Mark Mutti acceptableEngineering

SysOps Tricks

LOG Traffic with iptables

Specific IP:

Replace SOURCE_IP with an actual CIDR range (0.0.0.0/0 for all)

sudo iptables -I INPUT -s SOURCE_IP -j LOG --log-prefix "SOME_LABEL_HERE-INPUT: "
sudo iptables -I FORWARD -s SOURCE_IP -j LOG --log-prefix "SOME_LABEL_HERE-FORWARD: "
sudo iptables -I OUTPUT -d SOURCE_IP -j LOG --log-prefix "SOME_LABEL_HERE-OUTPUT: "

SSL

Lookup an SSL certificate (for any service/port)

$ DOMAIN=www.shoutdrive.com && echo | openssl s_client -showcerts -servername ${DOMAIN} -connect ${DOMAIN}:443 2>/dev/null | openssl x509 -inform pem -noout -text

Mount a Remote Service Locally

$ ssh -L 15672:localhost:15672 user@remoteHost

Description

These are commands I use on a regular basis. For the sake of simplicity, the filenames I use in the examples below are in.mp4 and out.mp4, though you can use your imagination to picture blah.mov or audio.wav on a case-by-case basis.

	#!/bin/bash

	SPEEDTEST=$(/opt/homebrew/bin/speedtest -I en0 -f json)
	RESULT=$(echo $SPEEDTEST \| /opt/homebrew/bin/jq '.download.bandwidth')
	/usr/local/bin/aws cloudwatch put-metric-data --namespace "The Eyeris" --metric-name SpeedTest-Download --value ${RESULT} --region us-west-2
	RESULT=$(echo $SPEEDTEST \| /opt/homebrew/bin/jq '.upload.bandwidth')
	/usr/local/bin/aws cloudwatch put-metric-data --namespace "The Eyeris" --metric-name SpeedTest-Upload --value ${RESULT} --region us-west-2
	RESULT=$(echo $SPEEDTEST \| /opt/homebrew/bin/jq '.ping.latency')
	/usr/local/bin/aws cloudwatch put-metric-data --namespace "The Eyeris" --metric-name SpeedTest-Ping --value ${RESULT} --region us-west-2
	RESULT=$(echo $SPEEDTEST \| /opt/homebrew/bin/jq '.packetLoss')

	#!/bin/bash
	RESULT=$(/sbin/ping -s 1 -i 0.2 -c 20 8.8.8.8 \| grep "packet loss" \| /usr/bin/awk -F ',' '{print $3}' \| awk '{print $1}' \| /usr/bin/sed 's/%//')
	/usr/local/bin/aws cloudwatch put-metric-data --namespace "The Eyeris" --metric-name Outgoing-Ping-Loss --value ${RESULT} --region us-west-2

	RESULT=$(/sbin/ping -s 1 -i 0.2 -c 20 10.10.0.1 \| grep "packet loss" \| /usr/bin/awk -F ',' '{print $3}' \| awk '{print $1}' \| /usr/bin/sed 's/%//')
	/usr/local/bin/aws cloudwatch put-metric-data --namespace "The Eyeris" --metric-name Internal-Ping-Loss --value ${RESULT} --region us-west-2