prepare serverless

Author: wtao

.vscode/launch.json

@@ -13,6 +13,23 @@
             ],
             "program": "${workspaceFolder}/backend/index.mjs",
             "envFile": "${workspaceFolder}/backend/.envrc"
+        },
+        {
+            "type": "node",
+            "request": "launch",
+            "name": "Launch sls Program",
+            "skipFiles": [
+                "<node_internals>/**"
+            ],
+            "cwd": "${workspaceFolder}/backend",
+            "runtimeExecutable": "npm",
+            "runtimeArgs": [
+                "run",
+                "sls-debug"
+            ],
+            "attachSimplePort": 9229,
+            "sourceMaps": true,
+            "envFile": "${workspaceFolder}/backend/.envrc"
         }
     ]
 }

backend/express.mjs

@@ -0,0 +1,43 @@
+import { MongoClient } from "mongodb";
+import * as Query from "./query.mjs";
+import * as Mongo from "./mongo.mjs";
+
+// grafana: test datasource connect
+export const dbConfig = async (req, res) => {
+  let client = null;
+  try {
+    client = new MongoClient(req.body.db.url);
+    await client.connect();
+    res.send({
+      status: "success",
+      message: "MongoDB Connection test OK",
+    });
+  } catch (err) {
+    res.send({
+      status: "error",
+      message: "MongoDB Connection Error: " + err.message,
+    });
+  } finally {
+    client?.close();
+  }
+};
+
+// grafana: qeury
+export const dbQuery = async (req, res, next) => {
+  try {
+    const results = await Promise.all(
+      req.body.targets.map(async (target) => {
+        const queryArgs = Query.parseQuery(req, target);
+        const result = await Mongo.aggregate(
+          req.body.db.url,
+          req.body.db.db,
+          queryArgs
+        );
+        return result;
+      })
+    );
+    res.json(results);
+  } catch (err) {
+    next(err);
+  }
+};

backend/index-sls.mjs

@@ -0,0 +1,20 @@
+import express from "express";
+import serverless from "serverless-http";
+import { dbConfig, dbQuery } from "./express.mjs";
+
+const app = express();
+app.use(express.json());
+
+// grafana: test datasource connect
+app.all("/", dbConfig);
+
+// grafana: qeury
+app.all("/query", dbQuery);
+
+//default error handler
+app.use((err, req, res, next) => {
+  console.error(err.stack);
+  res.status(500).send(err.message ?? "unknown error");
+});
+
+export const handler = serverless(app);

backend/index.mjs

@@ -1,52 +1,16 @@
 import express from "express";
-import { MongoClient } from "mongodb";
-import * as Query from "./query.mjs";
-import * as Mongo from "./mongo.mjs";
 import cors from "cors";
+import { dbConfig, dbQuery } from "./express.mjs";
 
 const app = express();
 app.use(express.json());
 app.use(cors());
 
 // grafana: test datasource connect
-app.all("/", async (req, res) => {
-  let client = null;
-  try {
-    client = new MongoClient(req.body.db.url);
-    await client.connect();
-    res.send({
-      status: "success",
-      message: "MongoDB Connection test OK",
-    });
-  } catch (err) {
-    res.send({
-      status: "error",
-      message: "MongoDB Connection Error: " + err.message,
-    });
-  } finally {
-    client?.close();
-  }
-});
+app.all("/", dbConfig);
 
 // grafana: qeury
-app.all("/query", async (req, res, next) => {
-  try {
-    const results = await Promise.all(
-      req.body.targets.map(async (target) => {
-        const queryArgs = Query.parseQuery(req, target);
-        const result = await Mongo.aggregate(
-          req.body.db.url,
-          req.body.db.db,
-          queryArgs
-        );
-        return result;
-      })
-    );
-    res.json(results);
-  } catch (err) {
-    next(err);
-  }
-});
+app.all("/query", dbQuery);
 
 //default error handler
 app.use((err, req, res, next) => {

backend/package.json

@@ -5,13 +5,16 @@
   "main": "index.mjs",
   "scripts": {
     "start": "node index.mjs",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "sls-debug": "export SLS_DEBUG=* && node --inspect node_modules/serverless/bin/serverless offline"
   },
   "author": "",
   "license": "ISC",
   "dependencies": {
     "cors": "^2.8.5",
     "express": "^4.19.2",
-    "mongodb": "^6.5.0"
+    "mongodb": "^6.5.0",
+    "serverless-http": "^3.2.0",
+    "serverless-offline": "^13.5.0"
   }
 }

backend/serverless.yml

@@ -0,0 +1,21 @@
+	
+service: lambda-mongo-grafana
+ 
+provider:
+  name: aws
+  runtime: nodejs16.x
+  stage: default
+  region: us-west-2
+	
+plugins:
+  - serverless-offline
+
+custom:
+  serverless-offline:
+    httpPort: 4000
+
+functions:
+  app:
+    handler: index-sls.handler
+    events:
+      - http: 'ANY /{ANY+}'