Simple proxmox container scaling (Elastic cloud project)

rndhostname

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import datetime
import random

LEN = 5 
PREFIX = 'ct-dm-core-job-'

DIGITS = ''.join(str(x) for x in range(10))
LETTERS = ''.join(chr(x) for x in range(ord('a'), ord('z') + 1)) 
ALPHA = LETTERS + DIGITS

def get_rnd_hostname():
    random.seed(datetime.datetime.now())
    return PREFIX + ''.join(random.choice(ALPHA) for x in range(LEN))

if __name__ == '__main__':
    print(get_rnd_hostname())

scale-down

#!/bin/bash

MAX=$1
MAX=$(($MAX+0))
i=0

while [ $i -lt $MAX ]
do
    LAST=$(pct list|egrep -Ee '^4[0-9][0-9]'|sort|tail -1|sed -e 's/ .*$//')  # Get last machine number 4xx
    if [[ "$LAST" == "" ]]; then
        echo "No containers in range 400-499 found. Nothing to do." > /dev/stderr
        exit 1
    fi  

    echo Removing LXC worker $LAST
    pct shutdown $LAST -forceStop
    sleep 2
    pct destroy $LAST
    i=$(($i+1))
done

scale-up

#!/bin/bash

TEMPLATE=/var/lib/vz/dump/vzdump-lxc-400-2015_12_16-17_02_30.tar.lzo
STORAGE=pool0
GATEWAY=10.105.234.129
POOL=ceba
IFACE=eth0

LAST=$(pct list|egrep -Ee '^4[0-9][0-9]'|sort|tail -1|sed -e 's/ .*$//')  # Get last machine number 4xx
if [[ "$LAST" == "" ]]; then
   LAST=399  # Minimum VMID
fi

MAX=$1
MAX=$(($MAX+1))
i=1

NEW=$LAST
while [ $i -lt $MAX ]
do
    NEW=$(($NEW+1))
    echo Deploying new LXC container VMID $NEW
    pct restore $NEW $TEMPLATE -storage=$STORAGE -pool=$POOL
    #pct create $NEW $TEMPLATE -storage=$STORAGE -pool=$POOL  # This will regenerate SSH keys
    pct set $NEW -hostname $(./rndhostname)
    pct set $NEW -net0 name=$IFACE,bridge=vmbr0
    pct start $NEW
    sleep 2
    pct exec $NEW -- /usr/local/bin/waitforiface $IFACE >/dev/null
    sleep 2
    pct exec $NEW -- /bin/ping -c2 -q $GATEWAY >/dev/null
    i=$(($i+1))
done
exit 1

-Use ./scale-up <number_of_containers> to scale up the cluster adding N new containers.
-Use ./scale-down <number_of_containers> to shutdown and destroy N containers.
-The rndhostname.py is a script to generate a random hostname with a prefix avoiding name-repetitions.

The waitforiface is a bash script that waits until the eth0 interface is up.