handy-commands.md

commands

ansible localhost -m setup
ansible all -i inventory/demo.ini -m ping
scp -6 root@\[ffee:40b::10\]:/home/stack/images/overcloud-full.qcow2 .
%!python -mjson.tool
ip -6 neighbor show
tailf /var/log/nova/nova-scheduler.log | grep  "not match requested node"
sudo sysctl –p /etc/sysctl.conf

shorten encryption to fix SSH connectivity issues

ssh -o MACs=hmac-sha2-256 root@192.168.10.5

SSH to all the hosts and execute a specific command:
for i in `cat hosts` ; do echo $i; ssh -l root -oStrictHostKeyChecking=no \
      $i "sudo journalctl -t kernel | grep vrouter"; done

docker inspect aae5cbb9be28 | jq '.[].LogPath' | sed -e 's/^"//' -e 's/"$//'

while loop

while true; do echo "Keep printing"; sleep 3; done

command to check parent PID

ps jfx

ping a host with timestamp

ping <host_ip_fqdn> | xargs -L 1 -I '{}' date '+%Y-%m-%d %H:%M:%S: {}' | tee ping_output.txt
ping <host_ip_fqdn> | xargs -L 1 -I '{}' date '+%Y-%m-%d %H:%M:%S: {}' > ping_output.txt &

Capture MPLSoUDP packets

tshark -I eth1 -V udp and host 10.1.1.5 | egrep “MPLS Label|Internet Protocol|UDP”
tcpdump -i enp0s3 -nn udp port 6635 

Convert JSON input to single line JSON to provide as payload to curl command

awk -v RS= '{$1=$1}1' host.json
cat host.json | jq -c .

NC

nc -z -v 10.10.8.8 20-80 2>&1 | grep succeeded