1
0
mirror of https://github.com/imgproxy/imgproxy.git synced 2025-02-02 11:34:20 +02:00

Get rid of os.Exit

This commit is contained in:
DarthSim 2020-02-27 21:44:59 +06:00
parent 5d3b8f19fc
commit 8e3cf54d85
14 changed files with 225 additions and 109 deletions

View File

@ -1,6 +1,9 @@
# Changelog
## [Unreleased]
### Changed
- `imgproxy -v` is replaced with `imgproxy version`.
### Fixed
- Fix loadind BMP stored in ICO.
- Fix ambiguous HEIC magic bytes (MP4 videos has been detected as HEIC).

130
config.go
View File

@ -58,7 +58,7 @@ func boolEnvConfig(b *bool, name string) {
}
}
func hexEnvConfig(b *[]securityKey, name string) {
func hexEnvConfig(b *[]securityKey, name string) error {
var err error
if env := os.Getenv(name); len(env) > 0 {
@ -68,22 +68,24 @@ func hexEnvConfig(b *[]securityKey, name string) {
for i, part := range parts {
if keys[i], err = hex.DecodeString(part); err != nil {
logFatal("%s expected to be hex-encoded strings. Invalid: %s\n", name, part)
return fmt.Errorf("%s expected to be hex-encoded strings. Invalid: %s\n", name, part)
}
}
*b = keys
}
return nil
}
func hexFileConfig(b *[]securityKey, filepath string) {
func hexFileConfig(b *[]securityKey, filepath string) error {
if len(filepath) == 0 {
return
return nil
}
f, err := os.Open(filepath)
if err != nil {
logFatal("Can't open file %s\n", filepath)
return fmt.Errorf("Can't open file %s\n", filepath)
}
keys := []securityKey{}
@ -99,49 +101,55 @@ func hexFileConfig(b *[]securityKey, filepath string) {
if key, err := hex.DecodeString(part); err == nil {
keys = append(keys, key)
} else {
logFatal("%s expected to contain hex-encoded strings. Invalid: %s\n", filepath, part)
return fmt.Errorf("%s expected to contain hex-encoded strings. Invalid: %s\n", filepath, part)
}
}
if err := scanner.Err(); err != nil {
logFatal("Failed to read file %s: %s", filepath, err)
return fmt.Errorf("Failed to read file %s: %s", filepath, err)
}
*b = keys
return nil
}
func presetEnvConfig(p presets, name string) {
func presetEnvConfig(p presets, name string) error {
if env := os.Getenv(name); len(env) > 0 {
presetStrings := strings.Split(env, ",")
for _, presetStr := range presetStrings {
if err := parsePreset(p, presetStr); err != nil {
logFatal(err.Error())
return fmt.Errorf(err.Error())
}
}
}
return nil
}
func presetFileConfig(p presets, filepath string) {
func presetFileConfig(p presets, filepath string) error {
if len(filepath) == 0 {
return
return nil
}
f, err := os.Open(filepath)
if err != nil {
logFatal("Can't open file %s\n", filepath)
return fmt.Errorf("Can't open file %s\n", filepath)
}
scanner := bufio.NewScanner(f)
for scanner.Scan() {
if err := parsePreset(p, scanner.Text()); err != nil {
logFatal(err.Error())
return fmt.Errorf(err.Error())
}
}
if err := scanner.Err(); err != nil {
logFatal("Failed to read presets file: %s", err)
return fmt.Errorf("Failed to read presets file: %s", err)
}
return nil
}
type config struct {
@ -263,18 +271,12 @@ var conf = config{
BufferPoolCalibrationThreshold: 1024,
}
func configure() {
func configure() error {
keyPath := flag.String("keypath", "", "path of the file with hex-encoded key")
saltPath := flag.String("saltpath", "", "path of the file with hex-encoded salt")
presetsPath := flag.String("presets", "", "path of the file with presets")
showVersion := flag.Bool("v", false, "show version")
flag.Parse()
if *showVersion {
fmt.Println(version)
os.Exit(0)
}
if port := os.Getenv("PORT"); len(port) > 0 {
conf.Bind = fmt.Sprintf(":%s", port)
}
@ -321,12 +323,20 @@ func configure() {
boolEnvConfig(&conf.UseLinearColorspace, "IMGPROXY_USE_LINEAR_COLORSPACE")
boolEnvConfig(&conf.DisableShrinkOnLoad, "IMGPROXY_DISABLE_SHRINK_ON_LOAD")
hexEnvConfig(&conf.Keys, "IMGPROXY_KEY")
hexEnvConfig(&conf.Salts, "IMGPROXY_SALT")
if err := hexEnvConfig(&conf.Keys, "IMGPROXY_KEY"); err != nil {
return err
}
if err := hexEnvConfig(&conf.Salts, "IMGPROXY_SALT"); err != nil {
return err
}
intEnvConfig(&conf.SignatureSize, "IMGPROXY_SIGNATURE_SIZE")
hexFileConfig(&conf.Keys, *keyPath)
hexFileConfig(&conf.Salts, *saltPath)
if err := hexFileConfig(&conf.Keys, *keyPath); err != nil {
return err
}
if err := hexFileConfig(&conf.Salts, *saltPath); err != nil {
return err
}
strEnvConfig(&conf.Secret, "IMGPROXY_SECRET")
@ -350,8 +360,12 @@ func configure() {
strEnvConfig(&conf.BaseURL, "IMGPROXY_BASE_URL")
presetEnvConfig(conf.Presets, "IMGPROXY_PRESETS")
presetFileConfig(conf.Presets, *presetsPath)
if err := presetEnvConfig(conf.Presets, "IMGPROXY_PRESETS"); err != nil {
return err
}
if err := presetFileConfig(conf.Presets, *presetsPath); err != nil {
return err
}
boolEnvConfig(&conf.OnlyPresets, "IMGPROXY_ONLY_PRESETS")
strEnvConfig(&conf.WatermarkData, "IMGPROXY_WATERMARK_DATA")
@ -379,7 +393,7 @@ func configure() {
intEnvConfig(&conf.BufferPoolCalibrationThreshold, "IMGPROXY_BUFFER_POOL_CALIBRATION_THRESHOLD")
if len(conf.Keys) != len(conf.Salts) {
logFatal("Number of keys and number of salts should be equal. Keys: %d, salts: %d", len(conf.Keys), len(conf.Salts))
return fmt.Errorf("Number of keys and number of salts should be equal. Keys: %d, salts: %d", len(conf.Keys), len(conf.Salts))
}
if len(conf.Keys) == 0 {
logWarning("No keys defined, so signature checking is disabled")
@ -391,30 +405,30 @@ func configure() {
}
if conf.SignatureSize < 1 || conf.SignatureSize > 32 {
logFatal("Signature size should be within 1 and 32, now - %d\n", conf.SignatureSize)
return fmt.Errorf("Signature size should be within 1 and 32, now - %d\n", conf.SignatureSize)
}
if len(conf.Bind) == 0 {
logFatal("Bind address is not defined")
return fmt.Errorf("Bind address is not defined")
}
if conf.ReadTimeout <= 0 {
logFatal("Read timeout should be greater than 0, now - %d\n", conf.ReadTimeout)
return fmt.Errorf("Read timeout should be greater than 0, now - %d\n", conf.ReadTimeout)
}
if conf.WriteTimeout <= 0 {
logFatal("Write timeout should be greater than 0, now - %d\n", conf.WriteTimeout)
return fmt.Errorf("Write timeout should be greater than 0, now - %d\n", conf.WriteTimeout)
}
if conf.KeepAliveTimeout < 0 {
logFatal("KeepAlive timeout should be greater than or equal to 0, now - %d\n", conf.KeepAliveTimeout)
return fmt.Errorf("KeepAlive timeout should be greater than or equal to 0, now - %d\n", conf.KeepAliveTimeout)
}
if conf.DownloadTimeout <= 0 {
logFatal("Download timeout should be greater than 0, now - %d\n", conf.DownloadTimeout)
return fmt.Errorf("Download timeout should be greater than 0, now - %d\n", conf.DownloadTimeout)
}
if conf.Concurrency <= 0 {
logFatal("Concurrency should be greater than 0, now - %d\n", conf.Concurrency)
return fmt.Errorf("Concurrency should be greater than 0, now - %d\n", conf.Concurrency)
}
if conf.MaxClients <= 0 {
@ -422,43 +436,43 @@ func configure() {
}
if conf.TTL <= 0 {
logFatal("TTL should be greater than 0, now - %d\n", conf.TTL)
return fmt.Errorf("TTL should be greater than 0, now - %d\n", conf.TTL)
}
if conf.MaxSrcDimension < 0 {
logFatal("Max src dimension should be greater than or equal to 0, now - %d\n", conf.MaxSrcDimension)
return fmt.Errorf("Max src dimension should be greater than or equal to 0, now - %d\n", conf.MaxSrcDimension)
} else if conf.MaxSrcDimension > 0 {
logWarning("IMGPROXY_MAX_SRC_DIMENSION is deprecated and can be removed in future versions. Use IMGPROXY_MAX_SRC_RESOLUTION")
}
if conf.MaxSrcResolution <= 0 {
logFatal("Max src resolution should be greater than 0, now - %d\n", conf.MaxSrcResolution)
return fmt.Errorf("Max src resolution should be greater than 0, now - %d\n", conf.MaxSrcResolution)
}
if conf.MaxSrcFileSize < 0 {
logFatal("Max src file size should be greater than or equal to 0, now - %d\n", conf.MaxSrcFileSize)
return fmt.Errorf("Max src file size should be greater than or equal to 0, now - %d\n", conf.MaxSrcFileSize)
}
if conf.MaxAnimationFrames <= 0 {
logFatal("Max animation frames should be greater than 0, now - %d\n", conf.MaxAnimationFrames)
return fmt.Errorf("Max animation frames should be greater than 0, now - %d\n", conf.MaxAnimationFrames)
}
if conf.PngQuantizationColors < 2 {
logFatal("Png quantization colors should be greater than 1, now - %d\n", conf.PngQuantizationColors)
return fmt.Errorf("Png quantization colors should be greater than 1, now - %d\n", conf.PngQuantizationColors)
} else if conf.PngQuantizationColors > 256 {
logFatal("Png quantization colors can't be greater than 256, now - %d\n", conf.PngQuantizationColors)
return fmt.Errorf("Png quantization colors can't be greater than 256, now - %d\n", conf.PngQuantizationColors)
}
if conf.Quality <= 0 {
logFatal("Quality should be greater than 0, now - %d\n", conf.Quality)
return fmt.Errorf("Quality should be greater than 0, now - %d\n", conf.Quality)
} else if conf.Quality > 100 {
logFatal("Quality can't be greater than 100, now - %d\n", conf.Quality)
return fmt.Errorf("Quality can't be greater than 100, now - %d\n", conf.Quality)
}
if conf.GZipCompression < 0 {
logFatal("GZip compression should be greater than or equal to 0, now - %d\n", conf.GZipCompression)
return fmt.Errorf("GZip compression should be greater than or equal to 0, now - %d\n", conf.GZipCompression)
} else if conf.GZipCompression > 9 {
logFatal("GZip compression can't be greater than 9, now - %d\n", conf.GZipCompression)
return fmt.Errorf("GZip compression can't be greater than 9, now - %d\n", conf.GZipCompression)
}
if conf.GZipCompression > 0 {
@ -473,11 +487,11 @@ func configure() {
stat, err := os.Stat(conf.LocalFileSystemRoot)
if err != nil {
logFatal("Cannot use local directory: %s", err)
return fmt.Errorf("Cannot use local directory: %s", err)
}
if !stat.IsDir() {
logFatal("Cannot use local directory: not a directory")
return fmt.Errorf("Cannot use local directory: not a directory")
}
if conf.LocalFileSystemRoot == "/" {
@ -491,32 +505,34 @@ func configure() {
}
if conf.WatermarkOpacity <= 0 {
logFatal("Watermark opacity should be greater than 0")
return fmt.Errorf("Watermark opacity should be greater than 0")
} else if conf.WatermarkOpacity > 1 {
logFatal("Watermark opacity should be less than or equal to 1")
return fmt.Errorf("Watermark opacity should be less than or equal to 1")
}
if len(conf.PrometheusBind) > 0 && conf.PrometheusBind == conf.Bind {
logFatal("Can't use the same binding for the main server and Prometheus")
return fmt.Errorf("Can't use the same binding for the main server and Prometheus")
}
if conf.FreeMemoryInterval <= 0 {
logFatal("Free memory interval should be greater than zero")
return fmt.Errorf("Free memory interval should be greater than zero")
}
if conf.DownloadBufferSize < 0 {
logFatal("Download buffer size should be greater than or equal to 0")
return fmt.Errorf("Download buffer size should be greater than or equal to 0")
} else if conf.DownloadBufferSize > math.MaxInt32 {
logFatal("Download buffer size can't be greater than %d", math.MaxInt32)
return fmt.Errorf("Download buffer size can't be greater than %d", math.MaxInt32)
}
if conf.GZipBufferSize < 0 {
logFatal("GZip buffer size should be greater than or equal to 0")
return fmt.Errorf("GZip buffer size should be greater than or equal to 0")
} else if conf.GZipBufferSize > math.MaxInt32 {
logFatal("GZip buffer size can't be greater than %d", math.MaxInt32)
return fmt.Errorf("GZip buffer size can't be greater than %d", math.MaxInt32)
}
if conf.BufferPoolCalibrationThreshold < 64 {
logFatal("Buffer pool calibration threshold should be greater than or equal to 64")
return fmt.Errorf("Buffer pool calibration threshold should be greater than or equal to 64")
}
return nil
}

View File

@ -59,7 +59,7 @@ func (lr *limitReader) Read(p []byte) (n int, err error) {
return
}
func initDownloading() {
func initDownloading() error {
transport := &http.Transport{
Proxy: http.ProxyFromEnvironment,
MaxIdleConns: conf.Concurrency,
@ -77,11 +77,19 @@ func initDownloading() {
}
if conf.S3Enabled {
transport.RegisterProtocol("s3", newS3Transport())
if t, err := newS3Transport(); err != nil {
return err
} else {
transport.RegisterProtocol("s3", t)
}
}
if conf.GCSEnabled {
transport.RegisterProtocol("gs", newGCSTransport())
if t, err := newGCSTransport(); err != nil {
return err
} else {
transport.RegisterProtocol("gs", t)
}
}
downloadClient = &http.Client{
@ -92,6 +100,8 @@ func initDownloading() {
downloadBufPool = newBufPool("download", conf.Concurrency, conf.DownloadBufferSize)
imagemeta.SetMaxSvgCheckRead(conf.MaxSvgCheckBytes)
return nil
}
func checkDimensions(width, height int) error {

View File

@ -2,6 +2,7 @@ package main
import (
"context"
"fmt"
"net/http"
"strconv"
"strings"
@ -14,7 +15,7 @@ type gcsTransport struct {
client *storage.Client
}
func newGCSTransport() http.RoundTripper {
func newGCSTransport() (http.RoundTripper, error) {
var (
client *storage.Client
err error
@ -27,10 +28,10 @@ func newGCSTransport() http.RoundTripper {
}
if err != nil {
logFatal("Can't create GCS client: %s", err)
return nil, fmt.Errorf("Can't create GCS client: %s", err)
}
return gcsTransport{client}
return gcsTransport{client}, nil
}
func (t gcsTransport) RoundTrip(req *http.Request) (*http.Response, error) {

View File

@ -2,6 +2,7 @@ package main
import (
"compress/gzip"
"fmt"
"io"
"io/ioutil"
"sync"
@ -17,26 +18,30 @@ type gzipPoolEntry struct {
next *gzipPoolEntry
}
func newGzipPool(n int) *gzipPool {
func newGzipPool(n int) (*gzipPool, error) {
pool := new(gzipPool)
for i := 0; i < n; i++ {
pool.grow()
if err := pool.grow(); err != nil {
return nil, err
}
}
return pool
return pool, nil
}
func (p *gzipPool) grow() {
func (p *gzipPool) grow() error {
gz, err := gzip.NewWriterLevel(ioutil.Discard, conf.GZipCompression)
if err != nil {
logFatal("Can't init GZip compression: %s", err)
return fmt.Errorf("Can't init GZip compression: %s", err)
}
p.top = &gzipPoolEntry{
gz: gz,
next: p.top,
}
return nil
}
func (p *gzipPool) Get(w io.Writer) *gzip.Writer {

View File

@ -9,7 +9,7 @@ import (
"os"
)
func healthcheck() {
func healthcheck() int {
network := conf.Network
bind := conf.Bind
@ -27,7 +27,7 @@ func healthcheck() {
res, err := httpc.Get("http://imgproxy/health")
if err != nil {
fmt.Fprintln(os.Stderr, err.Error())
os.Exit(1)
return 1
}
defer res.Body.Close()
@ -35,8 +35,8 @@ func healthcheck() {
fmt.Fprintln(os.Stderr, string(msg))
if res.StatusCode != 200 {
os.Exit(1)
return 1
}
os.Exit(0)
return 0
}

11
log.go
View File

@ -1,12 +1,13 @@
package main
import (
"fmt"
"net/http"
logrus "github.com/sirupsen/logrus"
)
func initLog() {
func initLog() error {
logFormat := "pretty"
strEnvConfig(&logFormat, "IMGPROXY_LOG_FORMAT")
@ -32,11 +33,13 @@ func initLog() {
if isSyslogEnabled() {
slHook, err := newSyslogHook()
if err != nil {
logFatal("Unable to connect to local syslog daemon")
return fmt.Errorf("Unable to connect to syslog daemon: %s", err)
}
logrus.AddHook(slHook)
}
return nil
}
func logRequest(reqID string, r *http.Request) {
@ -96,6 +99,10 @@ func logWarning(f string, args ...interface{}) {
logrus.Warnf(f, args...)
}
func logError(f string, args ...interface{}) {
logrus.Errorf(f, args...)
}
func logFatal(f string, args ...interface{}) {
logrus.Fatalf(f, args...)
}

77
main.go
View File

@ -1,6 +1,8 @@
package main
import (
"context"
"fmt"
"log"
"os"
"os/signal"
@ -13,29 +15,46 @@ const version = "2.10.0"
type ctxKey string
func initialize() {
func initialize() error {
log.SetOutput(os.Stdout)
initLog()
configure()
initNewrelic()
if err := initLog(); err != nil {
return err
}
if err := configure(); err != nil {
return err
}
if err := initNewrelic(); err != nil {
return err
}
initPrometheus()
initDownloading()
if err := initDownloading(); err != nil {
return err
}
initErrorsReporting()
initVips()
if err := initVips(); err != nil {
return err
}
if err := checkPresets(conf.Presets); err != nil {
shutdownVips()
logFatal(err.Error())
return err
}
return nil
}
func main() {
if len(os.Args) > 1 && os.Args[1] == "health" {
healthcheck()
func run() error {
if err := initialize(); err != nil {
return err
}
initialize()
defer shutdownVips()
go func() {
@ -52,11 +71,43 @@ func main() {
}
}()
s := startServer()
ctx, cancel := context.WithCancel(context.Background())
if prometheusEnabled {
if err := startPrometheusServer(cancel); err != nil {
return err
}
}
s, err := startServer(cancel)
if err != nil {
return err
}
defer shutdownServer(s)
stop := make(chan os.Signal, 1)
signal.Notify(stop, syscall.SIGINT, syscall.SIGTERM)
<-stop
select {
case <-ctx.Done():
case <-stop:
}
return nil
}
func main() {
if len(os.Args) > 1 {
switch os.Args[1] {
case "health":
os.Exit(healthcheck())
case "version":
fmt.Println(version)
os.Exit(0)
}
}
if err := run(); err != nil {
logFatal(err.Error())
}
}

View File

@ -2,6 +2,7 @@ package main
import (
"context"
"fmt"
"net/http"
"time"
@ -16,9 +17,9 @@ var (
newRelicTransactionCtxKey = ctxKey("newRelicTransaction")
)
func initNewrelic() {
func initNewrelic() error {
if len(conf.NewRelicKey) == 0 {
return
return nil
}
name := conf.NewRelicAppName
@ -32,10 +33,12 @@ func initNewrelic() {
newRelicApp, err = newrelic.NewApplication(config)
if err != nil {
logFatal("Can't init New Relic agent: %s", err)
return fmt.Errorf("Can't init New Relic agent: %s", err)
}
newRelicEnabled = true
return nil
}
func startNewRelicTransaction(ctx context.Context, rw http.ResponseWriter, r *http.Request) (context.Context, context.CancelFunc) {

View File

@ -18,12 +18,15 @@ var (
headerVaryValue string
)
func initProcessingHandler() {
func initProcessingHandler() error {
processingSem = make(chan struct{}, conf.Concurrency)
if conf.GZipCompression > 0 {
var err error
responseGzipBufPool = newBufPool("gzip", conf.Concurrency, conf.GZipBufferSize)
responseGzipPool = newGzipPool(conf.Concurrency)
if responseGzipPool, err = newGzipPool(conf.Concurrency); err != nil {
return err
}
}
vary := make([]string, 0)
@ -41,6 +44,8 @@ func initProcessingHandler() {
}
headerVaryValue = strings.Join(vary, ", ")
return nil
}
func respondWithImage(ctx context.Context, reqID string, r *http.Request, rw http.ResponseWriter, data []byte) {

View File

@ -1,6 +1,8 @@
package main
import (
"context"
"fmt"
"net/http"
"time"
@ -99,20 +101,25 @@ func initPrometheus() {
)
prometheusEnabled = true
}
func startPrometheusServer(cancel context.CancelFunc) error {
s := http.Server{Handler: promhttp.Handler()}
go func() {
l, err := listenReuseport("tcp", conf.PrometheusBind)
if err != nil {
logFatal(err.Error())
}
l, err := listenReuseport("tcp", conf.PrometheusBind)
if err != nil {
return fmt.Errorf("Can't start Prometheus metrics server: %s", err)
}
go func() {
logNotice("Starting Prometheus server at %s", conf.PrometheusBind)
if err := s.Serve(l); err != nil && err != http.ErrServerClosed {
logFatal(err.Error())
logError(err.Error())
}
cancel()
}()
return nil
}
func startPrometheusDuration(m prometheus.Histogram) func() {

View File

@ -1,6 +1,7 @@
package main
import (
"fmt"
http "net/http"
"github.com/aws/aws-sdk-go/aws"
@ -13,7 +14,7 @@ type s3Transport struct {
svc *s3.S3
}
func newS3Transport() http.RoundTripper {
func newS3Transport() (http.RoundTripper, error) {
s3Conf := aws.NewConfig()
if len(conf.S3Region) != 0 {
@ -27,14 +28,14 @@ func newS3Transport() http.RoundTripper {
sess, err := session.NewSession()
if err != nil {
logFatal("Can't create S3 session: %s", err)
return nil, fmt.Errorf("Can't create S3 session: %s", err)
}
if sess.Config.Region == nil || len(*sess.Config.Region) == 0 {
sess.Config.Region = aws.String("us-west-1")
}
return s3Transport{s3.New(sess, s3Conf)}
return s3Transport{s3.New(sess, s3Conf)}, nil
}
func (t s3Transport) RoundTrip(req *http.Request) (resp *http.Response, err error) {

View File

@ -31,10 +31,10 @@ func buildRouter() *router {
return r
}
func startServer() *http.Server {
func startServer(cancel context.CancelFunc) (*http.Server, error) {
l, err := listenReuseport(conf.Network, conf.Bind)
if err != nil {
logFatal(err.Error())
return nil, fmt.Errorf("Can't start server: %s", err)
}
l = netutil.LimitListener(l, conf.MaxClients)
@ -50,16 +50,19 @@ func startServer() *http.Server {
s.SetKeepAlivesEnabled(false)
}
initProcessingHandler()
if err := initProcessingHandler(); err != nil {
return nil, err
}
go func() {
logNotice("Starting server at %s", conf.Bind)
if err := s.Serve(l); err != nil && err != http.ErrServerClosed {
logFatal(err.Error())
logError(err.Error())
}
cancel()
}()
return s
return s, nil
}
func shutdownServer(s *http.Server) {

10
vips.go
View File

@ -9,6 +9,7 @@ package main
import "C"
import (
"context"
"fmt"
"math"
"os"
"runtime"
@ -43,13 +44,13 @@ const (
vipsAngleD270 = C.VIPS_ANGLE_D270
)
func initVips() {
func initVips() error {
runtime.LockOSThread()
defer runtime.UnlockOSThread()
if err := C.vips_initialize(); err != 0 {
C.vips_shutdown()
logFatal("unable to start vips!")
return fmt.Errorf("unable to start vips!")
}
// Disable libvips cache. Since processing pipeline is fine tuned, we won't get much profit from it.
@ -95,10 +96,13 @@ func initVips() {
vipsConf.WatermarkOpacity = C.double(conf.WatermarkOpacity)
if err := vipsLoadWatermark(); err != nil {
logFatal(err.Error())
C.vips_shutdown()
return fmt.Errorf("Can't load watermark: %s", err)
}
vipsCollectMetrics()
return nil
}
func shutdownVips() {