feat(agentproxy): simplify configuration handling and related header management

agent/pkg/agentproxy/config.go

@@ -0,0 +1,76 @@
+package agentproxy
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"net/http"
+	"strconv"
+	"time"
+
+	route "github.com/yusing/go-proxy/internal/route/types"
+)
+
+type Config struct {
+	Scheme string `json:"scheme,omitempty"`
+	Host   string `json:"host,omitempty"` // host or host:port
+
+	route.HTTPConfig
+}
+
+func ConfigFromHeaders(h http.Header) (Config, error) {
+	cfg, err := proxyConfigFromHeaders(h)
+	if err != nil {
+		return cfg, err
+	}
+	if cfg.Host == "" {
+		cfg = proxyConfigFromHeadersLegacy(h)
+	}
+	return cfg, nil
+}
+
+func proxyConfigFromHeadersLegacy(h http.Header) (cfg Config) {
+	cfg.Host = h.Get(HeaderXProxyHost)
+	isHTTPS, _ := strconv.ParseBool(h.Get(HeaderXProxyHTTPS))
+	cfg.NoTLSVerify, _ = strconv.ParseBool(h.Get(HeaderXProxySkipTLSVerify))
+	responseHeaderTimeout, err := strconv.Atoi(h.Get(HeaderXProxyResponseHeaderTimeout))
+	if err != nil {
+		responseHeaderTimeout = 0
+	}
+	cfg.ResponseHeaderTimeout = time.Duration(responseHeaderTimeout) * time.Second
+
+	cfg.Scheme = "http"
+	if isHTTPS {
+		cfg.Scheme = "https"
+	}
+
+	return
+}
+
+func proxyConfigFromHeaders(h http.Header) (cfg Config, err error) {
+	cfg.Scheme = h.Get(HeaderXProxyScheme)
+	cfg.Host = h.Get(HeaderXProxyHost)
+
+	cfgBase64 := h.Get(HeaderXProxyConfig)
+	cfgJSON, err := base64.StdEncoding.DecodeString(cfgBase64)
+	if err != nil {
+		return cfg, err
+	}
+
+	err = json.Unmarshal(cfgJSON, &cfg)
+	return cfg, err
+}
+
+func (cfg *Config) SetAgentProxyConfigHeadersLegacy(h http.Header) {
+	h.Set(HeaderXProxyHost, cfg.Host)
+	h.Set(HeaderXProxyHTTPS, strconv.FormatBool(cfg.Scheme == "https"))
+	h.Set(HeaderXProxySkipTLSVerify, strconv.FormatBool(cfg.NoTLSVerify))
+	h.Set(HeaderXProxyResponseHeaderTimeout, strconv.Itoa(int(cfg.ResponseHeaderTimeout.Round(time.Second).Seconds())))
+}
+
+func (cfg *Config) SetAgentProxyConfigHeaders(h http.Header) {
+	h.Set(HeaderXProxyHost, cfg.Host)
+	h.Set(HeaderXProxyScheme, string(cfg.Scheme))
+	cfgJSON, _ := json.Marshal(cfg.HTTPConfig)
+	cfgBase64 := base64.StdEncoding.EncodeToString(cfgJSON)
+	h.Set(HeaderXProxyConfig, cfgBase64)
+}