configure_networking.sh

#!/bin/bash
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# to you under the Apache License, Version 2.0 (the
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#
#   http://www.apache.org/licenses/LICENSE-2.0
#
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set -e
set -x

HOSTNAME=systemvm

function configure_resolv_conf() {
  grep 8.8.8.8 /etc/resolv.conf && grep 8.8.4.4 /etc/resolv.conf && return

  cat > /etc/resolv.conf << EOF
nameserver 8.8.8.8
nameserver 8.8.4.4
EOF
}

# Delete entry in /etc/hosts derived from dhcp
function delete_dhcp_ip() {
  result=$(grep 127.0.1.1 /etc/hosts || true)
  [ "${result}" == "" ] && return

  sed -i '/127.0.1.1/d' /etc/hosts
}

function configure_hostname() {
  sed -i "s/root@\(.*\)$/root@$HOSTNAME/g" /etc/ssh/ssh_host_*.pub

  echo "$HOSTNAME" > /etc/hostname
  hostname $HOSTNAME
}

function configure_interfaces() {
  cat > /etc/network/interfaces << EOF
source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet dhcp

EOF
}

function configure_networking() {
  configure_interfaces
  configure_resolv_conf
  delete_dhcp_ip
  configure_hostname
}

return 2>/dev/null || configure_networking