From 91f34dde79190a30162d7faa20ecbf44dafd2551 Mon Sep 17 00:00:00 2001
From: Fabian Triebsch <fabian@triebsch.eu>
Date: Wed, 4 Jun 2025 13:25:43 +0200
Subject: [PATCH] added option to force ipv4 or ipv6 for http(s) monitor type

---
 .../2025-06-03-0000-add-force-ipv4-ipv6.js       | 13 +++++++++++++
 server/model/monitor.js                          | 14 ++++++++++++++
 server/server.js                                 |  1 +
 src/pages/EditMonitor.vue                        | 16 ++++++++++++++++
 4 files changed, 44 insertions(+)
 create mode 100644 db/knex_migrations/2025-06-03-0000-add-force-ipv4-ipv6.js

diff --git a/db/knex_migrations/2025-06-03-0000-add-force-ipv4-ipv6.js b/db/knex_migrations/2025-06-03-0000-add-force-ipv4-ipv6.js
new file mode 100644
index 000000000..af6011cb3
--- /dev/null
+++ b/db/knex_migrations/2025-06-03-0000-add-force-ipv4-ipv6.js
@@ -0,0 +1,13 @@
+exports.up = function (knex) {
+    return knex.schema
+        .alterTable("monitor", function (table) {
+            table.boolean("force_ip").defaultTo(null);
+        });
+};
+
+exports.down = function (knex) {
+    return knex.schema
+        .alterTable("monitor", function (table) {
+            table.dropColumn("force_ip");
+        });
+};
diff --git a/server/model/monitor.js b/server/model/monitor.js
index 741fb940e..8cbd8b16b 100644
--- a/server/model/monitor.js
+++ b/server/model/monitor.js
@@ -160,6 +160,7 @@ class Monitor extends BeanModel {
             smtpSecurity: this.smtpSecurity,
             rabbitmqNodes: JSON.parse(this.rabbitmqNodes),
             conditions: JSON.parse(this.conditions),
+            forceIp: this.forceIp,
 
             // ping advanced options
             ping_numeric: this.isPingNumeric(),
@@ -426,10 +427,18 @@ class Monitor extends BeanModel {
                         }
                     }
 
+                    const agentFamily = this.forceIp ? (this.forceIp === "ipv4" ? 4 : 6) : undefined;
+
                     const httpsAgentOptions = {
                         maxCachedSessions: 0, // Use Custom agent to disable session reuse (https://github.com/nodejs/node/issues/3940)
                         rejectUnauthorized: !this.getIgnoreTls(),
                         secureOptions: crypto.constants.SSL_OP_LEGACY_SERVER_CONNECT,
+                        ...(agentFamily ? { family: agentFamily } : {})
+                    };
+
+                    const httpAgentOptions = {
+                        maxCachedSessions: 0,
+                        ...(agentFamily ? { family: agentFamily } : {})
                     };
 
                     log.debug("monitor", `[${this.name}] Prepare Options for axios`);
@@ -491,6 +500,7 @@ class Monitor extends BeanModel {
                         if (proxy && proxy.active) {
                             const { httpAgent, httpsAgent } = Proxy.createAgents(proxy, {
                                 httpsAgentOptions: httpsAgentOptions,
+                                httpAgentOptions: httpAgentOptions,
                             });
 
                             options.proxy = false;
@@ -499,6 +509,10 @@ class Monitor extends BeanModel {
                         }
                     }
 
+                    if (!options.httpAgent) {
+                        options.httpAgent = new http.Agent(httpAgentOptions);
+                    }
+
                     if (!options.httpsAgent) {
                         let jar = new CookieJar();
                         let httpsCookieAgentOptions = {
diff --git a/server/server.js b/server/server.js
index cba02174d..ad9ec1080 100644
--- a/server/server.js
+++ b/server/server.js
@@ -792,6 +792,7 @@ let needSetup = false;
                 bean.url = monitor.url;
                 bean.method = monitor.method;
                 bean.body = monitor.body;
+                bean.forceIp = monitor.forceIp;
                 bean.headers = monitor.headers;
                 bean.basic_auth_user = monitor.basic_auth_user;
                 bean.basic_auth_pass = monitor.basic_auth_pass;
diff --git a/src/pages/EditMonitor.vue b/src/pages/EditMonitor.vue
index 95b29aa58..a998ee374 100644
--- a/src/pages/EditMonitor.vue
+++ b/src/pages/EditMonitor.vue
@@ -906,6 +906,21 @@
                                     </select>
                                 </div>
 
+                                <div class="my-3">
+                                    <label for="forceIp" class="form-label">{{ $t("Force Ip") }}</label>
+                                    <select id="forceIp" v-model="monitor.forceIp" class="form-select">
+                                        <option :value="null">
+                                            {{ $t("None") }}
+                                        </option>
+                                        <option value="ipv4">
+                                            ipv4
+                                        </option>
+                                        <option value="ipv6">
+                                            ipv6
+                                        </option>
+                                    </select>
+                                </div>
+
                                 <!-- Encoding -->
                                 <div class="my-3">
                                     <label for="httpBodyEncoding" class="form-label">{{ $t("Body Encoding") }}</label>
@@ -1129,6 +1144,7 @@ const monitorDefaults = {
     parent: null,
     url: "https://",
     method: "GET",
+    forceIp: null,
     interval: 60,
     retryInterval: 60,
     resendInterval: 0,