Make staticcheck happy

fetcher/fetcher_file.go

@@ -23,7 +23,7 @@ type File struct {
 // Init sets the Path and Interval options
 func (f *File) Init() error {
 	if f.Path == "" {
-		return fmt.Errorf("Path required")
+		return errors.New("path required")
 	}
 	if f.Interval < 1*time.Second {
 		f.Interval = 1 * time.Second
@@ -88,12 +88,12 @@ func (f *File) updateHash() error {
 		if os.IsNotExist(err) {
 			return nil
 		}
-		return fmt.Errorf("Open file error: %s", err)
+		return fmt.Errorf("open file error: %w", err)
 	}
 	defer file.Close()
 	s, err := file.Stat()
 	if err != nil {
-		return fmt.Errorf("Get file stat error: %s", err)
+		return fmt.Errorf("get file stat error: %w", err)
 	}
 	f.hash = fmt.Sprintf("%d|%d", s.ModTime().UnixNano(), s.Size())
 	return nil

fetcher/fetcher_github.go

@@ -3,6 +3,7 @@ package fetcher
 import (
 	"compress/gzip"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"log"
@@ -46,10 +47,10 @@ func (h *Github) defaultAsset(filename string) bool {
 func (h *Github) Init() error {
 	//apply defaults
 	if h.User == "" {
-		return fmt.Errorf("User required")
+		return errors.New("user required")
 	}
 	if h.Repo == "" {
-		return fmt.Errorf("Repo required")
+		return errors.New("repo required")
 	}
 	if h.Asset == nil {
 		h.Asset = h.defaultAsset
@@ -73,7 +74,7 @@ func (h *Github) Fetch() (io.Reader, error) {
 	//check release status
 	resp, err := http.Get(h.releaseURL)
 	if err != nil {
-		return nil, fmt.Errorf("release info request failed (%s)", err)
+		return nil, fmt.Errorf("release info request failed (%w)", err)
 	}
 	if resp.StatusCode != http.StatusOK {
 		resp.Body.Close()
@@ -82,7 +83,7 @@ func (h *Github) Fetch() (io.Reader, error) {
 	//clear assets
 	h.latestRelease.Assets = nil
 	if err := json.NewDecoder(resp.Body).Decode(&h.latestRelease); err != nil {
-		return nil, fmt.Errorf("invalid request info (%s)", err)
+		return nil, fmt.Errorf("invalid request info (%w)", err)
 	}
 	resp.Body.Close()
 	//find appropriate asset
@@ -100,7 +101,7 @@ func (h *Github) Fetch() (io.Reader, error) {
 	req, _ := http.NewRequest("HEAD", assetURL, nil)
 	resp, err = http.DefaultTransport.RoundTrip(req)
 	if err != nil {
-		return nil, fmt.Errorf("release location request failed (%s)", err)
+		return nil, fmt.Errorf("release location request failed (%w)", err)
 	}
 	resp.Body.Close()
 	if resp.StatusCode != http.StatusFound {
@@ -110,12 +111,12 @@ func (h *Github) Fetch() (io.Reader, error) {
 	//pseudo-HEAD request
 	req, err = http.NewRequest("GET", s3URL, nil)
 	if err != nil {
-		return nil, fmt.Errorf("release location url error (%s)", err)
+		return nil, fmt.Errorf("release location url error (%w)", err)
 	}
 	req.Header.Set("Range", "bytes=0-0") // HEAD not allowed so we request for 1 byte
 	resp, err = http.DefaultTransport.RoundTrip(req)
 	if err != nil {
-		return nil, fmt.Errorf("release location request failed (%s)", err)
+		return nil, fmt.Errorf("release location request failed (%w)", err)
 	}
 	resp.Body.Close()
 	if resp.StatusCode != http.StatusPartialContent {
@@ -128,7 +129,7 @@ func (h *Github) Fetch() (io.Reader, error) {
 	//get binary request
 	resp, err = http.Get(s3URL)
 	if err != nil {
-		return nil, fmt.Errorf("release binary request failed (%s)", err)
+		return nil, fmt.Errorf("release binary request failed (%w)", err)
 	}
 	if resp.StatusCode != http.StatusOK {
 		resp.Body.Close()

fetcher/fetcher_http.go

@@ -51,7 +51,7 @@ func (h *HTTP) Fetch() (io.Reader, error) {
 	//status check using HEAD
 	resp, err := http.Head(h.URL)
 	if err != nil {
-		return nil, fmt.Errorf("HEAD request failed (%s)", err)
+		return nil, fmt.Errorf("HEAD request failed (%w)", err)
 	}
 	resp.Body.Close()
 	if resp.StatusCode != http.StatusOK {
@@ -74,7 +74,7 @@ func (h *HTTP) Fetch() (io.Reader, error) {
 	//binary fetch using GET
 	resp, err = http.Get(h.URL)
 	if err != nil {
-		return nil, fmt.Errorf("GET request failed (%s)", err)
+		return nil, fmt.Errorf("GET request failed (%w)", err)
 	}
 	if resp.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("GET request failed (status code %d)", resp.StatusCode)

fetcher/fetcher_s3.go

@@ -34,7 +34,6 @@ type S3 struct {
 	//GetTimeout defaults to 5 minutes
 	GetTimeout time.Duration
 	//interal state
-	client   *http.Client
 	delay    bool
 	lastETag string
 }
@@ -94,7 +93,7 @@ func (s *S3) Fetch() (io.Reader, error) {
 	c.Timeout = s.HeadTimeout
 	resp, err := c.Do(req)
 	if err != nil {
-		return nil, fmt.Errorf("HEAD request failed (%s)", err)
+		return nil, fmt.Errorf("HEAD request failed (%w)", err)
 	}
 	if resp.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("HEAD request failed (%s)", resp.Status)
@@ -112,7 +111,7 @@ func (s *S3) Fetch() (io.Reader, error) {
 	c.Timeout = s.GetTimeout
 	resp, err = c.Do(req)
 	if err != nil {
-		return nil, fmt.Errorf("GET request failed (%s)", err)
+		return nil, fmt.Errorf("GET request failed (%w)", err)
 	}
 	if resp.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("GET request failed (%s)", resp.Status)

overseer.go

@@ -99,9 +99,9 @@ func Run(c Config) {
 	err := runErr(&c)
 	if err != nil {
 		if c.Required {
-			log.Fatalf("[overseer] %s", err)
+			log.Fatalf("[overseer] %+v", err)
 		} else if c.Debug || !c.NoWarn {
-			log.Printf("[overseer] disabled. run failed: %s", err)
+			log.Printf("[overseer] disabled. run failed: %+v", err)
 		}
 		c.Program(DisabledState)
 		return

proc_master.go

@@ -14,7 +14,6 @@ import (
 	"os/signal"
 	"path/filepath"
 	"strconv"
-	"sync"
 	"syscall"
 	"time"
 )
@@ -27,10 +26,9 @@ type master struct {
 	slaveID             int
 	slaveCmd            *exec.Cmd
 	slaveExtraFiles     []*os.File
-	binPath, tmpBinPath string
+	binPath             string
 	binPerms            os.FileMode
 	binHash             []byte
-	restartMux          sync.Mutex
 	restarting          bool
 	restartedAt         time.Time
 	restarted           chan bool
@@ -47,7 +45,7 @@ func (mp *master) run() error {
 	}
 	if mp.Config.Fetcher != nil {
 		if err := mp.Config.Fetcher.Init(); err != nil {
-			mp.warnf("fetcher init failed (%s). fetcher disabled.", err)
+			mp.warnf("fetcher init failed (%w). fetcher disabled.", err)
 			mp.Config.Fetcher = nil
 		}
 	}
@@ -67,11 +65,11 @@ func (mp *master) checkBinary() error {
 	//get path to binary and confirm its writable
 	binPath, err := os.Executable()
 	if err != nil {
-		return fmt.Errorf("failed to find binary path (%s)", err)
+		return fmt.Errorf("failed to find binary path (%w)", err)
 	}
 	mp.binPath = binPath
 	if info, err := os.Stat(binPath); err != nil {
-		return fmt.Errorf("failed to stat binary (%s)", err)
+		return fmt.Errorf("failed to stat binary (%w)", err)
 	} else if info.Size() == 0 {
 		return fmt.Errorf("binary file is empty")
 	} else {
@@ -80,7 +78,7 @@ func (mp *master) checkBinary() error {
 	}
 	f, err := os.Open(binPath)
 	if err != nil {
-		return fmt.Errorf("cannot read binary (%s)", err)
+		return fmt.Errorf("cannot read binary (%w)", err)
 	}
 	//initial hash of file
 	hash := sha1.New()
@@ -90,10 +88,10 @@ func (mp *master) checkBinary() error {
 	//test bin<->tmpbin moves
 	if mp.Config.Fetcher != nil {
 		if err := move(tmpBinPath, mp.binPath); err != nil {
-			return fmt.Errorf("cannot move binary (%s)", err)
+			return fmt.Errorf("cannot move binary (%w)", err)
 		}
 		if err := move(mp.binPath, tmpBinPath); err != nil {
-			return fmt.Errorf("cannot move binary back (%s)", err)
+			return fmt.Errorf("cannot move binary back (%w)", err)
 		}
 	}
 	return nil
@@ -146,7 +144,7 @@ func (mp *master) handleSignal(s os.Signal) {
 func (mp *master) sendSignal(s os.Signal) {
 	if mp.slaveCmd != nil && mp.slaveCmd.Process != nil {
 		if err := mp.slaveCmd.Process.Signal(s); err != nil {
-			mp.debugf("signal failed (%s), assuming slave process died unexpectedly", err)
+			mp.debugf("signal failed (%w), assuming slave process died unexpectedly", err)
 			os.Exit(1)
 		}
 	}
@@ -157,18 +155,18 @@ func (mp *master) retreiveFileDescriptors() error {
 	for i, addr := range mp.Config.Addresses {
 		a, err := net.ResolveTCPAddr("tcp", addr)
 		if err != nil {
-			return fmt.Errorf("Invalid address %s (%s)", addr, err)
+			return fmt.Errorf("invalid address %s (%w)", addr, err)
 		}
 		l, err := net.ListenTCP("tcp", a)
 		if err != nil {
 			return err
 		}
 		f, err := l.File()
 		if err != nil {
-			return fmt.Errorf("Failed to retreive fd for: %s (%s)", addr, err)
+			return fmt.Errorf("failed to retreive fd for: %s (%w)", addr, err)
 		}
 		if err := l.Close(); err != nil {
-			return fmt.Errorf("Failed to close listener for: %s (%s)", addr, err)
+			return fmt.Errorf("failed to close listener for: %s (%w)", addr, err)
 		}
 		mp.slaveExtraFiles[i] = f
 	}
@@ -183,7 +181,7 @@ func (mp *master) fetchLoop() {
 		t0 := time.Now()
 		mp.fetch()
 		//duration fetch of fetch
-		diff := time.Now().Sub(t0)
+		diff := time.Since(t0)
 		if diff < min {
 			delay := min - diff
 			//ensures at least MinFetchInterval delay.
@@ -202,7 +200,7 @@ func (mp *master) fetch() {
 	}
 	reader, err := mp.Fetcher.Fetch()
 	if err != nil {
-		mp.debugf("failed to get latest version: %s", err)
+		mp.debugf("failed to get latest version: %w", err)
 		return
 	}
 	if reader == nil {
@@ -220,7 +218,7 @@ func (mp *master) fetch() {
 	}
 	tmpBin, err := os.OpenFile(tmpBinPath, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0666)
 	if err != nil {
-		mp.warnf("failed to open temp binary: %s", err)
+		mp.warnf("failed to open temp binary: %w", err)
 		return
 	}
 	defer func() {
@@ -233,7 +231,7 @@ func (mp *master) fetch() {
 	//write to a temp file
 	_, err = io.Copy(tmpBin, reader)
 	if err != nil {
-		mp.warnf("failed to write temp binary: %s", err)
+		mp.warnf("failed to write temp binary: %w", err)
 		return
 	}
 	//compare hash
@@ -244,25 +242,25 @@ func (mp *master) fetch() {
 	}
 	//copy permissions
 	if err := chmod(tmpBin, mp.binPerms); err != nil {
-		mp.warnf("failed to make temp binary executable: %s", err)
+		mp.warnf("failed to make temp binary executable: %w", err)
 		return
 	}
 	if err := chown(tmpBin, uid, gid); err != nil {
-		mp.warnf("failed to change owner of binary: %s", err)
+		mp.warnf("failed to change owner of binary: %w", err)
 		return
 	}
 	if _, err := tmpBin.Stat(); err != nil {
-		mp.warnf("failed to stat temp binary: %s", err)
+		mp.warnf("failed to stat temp binary: %w", err)
 		return
 	}
 	tmpBin.Close()
 	if _, err := os.Stat(tmpBinPath); err != nil {
-		mp.warnf("failed to stat temp binary by path: %s", err)
+		mp.warnf("failed to stat temp binary by path: %w", err)
 		return
 	}
 	if mp.Config.PreUpgrade != nil {
 		if err := mp.Config.PreUpgrade(tmpBinPath); err != nil {
-			mp.warnf("user cancelled upgrade: %s", err)
+			mp.warnf("user cancelled upgrade: %w", err)
 			return
 		}
 	}
@@ -284,7 +282,7 @@ func (mp *master) fetch() {
 	tokenOut, err := cmd.CombinedOutput()
 	returned = true
 	if err != nil {
-		mp.warnf("failed to run temp binary: %s (%s) output \"%s\"", err, tmpBinPath, tokenOut)
+		mp.warnf("failed to run temp binary: %w (%s) output \"%s\"", err, tmpBinPath, tokenOut)
 		return
 	}
 	if tokenIn != string(tokenOut) {
@@ -293,7 +291,7 @@ func (mp *master) fetch() {
 	}
 	//overwrite!
 	if err := move(mp.binPath, tmpBinPath); err != nil {
-		mp.warnf("failed to overwrite binary: %s", err)
+		mp.warnf("failed to overwrite binary: %w", err)
 		return
 	}
 	mp.debugf("upgraded binary (%x -> %x)", mp.binHash[:12], newHash[:12])
@@ -303,7 +301,6 @@ func (mp *master) fetch() {
 		mp.triggerRestart()
 	}
 	//and keep fetching...
-	return
 }
 
 func (mp *master) triggerRestart() {
@@ -363,7 +360,7 @@ func (mp *master) fork() error {
 	//include socket files
 	cmd.ExtraFiles = mp.slaveExtraFiles
 	if err := cmd.Start(); err != nil {
-		return fmt.Errorf("Failed to start slave process: %s", err)
+		return fmt.Errorf("failed to start slave process: %w", err)
 	}
 	//was scheduled to restart, notify success
 	if mp.restarting {

proc_slave.go

@@ -145,9 +145,3 @@ func (sp *slave) debugf(f string, args ...interface{}) {
 		log.Printf("[overseer slave#"+sp.id+"] "+f, args...)
 	}
 }
-
-func (sp *slave) warnf(f string, args ...interface{}) {
-	if sp.Config.Debug || !sp.Config.NoWarn {
-		log.Printf("[overseer slave#"+sp.id+"] "+f, args...)
-	}
-}

proc_slave_others.go

@@ -13,7 +13,7 @@ func (sp *slave) watchParent() error {
 	sp.masterPid = os.Getppid()
 	proc, err := os.FindProcess(sp.masterPid)
 	if err != nil {
-		return fmt.Errorf("master process: %s", err)
+		return fmt.Errorf("master process: %w", err)
 	}
 	sp.masterProc = proc
 	go func() {

proc_slave_windows.go

@@ -5,9 +5,10 @@ package overseer
 import (
 	"context"
 	"fmt"
-	"github.com/StackExchange/wmi"
 	"os"
 	"time"
+
+	"github.com/StackExchange/wmi"
 )
 
 var (
@@ -57,7 +58,7 @@ func (sp *slave) watchParent() error {
 	sp.masterPid = os.Getppid()
 	proc, err := os.FindProcess(sp.masterPid)
 	if err != nil {
-		return fmt.Errorf("master process: %s", err)
+		return fmt.Errorf("master process: %w", err)
 	}
 	sp.masterProc = proc
 	go func() {

sys_windows.go

@@ -34,7 +34,7 @@ func move(dst, src string) error {
 	R := func(s string) string { return replShellMeta.Replace(syscall.EscapeArg(s)) }
 	cmd := exec.Command("cmd", "/c", `move /y `+R(src)+` `+R(dst))
 	if b, err := cmd.CombinedOutput(); err != nil {
-		return fmt.Errorf("%v: %q: %v", cmd.Args, bytes.TrimSpace(b), err)
+		return fmt.Errorf("%v: %q: %w", cmd.Args, bytes.TrimSpace(b), err)
 	}
 	return nil
 }