Header comma (#101)

* allow comma inside of header env list #100

* set proxy header to manually split version

app/main.go

@@ -33,8 +33,9 @@ var opts struct {
 	Listen       string   `short:"l" long:"listen" env:"LISTEN" description:"listen on host:port (default: 0.0.0.0:8080/8443 under docker, 127.0.0.1:80/443 without)"`
 	MaxSize      string   `short:"m" long:"max" env:"MAX_SIZE" default:"64K" description:"max request size"`
 	GzipEnabled  bool     `short:"g" long:"gzip" env:"GZIP" description:"enable gz compression"`
-	ProxyHeaders []string `short:"x" long:"header" env:"HEADER" description:"proxy headers" env-delim:","`
-	LBType       string   `long:"lb-type" env:"LB_TYPE" description:"load balancer type" choice:"random" choice:"failover" default:"random"` //nolint
+	ProxyHeaders []string `short:"x" long:"header" description:"proxy headers"` // env HEADER split in code to allow , inside ""
+
+	LBType string `long:"lb-type" env:"LB_TYPE" description:"load balancer type" choice:"random" choice:"failover" default:"random"` //nolint
 
 	SSL struct {
 		Type          string   `long:"type" env:"TYPE" description:"ssl (auto) support" choice:"none" choice:"static" choice:"auto" default:"none"` //nolint
@@ -221,6 +222,11 @@ func run() error {
 		return fmt.Errorf("failed to convert MaxSize: %w", err)
 	}
 
+	proxyHeaders := opts.ProxyHeaders
+	if len(proxyHeaders) == 0 {
+		proxyHeaders = splitAtCommas(os.Getenv("HEADER")) // env value may have comma inside "", parsed separately
+	}
+
 	px := &proxy.Http{
 		Version:        revision,
 		Matcher:        svc,
@@ -232,7 +238,7 @@ func run() error {
 		CacheControl:   cacheControl,
 		GzEnabled:      opts.GzipEnabled,
 		SSLConfig:      sslConfig,
-		ProxyHeaders:   opts.ProxyHeaders,
+		ProxyHeaders:   proxyHeaders,
 		AccessLog:      accessLog,
 		StdOutEnabled:  opts.Logger.StdOut,
 		Signature:      opts.Signature,
@@ -479,6 +485,35 @@ func sizeParse(inp string) (uint64, error) {
 	return strconv.ParseUint(inp, 10, 64)
 }
 
+// splitAtCommas split s at commas, ignoring commas in strings.
+// based on https://stackoverflow.com/a/59318708
+func splitAtCommas(s string) []string {
+	var res []string
+	var beg int
+	var inString bool
+
+	for i := 0; i < len(s); i++ {
+		if s[i] == ',' && !inString {
+			res = append(res, strings.TrimSpace(s[beg:i]))
+			beg = i + 1
+			continue
+		}
+
+		if s[i] == '"' {
+			if !inString {
+				inString = true
+			} else if i > 0 && s[i-1] != '\\' {
+				inString = false
+			}
+		}
+	}
+	res = append(res, strings.TrimSpace(s[beg:]))
+	if len(res) == 1 && res[0] == "" {
+		return []string{}
+	}
+	return res
+}
+
 type nopWriteCloser struct{ io.Writer }
 
 func (n nopWriteCloser) Close() error { return nil }

app/main_test.go

@@ -352,3 +352,27 @@ func (h *TestPlugin) ErrorThing(req lib.Request, res *lib.Response) (err error)
 	res.StatusCode = 200
 	return nil
 }
+
+func Test_splitAtCommas(t *testing.T) {
+
+	tbl := []struct {
+		inp string
+		res []string
+	}{
+		{"a string", []string{"a string"}},
+		{"vv1, vv2, vv3", []string{"vv1", "vv2", "vv3"}},
+		{`"vv1, blah", vv2, vv3`, []string{"\"vv1, blah\"", "vv2", "vv3"}},
+		{
+			`Access-Control-Allow-Headers:"DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type",header123:val, foo:"bar1,bar2"`,
+			[]string{"Access-Control-Allow-Headers:\"DNT,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type\"", "header123:val", "foo:\"bar1,bar2\""},
+		},
+		{"", []string{}},
+	}
+
+	for i, tt := range tbl {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			assert.Equal(t, tt.res, splitAtCommas(tt.inp))
+		})
+	}
+
+}