add custom language support (closes #14)

- new formatting for vue/js files
- add lang customization to api docs

Signed-off-by: Liam Stanley <[email protected]>

Author: lrstanley

api.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"net"
 	"net/http"
+	"regexp"
 	"strconv"
 	"strings"
 
@@ -22,10 +23,30 @@ func registerAPI(r chi.Router) {
 	r.Get("/api/{addr}/{filters}", apiLookup)
 }
 
+var reLanguage = regexp.MustCompile(`^[^a-zA-Z, ]+.*?$`)
+
 func apiLookup(w http.ResponseWriter, r *http.Request) {
 	addr := strings.TrimSpace(chi.URLParam(r, "addr"))
 	filters := strings.Split(chi.URLParam(r, "filters"), ",")
 
+	// Prioritize "lang" query param.
+	lang := matchLanguage(strings.ReplaceAll(r.FormValue("lang"), " ", ""))
+
+	if lang == "" {
+		// Try to get the language from the Accept-Language header.
+		for _, l := range strings.Split(reLanguage.ReplaceAllString(r.Header.Get("Accept-Language"), ""), ",") {
+			lang = matchLanguage(l)
+			if lang != "" {
+				break
+			}
+		}
+	}
+
+	// If we still don't have a language, default to global language default.
+	if lang == "" {
+		lang = flags.DefaultLanguage
+	}
+
 	// If they're trying to send us way too many filters (which could cause
 	// unwanted extra memory usage/be considered a resource usage attack),
 	// we shouldn't handle their request.
@@ -59,6 +80,8 @@ func apiLookup(w http.ResponseWriter, r *http.Request) {
 		key = addr + ":" + strings.Join(filters, ",")
 	}
 
+	key += "," + lang
+
 	var result *AddrResult
 
 	query, err := arc.GetIFPresent(key)
@@ -98,7 +121,7 @@ func apiLookup(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	result, err = addrLookup(r.Context(), ip, filters)
+	result, err = addrLookup(r.Context(), ip, filters, lang)
 	if err != nil {
 		logger.Printf("error looking up address %q (%q): %s", addr, ip, err)
 		w.WriteHeader(http.StatusServiceUnavailable)

db.go

@@ -22,6 +22,42 @@ import (
 	maxminddb "github.com/oschwald/maxminddb-golang"
 )
 
+var supportedLanguages = []string{
+	"de", "en", "es", "fr", "ja", "pt-BR", "ru", "zh-CN",
+}
+
+func matchLanguage(lang string) string {
+	if lang == "" {
+		return ""
+	}
+
+	for i := 0; i < len(supportedLanguages); i++ {
+		if strings.EqualFold(lang, supportedLanguages[i]) {
+			return supportedLanguages[i]
+		}
+
+		if j := strings.Index(supportedLanguages[i], "-"); j > 0 {
+			if strings.EqualFold(lang, supportedLanguages[i][:j]) {
+				return supportedLanguages[i]
+			}
+
+			if k := strings.Index(lang, "-"); k > 0 {
+				if strings.EqualFold(lang[:k], supportedLanguages[i][:j]) {
+					return supportedLanguages[i]
+				}
+			}
+		}
+
+		if j := strings.Index(lang, "-"); j > 0 {
+			if strings.EqualFold(lang[:j], supportedLanguages[i]) {
+				return supportedLanguages[i]
+			}
+		}
+	}
+
+	return ""
+}
+
 type DB struct {
 	path string
 }
@@ -234,7 +270,7 @@ type AddrResult struct {
 // addrLookup does a geoip lookup of an IP address. filters is passed into
 // this function, in case there are any long running tasks which the user
 // may not even want (e.g. reverse dns lookups).
-func addrLookup(ctx context.Context, addr net.IP, filters []string) (*AddrResult, error) {
+func addrLookup(ctx context.Context, addr net.IP, filters []string, lang string) (*AddrResult, error) {
 	var result *AddrResult
 	var err error
 
@@ -254,10 +290,10 @@ func addrLookup(ctx context.Context, addr net.IP, filters []string) (*AddrResult
 
 	result = &AddrResult{
 		IP:            addr,
-		City:          query.City.Names["en"],
-		Country:       query.Country.Names["en"],
+		City:          query.City.Names[lang],
+		Country:       query.Country.Names[lang],
 		CountryCode:   query.Country.Code,
-		Continent:     query.Continent.Names["en"],
+		Continent:     query.Continent.Names[lang],
 		ContinentCode: query.Continent.Code,
 		Lat:           query.Location.Lat,
 		Long:          query.Location.Long,
@@ -268,7 +304,7 @@ func addrLookup(ctx context.Context, addr net.IP, filters []string) (*AddrResult
 
 	var subdiv []string
 	for i := 0; i < len(query.Subdivisions); i++ {
-		subdiv = append(subdiv, query.Subdivisions[i].Names["en"])
+		subdiv = append(subdiv, query.Subdivisions[i].Names[lang])
 	}
 	result.Subdivision = strings.Join(subdiv, ", ")
 

main.go

@@ -29,13 +29,14 @@ var (
 )
 
 type Flags struct {
-	Debug          bool          `env:"DEBUG" short:"d" long:"debug" description:"enable exception display and pprof endpoints (warn: dangerous)"`
-	Quiet          bool          `env:"QUIET" short:"q" long:"quiet" description:"disable verbose output"`
-	DBPath         string        `env:"DB_PATH" long:"db" description:"path to read/store Maxmind DB" default:"geoip.db"`
-	UpdateInterval time.Duration `env:"UPDATE_INTERVAL" long:"interval" description:"interval of time between database update checks" default:"12h"`
-	UpdateURL      string        `env:"MAXMIND_UPDATE_URL" long:"update-url" description:"maxmind database file download location (must be gzipped)" default:"https://download.maxmind.com/app/geoip_download?edition_id=GeoLite2-City&license_key=%s&suffix=tar.gz"`
-	LicenseKey     string        `env:"MAXMIND_LICENSE_KEY" long:"license-key" description:"maxmind license key (must register for a maxmind account)" required:"true"`
-	Cache          struct {
+	Debug           bool          `env:"DEBUG" short:"d" long:"debug" description:"enable exception display and pprof endpoints (warn: dangerous)"`
+	Quiet           bool          `env:"QUIET" short:"q" long:"quiet" description:"disable verbose output"`
+	DBPath          string        `env:"DB_PATH" long:"db" description:"path to read/store Maxmind DB" default:"geoip.db"`
+	UpdateInterval  time.Duration `env:"UPDATE_INTERVAL" long:"interval" description:"interval of time between database update checks" default:"12h"`
+	UpdateURL       string        `env:"MAXMIND_UPDATE_URL" long:"update-url" description:"maxmind database file download location (must be gzipped)" default:"https://download.maxmind.com/app/geoip_download?edition_id=GeoLite2-City&license_key=%s&suffix=tar.gz"`
+	LicenseKey      string        `env:"MAXMIND_LICENSE_KEY" long:"license-key" description:"maxmind license key (must register for a maxmind account)" required:"true"`
+	DefaultLanguage string        `env:"DEFAULT_LANGUAGE" long:"lang" description:"default language to use for geolocation" default:"en"`
+	Cache           struct {
 		Size   int           `env:"CACHE_SIZE" long:"size" description:"total number of lookups to keep in ARC cache (50% most recent, 50% most requested)" default:"500"`
 		Expire time.Duration `env:"CACHE_EXPIRE" long:"expire" description:"expiration time of cache" default:"20m"`
 	} `group:"Cache Options" namespace:"cache"`

public/index.html

@@ -1,21 +1,30 @@
 <!DOCTYPE html>
 <html lang="en">
-  <head>
-    <meta charset="utf-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
-    <link rel="icon" href="/static/img/favicon.ico">
-    <title>GeoIP</title>
-    <link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.3.1/semantic.min.css" crossorigin="anonymous">
-    <link rel="stylesheet" href="https://unpkg.com/[email protected]/dist/leaflet.css" integrity="sha512-xodZBNTC5n17Xt2atTPuE1HxjVMSvLVW9ocqUKLsCC5CXdbqCmblAshOMAS6/keqq/sMZMZ19scR4PsZChSR7A==" crossorigin="" />
-    <link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/toastr.js/2.1.3/toastr.min.css" crossorigin="anonymous">
-  </head>
-  <body>
-    <div id="vue"><app></app></div>
-    <script src="https://unpkg.com/[email protected]/dist/leaflet.js" integrity="sha512-XQoYMqMTK8LvdxXYG3nZ448hOEQiglfqkJs1NOQV44cWnUrBc8PkAOcXy20w0vlaXaVUearIOBhiXZ5V3ynxwA==" crossorigin=""></script>
-    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.slim.min.js" crossorigin="anonymous"></script>
-    <script src="https://cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.3.1/semantic.min.js" crossorigin="anonymous"></script>
-    <script src="https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/1.7.1/clipboard.min.js" crossorigin="anonymous"></script>
-    <script src="https://cdnjs.cloudflare.com/ajax/libs/toastr.js/2.1.3/toastr.min.js" crossorigin="anonymous"></script>
-    <script type="module" src="/src/main.js"></script>
-  </body>
+    <head>
+        <meta charset="utf-8" />
+        <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no" />
+        <link rel="icon" href="/static/img/favicon.ico" />
+        <title>GeoIP</title>
+        <link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.3.1/semantic.min.css" crossorigin="anonymous" />
+        <link
+            rel="stylesheet"
+            href="https://unpkg.com/[email protected]/dist/leaflet.css"
+            integrity="sha512-xodZBNTC5n17Xt2atTPuE1HxjVMSvLVW9ocqUKLsCC5CXdbqCmblAshOMAS6/keqq/sMZMZ19scR4PsZChSR7A=="
+            crossorigin=""
+        />
+        <link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/toastr.js/2.1.3/toastr.min.css" crossorigin="anonymous" />
+    </head>
+    <body>
+        <div id="vue"><app></app></div>
+        <script
+            src="https://unpkg.com/[email protected]/dist/leaflet.js"
+            integrity="sha512-XQoYMqMTK8LvdxXYG3nZ448hOEQiglfqkJs1NOQV44cWnUrBc8PkAOcXy20w0vlaXaVUearIOBhiXZ5V3ynxwA=="
+            crossorigin=""
+        ></script>
+        <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.slim.min.js" crossorigin="anonymous"></script>
+        <script src="https://cdnjs.cloudflare.com/ajax/libs/semantic-ui/2.3.1/semantic.min.js" crossorigin="anonymous"></script>
+        <script src="https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/1.7.1/clipboard.min.js" crossorigin="anonymous"></script>
+        <script src="https://cdnjs.cloudflare.com/ajax/libs/toastr.js/2.1.3/toastr.min.js" crossorigin="anonymous"></script>
+        <script type="module" src="/src/main.js"></script>
+    </body>
 </html>