Update error message handling

Use Go 1.13 `%w` error formatting
* Update minimum Go version to 1.13.
* Bump vendoring.
* Update all error format strings to use %w.
* Cleanup consistency of use.
* Cleanup use of `errors.New("string" + var)` to use `fmt.Errorf()`.

#310

Signed-off-by: Ben Kochie <superq@gmail.com>

Author: SuperQ

arp.go

@@ -36,7 +36,7 @@ type ARPEntry struct {
 func (fs FS) GatherARPEntries() ([]ARPEntry, error) {
 	data, err := ioutil.ReadFile(fs.proc.Path("net/arp"))
 	if err != nil {
-		return nil, fmt.Errorf("error reading arp %s: %s", fs.proc.Path("net/arp"), err)
+		return nil, fmt.Errorf("error reading arp %q: %w", fs.proc.Path("net/arp"), err)
 	}
 
 	return parseARPEntries(data)
@@ -59,7 +59,7 @@ func parseARPEntries(data []byte) ([]ARPEntry, error) {
 		} else if width == expectedDataWidth {
 			entry, err := parseARPEntry(columns)
 			if err != nil {
-				return []ARPEntry{}, fmt.Errorf("failed to parse ARP entry: %s", err)
+				return []ARPEntry{}, fmt.Errorf("failed to parse ARP entry: %w", err)
 			}
 			entries = append(entries, entry)
 		} else {

bcache/get.go

@@ -329,12 +329,12 @@ func (p *parser) getPriorityStats() PriorityStats {
 	for scanner.Scan() {
 		err = parsePriorityStats(scanner.Text(), &res)
 		if err != nil {
-			p.err = fmt.Errorf("failed to parse: %s (%s)", path, err)
+			p.err = fmt.Errorf("failed to parse path %q: %w", path, err)
 			return res
 		}
 	}
 	if err := scanner.Err(); err != nil {
-		p.err = fmt.Errorf("failed to parse: %s (%s)", path, err)
+		p.err = fmt.Errorf("failed to parse path %q: %w", path, err)
 		return res
 	}
 	return res
@@ -358,12 +358,12 @@ func (p *parser) getWritebackRateDebug() WritebackRateDebugStats {
 	for scanner.Scan() {
 		err = parseWritebackRateDebug(scanner.Text(), &res)
 		if err != nil {
-			p.err = fmt.Errorf("failed to parse: %s (%s)", path, err)
+			p.err = fmt.Errorf("failed to parse path %q: %w", path, err)
 			return res
 		}
 	}
 	if err := scanner.Err(); err != nil {
-		p.err = fmt.Errorf("failed to parse: %s (%s)", path, err)
+		p.err = fmt.Errorf("failed to parse path %q: %w", path, err)
 		return res
 	}
 	return res

buddyinfo.go

@@ -74,7 +74,7 @@ func parseBuddyInfo(r io.Reader) ([]BuddyInfo, error) {
 		for i := 0; i < arraySize; i++ {
 			sizes[i], err = strconv.ParseFloat(parts[i+4], 64)
 			if err != nil {
-				return nil, fmt.Errorf("invalid value in buddyinfo: %s", err)
+				return nil, fmt.Errorf("invalid value in buddyinfo: %w", err)
 			}
 		}
 

cpuinfo.go

@@ -18,7 +18,7 @@ package procfs
 import (
 	"bufio"
 	"bytes"
-	"errors"
+	"fmt"
 	"regexp"
 	"strconv"
 	"strings"
@@ -77,7 +77,7 @@ func parseCPUInfoX86(info []byte) ([]CPUInfo, error) {
 	// find the first "processor" line
 	firstLine := firstNonEmptyLine(scanner)
 	if !strings.HasPrefix(firstLine, "processor") || !strings.Contains(firstLine, ":") {
-		return nil, errors.New("invalid cpuinfo file: " + firstLine)
+		return nil, fmt.Errorf("invalid cpuinfo file: %q", firstLine)
 	}
 	field := strings.SplitN(firstLine, ": ", 2)
 	v, err := strconv.ParseUint(field[1], 0, 32)
@@ -192,7 +192,7 @@ func parseCPUInfoARM(info []byte) ([]CPUInfo, error) {
 	firstLine := firstNonEmptyLine(scanner)
 	match, _ := regexp.MatchString("^[Pp]rocessor", firstLine)
 	if !match || !strings.Contains(firstLine, ":") {
-		return nil, errors.New("invalid cpuinfo file: " + firstLine)
+		return nil, fmt.Errorf("invalid cpuinfo file: %q", firstLine)
 	}
 	field := strings.SplitN(firstLine, ": ", 2)
 	cpuinfo := []CPUInfo{}
@@ -256,7 +256,7 @@ func parseCPUInfoS390X(info []byte) ([]CPUInfo, error) {
 
 	firstLine := firstNonEmptyLine(scanner)
 	if !strings.HasPrefix(firstLine, "vendor_id") || !strings.Contains(firstLine, ":") {
-		return nil, errors.New("invalid cpuinfo file: " + firstLine)
+		return nil, fmt.Errorf("invalid cpuinfo file: %q", firstLine)
 	}
 	field := strings.SplitN(firstLine, ": ", 2)
 	cpuinfo := []CPUInfo{}
@@ -281,7 +281,7 @@ func parseCPUInfoS390X(info []byte) ([]CPUInfo, error) {
 		if strings.HasPrefix(line, "processor") {
 			match := cpuinfoS390XProcessorRegexp.FindStringSubmatch(line)
 			if len(match) < 2 {
-				return nil, errors.New("Invalid line found in cpuinfo: " + line)
+				return nil, fmt.Errorf("invalid cpuinfo file: %q", firstLine)
 			}
 			cpu := commonCPUInfo
 			v, err := strconv.ParseUint(match[1], 0, 32)
@@ -341,7 +341,7 @@ func parseCPUInfoMips(info []byte) ([]CPUInfo, error) {
 	// find the first "processor" line
 	firstLine := firstNonEmptyLine(scanner)
 	if !strings.HasPrefix(firstLine, "system type") || !strings.Contains(firstLine, ":") {
-		return nil, errors.New("invalid cpuinfo file: " + firstLine)
+		return nil, fmt.Errorf("invalid cpuinfo file: %q", firstLine)
 	}
 	field := strings.SplitN(firstLine, ": ", 2)
 	cpuinfo := []CPUInfo{}
@@ -383,7 +383,7 @@ func parseCPUInfoPPC(info []byte) ([]CPUInfo, error) {
 
 	firstLine := firstNonEmptyLine(scanner)
 	if !strings.HasPrefix(firstLine, "processor") || !strings.Contains(firstLine, ":") {
-		return nil, errors.New("invalid cpuinfo file: " + firstLine)
+		return nil, fmt.Errorf("invalid cpuinfo file: %q", firstLine)
 	}
 	field := strings.SplitN(firstLine, ": ", 2)
 	v, err := strconv.ParseUint(field[1], 0, 32)
@@ -428,7 +428,7 @@ func parseCPUInfoRISCV(info []byte) ([]CPUInfo, error) {
 
 	firstLine := firstNonEmptyLine(scanner)
 	if !strings.HasPrefix(firstLine, "processor") || !strings.Contains(firstLine, ":") {
-		return nil, errors.New("invalid cpuinfo file: " + firstLine)
+		return nil, fmt.Errorf("invalid cpuinfo file: %q", firstLine)
 	}
 	field := strings.SplitN(firstLine, ": ", 2)
 	v, err := strconv.ParseUint(field[1], 0, 32)
@@ -464,7 +464,7 @@ func parseCPUInfoRISCV(info []byte) ([]CPUInfo, error) {
 }
 
 func parseCPUInfoDummy(_ []byte) ([]CPUInfo, error) { // nolint:unused,deadcode
-	return nil, errors.New("not implemented")
+	return nil, fmt.Errorf("not implemented")
 }
 
 // firstNonEmptyLine advances the scanner to the first non-empty line

crypto.go

@@ -55,12 +55,12 @@ func (fs FS) Crypto() ([]Crypto, error) {
 	path := fs.proc.Path("crypto")
 	b, err := util.ReadFileNoStat(path)
 	if err != nil {
-		return nil, fmt.Errorf("error reading crypto %s: %s", path, err)
+		return nil, fmt.Errorf("error reading crypto %q: %w", path, err)
 	}
 
 	crypto, err := parseCrypto(bytes.NewReader(b))
 	if err != nil {
-		return nil, fmt.Errorf("error parsing crypto %s: %s", path, err)
+		return nil, fmt.Errorf("error parsing crypto %q: %w", path, err)
 	}
 
 	return crypto, nil

fscache.go

@@ -236,7 +236,7 @@ func (fs FS) Fscacheinfo() (Fscacheinfo, error) {
 
 	m, err := parseFscacheinfo(bytes.NewReader(b))
 	if err != nil {
-		return Fscacheinfo{}, fmt.Errorf("failed to parse Fscacheinfo: %v", err)
+		return Fscacheinfo{}, fmt.Errorf("failed to parse Fscacheinfo: %w", err)
 	}
 
 	return *m, nil

go.mod

@@ -1,9 +1,9 @@
 module github.com/prometheus/procfs
 
-go 1.12
+go 1.13
 
 require (
-	github.com/google/go-cmp v0.3.1
-	golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e
-	golang.org/x/sys v0.0.0-20200106162015-b016eb3dc98e
+	github.com/google/go-cmp v0.5.4
+	golang.org/x/sync v0.0.0-20201207232520-09787c993a3a
+	golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c
 )

go.sum

@@ -1,6 +1,8 @@
-github.com/google/go-cmp v0.3.1 h1:Xye71clBPdm5HgqGwUkwhbynsUJZhDbS20FvLhQ2izg=
-github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
-golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e h1:vcxGaoTs7kV8m5Np9uUNQin4BrLOthgV7252N8V+FwY=
-golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sys v0.0.0-20200106162015-b016eb3dc98e h1:LwyF2AFISC9nVbS6MgzsaQNSUsRXI49GS+YQ5KX/QH0=
-golang.org/x/sys v0.0.0-20200106162015-b016eb3dc98e/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+github.com/google/go-cmp v0.5.4 h1:L8R9j+yAqZuZjsqh/z+F1NCffTKKLShY6zXTItVIZ8M=
+github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+golang.org/x/sync v0.0.0-20201207232520-09787c993a3a h1:DcqTD9SDLc+1P/r1EmRBwnVsrOwW+kk2vWf9n+1sGhs=
+golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c h1:VwygUrnw9jn88c4u8GD3rZQbqrP/tgas88tPUbBxQrk=
+golang.org/x/sys v0.0.0-20210124154548-22da62e12c0c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

internal/fs/fs.go

@@ -39,10 +39,10 @@ type FS string
 func NewFS(mountPoint string) (FS, error) {
 	info, err := os.Stat(mountPoint)
 	if err != nil {
-		return "", fmt.Errorf("could not read %s: %s", mountPoint, err)
+		return "", fmt.Errorf("could not read %q: %w", mountPoint, err)
 	}
 	if !info.IsDir() {
-		return "", fmt.Errorf("mount point %s is not a directory", mountPoint)
+		return "", fmt.Errorf("mount point %q is not a directory", mountPoint)
 	}
 
 	return FS(mountPoint), nil

iscsi/get.go

@@ -36,7 +36,7 @@ func GetStats(iqnPath string) (*Stats, error) {
 
 	matches, err := filepath.Glob(filepath.Join(iqnPath, "tpgt*"))
 	if err != nil {
-		return nil, fmt.Errorf("iscsi: GetStats: get TPGT path error %v", err)
+		return nil, fmt.Errorf("iscsi: GetStats: get TPGT path error %w", err)
 	}
 	istats.Tpgt = make([]TPGT, len(matches))
 
@@ -63,11 +63,11 @@ func GetStats(iqnPath string) (*Stats, error) {
 func isPathEnable(path string) (bool, error) {
 	enableReadout, err := ioutil.ReadFile(filepath.Join(path, "enable"))
 	if err != nil {
-		return false, fmt.Errorf("iscsi: isPathEnable ReadFile error %v", err)
+		return false, fmt.Errorf("iscsi: isPathEnable ReadFile error %w", err)
 	}
 	isEnable, err := strconv.ParseBool(strings.TrimSpace(string(enableReadout)))
 	if err != nil {
-		return false, fmt.Errorf("iscsi: isPathEnable ParseBool error %v", err)
+		return false, fmt.Errorf("iscsi: isPathEnable ParseBool error %w", err)
 	}
 	return isEnable, nil
 }
@@ -77,14 +77,14 @@ func getLunLinkTarget(lunPath string) (lunObject LUN, err error) {
 	lunObject.LunPath = lunPath
 	files, err := ioutil.ReadDir(lunPath)
 	if err != nil {
-		return lunObject, fmt.Errorf("getLunLinkTarget: ReadDir path %s error %v", lunPath, err)
+		return lunObject, fmt.Errorf("getLunLinkTarget: ReadDir path %q: %w", lunPath, err)
 	}
 	for _, file := range files {
 		fileInfo, _ := os.Lstat(filepath.Join(lunPath, file.Name()))
 		if fileInfo.Mode()&os.ModeSymlink != 0 {
 			target, err := os.Readlink(filepath.Join(lunPath, fileInfo.Name()))
 			if err != nil {
-				return lunObject, fmt.Errorf("getLunLinkTarget: Readlink err %v", err)
+				return lunObject, fmt.Errorf("getLunLinkTarget: Readlink: %w", err)
 			}
 			targetPath, objectName := filepath.Split(target)
 			_, typeWithNumber := filepath.Split(filepath.Clean(targetPath))
@@ -112,24 +112,21 @@ func ReadWriteOPS(iqnPath string, tpgt string, lun string) (readmb uint64,
 		"statistics/scsi_tgt_port/read_mbytes")
 	readmb, err = util.ReadUintFromFile(readmbPath)
 	if err != nil {
-		return 0, 0, 0, fmt.Errorf("iscsi: ReadWriteOPS: read_mbytes error file %s and %v",
-			readmbPath, err)
+		return 0, 0, 0, fmt.Errorf("iscsi: ReadWriteOPS: read_mbytes error file %q: %w", readmbPath, err)
 	}
 
 	writembPath := filepath.Join(iqnPath, tpgt, "lun", lun,
 		"statistics/scsi_tgt_port/write_mbytes")
 	writemb, err = util.ReadUintFromFile(writembPath)
 	if err != nil {
-		return 0, 0, 0, fmt.Errorf("iscsi: ReadWriteOPS: write_mbytes error file %s and %v",
-			writembPath, err)
+		return 0, 0, 0, fmt.Errorf("iscsi: ReadWriteOPS: write_mbytes error file %q: %w", writembPath, err)
 	}
 
 	iopsPath := filepath.Join(iqnPath, tpgt, "lun", lun,
 		"statistics/scsi_tgt_port/in_cmds")
 	iops, err = util.ReadUintFromFile(iopsPath)
 	if err != nil {
-		return 0, 0, 0, fmt.Errorf("iscsi: ReadWriteOPS: in_cmds error file %s and %v",
-			iopsPath, err)
+		return 0, 0, 0, fmt.Errorf("iscsi: ReadWriteOPS: in_cmds error file %q: %w", iopsPath, err)
 	}
 
 	return readmb, writemb, iops, nil
@@ -150,7 +147,7 @@ func (fs FS) GetFileioUdev(fileioNumber string, objectName string) (*FILEIO, err
 	}
 	filename, err := ioutil.ReadFile(udevPath)
 	if err != nil {
-		return nil, fmt.Errorf("iscsi: GetFileioUdev: Cannot read filename from udev link :%s", udevPath)
+		return nil, fmt.Errorf("iscsi: GetFileioUdev: Cannot read filename from udev link: %s", udevPath)
 	}
 	fileio.Filename = strings.TrimSpace(string(filename))
 
@@ -238,7 +235,7 @@ func (fs FS) GetRDMCPPath(rdmcpNumber string, objectName string) (*RDMCP, error)
 	}
 	isEnable, err := isPathEnable(rdmcpPath)
 	if err != nil {
-		return nil, fmt.Errorf("iscsi: GetRDMCPPath: error %v", err)
+		return nil, fmt.Errorf("iscsi: GetRDMCPPath: error %w", err)
 	}
 	if isEnable {
 		return &rdmcp, nil