For the past few days I've been trying to solve the problem of publishing a message from Lambda to the AWS cloud, using Greengrass v2.
The code in python was even provided in the documentation, only had to be slightly reworked.
When it comes to SDK v2 JS in documentation there is only minimal mention about publish function in AWS-CRT library.
I tried to create code using components from this library, but it looks like the library also requires a script with parameters.
This is my code that requires installation of aws-iot-sdk-v2 js.
const iotsdk = require("aws-iot-device-sdk-v2");
const mqtt = iotsdk.mqtt;
const os = require("os");
const util = require("util");
const GROUP_ID = process.env.GROUP_ID;
const THING_NAME = process.env.AWS_IOT_THING_NAME;
const THING_ARN = process.env.AWS_IOT_THING_ARN;
(topic = "gg/message"),
(payload = JSON.stringify({ message: util.format("ping") }));
function greengrassHelloWorldRun() {
mqtt.MqttClientConnection.prototype.publish(topic, payload);
}
console.log(topic);
console.log(payload);
setInterval(greengrassHelloWorldRun, 5000);
exports.handler = function (event, context) {
console.log("event: " + JSON.stringify(event));
console.log("context: " + JSON.stringify(context));
};
I get errors about arguments and NAPI.
The same errors also appear when using this function as lambda component in greengrass logs
Maybe someone has some example how to publish some message on topic using Node lambda with sdk v2.
After contacting AWS Support I know it is impossible.
AWS doesn't support mqttProxy IPC for SDK V2 JS yet.
ChristopherTal
I'm also using the Greengrass SDKs for JS and indeed they're still a work in progress. But I was able to send messages to the IoTCore from Greengrass using the JS SDKs.
A few things to mention:
You seem to use the aws-iot-device-sdk-v2 SDK which is for things
The aws-greengrass-core-sdk npm package is made for components
It is important to differ between things and components and decide who's doing what.
To send data to IoTCore from a thing, you need indeed to use MQTT. On the deployment page on the Greengrass console, you need to revise the deployment and add following components:
MQTT Broker
MQTT Bridge
Client device auth
This way your thing connects to the local MQTT Broker through the client device auth component and the MQTT Bridge decides how the traffic is routed. You can read all info on the links above.
I even realised this using the standard mqtt npm package. You need to create a certificate and a thing using lambda or the console and use those certificates to access the broker.
const mqtt = require('mqtt')
const fs = require('fs')
const ca = fs.readFileSync(locationOfTheCA)
const key = fs.readFileSync(locationOfThePrivateKey)
const cert = fs.readFileSync(locationOfTheCertificate)
console.log('Welcome to MQTT Connector')
const client = mqtt.connect('mqtts://localhost:8883', {
clientId: 'yourThingNameHere',
ca: ca,
key: key,
cert: cert
})
client.on('connect', function () {
console.log('Connected to MQTT')
/* client.subscribe('$aws/*', function (err) {
if (!err) {
//client.publish('presence', 'Hello mqtt')
}
})*/
})
client.on('message', function (topic, message) {
// message is Buffer
console.log(message.toString())
client.end()
})
Hopefully this helps you out!
Warm regards
Hacor
Related
We recently decided to include E2E to our front-end pipeline and we are using testCafe for that and since we use AWS as our SaaS we're being asked to use Devicefarm for remote testing and I'm facing the problem to connect them. I'm based on the selenium implementations and the testCafe documentation but it seems not to be able to establish connection between them, anyone has any idea why?
My code:
const AWS = require('aws-sdk');
const createTestCafe = require('testcafe');
const PROJECT_ARN = "arn:aws:devicefarm:us-west-2:XXXXXXXX:testgrid-project:XXXXXX-XXXX-XXXX-XXXX-XXXXXXXX";
const devicefarm = new AWS.DeviceFarm({ region: "us-west-2", credentials: AWS.config.credentials });
(async () => {
const testGridUrlResult = await devicefarm.createTestGridUrl({
projectArn: PROJECT_ARN,
expiresInSeconds: 6000
}).promise();
const url = new URL(testGridUrlResult.url || '');
const testCafe = await createTestCafe(url.host, 443);
const runner = testCafe.createRunner();
const remoteConnection = await testCafe.createBrowserConnection();
remoteConnection.once('ready', async () => {
await runner
.src(['./load-mfc.ts'])
.browsers('devicefarm:firefox')
.run();
await testCafe.close();
});
})().catch((e) => console.error(e));
According to the AWS Device Farm documentation about the CreateTestGridUrl method:
Creates a signed, short-term URL that can be passed to a Selenium RemoteWebDriver constructor.
This URL can't be passed to the hostname property of the createTestCafe method because TestCafe doesn't implement the WebDriver protocol. TestCafe works differently then Selenium. Once you created a remote browser connection using TestCafe, you should navigate your remote browser to the browserConnection.url URL to connect to a TestCafe server instance and start test execution in this browser.
As the AWS Device Farm service uses the WebDriver protocol to operate remote browsers, you would need to write a custom Browser Provider Plugin for TestCafe. It may be helpful to read more in the TestCafe documentation about this topic and see how a similar thing is implemented in the BrowserStack provider.
Hi everybody and thanks for taking time to look at my issue/question.
I am getting different results when deploying my AWS Lambda stand-alone versus within an Application Stack.
I'm trying to connect to AWS Elasticache Redis from within my Lambda. I have .Net Core 3.1 Lambdas (using StackExchange.Redis) which can connect. But I also need to be able to connect from my Node.js Lambdas.
For the Node.js Lambdas, I'm using "node-redis" and "async-redis". I have two Lambdas which are essentially identical except that one is deployed in an Application Stack and the other is deployed as a stand-alone Lambda. Both Lambdas reference the same Lambda Layer (i.e. same "node_modules"), have the same VPC settings, the same Execution Role, and essentially the same code. So they've pushed it up to another group.
The stand-alone Lambda connects to Redis without issue. The Application Stack Lambda does not and exits processing before completing but without raising any error.
At first I thought I might just need to configure my Application Stack but I cannot find any information indicating we even can configure Application Stacks. So I'm at a loss.
The stand-alone Lambda:
exports.handler = async (event) => {
const asyncRedis = require("async-redis");
const redisOptions =
{
host: "XXXXXXXXX.XXXXX.XXXX.use2.cache.amazonaws.com",
port: 6379
}
console.log('A');
const client = asyncRedis.createClient(redisOptions);
console.log(client);
console.log('B');
const value = await client.get("Key");
console.log('C');
console.log(value);
console.log('D');
console.log(client);
};
The output of this function is essentially:
A
{RedisClient} --> the "client" object --> Shows connected = false
B
C
{ Correct Data From Redis }
D
{RedisClient} --> the "client" object --> Shows connected = true
The Application Stack Lambda:
async function testRedis2(event, context) {
console.log('In TestRedis2');
const asyncRedis = require("async-redis");
const redisOptions =
{
host: "XXXXXXXXX.XXXXX.XXXX.use2.cache.amazonaws.com",
port: 6379
}
console.log('A');
const client = asyncRedis.createClient(redisOptions);
console.log(client);
console.log('B');
var value = await client.get("Key");
console.log('C');
console.log(value);
console.log('D');
console.log(client);
}
module.exports = {
testRedis2
};
The output of this function is essentially:
In TestRedis2
A
{RedisClient} --> the "client" object --> Shows connected = false
B
I don't understand why these don't perform identically. And I don't get why I don't see further entries in the output.
Has anyone else experienced issues connecting to VPC resources from within an Application Stack?
Thanks
I stumbled across the answer through extensive trial and error. It may be obvious to Node/js developers but, just in case another Javascript/Node newbie has the same issue, I'll post the answer here.
The import/require and creation of the client must be at the top of the module. Not in the function itself.
So, the following does work in my application stack:
const asyncRedis = require("async-redis");
const redisOptions = {
host: "XXXXXXXXX.XXXXX.XXXX.use2.cache.amazonaws.com",
port: 6379
};
const client = asyncRedis.createClient(redisOptions);
async function redisGet(key: string){
// console.log('In redisGet');
return await client.get(key);
}
New to Google Cloud Run and trying to have two node.js microservices communicate internally via gRPC.
The client interface:
constructor(address: string, credentials: grpc.ChannelCredentials, options?: object);
The client code:
const client: MyClient = new MyClient('my-service-abcdefgh3a-ew.a.run.app:443', grpc.credentials.createSsl());
The server code:
const server = new grpc.Server();
server.addService<IMyServer>(MyService, new MyServer());
server.bind(`0.0.0.0:${process.env.PORT}`, grpc.ServerCredentials.createInsecure());
server.start();
The server is set to listen to 443.
The above seems to work when the service is open to public requests but doesn't work when you have the server set as internal. Any ideas?
You have to add the credentials in the request metadata. Here an example
...
// Create a client for the protobuf spec
const client = new protoObj.Greeter(HOST, grpc.credentials.createInsecure());
// Build gRPC request
const metadata = new grpc.Metadata();
metadata.add('authorization', `Bearer ${JWT_AUTH_TOKEN}`);
// Execute gRPC request
client.sayHello({name: GREETEE}, metadata, (err, response) => {...
Second question, how to get the JWT_AUTH_TOKEN. Here the documentation of Cloud Run to do this. But not completely, simply get the token and use it in the metadata of the request
...
request(tokenRequestOptions)
.then((token) => {
// add the token to the metadata
});
// Make the call
...
I am building a SOA with deepstream and I want to use a deepstream client server to perform API-KEY based look ups that the user should not know. How do I actually set up an RPC client provider? I have looked in the deepstream docs and on google, but there is not a full code example on how to do this. I have created a file like below and run it with node. The output I get is below it:
var deepstream = require('deepstream.io-client-js')
const client = deepstream('localhost:6020').login()
console.log('Starting up')
client.on('error', (error,event,topic) => {
console.log(error, event, topic);
})
client.on('connectionStateChanged', connectionState => {
console.log(connectionState);
})
client.login({username: 'USER', password: 'PASSWORD'}, (success, data) => {
if (success) {
client.rpc.provide('the-rpc', function( data, response ){
response.send(data);
});
} else {
console.log(data);
}
})
--
Starting up
AWAITING_CONNECTION
As you can see it runs the code, but does not actually connect to the deepstream server. I already have the deepstream server running, and a browser client that connects to it, so the config is correct. Please help!
I think your issue is based on the fact your trying to connect node via the webport. Try using port 6021 instead for tcp ( used by the node client ).
const client = deepstream('localhost:6021').login()
You should also only call .login() once, so the line would be:
const client = deepstream('localhost:6021')
We are working on a 2.0 release coming out very soon which will remove tcp entirely and only require a single port to make life easier in terms of deployment and performance.
I am currently in the middle of a project which include the use of MQTT. I'm writing my application in node.js. My project requires to connect/communicate to multiple devices which each device has specified and different topic(s). Later, the data from the each message will be stored into database (MongoDB). I'm using mqtt package from npmjs.com 1.
Below is an example of mqtt package code:
var mqtt = require('mqtt');
var client = mqtt.connect('mqtt://test.mosquitto.org');
client.on('connect', function () {
client.subscribe('presence');
client.publish('presence', 'Hello mqtt');
});
client.on('message', function (topic, message) {
// message is Buffer
console.log(message.toString());
client.end();
});
My problem is what should I do to get messages from the devices. I can easily list to a single topic using "#" to get all topics but I have to manually sort/split the topic and etc.
However, I'm thinking of another option in which I will create new mqtt client instance for each topic but I do not know if there is any limit of instances. I might use forever function from async package 2. My code might be like this:
var async = require('async');
var mqtt = require('mqtt');
var client = mqtt.connect("URL of MQTT broker");
var _topic = "";
var Subscriber = function(topic){
this._topic = topic;
client.on('connect', function () {
client.subscribe(this.topic.setter);
});
async.forever(
function(next){
client.on('message', function (topic, message) {
// TO DO store message
});
},
function(err){
client.end();
}
);
};
module.exports = Subscriber;
Does anyone have any recommendation?
I would not recommend creating a separate connection for each subscription you want to make. Each connection is a new TCP connection and would waste resources in both your application and the broker.
The normal pattern here would be to use a wildcard subscription. The message callback handler is handed the topic the message came on, so, as long as your sensibly structure your topic space, there is very little overhead in having to route the message appropriately in your application.