github.com/Ilhicas/nomad@v1.0.4-0.20210304152020-e86851182bc3/e2e/terraform/packer/ubuntu-bionic-amd64/dnsconfig.sh (about)

     1  #!/bin/bash
     2  set -e
     3  
     4  # These tasks can't be executed during AMI builds because they rely on
     5  # instance-specific data.
     6  
     7  mkdir -p /var/run/dnsmasq
     8  mkdir -p /etc/dnsmasq.d
     9  
    10  # Add hostname to /etc/hosts
    11  echo "127.0.0.1 $(hostname)" | tee --append /etc/hosts
    12  
    13  # this script should run after docker.service but we can't guarantee
    14  # it's created docker0 yet, so wait to make sure
    15  while ! (ip link | grep -q docker0)
    16  do
    17      sleep 1
    18  done
    19  
    20  # Use dnsmasq first and then docker bridge network for DNS resolution
    21  DOCKER_BRIDGE_IP_ADDRESS=$(/usr/local/bin/sockaddr eval 'GetInterfaceIP "docker0"')
    22  cat <<EOF > /tmp/resolv.conf
    23  nameserver 127.0.0.1
    24  nameserver $DOCKER_BRIDGE_IP_ADDRESS
    25  EOF
    26  cp /tmp/resolv.conf /etc/resolv.conf
    27  
    28  # need to get the interface for dnsmasq config so that we can
    29  # accomodate both "predictable" and old-style interface names
    30  IFACE=$(/usr/local/bin/sockaddr eval 'GetDefaultInterfaces | attr "Name"')
    31  
    32  cat <<EOF > /tmp/dnsmasq
    33  port=53
    34  resolv-file=/var/run/dnsmasq/resolv.conf
    35  bind-interfaces
    36  interface=docker0
    37  interface=lo
    38  interface=$IFACE
    39  listen-address=127.0.0.1
    40  server=/consul/127.0.0.1#8600
    41  EOF
    42  cp /tmp/dnsmasq /etc/dnsmasq.d/default
    43  
    44  # need to get the AWS DNS address from the VPC...
    45  # this is pretty hacky but will work for any typical case
    46  MAC=$(curl -s --fail http://169.254.169.254/latest/meta-data/mac)
    47  CIDR_BLOCK=$(curl -s --fail "http://169.254.169.254/latest/meta-data/network/interfaces/macs/$MAC/vpc-ipv4-cidr-block")
    48  VPC_DNS_ROOT=$(echo "$CIDR_BLOCK" | cut -d'.' -f1-3)
    49  echo "nameserver ${VPC_DNS_ROOT}.2" > /tmp/dnsmasq-resolv.conf
    50  cp /tmp/dnsmasq-resolv.conf /var/run/dnsmasq/resolv.conf
    51  
    52  /usr/sbin/dnsmasq --test