imgproxy/config.go

package main

import (
	"bufio"
	"bytes"
	"encoding/hex"
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"runtime"
	"strconv"
	"strings"
)

func intEnvConfig(i *int, name string) {
	if env, err := strconv.Atoi(os.Getenv(name)); err == nil {
		*i = env
	}
}

func floatEnvConfig(i *float64, name string) {
	if env, err := strconv.ParseFloat(os.Getenv(name), 64); err == nil {
		*i = env
	}
}

func megaIntEnvConfig(f *int, name string) {
	if env, err := strconv.ParseFloat(os.Getenv(name), 64); err == nil {
		*f = int(env * 1000000)
	}
}

func strEnvConfig(s *string, name string) {
	if env := os.Getenv(name); len(env) > 0 {
		*s = env
	}
}

func boolEnvConfig(b *bool, name string) {
	*b = false
	if env, err := strconv.ParseBool(os.Getenv(name)); err == nil {
		*b = env
	}
}

func hexEnvConfig(b *[]byte, name string) {
	var err error

	if env := os.Getenv(name); len(env) > 0 {
		if *b, err = hex.DecodeString(env); err != nil {
			log.Fatalf("%s expected to be hex-encoded string\n", name)
		}
	}
}

func hexFileConfig(b *[]byte, filepath string) {
	if len(filepath) == 0 {
		return
	}

	f, err := os.Open(filepath)
	if err != nil {
		log.Fatalf("Can't open file %s\n", filepath)
	}

	src, err := ioutil.ReadAll(f)
	if err != nil {
		log.Fatalln(err)
	}

	src = bytes.TrimSpace(src)

	dst := make([]byte, hex.DecodedLen(len(src)))
	n, err := hex.Decode(dst, src)
	if err != nil {
		log.Fatalf("%s expected to contain hex-encoded string\n", filepath)
	}

	*b = dst[:n]
}

func presetEnvConfig(p presets, name string) {
	if env := os.Getenv(name); len(env) > 0 {
		presetStrings := strings.Split(env, ",")

		for _, presetStr := range presetStrings {
			if err := parsePreset(p, presetStr); err != nil {
				log.Fatalln(err)
			}
		}
	}
}

func presetFileConfig(p presets, filepath string) {
	if len(filepath) == 0 {
		return
	}

	f, err := os.Open(filepath)
	if err != nil {
		log.Fatalf("Can't open file %s\n", filepath)
	}

	scanner := bufio.NewScanner(f)
	for scanner.Scan() {
		if err := parsePreset(p, scanner.Text()); err != nil {
			log.Fatalln(err)
		}
	}

	if err := scanner.Err(); err != nil {
		log.Fatalf("Failed to read presets file: %s", err)
	}
}

type config struct {
	Bind            string
	ReadTimeout     int
	WaitTimeout     int
	WriteTimeout    int
	DownloadTimeout int
	Concurrency     int
	MaxClients      int
	TTL             int

	MaxSrcDimension  int
	MaxSrcResolution int

	JpegProgressive bool
	PngInterlaced   bool
	Quality         int
	GZipCompression int

	EnableWebpDetection bool
	EnforceWebp         bool
	EnableClientHints   bool

	Key           []byte
	Salt          []byte
	AllowInsecure bool
	SignatureSize int

	Secret string

	AllowOrigin string

	UserAgent string

	IgnoreSslVerification bool

	LocalFileSystemRoot string
	S3Enabled           bool
	GCSKey              string

	ETagEnabled bool

	BaseURL string

	Presets presets

	WatermarkData    string
	WatermarkPath    string
	WatermarkURL     string
	WatermarkOpacity float64

	NewRelicAppName string
	NewRelicKey     string

	PrometheusBind string
}

var conf = config{
	Bind:                  ":8080",
	ReadTimeout:           10,
	WriteTimeout:          10,
	DownloadTimeout:       5,
	Concurrency:           runtime.NumCPU() * 2,
	TTL:                   3600,
	IgnoreSslVerification: false,
	MaxSrcDimension:       8192,
	MaxSrcResolution:      16800000,
	AllowInsecure:         false,
	SignatureSize:         32,
	Quality:               80,
	GZipCompression:       5,
	UserAgent:             fmt.Sprintf("imgproxy/%s", version),
	ETagEnabled:           false,
	S3Enabled:             false,
	WatermarkOpacity:      1,
}

func init() {
	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)
	}

	strEnvConfig(&conf.Bind, "IMGPROXY_BIND")
	intEnvConfig(&conf.ReadTimeout, "IMGPROXY_READ_TIMEOUT")
	intEnvConfig(&conf.WriteTimeout, "IMGPROXY_WRITE_TIMEOUT")
	intEnvConfig(&conf.DownloadTimeout, "IMGPROXY_DOWNLOAD_TIMEOUT")
	intEnvConfig(&conf.Concurrency, "IMGPROXY_CONCURRENCY")
	intEnvConfig(&conf.MaxClients, "IMGPROXY_MAX_CLIENTS")

	intEnvConfig(&conf.TTL, "IMGPROXY_TTL")

	intEnvConfig(&conf.MaxSrcDimension, "IMGPROXY_MAX_SRC_DIMENSION")
	megaIntEnvConfig(&conf.MaxSrcResolution, "IMGPROXY_MAX_SRC_RESOLUTION")

	boolEnvConfig(&conf.JpegProgressive, "IMGPROXY_JPEG_PROGRESSIVE")
	boolEnvConfig(&conf.PngInterlaced, "IMGPROXY_PNG_INTERLACED")
	intEnvConfig(&conf.Quality, "IMGPROXY_QUALITY")
	intEnvConfig(&conf.GZipCompression, "IMGPROXY_GZIP_COMPRESSION")

	boolEnvConfig(&conf.EnableWebpDetection, "IMGPROXY_ENABLE_WEBP_DETECTION")
	boolEnvConfig(&conf.EnforceWebp, "IMGPROXY_ENFORCE_WEBP")
	boolEnvConfig(&conf.EnableClientHints, "IMGPROXY_ENABLE_CLIENT_HINTS")

	hexEnvConfig(&conf.Key, "IMGPROXY_KEY")
	hexEnvConfig(&conf.Salt, "IMGPROXY_SALT")
	intEnvConfig(&conf.SignatureSize, "IMGPROXY_SIGNATURE_SIZE")

	hexFileConfig(&conf.Key, *keyPath)
	hexFileConfig(&conf.Salt, *saltPath)

	strEnvConfig(&conf.Secret, "IMGPROXY_SECRET")

	strEnvConfig(&conf.AllowOrigin, "IMGPROXY_ALLOW_ORIGIN")

	strEnvConfig(&conf.UserAgent, "IMGPROXY_USER_AGENT")

	boolEnvConfig(&conf.IgnoreSslVerification, "IMGPROXY_IGNORE_SSL_VERIFICATION")

	strEnvConfig(&conf.LocalFileSystemRoot, "IMGPROXY_LOCAL_FILESYSTEM_ROOT")

	boolEnvConfig(&conf.S3Enabled, "IMGPROXY_USE_S3")
	strEnvConfig(&conf.GCSKey, "IMGPROXY_GCS_KEY")

	boolEnvConfig(&conf.ETagEnabled, "IMGPROXY_USE_ETAG")

	strEnvConfig(&conf.BaseURL, "IMGPROXY_BASE_URL")

	conf.Presets = make(presets)
	presetEnvConfig(conf.Presets, "IMGPROXY_PRESETS")
	presetFileConfig(conf.Presets, *presetsPath)

	strEnvConfig(&conf.WatermarkData, "IMGPROXY_WATERMARK_DATA")
	strEnvConfig(&conf.WatermarkPath, "IMGPROXY_WATERMARK_PATH")
	strEnvConfig(&conf.WatermarkURL, "IMGPROXY_WATERMARK_URL")
	floatEnvConfig(&conf.WatermarkOpacity, "IMGPROXY_WATERMARK_OPACITY")

	strEnvConfig(&conf.NewRelicAppName, "IMGPROXY_NEW_RELIC_APP_NAME")
	strEnvConfig(&conf.NewRelicKey, "IMGPROXY_NEW_RELIC_KEY")

	strEnvConfig(&conf.PrometheusBind, "IMGPROXY_PROMETHEUS_BIND")

	if len(conf.Key) == 0 {
		warning("Key is not defined, so signature checking is disabled")
		conf.AllowInsecure = true
	}
	if len(conf.Salt) == 0 {
		warning("Salt is not defined, so signature checking is disabled")
		conf.AllowInsecure = true
	}
	if conf.SignatureSize < 1 || conf.SignatureSize > 32 {
		log.Fatalf("Signature size should be within 1 and 32, now - %d\n", conf.SignatureSize)
	}

	if len(conf.Bind) == 0 {
		log.Fatalln("Bind address is not defined")
	}

	if conf.ReadTimeout <= 0 {
		log.Fatalf("Read timeout should be greater than 0, now - %d\n", conf.ReadTimeout)
	}

	if conf.WriteTimeout <= 0 {
		log.Fatalf("Write timeout should be greater than 0, now - %d\n", conf.WriteTimeout)
	}

	if conf.DownloadTimeout <= 0 {
		log.Fatalf("Download timeout should be greater than 0, now - %d\n", conf.DownloadTimeout)
	}

	if conf.Concurrency <= 0 {
		log.Fatalf("Concurrency should be greater than 0, now - %d\n", conf.Concurrency)
	}

	if conf.MaxClients <= 0 {
		conf.MaxClients = conf.Concurrency * 10
	}

	if conf.TTL <= 0 {
		log.Fatalf("TTL should be greater than 0, now - %d\n", conf.TTL)
	}

	if conf.MaxSrcDimension <= 0 {
		log.Fatalf("Max src dimension should be greater than 0, now - %d\n", conf.MaxSrcDimension)
	}

	if conf.MaxSrcResolution <= 0 {
		log.Fatalf("Max src resolution should be greater than 0, now - %d\n", conf.MaxSrcResolution)
	}

	if conf.Quality <= 0 {
		log.Fatalf("Quality should be greater than 0, now - %d\n", conf.Quality)
	} else if conf.Quality > 100 {
		log.Fatalf("Quality can't be greater than 100, now - %d\n", conf.Quality)
	}

	if conf.GZipCompression < 0 {
		log.Fatalf("GZip compression should be greater than or quual to 0, now - %d\n", conf.GZipCompression)
	} else if conf.GZipCompression > 9 {
		log.Fatalf("GZip compression can't be greater than 9, now - %d\n", conf.GZipCompression)
	}

	if conf.IgnoreSslVerification {
		warning("Ignoring SSL verification is very unsafe")
	}

	if conf.LocalFileSystemRoot != "" {
		stat, err := os.Stat(conf.LocalFileSystemRoot)
		if err != nil {
			log.Fatalf("Cannot use local directory: %s", err)
		} else {
			if !stat.IsDir() {
				log.Fatalf("Cannot use local directory: not a directory")
			}
		}
		if conf.LocalFileSystemRoot == "/" {
			log.Print("Exposing root via IMGPROXY_LOCAL_FILESYSTEM_ROOT is unsafe")
		}
	}

	if err := checkPresets(conf.Presets); err != nil {
		log.Fatalln(err)
	}

	if conf.WatermarkOpacity <= 0 {
		log.Fatalln("Watermark opacity should be greater than 0")
	} else if conf.WatermarkOpacity > 1 {
		log.Fatalln("Watermark opacity should be less than or equal to 1")
	}

	if len(conf.PrometheusBind) > 0 && conf.PrometheusBind == conf.Bind {
		log.Fatalln("Can't use the same binding for the main server and Prometheus")
	}

	initDownloading()
	initNewrelic()
	initPrometheus()
	initVips()
}