add server code for zookeeper monitor

server/model/monitor.js

@@ -6,7 +6,7 @@ const { log, UP, DOWN, PENDING, MAINTENANCE, flipStatus, MAX_INTERVAL_SECOND, MI
     SQL_DATETIME_FORMAT
 } = require("../../src/util");
 const { tcping, ping, checkCertificate, checkStatusCode, getTotalClientInRoom, setting, mssqlQuery, postgresQuery, mysqlQuery, mqttAsync, setSetting, httpNtlm, radius, grpcQuery,
-    redisPingAsync, mongodbPing, kafkaProducerAsync, getOidcTokenClientCredentials, rootCertificatesFingerprints, axiosAbortSignal
+    redisPingAsync, mongodbPing, kafkaProducerAsync, getOidcTokenClientCredentials, rootCertificatesFingerprints, axiosAbortSignal, zookeeperConnect
 } = require("../util-server");
 const { R } = require("redbean-node");
 const { BeanModel } = require("redbean-node/dist/bean-model");
@@ -182,6 +182,8 @@ class Monitor extends BeanModel {
                 tlsCert: this.tlsCert,
                 tlsKey: this.tlsKey,
                 kafkaProducerSaslOptions: JSON.parse(this.kafkaProducerSaslOptions),
+                zookeeperHost: this.zookeeperHost,
+                zookeeperTimeout: this.zookeeperTimeout,
             };
         }
 
@@ -884,6 +886,12 @@ class Monitor extends BeanModel {
                     bean.status = UP;
                     bean.ping = dayjs().valueOf() - startTime;
 
+                } else if (this.type === "zookeeper") {
+                    let startTime = dayjs().valueOf();
+
+                    bean.msg = await zookeeperConnect(this.zookeeperHost, this.zookeeperTimeout);
+                    bean.status = UP;
+                    bean.ping = dayjs().valueOf() - startTime;
                 } else {
                     throw new Error("Unknown Monitor Type");
                 }

server/server.js

@@ -827,6 +827,8 @@ let needSetup = false;
                 bean.kafkaProducerAllowAutoTopicCreation =
                     monitor.kafkaProducerAllowAutoTopicCreation;
                 bean.gamedigGivenPortOnly = monitor.gamedigGivenPortOnly;
+                bean.zookeeperHost = monitor.zookeeperHost;
+                bean.zookeeperTimeout = monitor.zookeeperTimeout;
 
                 bean.validate();
 

server/util-server.js

@@ -526,35 +526,6 @@ exports.mongodbPing = async function (connectionString) {
     }
 };
 
-exports.zookeeperConnect = function (zookeeperHost, timeoutMs = 5000) {
-    return new Promise((resolve, reject) => {
-        const timer = setTimeout(() => {
-            reject(Error("Zookeeper operation timed out"));
-        }, timeoutMs);
-
-        const config = {
-            connect: zookeeperHost,
-            timeout: 1000,
-            debug_level: ZooKeeper.ZOO_LOG_LEVEL_WARN,
-            host_order_deterministic: false,
-        };
-
-        const client = new ZooKeeper(config);
-
-        client.connect(config, (err, _) => {
-            if (err) {
-                clearTimeout(timer);
-                reject(err);
-            } else {
-                clearTimeout(timer);
-                resolve("Successfully connected");
-            }
-
-            client.close();
-        });
-    });
-};
-
 /**
  * Query radius server
  * @param {string} hostname Hostname of radius server
@@ -1194,3 +1165,40 @@ module.exports.axiosAbortSignal = (timeoutMs) => {
         }
     }
 };
+
+/**
+ * Attempt to connect to the given zookeeper host under the given timeout.
+ * @param {string} zookeeperHost - The connection string for a single host in the form 'host:port'
+ * @param {number} timeoutMs - Timeout in milliseconds under which connection must be established.
+ * @returns {Promise<any>} The result of connection attempt
+ */
+exports.zookeeperConnect = function (zookeeperHost, timeoutMs = 5000) {
+    return new Promise((resolve, reject) => {
+        // Seems like zookeeper client behavior is to retry indefitiely on timeout.
+        // So, an explicit timer is needed to prevent the monitor from getting stuck.
+        const timer = setTimeout(() => {
+            reject(Error("Zookeeper operation timed out"));
+        }, timeoutMs);
+
+        const config = {
+            connect: zookeeperHost,
+            timeout: timeoutMs, // Causes the client to retry and does not fail.
+            debug_level: ZooKeeper.ZOO_LOG_LEVEL_WARN,
+            host_order_deterministic: false,
+        };
+
+        const client = new ZooKeeper(config);
+
+        client.connect(config, (err, _) => {
+            if (err) {
+                clearTimeout(timer);
+                reject(err);
+            } else {
+                clearTimeout(timer);
+                resolve("Successfully connected");
+            }
+
+            client.close();
+        });
+    });
+};