 0)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return err
 	}
 

internal/services/configstore/configstore.go

@@ -40,6 +40,7 @@ import (
 	"go.etcd.io/etcd/mvcc/mvccpb"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
+	errors "golang.org/x/xerrors"
 )
 
 var level = zap.NewAtomicLevelAt(zapcore.InfoLevel)
@@ -67,7 +68,7 @@ func (s *Configstore) maintenanceModeWatcherLoop(ctx context.Context, runCtxCanc
 func (s *Configstore) maintenanceModeWatcher(ctx context.Context, runCtxCancel context.CancelFunc, maintenanceModeEnabled bool) error {
 	log.Infof("watcher: maintenance mode enabled: %t", maintenanceModeEnabled)
 	resp, err := s.e.Get(ctx, common.EtcdMaintenanceKey, 0)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return err
 	}
 
@@ -351,7 +352,7 @@ func (s *Configstore) run(ctx context.Context) error {
 	}
 
 	resp, err := s.e.Get(ctx, common.EtcdMaintenanceKey, 0)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return err
 	}
 

internal/services/configstore/readdb/readdb.go

@@ -144,7 +144,7 @@ func (r *ReadDB) SyncFromDump(ctx context.Context) (string, error) {
 				var de *datamanager.DataEntry
 
 				err := dec.Decode(&de)
-				if err == io.EOF {
+				if errors.Is(err, io.EOF) {
 					// all done
 					break
 				}
@@ -488,7 +488,7 @@ func (r *ReadDB) handleEvents(ctx context.Context) error {
 	err := r.rdb.Do(ctx, func(tx *db.Tx) error {
 		err := tx.QueryRow("select revision from revision order by revision desc limit 1").Scan(&revision)
 		if err != nil {
-			if err == sql.ErrNoRows {
+			if errors.Is(err, sql.ErrNoRows) {
 				revision = 0
 			} else {
 				return err
@@ -508,7 +508,7 @@ func (r *ReadDB) handleEvents(ctx context.Context) error {
 		r.log.Debugf("we: %s", util.Dump(we))
 		if we.Err != nil {
 			err := we.Err
-			if err == datamanager.ErrCompacted {
+			if errors.Is(err, datamanager.ErrCompacted) {
 				r.log.Warnf("required events already compacted, reinitializing readdb")
 				r.Initialized = false
 				return nil
@@ -612,7 +612,7 @@ func (r *ReadDB) applyWal(tx *db.Tx, walDataFileID string) error {
 		var action *datamanager.Action
 
 		err := dec.Decode(&action)
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			// all done
 			break
 		}
@@ -755,7 +755,7 @@ func (r *ReadDB) getRevision(tx *db.Tx) (int64, error) {
 	}
 
 	err = tx.QueryRow(q, args...).Scan(&revision)
-	if err == sql.ErrNoRows {
+	if errors.Is(err, sql.ErrNoRows) {
 		return 0, nil
 	}
 	return revision, err
@@ -787,7 +787,7 @@ func (r *ReadDB) GetCommittedWalSequence(tx *db.Tx) (string, error) {
 	}
 
 	err = tx.QueryRow(q, args...).Scan(&seq)
-	if err == sql.ErrNoRows {
+	if errors.Is(err, sql.ErrNoRows) {
 		return "", nil
 	}
 	return seq, err

internal/services/executor/driver/k8s.go

@@ -106,7 +106,7 @@ func NewK8sDriver(logger *zap.Logger, executorID, toolboxPath, initImage string,
 	}
 	kubecli, err := kubernetes.NewForConfig(kubecfg)
 	if err != nil {
-		return nil, fmt.Errorf("cannot create kubernetes client: %v", err)
+		return nil, fmt.Errorf("cannot create kubernetes client: %w", err)
 	}
 
 	namespace, _, err := kubeClientConfig.Namespace()
@@ -133,7 +133,7 @@ func NewK8sDriver(logger *zap.Logger, executorID, toolboxPath, initImage string,
 	sv, err := parseGitVersion(serverVersion.GitVersion)
 	// if server version parsing fails just warn but ignore it
 	if err != nil {
-		d.log.Warnf("failed to parse k8s server version: %v", err)
+		d.log.Warnf("failed to parse k8s server version: %w", err)
 	}
 	if sv != nil {
 		// for k8s version < v1.14.x use old arch label
@@ -800,10 +800,10 @@ func (e *K8sContainerExec) Wait(ctx context.Context) (int, error) {
 
 	var exitCode int
 	if err != nil {
-		switch err := err.(type) {
+		var verr utilexec.ExitError
-		case utilexec.ExitError:
+		if errors.As(err, &verr) {
-			exitCode = err.ExitStatus()
+			exitCode = verr.ExitStatus()
-		default:
+		} else {
 			return -1, err
 		}
 	}

internal/services/gateway/action/user.go

@@ -571,7 +571,7 @@ func (h *ActionHandler) HandleRemoteSourceAuth(ctx context.Context, remoteSource
 		tokenName := "agola-" + h.agolaID
 		accessToken, err := passwordSource.LoginPassword(loginName, loginPassword, tokenName)
 		if err != nil {
-			if err == gitsource.ErrUnauthorized {
+			if errors.Is(err, gitsource.ErrUnauthorized) {
 				return nil, util.NewErrUnauthorized(errors.Errorf("failed to login to remotesource %q: %w", remoteSourceName, err))
 			}
 			return nil, errors.Errorf("failed to login to remote source %q with login name %q: %w", rs.Name, loginName, err)
@@ -836,7 +836,7 @@ func (h *ActionHandler) UserCreateRun(ctx context.Context, req *UserCreateRunReq
 	for _, res := range req.PullRequestRefRegexes {
 		re, err := regexp.Compile(res)
 		if err != nil {
-			return fmt.Errorf("wrong regular expression %q: %v", res, err)
+			return fmt.Errorf("wrong regular expression %q: %w", res, err)
 		}
 		prRefRegexes = append(prRefRegexes, re)
 	}

internal/services/runservice/action/action.go

@@ -591,7 +591,7 @@ func (h *ActionHandler) getRunCounter(ctx context.Context, group string) (uint64
 
 func (h *ActionHandler) GetExecutorTask(ctx context.Context, etID string) (*types.ExecutorTask, error) {
 	et, err := store.GetExecutorTask(ctx, h.e, etID)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return nil, err
 	}
 	if et == nil {
@@ -619,7 +619,7 @@ func (h *ActionHandler) GetExecutorTask(ctx context.Context, etID string) (*type
 
 func (h *ActionHandler) GetExecutorTasks(ctx context.Context, executorID string) ([]*types.ExecutorTask, error) {
 	ets, err := store.GetExecutorTasksForExecutor(ctx, h.e, executorID)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return nil, err
 	}
 

internal/services/runservice/action/maintenance.go

@@ -27,7 +27,7 @@ import (
 
 func (h *ActionHandler) MaintenanceMode(ctx context.Context, enable bool) error {
 	resp, err := h.e.Get(ctx, common.EtcdMaintenanceKey, 0)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return err
 	}
 

internal/services/runservice/api/api.go

@@ -241,14 +241,14 @@ func (h *LogsHandler) readTaskLogs(ctx context.Context, runID, taskID string, se
 
 	et, err := store.GetExecutorTask(ctx, h.e, task.ID)
 	if err != nil {
-		if err == etcd.ErrKeyNotFound {
+		if errors.Is(err, etcd.ErrKeyNotFound) {
 			return util.NewErrNotExist(errors.Errorf("executor task with id %q doesn't exist", task.ID)), true
 		}
 		return err, true
 	}
 	executor, err := store.GetExecutor(ctx, h.e, et.Spec.ExecutorID)
 	if err != nil {
-		if err == etcd.ErrKeyNotFound {
+		if errors.Is(err, etcd.ErrKeyNotFound) {
 			return util.NewErrNotExist(errors.Errorf("executor with id %q doesn't exist", et.Spec.ExecutorID)), true
 		}
 		return err, true
@@ -832,7 +832,7 @@ func (h *RunEventsHandler) sendRunEvents(ctx context.Context, startRunEventID st
 	for wresp := range wch {
 		if wresp.Canceled {
 			err := wresp.Err()
-			if err == etcdclientv3rpc.ErrCompacted {
+			if errors.Is(err, etcdclientv3rpc.ErrCompacted) {
 				h.log.Errorf("required events already compacted")
 			}
 			return errors.Errorf("watch error: %w", err)

internal/services/runservice/readdb/readdb.go

@@ -400,7 +400,7 @@ func (r *ReadDB) handleEvents(ctx context.Context) error {
 	for wresp := range wch {
 		if wresp.Canceled {
 			err = wresp.Err()
-			if err == etcdclientv3rpc.ErrCompacted {
+			if errors.Is(err, etcdclientv3rpc.ErrCompacted) {
 				r.log.Errorf("required events already compacted, reinitializing readdb")
 				r.SetInitialized(false)
 			}
@@ -682,7 +682,7 @@ func (r *ReadDB) SyncFromDump(ctx context.Context) (string, error) {
 				var de *datamanager.DataEntry
 
 				err := dec.Decode(&de)
-				if err == io.EOF {
+				if errors.Is(err, io.EOF) {
 					// all done
 					break
 				}
@@ -784,7 +784,7 @@ func (r *ReadDB) handleEventsOST(ctx context.Context) error {
 	err := r.rdb.Do(ctx, func(tx *db.Tx) error {
 		err := tx.QueryRow("select revision from revision order by revision desc limit 1").Scan(&revision)
 		if err != nil {
-			if err == sql.ErrNoRows {
+			if errors.Is(err, sql.ErrNoRows) {
 				revision = 0
 			} else {
 				return err
@@ -804,7 +804,7 @@ func (r *ReadDB) handleEventsOST(ctx context.Context) error {
 		r.log.Debugf("we: %s", util.Dump(we))
 		if we.Err != nil {
 			err := we.Err
-			if err == datamanager.ErrCompacted {
+			if errors.Is(err, datamanager.ErrCompacted) {
 				r.log.Warnf("required events already compacted, reinitializing readdb")
 				r.Initialized = false
 				return nil
@@ -876,7 +876,7 @@ func (r *ReadDB) applyWal(tx *db.Tx, walDataFileID string) error {
 		var action *datamanager.Action
 
 		err := dec.Decode(&action)
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			// all done
 			break
 		}
@@ -1104,7 +1104,7 @@ func (r *ReadDB) getRevision(tx *db.Tx) (int64, error) {
 	}
 
 	err = tx.QueryRow(q, args...).Scan(&revision)
-	if err == sql.ErrNoRows {
+	if errors.Is(err, sql.ErrNoRows) {
 		return 0, nil
 	}
 	return revision, err
@@ -1485,7 +1485,7 @@ func (r *ReadDB) GetCommittedWalSequenceOST(tx *db.Tx) (string, error) {
 	}
 
 	err = tx.QueryRow(q, args...).Scan(&seq)
-	if err == sql.ErrNoRows {
+	if errors.Is(err, sql.ErrNoRows) {
 		return "", nil
 	}
 	return seq, err
@@ -1593,7 +1593,7 @@ func (r *ReadDB) GetRunCounterOST(tx *db.Tx, group string) (uint64, error) {
 	}
 
 	err = tx.QueryRow(q, args...).Scan(&g, &counter)
-	if err == sql.ErrNoRows {
+	if errors.Is(err, sql.ErrNoRows) {
 		return 0, nil
 	}
 	return counter, err

internal/services/runservice/runservice.go

@@ -40,6 +40,7 @@ import (
 	"go.etcd.io/etcd/mvcc/mvccpb"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
+	errors "golang.org/x/xerrors"
 )
 
 var level = zap.NewAtomicLevelAt(zapcore.InfoLevel)
@@ -94,7 +95,7 @@ func (s *Runservice) maintenanceModeWatcherLoop(ctx context.Context, runCtxCance
 func (s *Runservice) maintenanceModeWatcher(ctx context.Context, runCtxCancel context.CancelFunc, maintenanceModeEnabled bool) error {
 	log.Infof("watcher: maintenance mode enabled: %t", maintenanceModeEnabled)
 	resp, err := s.e.Get(ctx, common.EtcdMaintenanceKey, 0)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return err
 	}
 
@@ -330,7 +331,7 @@ func (s *Runservice) run(ctx context.Context) error {
 	}
 
 	resp, err := s.e.Get(ctx, common.EtcdMaintenanceKey, 0)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return err
 	}
 

internal/services/runservice/scheduler.go

@@ -247,7 +247,7 @@ func (s *Runservice) submitRunTasks(ctx context.Context, r *types.Run, rc *types
 		// just a check but it's not really needed since the call to
 		// atomicPutExecutorTask will fail if it already exists
 		tet, err := store.GetExecutorTask(ctx, s.e, et.ID)
-		if err != nil && err != etcd.ErrKeyNotFound {
+		if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 			return err
 		}
 		if tet != nil {
@@ -335,7 +335,7 @@ func chooseExecutor(executors []*types.Executor, executorTasksCount map[string]i
 // will periodically fetch the executortask anyway
 func (s *Runservice) sendExecutorTask(ctx context.Context, et *types.ExecutorTask) error {
 	executor, err := store.GetExecutor(ctx, s.e, et.Spec.ExecutorID)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return err
 	}
 	if executor == nil {
@@ -768,7 +768,7 @@ func (s *Runservice) executorTaskCleaner(ctx context.Context, et *types.Executor
 	if et.Status.Phase.IsFinished() {
 		r, _, err := store.GetRun(ctx, s.e, et.Spec.RunID)
 		if err != nil {
-			if err == etcd.ErrKeyNotFound {
+			if errors.Is(err, etcd.ErrKeyNotFound) {
 				// run doesn't exists, remove executor task
 				if err := store.DeleteExecutorTask(ctx, s.e, et.ID); err != nil {
 					log.Errorf("err: %+v", err)
@@ -798,7 +798,7 @@ func (s *Runservice) executorTaskCleaner(ctx context.Context, et *types.Executor
 	if !et.Status.Phase.IsFinished() {
 		// if the executor doesn't exists anymore mark the not finished executor tasks as failed
 		executor, err := store.GetExecutor(ctx, s.e, et.Spec.ExecutorID)
-		if err != nil && err != etcd.ErrKeyNotFound {
+		if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 			return err
 		}
 		if executor == nil {
@@ -886,7 +886,7 @@ func (s *Runservice) OSTFileExists(path string) (bool, error) {
 
 func (s *Runservice) fetchLog(ctx context.Context, rt *types.RunTask, setup bool, stepnum int) error {
 	et, err := store.GetExecutorTask(ctx, s.e, rt.ID)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return err
 	}
 	if et == nil {
@@ -896,7 +896,7 @@ func (s *Runservice) fetchLog(ctx context.Context, rt *types.RunTask, setup bool
 		return nil
 	}
 	executor, err := store.GetExecutor(ctx, s.e, et.Spec.ExecutorID)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return err
 	}
 	if executor == nil {
@@ -1049,7 +1049,7 @@ func (s *Runservice) fetchTaskLogs(ctx context.Context, runID string, rt *types.
 
 func (s *Runservice) fetchArchive(ctx context.Context, rt *types.RunTask, stepnum int) error {
 	et, err := store.GetExecutorTask(ctx, s.e, rt.ID)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return err
 	}
 	if et == nil {
@@ -1059,7 +1059,7 @@ func (s *Runservice) fetchArchive(ctx context.Context, rt *types.RunTask, stepnu
 		return nil
 	}
 	executor, err := store.GetExecutor(ctx, s.e, et.Spec.ExecutorID)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return err
 	}
 	if executor == nil {

internal/services/runservice/store/store.go

@@ -420,10 +420,10 @@ func AtomicPutRun(ctx context.Context, e *etcd.Store, r *types.Run, runEvent *ty
 
 	// insert only if the run as changed
 	curRun, _, err := GetRun(ctx, e, r.ID)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return nil, err
 	}
-	if err != etcd.ErrKeyNotFound {
+	if !errors.Is(err, etcd.ErrKeyNotFound) {
 		if curRun.Revision != r.Revision {
 			// fast fail path if the run was already updated
 			return nil, errors.Errorf("run modified")
@@ -522,7 +522,7 @@ func GetRuns(ctx context.Context, e *etcd.Store) ([]*types.Run, error) {
 
 func GetRunEtcdOrOST(ctx context.Context, e *etcd.Store, dm *datamanager.DataManager, runID string) (*types.Run, error) {
 	r, _, err := GetRun(ctx, e, runID)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return nil, err
 	}
 	if r == nil {

internal/testutil/utils.go

@@ -38,6 +38,7 @@ import (
 
 	"github.com/gofrs/uuid"
 	"github.com/sgotti/gexpect"
+	errors "golang.org/x/xerrors"
 )
 
 const (
@@ -193,7 +194,7 @@ func NewTestEmbeddedEtcd(t *testing.T, logger *zap.Logger, dir string, a ...stri
 	}
 	e, err := etcd.New(storeConfig)
 	if err != nil {
-		return nil, fmt.Errorf("cannot create store: %v", err)
+		return nil, fmt.Errorf("cannot create store: %w", err)
 	}
 
 	tectd := &TestEmbeddedEtcd{
@@ -267,7 +268,7 @@ func NewTestExternalEtcd(t *testing.T, logger *zap.Logger, dir string, a ...stri
 	}
 	e, err := etcd.New(storeConfig)
 	if err != nil {
-		return nil, fmt.Errorf("cannot create store: %v", err)
+		return nil, fmt.Errorf("cannot create store: %w", err)
 	}
 
 	bin := os.Getenv("ETCD_BIN")
@@ -303,7 +304,7 @@ func (te *TestEtcd) Compact() error {
 	ctx, cancel := context.WithTimeout(context.Background(), etcdTimeout)
 	defer cancel()
 	resp, err := te.Get(ctx, "anykey", 0)
-	if err != nil && err != etcd.ErrKeyNotFound {
+	if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 		return err
 	}
 
@@ -317,7 +318,7 @@ func (te *TestEtcd) WaitUp(timeout time.Duration) error {
 		ctx, cancel := context.WithTimeout(context.Background(), etcdTimeout)
 		defer cancel()
 		_, err := te.Get(ctx, "anykey", 0)
-		if err != nil && err == etcd.ErrKeyNotFound {
+		if err != nil && errors.Is(err, etcd.ErrKeyNotFound) {
 			return nil
 		}
 		if err == nil {
@@ -335,7 +336,7 @@ func (te *TestEtcd) WaitDown(timeout time.Duration) error {
 		ctx, cancel := context.WithTimeout(context.Background(), etcdTimeout)
 		defer cancel()
 		_, err := te.Get(ctx, "anykey", 0)
-		if err != nil && err != etcd.ErrKeyNotFound {
+		if err != nil && !errors.Is(err, etcd.ErrKeyNotFound) {
 			return nil
 		}
 		time.Sleep(sleepInterval)
@@ -567,7 +568,7 @@ func GetFreePort(tcp bool, udp bool) (string, string, error) {
 	}
 	localhostIP, err := net.ResolveIPAddr("ip", "localhost")
 	if err != nil {
-		return "", "", fmt.Errorf("failed to resolve ip addr: %v", err)
+		return "", "", fmt.Errorf("failed to resolve ip addr: %w", err)
 	}
 	for {
 		curPort++

internal/toolbox/archive/archive.go

@@ -50,7 +50,7 @@ func CreateTar(archiveInfos []*ArchiveInfo, w io.Writer) error {
 
 		sourceDirInfo, err := os.Stat(sourceDir)
 		if err != nil {
-			return fmt.Errorf("%s: stat: %v", sourceDir, err)
+			return fmt.Errorf("%s: stat: %w", sourceDir, err)
 		}
 		if !sourceDirInfo.IsDir() {
 			return fmt.Errorf("sourceDir %q is not a directory", sourceDir)
@@ -62,7 +62,7 @@ func CreateTar(archiveInfos []*ArchiveInfo, w io.Writer) error {
 			}
 
 			if err != nil {
-				return fmt.Errorf("error accessing path %q: %v. Skipping.", path, err)
+				return fmt.Errorf("error accessing path %q: %w. Skipping.", path, err)
 			}
 			match := false
 			for _, pattern := range ai.Paths {
@@ -104,19 +104,19 @@ func CreateTar(archiveInfos []*ArchiveInfo, w io.Writer) error {
 				var err error
 				linkTarget, err = os.Readlink(path)
 				if err != nil {
-					return fmt.Errorf("%s: readlink: %v", path, err)
+					return fmt.Errorf("%s: readlink: %w", path, err)
 				}
 			}
 
 			hdr, err := tar.FileInfoHeader(fi, filepath.ToSlash(linkTarget))
 			if err != nil {
-				return fmt.Errorf("%s: making header: %v", path, err)
+				return fmt.Errorf("%s: making header: %w", path, err)
 			}
 			hdr.Name = destPath
 
 			err = tw.WriteHeader(hdr)
 			if err != nil {
-				return fmt.Errorf("%s: writing header: %v", hdr.Name, err)
+				return fmt.Errorf("%s: writing header: %w", hdr.Name, err)
 			}
 
 			if fi.IsDir() {
@@ -130,14 +130,14 @@ func CreateTar(archiveInfos []*ArchiveInfo, w io.Writer) error {
 				}
 				defer f.Close()
 				if _, err := io.Copy(tw, f); err != nil {
-					return fmt.Errorf("%s: copying contents: %v", f.Name(), err)
+					return fmt.Errorf("%s: copying contents: %w", f.Name(), err)
 				}
 			}
 
 			return nil
 		})
 		if err != nil {
-			return fmt.Errorf("error walking the path %q: %v\n", sourceDir, err)
+			return fmt.Errorf("error walking the path %q: %w", sourceDir, err)
 		}
 	}
 

internal/toolbox/unarchive/unarchive.go

@@ -16,6 +16,7 @@ package unarchive
 
 import (
 	"archive/tar"
+	"errors"
 	"fmt"
 	"io"
 	"log"
@@ -32,12 +33,12 @@ func Unarchive(source io.Reader, destDir string, overwrite, removeDestDir bool)
 	var err error
 	destDir, err = filepath.Abs(destDir)
 	if err != nil {
-		return fmt.Errorf("failed to calculate destination dir absolute path: %v", err)
+		return fmt.Errorf("failed to calculate destination dir absolute path: %w", err)
 	}
 	// don't follow destdir if it's a symlink
 	fi, err := os.Lstat(destDir)
 	if err != nil && !os.IsNotExist(err) {
-		return fmt.Errorf("failed to lstat destination dir: %v", err)
+		return fmt.Errorf("failed to lstat destination dir: %w", err)
 	}
 	if fi != nil && !fi.IsDir() {
 		return fmt.Errorf("destination path %q already exists and it's not a directory (mode: %q)", destDir, fi.Mode().String())
@@ -52,11 +53,11 @@ func Unarchive(source io.Reader, destDir string, overwrite, removeDestDir bool)
 
 	for {
 		err := untarNext(tr, destDir, overwrite)
-		if err == io.EOF {
+		if errors.Is(err, io.EOF) {
 			break
 		}
 		if err != nil {
-			return fmt.Errorf("error reading file in tar archive: %v", err)
+			return fmt.Errorf("error reading file in tar archive: %w", err)
 		}
 	}
 
@@ -132,7 +133,7 @@ func fileExists(name string) bool {
 func mkdir(dirPath string, mode os.FileMode) error {
 	err := os.MkdirAll(dirPath, mode)
 	if err != nil {
-		return fmt.Errorf("%s: making directory: %v", dirPath, err)
+		return fmt.Errorf("%s: making directory: %w", dirPath, err)
 	}
 	return nil
 }
@@ -140,23 +141,23 @@ func mkdir(dirPath string, mode os.FileMode) error {
 func writeNewFile(fpath string, in io.Reader, mode os.FileMode) error {
 	err := os.MkdirAll(filepath.Dir(fpath), defaultDirPerm)
 	if err != nil {
-		return fmt.Errorf("%s: making directory for file: %v", fpath, err)
+		return fmt.Errorf("%s: making directory for file: %w", fpath, err)
 	}
 
 	out, err := os.Create(fpath)
 	if err != nil {
-		return fmt.Errorf("%s: creating new file: %v", fpath, err)
+		return fmt.Errorf("%s: creating new file: %w", fpath, err)
 	}
 	defer out.Close()
 
 	err = out.Chmod(mode)
 	if err != nil && runtime.GOOS != "windows" {
-		return fmt.Errorf("%s: changing file mode: %v", fpath, err)
+		return fmt.Errorf("%s: changing file mode: %w", fpath, err)
 	}
 
 	_, err = io.Copy(out, in)
 	if err != nil {
-		return fmt.Errorf("%s: writing file: %v", fpath, err)
+		return fmt.Errorf("%s: writing file: %w", fpath, err)
 	}
 	return nil
 }
@@ -164,11 +165,11 @@ func writeNewFile(fpath string, in io.Reader, mode os.FileMode) error {
 func writeNewSymbolicLink(fpath string, target string) error {
 	err := os.MkdirAll(filepath.Dir(fpath), defaultDirPerm)
 	if err != nil {
-		return fmt.Errorf("%s: making directory for file: %v", fpath, err)
+		return fmt.Errorf("%s: making directory for file: %w", fpath, err)
 	}
 	err = os.Symlink(target, fpath)
 	if err != nil {
-		return fmt.Errorf("%s: making symbolic link for: %v", fpath, err)
+		return fmt.Errorf("%s: making symbolic link for: %w", fpath, err)
 	}
 	return nil
 }
@@ -176,11 +177,11 @@ func writeNewSymbolicLink(fpath string, target string) error {
 func writeNewHardLink(fpath string, target string) error {
 	err := os.MkdirAll(filepath.Dir(fpath), defaultDirPerm)
 	if err != nil {
-		return fmt.Errorf("%s: making directory for file: %v", fpath, err)
+		return fmt.Errorf("%s: making directory for file: %w", fpath, err)
 	}
 	err = os.Link(target, fpath)
 	if err != nil {
-		return fmt.Errorf("%s: making hard link for: %v", fpath, err)
+		return fmt.Errorf("%s: making hard link for: %w", fpath, err)
 	}
 	return nil
 }

internal/util/errors.go

@@ -47,7 +47,8 @@ func (e *Errors) Equal(e2 error) bool {
 	for _, err := range e.Errs {
 		errs1 = append(errs1, err.Error())
 	}
-	if es2, ok := e2.(*Errors); ok {
+	var es2 *Errors
+	if errors.As(e2, &es2) {
 		for _, err := range es2.Errs {
 			errs2 = append(errs2, err.Error())
 		}
@@ -72,13 +73,13 @@ func NewErrBadRequest(err error) *ErrBadRequest {
 	return &ErrBadRequest{Err: err}
 }
 
-func (*ErrBadRequest) Is(err error) bool {
+func (e *ErrBadRequest) Unwrap() error {
-	_, ok := err.(*ErrBadRequest)
+	return e.Err
-	return ok
 }
 
 func IsBadRequest(err error) bool {
-	return errors.Is(err, &ErrBadRequest{})
+	var e *ErrBadRequest
+	return errors.As(err, &e)
 }
 
 // ErrNotExist represent a not exist error
@@ -95,13 +96,13 @@ func NewErrNotExist(err error) *ErrNotExist {
 	return &ErrNotExist{Err: err}
 }
 
-func (*ErrNotExist) Is(err error) bool {
+func (e *ErrNotExist) Unwrap() error {
-	_, ok := err.(*ErrNotExist)
+	return e.Err
-	return ok
 }
 
 func IsNotExist(err error) bool {
-	return errors.Is(err, &ErrNotExist{})
+	var e *ErrNotExist
+	return errors.As(err, &e)
 }
 
 // ErrForbidden represent an error caused by an forbidden operation
@@ -118,13 +119,13 @@ func NewErrForbidden(err error) *ErrForbidden {
 	return &ErrForbidden{Err: err}
 }
 
-func (*ErrForbidden) Is(err error) bool {
+func (e *ErrForbidden) Unwrap() error {
-	_, ok := err.(*ErrForbidden)
+	return e.Err
-	return ok
 }
 
 func IsForbidden(err error) bool {
-	return errors.Is(err, &ErrForbidden{})
+	var e *ErrForbidden
+	return errors.As(err, &e)
 }
 
 // ErrUnauthorized represent an error caused by an unauthorized request
@@ -141,13 +142,13 @@ func NewErrUnauthorized(err error) *ErrUnauthorized {
 	return &ErrUnauthorized{Err: err}
 }
 
-func (*ErrUnauthorized) Is(err error) bool {
+func (e *ErrUnauthorized) Unwrap() error {
-	_, ok := err.(*ErrUnauthorized)
+	return e.Err
-	return ok
 }
 
 func IsUnauthorized(err error) bool {
-	return errors.Is(err, &ErrUnauthorized{})
+	var e *ErrUnauthorized
+	return errors.As(err, &e)
 }
 
 type ErrInternal struct {
@@ -163,11 +164,11 @@ func NewErrInternal(err error) *ErrInternal {
 	return &ErrInternal{Err: err}
 }
 
-func (*ErrInternal) Is(err error) bool {
+func (e *ErrInternal) Unwrap() error {
-	_, ok := err.(*ErrInternal)
+	return e.Err
-	return ok
 }
 
 func IsInternal(err error) bool {
-	return errors.Is(err, &ErrInternal{})
+	var e *ErrInternal
+	return errors.As(err, &e)
 }

internal/util/git.go

@@ -154,7 +154,8 @@ func (g *Git) ConfigGet(ctx context.Context, args ...string) (string, error) {
 	out, err := g.Output(ctx, nil, args...)
 
 	if err != nil {
-		if exitError, ok := err.(*exec.ExitError); ok {
+		var exitError *exec.ExitError
+		if errors.As(err, &exitError) {
 			if waitStatus, ok := exitError.Sys().(syscall.WaitStatus); ok {
 				if waitStatus.ExitStatus() == 1 {
 					return "", &ErrGitKeyNotFound{Key: args[len(args)-1]}
@@ -172,7 +173,8 @@ func (g *Git) ConfigSet(ctx context.Context, args ...string) (string, error) {
 	out, err := g.Output(ctx, nil, args...)
 
 	if err != nil {
-		if exitError, ok := err.(*exec.ExitError); ok {
+		var exitError *exec.ExitError
+		if errors.As(err, &exitError) {
 			if waitStatus, ok := exitError.Sys().(syscall.WaitStatus); ok {
 				if waitStatus.ExitStatus() == 1 {
 					return "", &ErrGitKeyNotFound{Key: args[len(args)-1]}

internal/util/password.go

@@ -16,6 +16,8 @@ package util
 
 import (
 	"golang.org/x/crypto/bcrypt"
+
+	errors "golang.org/x/xerrors"
 )
 
 func PasswordHash(password string) (string, error) {
@@ -25,7 +27,7 @@ func PasswordHash(password string) (string, error) {
 
 func CompareHashAndPassword(passwordHash, password string) (bool, error) {
 	if err := bcrypt.CompareHashAndPassword([]byte(passwordHash), []byte(password)); err != nil {
-		if err == bcrypt.ErrMismatchedHashAndPassword {
+		if errors.Is(err, bcrypt.ErrMismatchedHashAndPassword) {
 			return false, nil
 		}
 		return false, err

tests/setup_test.go

@@ -359,7 +359,7 @@ func setup(ctx context.Context, t *testing.T, dir string) (*testutil.TestEmbedde
 	go func() {
 		err := <-errCh
 		if err != nil {
-			panic(fmt.Errorf("agola component returned error: %+v", err))
+			panic(fmt.Errorf("agola component returned error: %w", err))
 		}
 	}()