Autograding using NGROK
In order to use an autograder to grade your web sites running on your local computer, we need to be able to access the web server running on your laptop or personal computer. In general, home gateways and most campus networks or coffee shops block incoming connections to your computer when you are connected to their network. This is very much on purpose and is designed to protect your computer from being attacked and compromised whenever it connects to the internet.
So while you can test your applications locally by connecting to the "loop-back" address using "localhost" and urls like:
http://localhost/wa4e/assn01/ http://localhost:8080/wa4e/assn01/ http://localhost:8888/wa4e/assn01/So even if you knew the local IP (Internet Protocol) address of your computer, it is not possible to connect from the internet to your computer due to a gateway or firewall.
But we need to be able to have our autograding software connect to your local web server to grade your assignments. And to so this, we use a piece of software called "ngrok" to give your local web server a internet-accessible address for a short period of time.
Installing ngrok for autograding
Installing ngrok is very simple, you can download a ZIP file from https://ngrok.com/ and unzip that file anywhere on your computer. You might want to read the documentation on the web site to familiarize yourself with ngrok. They have nice diagrams that explain how ngrok works and why ngrok is needed to allow access to your local web server.
Running Ngrok on Apple
Download the ngrok.zip file to your Downloads folder and then extract it by double clicking on the downloaded file and it will unzip and produce a single file called ngrok. You can put this file anywhere on your computer but for now we will just execute it from the Downloads folder. Make sure your web server (Apache, MAMP, etc..) is up and running and then open up a Terminal Window as follows:
$ cd Downloads/
$ ls
ngrok ngrok_2.0.19_darwin_amd64.zip
$ ./ngrok http 8888
Tunnel Status online
Version 2.0.19/2.0.19
Web Interface http://127.0.0.1:4040
Forwarding http://c5343c6e.ngrok.io -> localhost:8888
Forwarding https://c5343c6e.ngrok.io -> localhost:8888
Connections ttl opn rt1 rt5 p50 p90
0 0 0.00 0.00 0.00 0.00
Replace "8888" with whatever port your web server is running on. Then nagivate in your browser
to the address that ngrok has chosen for you. Do not include the port number on the ngrok address.
http://c5343c6e.ngrok.ioAt that point you should see the same thing as you would see if you went to
http://localhost:8888/And you can go to paths other than the root like:
http://c5343c6e.ngrok.io/guess/index.phpYour local web server will be visible to the Internet at the ngrok-chosen address until you end the ngrok application. To terminate the ngrok on the Apple, simply press "CTRL-C" to aport the program. At that point, your local web server can no longer be accessed through ngrok.
Each time you run ngrok you will get a new address unless you sign up and pay for an address that does not change each time you run it.
Running Ngrok on Windows
Download the ngrok.zip file to your Downloads folder and then extract it by clicking on the downloaded file and selecting "Extract All". It will make a folder like "ngrok_2.0.19_windows_386" and in that folder, you will find a single file named ngrok.exe. You You can put this file anywhere on your computer but for now we will just execute it from the Downloads folder. Make sure your web server (XAMPP, MAMP, etc..) is up and running and then open up a Command Line window as follows:
C:\...> cd Downloads\ngrok_2.0.19_windows_386 C:\...> ngrok http 8080 Tunnel Status online Version 2.0.19/2.0.19 Web Interface http://127.0.0.1:4040 Forwarding http://c5343c6e.ngrok.io -> localhost:8080 Forwarding https://c5343c6e.ngrok.io -> localhost:8080Replace "8080" with whatever port your web server is running on. Then nagivate in your browser to the address that ngrok has chosen for you. Do not include the port number on the ngrok address.
http://c5343c6e.ngrok.ioAt that point you should see the same thing as you would see if you went to
http://localhost:8080/And you can go to paths other than the root like:
http://c5343c6e.ngrok.io/guess/index.phpYour local web server will be visible to the Internet at the ngrok-chosen address until you end the ngrok application. To terminate the ngrok on the Apple, simply press "CTRL-Z" to aport the program. At that point, your local web server can no longer be accessed through ngrok.
Each time you run ngrok you will get a new address unless you sign up and pay for an address that does not change each time you run it.