Improve HTTP proxy parsing and support

- Export ParseHTTPProxy and ParseSOCKSProxy functions for reuse
- Add support for lowercase proxy environment variables (http_proxy, https_proxy)
- Add support for ALL_PROXY environment variable
- Follow convention where lowercase variables take precedence
- Add http.ProxyFromEnvironment to HTTP client configuration

Author: poupas

farcaster-go/dialers/dialers.go

@@ -306,8 +306,8 @@ func NewDialConfig() *DialConfig {
 		enableTLS:  os.Getenv("ENABLE_TLS") == "true",
 		enableWS:   os.Getenv("ENABLE_WS") == "true",
 		enableWSS:  os.Getenv("ENABLE_WSS") == "true",
-		httpProxy:  parseHTTPProxy(),
-		socksProxy: parseSOCKSProxy(),
+		httpProxy:  ParseHTTPProxy(),
+		socksProxy: ParseSOCKSProxy(),
 	}
 }
 
@@ -433,11 +433,27 @@ func (dc *DialConfig) Dialers(addr string, timeout time.Duration) []Dialer {
 	return dialers
 }
 
-func parseHTTPProxy() *url.URL {
-	proxyURLStr := os.Getenv("HTTP_PROXY")
-	if proxyURLStr == "" {
-		proxyURLStr = os.Getenv("HTTPS_PROXY")
+func ParseHTTPProxy() *url.URL {
+	proxyVars := []string{
+		"HTTP_PROXY",
+		"HTTPS_PROXY",
+		"ALL_PROXY",
 	}
+
+	var proxyURLStr string
+	for _, varName := range proxyVars {
+		// Convention says lowercase variables take precedence
+		if val := os.Getenv(strings.ToLower(varName)); val != "" {
+			proxyURLStr = val
+			break
+		}
+		if val := os.Getenv(varName); val != "" {
+			proxyURLStr = val
+			break
+		}
+
+	}
+
 	if proxyURLStr == "" {
 		return nil
 	}
@@ -453,7 +469,7 @@ func parseHTTPProxy() *url.URL {
 	return proxyURL
 }
 
-func parseSOCKSProxy() *url.URL {
+func ParseSOCKSProxy() *url.URL {
 	proxyURLStr := os.Getenv("SOCKS5_PROXY")
 	if proxyURLStr == "" {
 		return nil

farconn/services/config.go

@@ -51,6 +51,7 @@ func createHTTPClient() *http.Client {
 		TLSClientConfig: &tls.Config{
 			InsecureSkipVerify: skipVerify,
 		},
+		Proxy: http.ProxyFromEnvironment,
 	}
 
 	return &http.Client{