Implement HTTP proxy option (#515).

This commit adds a "Proxy" field to the network settings screen, which
can be used to specify a HTTP proxy for any outgoing requests from the
device.

internal/confparser/confparser.go

@@ -3,6 +3,7 @@ package confparser
 import (
 	"fmt"
 	"net"
+	"net/url"
 	"reflect"
 	"slices"
 	"strconv"
@@ -372,6 +373,10 @@ func (f *FieldConfig) validateField() error {
 			if _, err := idna.Lookup.ToASCII(val); err != nil {
 				return fmt.Errorf("field `%s` is not a valid hostname: %s", f.Name, val)
 			}
+		case "proxy":
+			if url, err := url.Parse(val); err != nil || (url.Scheme != "http" && url.Scheme != "https") || url.Host == "" {
+				return fmt.Errorf("field `%s` is not a valid HTTP proxy URL: %s", f.Name, val)
+			}
 		default:
 			return fmt.Errorf("field `%s` cannot use validate_type: unsupported validator: %s", f.Name, validateType)
 		}

internal/network/config.go

@@ -3,6 +3,8 @@ package network
 import (
 	"fmt"
 	"net"
+	"net/http"
+	"net/url"
 	"time"
 
 	"github.com/guregu/null/v6"
@@ -33,6 +35,7 @@ type IPv6StaticConfig struct {
 }
 type NetworkConfig struct {
 	Hostname  null.String `json:"hostname,omitempty" validate_type:"hostname"`
+	HTTPProxy null.String `json:"http_proxy,omitempty" validate_type:"proxy"`
 	Domain    null.String `json:"domain,omitempty" validate_type:"hostname"`
 
 	IPv4Mode   null.String       `json:"ipv4_mode,omitempty" one_of:"dhcp,static,disabled" default:"dhcp"`
@@ -69,6 +72,18 @@ func (c *NetworkConfig) GetMDNSMode() *mdns.MDNSListenOptions {
 
 	return listenOptions
 }
+
+func (s *NetworkConfig) GetTransportProxyFunc() func(*http.Request) (*url.URL, error) {
+	return func(*http.Request) (*url.URL, error) {
+		if s.HTTPProxy.String == "" {
+			return nil, nil
+		} else {
+			proxyUrl, _ := url.Parse(s.HTTPProxy.String)
+			return proxyUrl, nil
+		}
+	}
+}
+
 func (s *NetworkInterfaceState) GetHostname() string {
 	hostname := ToValidHostname(s.config.Hostname.String)
 

internal/timesync/http.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"math/rand"
 	"net/http"
+	"net/url"
 	"strconv"
 	"time"
 )
@@ -57,6 +58,7 @@ func (t *TimeSync) queryMultipleHttp(urls []string, timeout time.Duration) (now
 				ctx,
 				url,
 				timeout,
+				t.networkConfig.GetTransportProxyFunc(),
 			)
 			duration := time.Since(startTime)
 
@@ -111,10 +113,16 @@ func queryHttpTime(
 	ctx context.Context,
 	url string,
 	timeout time.Duration,
+	proxyFunc func(*http.Request) (*url.URL, error),
 ) (now *time.Time, response *http.Response, err error) {
+	transport := http.DefaultTransport.(*http.Transport).Clone()
+	transport.Proxy = proxyFunc
+
 	client := http.Client{
+		Transport: transport,
 		Timeout:   timeout,
 	}
+
 	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
 	if err != nil {
 		return nil, nil, err

ota.go

@@ -89,7 +89,14 @@ func fetchUpdateMetadata(ctx context.Context, deviceId string, includePreRelease
 		return nil, fmt.Errorf("error creating request: %w", err)
 	}
 
-	resp, err := http.DefaultClient.Do(req)
+	transport := http.DefaultTransport.(*http.Transport).Clone()
+	transport.Proxy = config.NetworkConfig.GetTransportProxyFunc()
+
+	client := &http.Client{
+		Transport: transport,
+	}
+
+	resp, err := client.Do(req)
 	if err != nil {
 		return nil, fmt.Errorf("error sending request: %w", err)
 	}
@@ -135,6 +142,7 @@ func downloadFile(ctx context.Context, path string, url string, downloadProgress
 	client := http.Client{
 		Timeout: 10 * time.Minute,
 		Transport: &http.Transport{
+			Proxy:               config.NetworkConfig.GetTransportProxyFunc(),
 			TLSHandshakeTimeout: 30 * time.Second,
 			TLSClientConfig: &tls.Config{
 				RootCAs: rootcerts.ServerCertPool(),

ui/src/hooks/stores.ts

@@ -730,6 +730,7 @@ export type TimeSyncMode =
 export interface NetworkSettings {
   hostname: string;
   domain: string;
+  http_proxy: string;
   ipv4_mode: IPv4Mode;
   ipv6_mode: IPv6Mode;
   lldp_mode: LLDPMode;

ui/src/routes/devices.$id.settings.network.tsx

@@ -34,6 +34,7 @@ dayjs.extend(relativeTime);
 
 const defaultNetworkSettings: NetworkSettings = {
   hostname: "",
+  http_proxy: "",
   domain: "",
   ipv4_mode: "unknown",
   ipv6_mode: "unknown",
@@ -185,6 +186,10 @@ export default function SettingsNetworkRoute() {
     setNetworkSettings({ ...networkSettings, hostname: value });
   };
 
+  const handleProxyChange = (value: string) => {
+    setNetworkSettings({ ...networkSettings, http_proxy: value });
+  };
+
   const handleDomainChange = (value: string) => {
     setNetworkSettings({ ...networkSettings, domain: value });
   };
@@ -253,6 +258,26 @@ export default function SettingsNetworkRoute() {
             </div>
           </SettingsItem>
         </div>
+        <div className="space-y-4">
+          <SettingsItem
+            title="HTTP Proxy"
+            description="Proxy server for outgoing HTTP(S) requests from the device. Blank for none."
+          >
+            <div className="relative">
+              <div>
+                <InputField
+                  size="SM"
+                  type="text"
+                  placeholder="http://proxy.example.com:8080/"
+                  defaultValue={networkSettings.http_proxy}
+                  onChange={e => {
+                    handleProxyChange(e.target.value);
+                  }}
+                />
+              </div>
+            </div>
+          </SettingsItem>
+        </div>
 
         <div className="space-y-4">
           <div className="space-y-1">