SysV initscript for mounting EC2 volumes, including creating a swap partition on the first available ephemeral drive.

etc-default-nimbus

# Default configuration values for nimbus startup.
region=us-west-2
role=nimbus-dev

# Ephemeral mounting
localmount=/project

# EBS mounting
mount=/ebs

# S3 mounting
s3user=ubuntu
s3fs=/usr/local/bin/s3fs
nimbusbucket=com.example.nimbus
clientbucket=com.example.nimbus-demo-client
s3mountbase=/s3

JAVA_HOME=/usr/lib/jvm/java-7-openjdk-amd64/jre

# Endpoint for us-west-2
EC2_URL=https://ec2.us-west-2.amazonaws.com

# Settings for the cluster resources.

etc-initd-nimbus

#!/bin/bash
### BEGIN INIT INFO
# Provides:          nimbus-volume-mounting
# Required-Start:    $network $local_fs
# Required-Stop:
# Should-Start:
# Should-Stop:
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: nimbus volume mounts
# Description:       Nimbus single-host pseudo-cluster instance provisioning
### END INIT INFO

#
# Nimbus - a cloudy day cluster
#

# Access authorization is from the IAM role the instance is started with.

# Include nimbus defaults if available.
# Includes: region, mnt
if [ -f /etc/default/nimbus ]
then
  . /etc/default/nimbus
fi

export JAVA_HOME

# Default region to Oregon.
if [ -z "$region" ] ; then
  region="us-west-2"
fi

# Default role to nimbus-dev
if [ -z "$role" ] ; then
  role="nimbus-dev"
fi

# Prefer system commands.
PATH=$PATH:/usr/bin:$HOME/bin

# Seconds to wait for volume to attach.
# MAX_TRIES=60

prog=$(basename $0)
logger="logger -t $prog "
curl="curl --retry 3 --silent --show-error --fail"

# Information about the current instance from here.
instance_data_url=http://169.254.169.254/latest

# Wait until networking is up on the instance.
perl -MIO::Socket::INET -e '
      until(new IO::Socket::INET("169.254.169.254:80"))
      {print "Waiting for network...\n";sleep 1}
      ' | $logger

# start/stop functions
start() {
  # Get the instance ID to work with.
  instance_id=$($curl $instance_data_url/meta-data/instance-id)
  $logger "starting on instance $instance_id"

  # Mount the ephemeral drives.
  count=1
  for device in $($curl $instance_data_url/meta-data/block-device-mapping/ | grep ephemeral)
  do
    local_dev=$($curl $instance_data_url/meta-data/block-device-mapping/$device/ | sed 's/^s/xv/')
    if ! /bin/lsblk "/dev/$local_dev" ; then
      continue
    fi

    # Partition the first ephemeral drive to include an 8G swap section.
    if [ "$count" == 1 ] ; then
      has_swap=$(/bin/lsblk /dev/${local_dev}1 2>/dev/null | /bin/grep -ic swap)
      if [ "$has_swap" == 0 ] ; then
        $logger "creating a swap partition on /dev/${local_dev}"
        sudo /bin/umount -f /dev/$local_dev

        # Partition the disk
        # new, primary 1, start at 2048, end at +8G, type, 82, new, primary 2, start at lowest, end at highest, write
        (echo n; echo p; echo 1; echo 2048; echo +8G; echo t; echo 82; echo n; echo p; echo 2; echo; echo; echo w) | sudo /sbin/fdisk /dev/$local_dev
      fi

      # Create and enable the swap partition.
      sudo /sbin/mkswap /dev/${local_dev}1
      sudo /sbin/swapon /dev/${local_dev}1
      $logger "swap partition enabled on /dev/${local_dev}1"

      # Adjust the device mounted as data.
      local_dev=${local_dev}2
    fi

    # Modify the formatting and mounting if TRIMS is supported on the instance drives.
    mkfs_opts=
    mnt_opts=
    discard_bytes=$(cat /sys/block/xvdb/queue/discard_max_bytes)
    if [ "$discard_bytes" != 0 ] ; then
      mkfs_opts=-K
      mnt_opts="-o discard"
    fi

    # Put a filesystem on the disk.
    $logger "creating filesystem on $local_dev"
    sudo /sbin/mkfs -t xfs $mkfs_opts /dev/$local_dev

    if [ ! -d "$localmount$count" ] ; then
      sudo /bin/mkdir -p "$localmount$count"
    fi
    $logger "mounting /dev/$local_dev"

    # Mount the ephemeral volume at $localmount$count
    /bin/echo "Mounting volume attached at /dev/$local_dev at $localmount$count."
    sudo /bin/mount $mnt_opts /dev/$local_dev "$localmount$count"
    $logger "mounted filesystem $localmount$count on $local_dev"

    count=`expr $count + 1`
  done

  # Mount the EBS volumes.
  count=1
  for device in $($curl $instance_data_url/meta-data/block-device-mapping/ | grep ebs)
  do
    # Get the attachment point for the EBS volume to mount.
    ebs_dev=$($curl $instance_data_url/meta-data/block-device-mapping/$device | sed 's/^s/xv/')
    if [ ! -d "$mount$count" ] ; then
      sudo /bin/mkdir -p "$mount$count"
    fi
    $logger "mounting /dev/$ebs_dev"

    # Mount the EBS volume at $mount$count
    /bin/echo "Mounting volume attached at /dev/$ebs_dev at $mount$count."
    sudo /bin/mount /dev/$ebs_dev "$mount$count"

    count=`expr $count + 1`
  done

#  # Check to see if we mounted any ephemeral drives.
#  device=$($curl $instance_data_url/meta-data/block-device-mapping/ | grep ephemeral | wc -l)
#  if [ "$device" != 0 ] ; then
#    # Add a swapfile on the first ephemeral drive
#    swapfile=${localmount}1/swapfile
#    if [ ! -e "$swapfile" ] ; then
#      sudo /bin/dd if=/dev/zero of=${localmount}1/swapfile bs=1M count=8192
#      sudo /bin/chmod 600 ${localmount}1/swapfile
#      sudo /sbin/mkswap ${localmount}1/swapfile
#      sudo /sbin/swapon ${localmount}1/swapfile
#    fi
#  fi

  # Ensure swapping is enabled.
  sudo /sbin/swapon -a
  $logger "swapping enabled"

  # Mount the s3 buckets.
  if [ -x "$s3fs" ] ; then
    /bin/echo "Mounting S3 buckets under $s3mountbase"
    $logger "mounting s3 buckets"

    # Ensure sharing the S3 FUSE mounts is enabled.
    sudo /bin/sed -i 's/#[ \t]*\(user_allow_other\)/\1/' /etc/fuse.conf
    sudo chmod o+r /etc/fuse.conf

    # Default s3 mount user to ubuntu.
    if [ -z "$s3user" ] ; then
      s3user="ubuntu"
    fi

    if [ ! -d "$s3mountbase" ] ; then
      sudo /bin/mkdir -p $s3mountbase/{nimbus,client}
      sudo /bin/chown $s3user.$s3user $s3mountbase/{nimbus,client}
      sudo /bin/chmod 02777 $s3mountbase/{nimbus,client}
    fi

    sudo -u $s3user $s3fs $nimbusbucket $s3mountbase/nimbus -o iam_role=$role -o allow_other
    sudo -u $s3user $s3fs $clientbucket $s3mountbase/client -o iam_role=$role -o allow_other
    $logger "mounted $s3mountbase/nimbus and $s3mountbase/client"
  fi

  $logger "volumes mounted at ${localmount}* ${mount}* and ${s3mountbase}*"
}

stop() {
  /bin/echo "Unmounting S3 FUSE Volumes."
  sudo /bin/umount $s3mountbase/nimbus
  sudo /bin/umount $s3mountbase/client

  /bin/echo "Unmounting EBS Volumes."
  count=1
  for device in $($curl $instance_data_url/meta-data/block-device-mapping/ | grep ebs)
  do
    # Unmount the EBS volume at $mount$count
    /bin/echo "Unmounting volume at $mount$count."
    $logger "unmounting $mount$count"
    sudo /bin/umount $mount$count

    count=`expr $count + 1`
  done

  /bin/echo "Unmounting Ephemeral Volumes."
  count=1
  for device in $($curl $instance_data_url/meta-data/block-device-mapping/ | grep ephemeral)
  do
    local_dev=$($curl $instance_data_url/meta-data/block-device-mapping/$device/ | sed 's/^s/xv/')
    if ! /bin/lsblk "/dev/$local_dev" ; then
      continue
    fi

    # Unmount the ephemeral volume at $localmount$count
    /bin/echo "Unmounting volume at $localmount$count."
    $logger "unmounting $localmount$count"
    sudo /bin/umount $localmount$count

    count=`expr $count + 1`
  done

  $logger "Ephemeral, EBS, and S3 volumes unmounted (${localmount}*, ${mount}*, ${s3mountbase}*)"

  # Disable swapping.
  sudo /sbin/swapoff -a
  $logger "swapping disabled"
}

case "$1" in
  start)
    start
    ;;

  stop)
    stop
    ;;

  restart)
    stop
    sleep 5
    start
    ;;

  *)
    echo "Usage: $SELF {start|stop|restart}"
    exit 1
    ;;

esac

exit 0