reselbob/pinger

A simple Node.js app that returns information about the runtime environment

pinger

A simple Node.js app that returns information about the runtime environment.

Go here to read the command line reference.

Running pinger on a local machine.

The following steps describe how to run pinger on a standalone computer or virtual machine. Please be advised that the machine needs to have Node.js and curl installed. An easy way to run this demo is to use a the Katacode Ubuntu Playground found at this URL:

https://katacoda.com/courses/ubuntu/playground

Step 1: Make sure that Node.js is running your computer or VM (virtual machine). Run the following command in a terminal window.

node -v

You'll get output similar to the following:

v8.11.3

(Version number may vary according to your machine.)

If Node.js in not installed, you'll get an error. In that case, you can find the instructions for downloading and installing Node.js here.

Step 2: Clone this repository to the local machine or VM.

git clone https://github.com/reselbob/pinger.git

Step 3: Navigate into the directory that has the pinger source code.

cd pinger/app

Step 4: Install the application's dependencies packages.

npm install

Step 5: Invoke the application.

node server.js

Step 6: Call the application for output using curl. In a new terminal window execute the following command.

curl localhost:3000

WHERE 3000 is the default port.

You can alter the runtime port of the app by setting the environment variable, PINGER_PORT to the port number you want to use.

You get output similar to the following:

{
    "APIVersion": "v2",
    "startTime": "2018-10-23T22:54:27.516Z",
    "interfaces": [
        {
            "ifname": "eth0",
            "ipaddress": "10.32.0.13"
        }
    ],
    "secretMessage": "Kube is Cool",
    "processId": 5,
    "requestHeaders": {
        "host": "xxx.241.xxx.171",
        "upgrade-insecure-requests": "1",
        "user-agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36",
        "accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8",
        "accept-encoding": "gzip, deflate",
        "accept-language": "en-US,en;q=0.9",
        "x-cloud-trace-context": "78f550b3bbf754251021bb4a582f8bf0/17461875170587409562",
        "via": "1.1 google",
        "x-forwarded-for": "xx.169.xxx.145, xxx.241.xxx.171",
        "x-forwarded-proto": "http",
        "connection": "Keep-Alive"
    },
    "currentTime": "2018-10-24T15:06:49.046Z",
    "requestUrl": "/"
}

Building and running pinger as a Docker container on Katacoda

Step 1: Go to the Ubuntu Playground on Katacoda

https://katacoda.com/courses/ubuntu/playground

Step 2: Clone the project source from GitHub

git clone https://github.com/reselbob/pinger.git

Step 3: Navigate to the application source code directory

cd pinger/app/

Step 4: Build the container image.

(You must be connected to the internet for this step to work.)

docker build -t pinger:beta .

Step 5: Create the container get it running

docker run -d --name pinger -p 3000:3000  -e CURRENT_VERSION=beta pinger:beta

You'll get the container id as output, similar to this:

6a619a913e0c25df5adccd5e11de899a97405c43de9cfb1a0945ee81148068ae Confirm the container is running:

docker ps -a | grep pinger

You'll get output similar to the following:

6a619a913e0c        pinger:beta         "node server.js"    About a minute ago   Up About a minute   0.0.0.0:3000->3000/tcp   pinger```

Step 6: Call the application for output using curl.

curl localhost:3000/?type=networkInfo

You'll get output similar to the following:

{
    "lo": [
        {
            "address": "127.0.0.1",
            "netmask": "255.0.0.0",
            "family": "IPv4",
            "mac": "00:00:00:00:00:00",
            "internal": true,
            "cidr": "127.0.0.1/8"
        }
    ],
    "eth0": [
        {
            "address": "172.18.0.2",
            "netmask": "255.255.255.0",
            "family": "IPv4",
            "mac": "02:42:ac:12:00:02",
            "internal": false,
            "cidr": "172.18.0.2/24"
        }
    ]
}

Step 7: Let's open pinger as a web page. Click the (+) sign on the right of the Katacoda menu page/

Step 8: click Select port to view on Host 1

Step 8: Enter the port number 3000 in the textbox on the web page. Then click the button, Display Port

The web page will appear. It's calling back to the running instance of pinger.

Step 9: If you need to work with pinger by calling into the Katacoda server, copy the URL in your browser's address bar and save it in a text file.

Congratulations! You've completed the exercise.