Introduction

For this programming assignment you will create the world's simplest reverse proxy. Again, as in the prior progrogramming assignment, you may program this in the language of your choice $($it doesn't even have to be the same language as the first assignment$).$ You will need at least four terminal$/$console windows running: one client, one proxy, and at least two $(2)$ server instances.

Please see the note at the bottom of this page if you were not able to complete the prior programming assignment, and need a client$/$server to complete this assignment.

Details

proxy

Arguments for upstream ports: array$/$tuple$/$set$/$list $($whatever your language supports$).$ These will be the dynamic ports for the server instances.

Accept traffic on a given port.

Send any 'PING' messages in a round$-$robin scheduleLinks to an external site. between all the given upstream ports.

Any replies it receives from upstream, it will send to the downstream client with $\text{'}$ via $$\{$SERVER$\_$PORT$\}[$$$\{$SERVER$\_$IDX$\}]\text{'}$ appended to the message

$$\{$SERVER$\_$PORT$\}$ is the upstream server port.

$$\{$SERVER$\_$IDX$\}$ is the upstream server index in the upstream array.

Example Diagram

port:$8001$

$$ server $$

$$

$$ client $$ proxy $$

$$ port:$8000$

$$ server $$

port:$8002$

In the above example diagram, the proxy is listening on port $8000,$ and is fronting two servers instances listening on port $8001,$ and $8002.$

Example Output with Client, Proxy, and two Server Instances

Client:

$\backslash$lambda python client.py $--$port $8000$

$1$ : sent PING... received b'PONG via $8001[0]\text{'}$

$2$ : sent PING... Timed Out

$3$ : sent PING... Timed Out

$4$ : sent PING... received b'PONG via $8002[1]\text{'}$

$5$ : sent PING... received b'PONG via $8001[0]\text{'}$

$6$ : sent PING... Timed Out

$7$ : sent PING... received b'PONG via $8001[0]\text{'}$

$8$ : sent PING... received b'PONG via $8002[1]\text{'}$

$9$ : sent PING... received b'PONG via $8001[0]\text{'}$

$10$ : sent PING... received b'PONG via $8002[1]\text{'}$

Proxy:

$\backslash$lambda python proxy.py $--$port $8000$

$[$proxy$]$ : ready to proxy data...

Server #$0$:

$\backslash$lambda python server.py $--$port $8001$

$[$server$]$ : ready to accept data...

$[$client$]$ : PING

$[$server$]$ : packet dropped

$[$client$]$ : PING

$[$client$]$ : PING

$[$client$]$ : PING

Server #$1$:

$\backslash$lambda python server.py $--$port $8002$

$[$server$]$ : ready to accept data...

$[$server$]$ : packet dropped

$[$client$]$ : PING

$[$server$]$ : packet dropped

$[$client$]$ : PING

$[$server$]$ : PING

Deliverables

One $(1)$ source code file for your proxy server $($e$.$g$.$ proxy.py$,$ main.go$,$ etc.$).$

A README file that explains how to run your program.

Screenshots of your program running $($they can be running on your own machine or the CSE machine$).$

NOTE: your screenshot should include your name $/$ EUID somewhere $($you can print it at the beginning of your program or change the command prompt to your name, etc$)$

Note: Free Client$/$Server UDP Zinger

If you were not able to complete the previous networking assignment, you may use this zinger program to complete this proxy programming assignment. If you encounter any issues with it$,$ please let me know.

The zinger program prints "ZING$/$ZONG$"$ so it cannot be used for the previous assignment.

Zinger Binary Table

OS Architecture Binary

Windows AMD$64/$x$64$ zinger$\_$windows$\_$amd$64.$exeDownload zinger$\_$windows$\_$amd$64.$exe

Windows ARM$64$ zinger$\_$windows$\_$arm$64.$exeDownload zinger$\_$windows$\_$arm$64.$exe

Linux AMD$64/$x$64$ zinger$\_$linux$\_$amd$64$Download zinger$\_$linux$\_$amd$64$

Linux ARM$64$ zinger$\_$linux$\_$arm$64$Download zinger$\_$linux$\_$arm$64$

macOS AMD$64/$x$64($Intel Macs$)$ zinger$\_$macos$\_$amd$64$Download zinger$\_$macos$\_$amd$64$

macOS ARM$64($Apple Silicon$)$ zinger$\_$macos$\_$arm$64$Download zinger$\_$macos$\_$arm$64$