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$)$