# Project contains four scripts -
1. automator.py - this automates the traffic shaping and HAR capturing
2. runchrome.py - run chrome with Quic enabled/disabled in a headless and 
                  benchmark mode
3. trafficshaper.sh - this shapes the traffic
4. HAR-parser.py - this parses the HAR files (in the HAR folder) and plots the cdf graph.

# How to enable Quic in google chrome?
1. chrome://flags/
2. Find Experimental QUIC protocol
3. Change the setting to "enable"
4. Restart chrome

# How to verify whether Quic is enabled or not?
1. got to: chrome://net-export/
2. start logging, save the log files, example- FILE: /Users/pratyushkr/Downloads/chrome-net-export-log.json
3. Reload the testing websites
4. Then go to https://netlog-viewer.appspot.com/#import
5. Load the saved json log file and click on the Quic tab to see the log.json

# How to setup chrome-har-capturer to capture har files?
1. Install capturer: npm install -g chrome-har-capturer
2. run chrome -  sudo /Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --remote-debugging-port=9222 --headless --enable-benchmarking --enable-net-benchmarking --enable-quic
3. run chrome-har-capturer: xargs chrome-har-capturer -o baseline.har < urls.txt 


# How to parse har files for loadtime caluclation?
1. install jq: brew install jq
2. use the below command to see the load time 
   jq -r '.log.pages[] | [.pageTimings.onLoad, .title]|@tsv' baseline.har

# How to shape the traffic for a given bandwidth and packet loss?
1. see the man pagr at: https://www.unix.com/man-page/mojave/8/dnctl/ 
2. see the file trafficshaper.sh

# Command Line cheat sheet for traffic shaping. 
0. dnctl and pfctl are built-in in macOS, install iperf: brew install iperf
1. Setup server: iperf -s
2. run a client for  7 seconds: iperf -c localhost -t 7
3. show all rules:
    sudo dnctl list
    sudo pfctl -sa -v -v
4. shape traffic:
    (cat /etc/pf.conf && echo "dummynet-anchor \"mop\"" && echo "anchor \"mop\"") | sudo pfctl -f -
    echo "dummynet in quick proto tcp from any to any port 5001 pipe 1" | sudo pfctl -a mop -f -
    sudo dnctl pipe 1 config bw 1Mbit/s
5. Observe traffic:
    iperf  -s -D # Run as Daemon (-D)
    iperf -c localhost -t 5 
6. Add 20ms delay:
    sudo dnctl pipe 1 config delay 20
7. 3% packet loss:
    sudo dnctl pipe 1 config plr 0.03
8. Reset pipe, undo any changes:
    sudo dnctl -q flush
    sudo pfctl -f /etc/pf.conf

# Command line utility for HAR -
-h, --help               output usage information
-t, --host <host>        Chrome Debugging Protocol host
-p, --port <port>        Chrome Debugging Protocol port
-x, --width <dip>        frame width in DIP
-y, --height <dip>       frame height in DIP
-o, --output <file>      write to file instead of stdout
-c, --content            also capture the requests body
-k, --cache              allow caching
-a, --agent <agent>      user agent override
-b, --block <URL>        URL pattern (*) to block (can be repeated)
-H, --header <header>    Additional headers (can be repeated)
-i, --insecure           ignore certificate errors
-g, --grace <ms>         time to wait after the load event
-u, --timeout <ms>       time to wait before giving up with a URL
-r, --retry <number>     number of retries on page load failure
-e, --retry-delay <ms>   time to wait before starting a new attempt
-f, --abort-on-failure   stop after the first failure (incompatible with parallel mode)
-d, --post-data <bytes>  maximum POST data size to be returned
-l, --parallel <n>       load <n> URLs in parallel