support yaml/json/toml configuration format, make ini deprecated (#3599)

pkg/config/legacy/value.go

@@ -0,0 +1,74 @@
+// Copyright 2020 The frp Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package legacy
+
+import (
+	"bytes"
+	"os"
+	"strings"
+	"text/template"
+)
+
+var glbEnvs map[string]string
+
+func init() {
+	glbEnvs = make(map[string]string)
+	envs := os.Environ()
+	for _, env := range envs {
+		pair := strings.SplitN(env, "=", 2)
+		if len(pair) != 2 {
+			continue
+		}
+		glbEnvs[pair[0]] = pair[1]
+	}
+}
+
+type Values struct {
+	Envs map[string]string // environment vars
+}
+
+func GetValues() *Values {
+	return &Values{
+		Envs: glbEnvs,
+	}
+}
+
+func RenderContent(in []byte) (out []byte, err error) {
+	tmpl, errRet := template.New("frp").Parse(string(in))
+	if errRet != nil {
+		err = errRet
+		return
+	}
+
+	buffer := bytes.NewBufferString("")
+	v := GetValues()
+	err = tmpl.Execute(buffer, v)
+	if err != nil {
+		return
+	}
+	out = buffer.Bytes()
+	return
+}
+
+func GetRenderedConfFromFile(path string) (out []byte, err error) {
+	var b []byte
+	b, err = os.ReadFile(path)
+	if err != nil {
+		return
+	}
+
+	out, err = RenderContent(b)
+	return
+}