Fix linter warnings

Fix most linter warnings reported by 'staticcheck'. This doesn't fix all
of them, some unused functions are still there, and some generated code
also still triggers some warnings. Most issues are fixed, though.

No functional changes, except for the captialisation of some error
messages.

internal/manager/api_impl/dummy/shaman.go

@@ -16,6 +16,7 @@ type DummyShaman struct{}
 
 var _ api_impl.Shaman = (*DummyShaman)(nil)
 
+//lint:ignore ST1005 Shaman is a name that's always capitalised, so also in errors.
 var ErrDummyShaman = errors.New("Shaman storage component is inactive, configure Flamenco first")
 
 func (ds *DummyShaman) IsEnabled() bool {

internal/manager/task_logs/log_rotation_test.go

@@ -5,7 +5,6 @@ package task_logs
 import (
 	"errors"
 	"io/fs"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -16,7 +15,7 @@ import (
 )
 
 func setUpTest(t *testing.T) string {
-	temppath, err := ioutil.TempDir("", "testlogs")
+	temppath, err := os.MkdirTemp("", "testlogs")
 	require.NoError(t, err)
 	return temppath
 }
@@ -78,12 +77,12 @@ func TestMultipleFilesWithHoles(t *testing.T) {
 	defer tearDownTest(temppath)
 
 	filepath := filepath.Join(temppath, "existing.txt")
-	require.NoError(t, ioutil.WriteFile(filepath, []byte("thefile"), 0666))
-	require.NoError(t, ioutil.WriteFile(filepath+".1", []byte("file .1"), 0666))
-	require.NoError(t, ioutil.WriteFile(filepath+".2", []byte("file .2"), 0666))
-	require.NoError(t, ioutil.WriteFile(filepath+".3", []byte("file .3"), 0666))
-	require.NoError(t, ioutil.WriteFile(filepath+".5", []byte("file .5"), 0666))
-	require.NoError(t, ioutil.WriteFile(filepath+".7", []byte("file .7"), 0666))
+	require.NoError(t, os.WriteFile(filepath, []byte("thefile"), 0666))
+	require.NoError(t, os.WriteFile(filepath+".1", []byte("file .1"), 0666))
+	require.NoError(t, os.WriteFile(filepath+".2", []byte("file .2"), 0666))
+	require.NoError(t, os.WriteFile(filepath+".3", []byte("file .3"), 0666))
+	require.NoError(t, os.WriteFile(filepath+".5", []byte("file .5"), 0666))
+	require.NoError(t, os.WriteFile(filepath+".7", []byte("file .7"), 0666))
 
 	err := rotateLogFile(zerolog.Nop(), filepath)
 
@@ -100,7 +99,7 @@ func TestMultipleFilesWithHoles(t *testing.T) {
 	assert.False(t, fileExists(filepath+".9"))
 
 	read := func(filename string) string {
-		content, err := ioutil.ReadFile(filename)
+		content, err := os.ReadFile(filename)
 		require.NoError(t, err)
 		return string(content)
 	}

internal/manager/task_logs/task_logs.go

@@ -185,7 +185,7 @@ func (s *Storage) Tail(jobID, taskID string) (string, error) {
 		return "", fmt.Errorf("unable to open log file for reading: %w", err)
 	}
 
-	fileSize, err := file.Seek(0, os.SEEK_END)
+	fileSize, err := file.Seek(0, io.SeekEnd)
 	if err != nil {
 		return "", fmt.Errorf("unable to seek to end of log file: %w", err)
 	}
@@ -197,14 +197,14 @@ func (s *Storage) Tail(jobID, taskID string) (string, error) {
 	)
 	if fileSize <= tailSize {
 		// The file is small, just read all of it.
-		_, err = file.Seek(0, os.SEEK_SET)
+		_, err = file.Seek(0, io.SeekStart)
 		if err != nil {
 			return "", fmt.Errorf("unable to seek to start of log file: %w", err)
 		}
 		buffer, err = io.ReadAll(file)
 	} else {
 		// Read the last 'tailSize' number of bytes.
-		_, err = file.Seek(-tailSize, os.SEEK_END)
+		_, err = file.Seek(-tailSize, io.SeekEnd)
 		if err != nil {
 			return "", fmt.Errorf("unable to seek in log file: %w", err)
 		}

internal/manager/task_logs/task_logs_test.go

@@ -6,7 +6,6 @@ import (
 	"errors"
 	"fmt"
 	"io/fs"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -43,7 +42,7 @@ func TestLogWriting(t *testing.T) {
 	require.NoError(t, err)
 
 	filename := filepath.Join(jobDir, "task-20ff9d06-53ec-4019-9e2e-1774f05f170a.txt")
-	contents, err := ioutil.ReadFile(filename)
+	contents, err := os.ReadFile(filename)
 	require.NoError(t, err, "the log file should exist")
 	assert.Equal(t, "Ovo je priča\nIma dvije linije\n", string(contents))
 }
@@ -67,7 +66,7 @@ func TestLogRotation(t *testing.T) {
 	filename := filepath.Join(jobDir, "task-20ff9d06-53ec-4019-9e2e-1774f05f170a.txt")
 	rotatedFilename := filename + ".1"
 
-	contents, err := ioutil.ReadFile(rotatedFilename)
+	contents, err := os.ReadFile(rotatedFilename)
 	require.NoError(t, err, "the rotated log file should exist")
 	assert.Equal(t, "Ovo je priča\n", string(contents))
 
@@ -216,7 +215,7 @@ type TaskLogsMocks struct {
 func taskLogsTestFixtures(t *testing.T) (*Storage, func(), *TaskLogsMocks) {
 	mockCtrl := gomock.NewController(t)
 
-	temppath, err := ioutil.TempDir("", "testlogs")
+	temppath, err := os.MkdirTemp("", "testlogs")
 	require.NoError(t, err)
 
 	mocks := &TaskLogsMocks{

internal/manager/task_state_machine/task_statuses.go

@@ -5,14 +5,6 @@ package task_state_machine
 import "projects.blender.org/studio/flamenco/pkg/api"
 
 var (
-	// Task statuses that always get requeued when the job is requeueing.
-	nonCompletedStatuses = []api.TaskStatus{
-		api.TaskStatusCanceled,
-		api.TaskStatusFailed,
-		api.TaskStatusPaused,
-		api.TaskStatusSoftFailed,
-	}
-
 	// Workers are allowed to keep running tasks when they are in this status.
 	// 'queued', 'claimed-by-manager', and 'soft-failed' aren't considered runnable,
 	// as those statuses indicate the task wasn't assigned to a Worker by the scheduler.

internal/stresser/stresser.go

@@ -79,6 +79,7 @@ func stressByRequestingTask(ctx context.Context, client worker.FlamencoClient) {
 	}
 }
 
+//lint:ignore U1000 stressBySendingTaskUpdate is currently unused, but someone may find it useful for different kinds of stess testing.
 func stressBySendingTaskUpdate(ctx context.Context, client worker.FlamencoClient, task *api.AssignedTask) {
 	logLine := "This is a log-line for stress testing. It will be repeated more than once.\n"
 	logToSend := strings.Repeat(logLine, 5)

internal/worker/autodiscovery.go

@@ -46,7 +46,7 @@ func AutodiscoverManager(ctx context.Context) (string, error) {
 
 	logger := log.Logger
 	if deadline, ok := ctx.Deadline(); ok {
-		timeout := deadline.Sub(time.Now()).Round(1 * time.Second)
+		timeout := time.Until(deadline).Round(1 * time.Second)
 		logger = logger.With().Str("timeout", timeout.String()).Logger()
 	}
 	logger.Info().Msg("auto-discovering Manager via UPnP/SSDP")

internal/worker/cli_runner/cli_runner.go

@@ -101,7 +101,6 @@ readloop:
 		// Prepend any leftovers from the previous line to the received bytes.
 		if len(leftovers) > 0 {
 			lineBytes = append(leftovers, lineBytes...)
-			leftovers = []byte{}
 		}
 		// Make sure long lines are broken on character boundaries.
 		lineBytes, leftovers = splitOnCharacterBoundary(lineBytes)

internal/worker/command_file_mgmt.go

@@ -133,7 +133,7 @@ func (ce *CommandExecutor) cmdCopyFile(ctx context.Context, logger zerolog.Logge
 		return err
 	}
 
-	err, logMsg := fileCopy(src, dest)
+	logMsg, err := fileCopy(src, dest)
 	return ce.errorLogProcess(ctx, logger, cmd, taskID, err, logMsg)
 }
 
@@ -171,48 +171,48 @@ func (ce *CommandExecutor) moveAndLog(ctx context.Context, taskID, cmdName, src,
 	return nil
 }
 
-func fileCopy(src, dest string) (error, string) {
+func fileCopy(src, dest string) (string, error) {
 	src_file, err := os.Open(src)
 	if err != nil {
 		msg := fmt.Sprintf("failed to open source file %q: %v", src, err)
-		return err, msg
+		return msg, err
 	}
 	defer src_file.Close()
 
 	src_file_stat, err := src_file.Stat()
 	if err != nil {
 		msg := fmt.Sprintf("failed to stat source file %q: %v", src, err)
-		return err, msg
+		return msg, err
 	}
 
 	if !src_file_stat.Mode().IsRegular() {
-		err := &os.PathError{Op: "stat", Path: src, Err: errors.New("Not a regular file")}
+		err := &os.PathError{Op: "stat", Path: src, Err: errors.New("not a regular file")}
 		msg := fmt.Sprintf("invalid source file %q: %v", src, err)
-		return err, msg
+		return msg, err
 	}
 
 	dest_dirpath := filepath.Dir(dest)
 	if !fileExists(dest_dirpath) {
 		if err := os.MkdirAll(dest_dirpath, 0750); err != nil {
 			msg := fmt.Sprintf("failed to create directories %q: %v", dest_dirpath, err)
-			return err, msg
+			return msg, err
 		}
 	}
 
 	dest_file, err := os.Create(dest)
 	if err != nil {
 		msg := fmt.Sprintf("failed to create destination file %q: %v", dest, err)
-		return err, msg
+		return msg, err
 	}
 	defer dest_file.Close()
 
 	if _, err := io.Copy(dest_file, src_file); err != nil {
 		msg := fmt.Sprintf("failed to copy %q to %q: %v", src, dest, err)
-		return err, msg
+		return msg, err
 	}
 
 	msg := fmt.Sprintf("copied %q to %q", src, dest)
-	return nil, msg
+	return msg, nil
 }
 
 func fileExists(filename string) bool {

internal/worker/command_file_mgmt_test.go

@@ -163,7 +163,7 @@ func TestTimestampedPathFile(t *testing.T) {
 
 	fileCreateEmpty("somefile.txt")
 	if err := os.Chtimes("somefile.txt", mtime, mtime); err != nil {
-		t.Fatalf(err.Error())
+		t.Fatal(err.Error())
 	}
 
 	newpath, err := timestampedPath("somefile.txt")
@@ -365,7 +365,7 @@ func TestCmdCopyFileSourceIsDir(t *testing.T) {
 		fmt.Sprintf("copy-file: copying %q to %q", f.absolute_src_path, f.absolute_dest_path))
 
 	f.mocks.listener.EXPECT().LogProduced(gomock.Any(), taskID,
-		fmt.Sprintf("copy-file: invalid source file %q: stat %s: Not a regular file",
+		fmt.Sprintf("copy-file: invalid source file %q: stat %s: not a regular file",
 			f.absolute_src_path, f.absolute_src_path))
 
 	assert.Error(t, f.run())

internal/worker/state_awake.go

@@ -185,7 +185,6 @@ checkloop:
 			break checkloop
 		case <-time.After(mayKeepRunningPeriod):
 			// Time to do another check.
-			break
 		}
 
 		mkr := w.mayIKeepRunning(taskCtx, task.Uuid)

pkg/shaman/checkout/manager.go

@@ -73,7 +73,7 @@ func (err ErrInvalidCheckoutPath) Error() string {
 
 // Errors returned by the Checkout Manager.
 var (
-	ErrCheckoutAlreadyExists = errors.New("A checkout with this ID already exists")
+	ErrCheckoutAlreadyExists = errors.New("a checkout with this ID already exists")
 )
 
 // NewManager creates and returns a new Checkout Manager.

pkg/shaman/fileserver/receivefile_test.go

@@ -26,7 +26,7 @@ import (
 	"bytes"
 	"context"
 	"io"
-	"io/ioutil"
+	"os"
 	"testing"
 
 	"projects.blender.org/studio/flamenco/pkg/shaman/config"
@@ -86,7 +86,7 @@ func TestStoreFile(t *testing.T) {
 	assert.Equal(t, filestore.StatusStored, status)
 	assert.FileExists(t, path)
 
-	savedContent, err := ioutil.ReadFile(path)
+	savedContent, err := os.ReadFile(path)
 	require.NoError(t, err)
 	assert.EqualValues(t, payload, savedContent, "The file should be saved uncompressed")
 }

pkg/shaman/fileserver/receivelistener.go

@@ -47,9 +47,7 @@ func (fs *FileServer) receiveListenerFor(checksum string, filesize int64) chan s
 
 	go func() {
 		// Wait until the channel closes.
-		select {
-		case <-channel:
-		}
+		<-channel
 
 		fs.receiverMutex.Lock()
 		defer fs.receiverMutex.Unlock()

pkg/shaman/filestore/filestore_test.go

@@ -23,7 +23,6 @@
 package filestore
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -115,7 +114,7 @@ func TestOpenForUpload(t *testing.T) {
 	assert.Equal(t, file.Name(), foundPath)
 	assert.Equal(t, StatusUploading, status)
 
-	readContents, err := ioutil.ReadFile(foundPath)
+	readContents, err := os.ReadFile(foundPath)
 	require.NoError(t, err)
 	assert.EqualValues(t, contents, readContents)
 }

pkg/shaman/filestore/testing.go

@@ -25,7 +25,6 @@ package filestore
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -36,7 +35,7 @@ import (
 
 // CreateTestStore returns a Store that can be used for unit testing.
 func CreateTestStore() *Store {
-	tempDir, err := ioutil.TempDir("", "shaman-filestore-test-")
+	tempDir, err := os.MkdirTemp("", "shaman-filestore-test-")
 	if err != nil {
 		panic(err)
 	}

pkg/shaman/touch/touch_test.go

@@ -23,7 +23,6 @@
 package touch
 
 import (
-	"io/ioutil"
 	"os"
 	"testing"
 	"time"
@@ -36,7 +35,7 @@ func TestTouch(t *testing.T) {
 	testPath := "_touch_test.txt"
 
 	// Create a file
-	assert.Nil(t, ioutil.WriteFile(testPath, []byte("just a test"), 0644))
+	assert.Nil(t, os.WriteFile(testPath, []byte("just a test"), 0644))
 	defer os.Remove(testPath)
 
 	// Make it old