This article is going to summarize how to have socket
connections within ACI. The containers for socket server and client are in the same container group, so the server and client locate in the same virtual machine. The sample code, for both socket server and client, is in
Node.js.
Define Socket Server
The following Node.js code creates a socket server, which
listens on port 1337 of localhost:
var net = require('net');
function getTimePrefix() {
return (new Date()).toString() + ' ';
}
var server = net.createServer(function(socket) {
socket.on('data', function(data){
textChunk = data.toString('utf8');
console.log(getTimePrefix() + textChunk);
socket.write(textChunk);
});
socket.on('error', function(err) {
console.log(getTimePrefix() + err)
})
});
server.listen(1337, 'localhost');
Define Socket Client
The following Node.js code creates 200 socket clients, which
try to connect to the socket server concurrently:
var connections = 200;
const cp = require('child_process');
var net = require('net');
function getTimePrefix() {
return (new Date()).toString() + ' ';
}
var onConnected = function(client, connection) {
return function() {
client.write(connection + ': Hello, server! Love,
Client.');
};
};
var onData = function(client, connection) {
return function(data) {
console.log(getTimePrefix() + 'Connection ' + connection + ' received: ' + data);
client.destroy();
};
}
var onClosed = function(connection) {
return function() {
console.log(getTimePrefix() + 'Connection ' + connection + ' closed');
};
};
var onError = function(connection) {
return function(err) {
console.log(getTimePrefix() + 'Connection ' + connection + ' has error: ' + err);
};
};
var startClient = function () {
for (var i = 0; i < connections; ++i) {
var client = new net.Socket();
client.connect(1337, 'localhost', onConnected(client, i));
client.on('data', onData(client, i));
client.on('close', onClosed(i));
client.on('error', onError(i));
}
};
setInterval(startClient, 10000);
Build Docker Image
We can build both server and client applications into docker
images. I’ve published the server image as containerinstance/socket-server, and
client image as containerinstance/socket-client in Docker Hub.
Create Azure Container Instance
If we include the socket server and client into an Azure
container instance, they can talk to each other. The following is a sample of
Azure container instance definition to deploy both the socket server and
client:
{
"properties": {
"containers": [
{
"name": "socket-server",
"properties": {
"command": [],
"image": "containerinstance/socket-server:20180731",
"ports": [
{
"port": 1337
}
],
"resources": {
"requests": {
"cpu": 1,
"memoryInGb": 1.5
}
}
}
},
{
"name": "socket-client",
"properties": {
"command": [],
"image": "containerinstance/socket-client:20180731",
"ports": [],
"resources": {
"requests": {
"cpu": 1,
"memoryInGb": 1.5
}
}
}
}
],
"osType": "Linux",
"ipAddress": {
"ports": [
{
"protocol": "TCP",
"port": 1337
}
],
"type": "Public"
}
},
"location": "westus"
}
The ACI logs API can demonstrate that these two containers talk
smoothly.
Notes
All the sample code files have been shared at https://github.com/zhedahht/ACISocketSample/tree/master/SocketInsideContainerGroup.
