Create an openVZ CT

crtct

#!/bin/bash

## Fail fast and be aware of exit codes
set -eo pipefail

# Guess unused CTID, by increasing the last one
get_ct_id() {
  #local ctid=$(/usr/sbin/vzlist -H -a -octid \
  #      2>/dev/null | tail -1)
  #[ -n "$ctid" ] || ctid=100
  #echo $((ctid+1))
  
  date +%s 
}

# Guess unused hostname, by increasing the last one
get_ct_hostname() {

  local prefix="${1:-ct}"

  local names=$(
    /usr/sbin/vzlist -H -a -ohostname \
    | grep ${prefix}
  )

  local suffix=$(
    for name in ${names}; do
      echo ${name//[A-Z\.]/}
    done \
    | sort -n \
    | tail -1
  )

  [ -n "${suffix}" ] || suffix=0
  echo "${prefix}$((suffix+1))"
}

# Configure CT interface to DHCP
set_ct_dhcp() {

  local ctid="${1}"
  local hostname="${2}"
  local eth="${3}"
  local osdist="${4}"

  [[ "${osdist}" == "alpine" ]] \
  && {

cat << _EOF_ >> /vz/root/${ctid}/etc/network/interfaces

# VETH private static IP
auto ${eth}
iface ${eth} inet dhcp
  hostname ${hostname}

_EOF_

  echo "${hostname}" > /vz/root/${ctid}/etc/hostname

  } \
  || {

cat << _EOF_ > /vz/root/${ctid}/etc/sysconfig/network-scripts/ifcfg-${eth}
DEVICE="${eth}"
BOOTPROTO="dhcp"
NM_CONTROLLED="no"
ONBOOT="yes"
DHCP_HOSTNAME="${hostname}"
_EOF_

  }

}

get_ct_ip() {

  local ctid="${1}"
  local ctip=$(vzctl exec ${ctid} ip -o -4 a show eth0 | awk '{print $4}')
  echo ${ctip/\/*/}
}

wait_for_ct_to_start() {

  local ctid="${1}"
  local count=0

  until [[ "$(vzlist -H ${ctid} -o status)" == "running" ]]; do
    echo -ne "  Waiting for CT ${ctid} to be up ($((++count)) Sec)\\r"
    sleep 1
  done

}

wait_for_ct_network() {

  local ctid="${1}"

  echo -e '
    count=0
    until $(ip -o -4 a show eth0 | awk \x27{print $4}\x27 | grep -q "/24"); do 
      echo -ne "  Waiting for network to be up ($((++count)) Sec)"\r; sleep 1
    done' \
  | vzctl exec ${ctid} - \
  && local ctip="$(get_ct_ip ${ctid})" \
  && echo -ne "\n  Network is up for ${hostname} : ${ctip} \n" 
}

# Configure CT authorized_keys
set_ct_authorized_keys() {

  local ctid="${1}"

  mkdir -p /vz/root/${ctid}/root/.ssh/
  chmod 0700 /vz/root/${ctid}/root/.ssh/
  cp /root/.ssh/authorized_keys /vz/root/${ctid}/root/.ssh/
  chmod 0700 /vz/root/${ctid}/root/.ssh/authorized_keys
}

# Configure CT proxy
set_ct_proxy() {

  local domain="${1}"

cat << _EOF_ > /vz/root/$ctid/etc/profile.d/proxy.sh
export http_proxy="http://proxy.service.${domain}:8080"
export https_proxy="http://proxy.service.${domain}:8080"
export no_proxy="localhost,127.0.0.1,.${domain}"
_EOF_

}

# Custom alias
set_custom_alias() {

  local ctid="${1}"

cat << _EOF_ > /vz/root/${ctid}/etc/profile.d/alias.sh
alias ll="ls -larth"
_EOF_

}

# Set xterm for screen
set_alpine_xterm() {

  local ctid="${1}"
  local osdist="${2}"

  [[ "${osdist}" == "alpine" ]] && {

cat << _EOF_ > /vz/root/${ctid}/etc/profile.d/screen.sh
export TERM=xterm-color
_EOF_

  } || return 0

}

function set_hn_known_hosts() {

  local ctid=${1}
  local ctname=${2}
  local ctip=${3}

  ssh-keygen -R ${ctname} >/dev/null 2>&1
  ssh-keygen -R ${ctip} >/dev/null 2>&1

  local ctkey=$(vzctl exec ${ctid} cat /etc/ssh/ssh_host_rsa_key.pub)

  echo "${ctname},${ctip} ${ctkey}" >> ~/.ssh/known_hosts
}


gen_template() {

  local TMPL_list=""

  [[ $# -gt 0 ]] \
  && while [  "${1:0:2}" == '--' ]; do 
    OPTION=${1:2}
    echo ${OPTION} | grep -q "=" \
    && {
      export "TMPL_${OPTION/=*/}=${OPTION/*=/}" \
      TMPL_list="${TMPL_list} TMPL_${OPTION/=*/}"
    }
    shift
  done

  echo "${TMPL_template}" | envsubst

  for i in ${TMPL_list}; do 
    #echo "${i} -> ${!i}"
    unset ${i}
  done
}


main() {

  local ostemplate="${1}"
  local osdist="${ostemplate%%-*}"
  local config="vswap-256m"
  local ctid="$(get_ct_id)"
  local domain="dev"
  local hostname_prefix="ct"
  local ct_ip_range=192.168.0.{21..254}
  local nameserver="ns1"
  local datacenter="xav"

  local ct_ip_hostname=$(/root/dhcp_ct ${datacenter} ${hostname_prefix} 192.168.0.{21..254}) \
  && local ctip=${ct_ip_hostname##* } \
  && local hostname=${ct_ip_hostname%% *} \
  && /usr/sbin/vzctl --quiet create ${ctid} \
  --ostemplate ${ostemplate} \
  --config ${config} \
  --diskspace 2G \
  --hostname "${hostname}" \
  --ipadd "${ctip}" \
  --name ${hostname} \
  > /dev/null \
  && vzctl --quiet mount ${ctid} \
  && set_ct_authorized_keys ${ctid} \
  && set_ct_proxy ${domain} \
  && set_custom_alias ${ctid} \
  && set_alpine_xterm ${ctid} ${osdist} \
  && vzctl --quiet start ${ctid} \
  && wait_for_ct_to_start ${ctid} \
  && vzctl --quiet set ${ctid} --userpasswd root:changeMe >/dev/null \
  && echo "  Container ${hostname} created" \
  && set_hn_known_hosts ${ctid} ${hostname} ${ctip} \
  && /usr/sbin/vzctl --quiet snapshot ${ctid} --skip-suspend --skip-config

}

main "${1-centos-6-x86_64-minimal-zz}"
#main "${1-alpine-3.2.3-x86_64}"