devops-toolbox

Bash Scripts

Scripting Tricks

Pipe and awk

Networking

1. nslookup

´´´ nslookup ´´´

2. Tricks when no curl

exec 3<> /dev/tcp/$DESTINY_IP/$DESTINY_PORT;echo $?

exec 3<> /dev/tcp/52.11.213.82/22;echo $?

3. show Ips by interface Ex: interface eth0

ip addr show eth0 | grep inet | awk '{ print $2; }' | sed 's/\/.*$//'

4. To find process that uses a port a. Good-ole netstat

netstat -ltnp | grep -w ':80' 

b. LSOF

lsof -i :80 

c. Using fuser and `ps``

fuser 80/tcp
ps -p 2053 -o comm=

PM2 CheatSheet

Fork mode

pm2 start app.js --name my-api # Name process

Cluster mode

pm2 start app.js -i 0        # Will start maximum processes with LB depending on available CPUs
pm2 start app.js -i max      # Same as above, but deprecated.

Listing

pm2 list               # Display all processes status
pm2 jlist              # Print process list in raw JSON
pm2 prettylist         # Print process list in beautified JSON

pm2 describe 0         # Display all informations about a specific process

pm2 monit              # Monitor all processes

Logs

pm2 logs [--raw]       # Display all processes logs in streaming
pm2 flush              # Empty all log files
pm2 reloadLogs         # Reload all logs

Actions

pm2 stop all           # Stop all processes
pm2 restart all        # Restart all processes

pm2 reload all         # Will 0s downtime reload (for NETWORKED apps)

pm2 stop 0             # Stop specific process id
pm2 restart 0          # Restart specific process id

pm2 delete 0           # Will remove process from pm2 list
pm2 delete all         # Will remove all processes from pm2 list

Misc

pm2 reset <process>    # Reset meta data (restarted time...)
pm2 updatePM2          # Update in memory pm2
pm2 ping               # Ensure pm2 daemon has been launched
pm2 sendSignal SIGUSR2 my-app # Send system signal to script
pm2 start app.js --no-daemon
pm2 start app.js --no-vizion
pm2 start app.js --no-autorestart

Kubernetes

Para listar pods ordenados por reinicios

kubectl get pods --all-namespaces --sort-by='.status.containerStatuses[0].restartCount'

Para extraer los detalles de deployment por namespace y escribir a un archivo de texto

kubectl get ns | awk '{cmd="kubectl describe deployment -n "$1" > "$1".txt"; system(cmd)}'

Para descargar todos los logs de un pod /namespace:

kgp -n podName |awk '{cmd="kubectl logs -n podName "$1" > "$1".txt"; if(NR>1)system(cmd)}'