Add MySQL replication status check lambda function

.gitignore

@@ -2,4 +2,4 @@
 .env
 node_modules
 vendor
-
+node_modules

mysql/replcation_lambda/index.js

@@ -0,0 +1,111 @@
+const AWS = require('aws-sdk');
+const mysql = require('mysql2/promise');
+const ssm = new AWS.SSM({ apiVersion: '2014-11-06' });
+
+
+async function loadSSMParam(name) {
+    var ssmParams = {
+        Name: name,
+        WithDecryption: true
+    };
+
+    return new Promise((resolve, reject) => {
+        ssm.getParameter(ssmParams, function (err, data) {
+            if (err) console.log(err);
+            else resolve(data.Parameter.Value);
+        });
+    });
+}
+
+function putMetricData(namespace, metricName, value, unit) {
+    console.log(`LOG|${value}|${unit}|${metricName}|${namespace}`);
+
+    callCloudWatch({
+        MetricData: [{
+            MetricName: metricName,
+            Value: value,
+            Timestamp: new Date(),
+            Unit: unit,
+        }],
+        Namespace: namespace
+    });
+}
+
+function putGroupMetricData(namespace, metricName, dimension, value, unit) {
+    console.log(`LOG|${value}|${unit}|${dimension}|${metricName}|${namespace}`);
+
+    callCloudWatch({
+        MetricData: [{
+            MetricName: metricName,
+            Dimensions: [{
+                Name: 'Group',
+                Value: dimension
+            }],
+            Value: value,
+            Timestamp: new Date(),
+            Unit: unit,
+        }],
+        Namespace: namespace
+    });
+}
+
+function callCloudWatch(params) {
+    let cloudWatch = new AWS.CloudWatch();
+
+    cloudWatch.putMetricData(params, function (err, data) {
+        if (err) console.log(err, err.stack); // an error occurred
+        else console.log(data); // successful response
+    });
+}
+
+exports.handler = async (event, context, callback) => {
+    try {
+        let namespace = event.cloudwatch_namespace;
+        let metricName = event.cloudwatch_metric_name;
+
+        let password = await loadSSMParam(event.mariadb_password);
+        let port = event.mariadb_port;
+        if (!port) {
+            port = 3306;
+        }
+
+        let dbConn = await mysql.createConnection({
+            host: event.mariadb_host,
+            user: event.mariadb_user,
+            port: port,
+            password: password,
+        });
+        let [rows, fields] = await dbConn.execute('SHOW SLAVE STATUS');
+        let status = JSON.parse(JSON.stringify(rows))[0];
+        putMetricData(namespace, metricName, status.Seconds_Behind_Master, 'Seconds');
+
+        let ioStatus = 0;
+        let sqlStatus = 0;
+        if (status.Slave_IO_Running === 'Yes') {
+            ioStatus = 1;
+        }
+        if (status.Slave_SQL_Running === 'Yes') {
+            sqlStatus = 1;
+        }
+        putGroupMetricData(namespace, metricName, 'Slave_IO_Running', ioStatus, 'Count');
+        putGroupMetricData(namespace, metricName, 'Slave_SQL_Running', sqlStatus, 'Count');
+
+        await dbConn.end();
+
+        let response = {
+            statusCode: 200,
+            body: '',
+        };
+
+        callback(null, response);
+    } catch (err) {
+        console.log(err);
+
+        let response = {
+            statusCode: 500,
+            body: err,
+        };
+
+        callback(null, response);
+    }
+};

mysql/replcation_lambda/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "metricReplicationLag",
+  "version": "1.0.0",
+  "license": "MIT",
+  "dependencies": {
+    "mysql2": "^1.6.4"
+  }
+}