Kubernetes minion-user-data script

minion-user-data

#! /bin/bash
SALT_MASTER='172.20.0.9'
DOCKER_OPTS=''
readonly DOCKER_STORAGE='aufs'



apt-get update
apt-get install --yes curl

download-or-bust() {
  local -r url="$1"
  local -r file="${url##*/}"
  rm -f "$file"
  until [[ -e "${1##*/}" ]]; do
    echo "Downloading file ($1)"
    curl --ipv4 -Lo "$file" --connect-timeout 20 --retry 6 --retry-delay 10 "$1"
    md5sum "$file"
  done
}



install-salt() {
  local salt_mode="$1"

  if dpkg -s salt-minion &>/dev/null; then
    echo "== SaltStack already installed, skipping install step =="
    return
  fi

  echo "== Refreshing package database =="
  until apt-get update; do
    echo "== apt-get update failed, retrying =="
    echo sleep 5
  done

  mkdir -p /var/cache/salt-install
  cd /var/cache/salt-install

  DEBS=(
    libzmq3_3.2.3+dfsg-1~bpo70~dst+1_amd64.deb
    python-zmq_13.1.0-1~bpo70~dst+1_amd64.deb
    salt-common_2014.1.13+ds-1~bpo70+1_all.deb
  )
  if [[ "${salt_mode}" == "master" ]]; then
    DEBS+=( salt-master_2014.1.13+ds-1~bpo70+1_all.deb )
  fi
  DEBS+=( salt-minion_2014.1.13+ds-1~bpo70+1_all.deb )
  URL_BASE="https://storage.googleapis.com/kubernetes-release/salt"

  for deb in "${DEBS[@]}"; do
    if [ ! -e "${deb}" ]; then
      download-or-bust "${URL_BASE}/${deb}"
    fi
  done

  for deb in "${DEBS[@]}"; do
    echo "== Installing ${deb}, ignore dependency complaints (will fix later) =="
    dpkg --skip-same-version --force-depends -i "${deb}"
  done

  # This will install any of the unmet dependencies from above.
  echo "== Installing unmet dependencies =="
  until apt-get install -f -y; do
    echo "== apt-get install failed, retrying =="
    echo sleep 5
  done

  # Log a timestamp
  echo "== Finished installing Salt =="
}



block_devices=()

ephemeral_devices=$(curl --silent http://169.254.169.254/2014-11-05/meta-data/block-device-mapping/ | grep ephemeral)
for ephemeral_device in $ephemeral_devices; do
  echo "Checking ephemeral device: ${ephemeral_device}"
  aws_device=$(curl --silent http://169.254.169.254/2014-11-05/meta-data/block-device-mapping/${ephemeral_device})

  device_path=""
  if [ -b /dev/$aws_device ]; then
    device_path="/dev/$aws_device"
  else
    # Check for the xvd-style name
    xvd_style=$(echo $aws_device | sed "s/sd/xvd/")
    if [ -b /dev/$xvd_style ]; then
      device_path="/dev/$xvd_style"
    fi
  fi

  if [[ -z ${device_path} ]]; then
    echo "  Could not find disk: ${ephemeral_device}@${aws_device}"
  else
    echo "  Detected ephemeral disk: ${ephemeral_device}@${device_path}"
    block_devices+=(${device_path})
  fi
done

move_docker=""
move_kubelet=""

apt-get update

docker_storage=${DOCKER_STORAGE:-aufs}

if [[ ${#block_devices[@]} == 0 ]]; then
  echo "No ephemeral block devices found; will use aufs on root"
  docker_storage="aufs"

  # Install aufs kernel module (for ubuntu)
  apt-get install --yes linux-image-extra-$(uname -r)

  # Install aufs tools (for debian)
  apt-get install --yes aufs-tools
else
  echo "Block devices: ${block_devices[@]}"

  # Remove any existing mounts
  for block_device in ${block_devices}; do
    echo "Unmounting ${block_device}"
    /bin/umount ${block_device}
    sed -i -e "\|^${block_device}|d" /etc/fstab
  done

  if [[ ${docker_storage} == "btrfs" ]]; then
    apt-get install --yes btrfs-tools

    if [[ ${#block_devices[@]} == 1 ]]; then
      echo "One ephemeral block device found; formatting with btrfs"
      mkfs.btrfs -f ${block_devices[0]}
    else
      echo "Found multiple ephemeral block devices, formatting with btrfs as RAID-0"
      mkfs.btrfs -f --data raid0 ${block_devices[@]}
    fi
    echo "${block_devices[0]}  /mnt/ephemeral  btrfs  noatime  0 0" >> /etc/fstab
    mkdir -p /mnt/ephemeral
    mount /mnt/ephemeral

    mkdir -p /mnt/ephemeral/kubernetes

    move_docker="/mnt/ephemeral"
    move_kubelet="/mnt/ephemeral/kubernetes"
  elif [[ ${docker_storage} == "aufs-nolvm" ]]; then
    if [[ ${#block_devices[@]} != 1 ]]; then
      echo "aufs-nolvm selected, but multiple ephemeral devices were found; only the first will be available"
    fi

    mkfs -t ext4 ${block_devices[0]}
    echo "${block_devices[0]}  /mnt/ephemeral  ext4     noatime  0 0" >> /etc/fstab
    mkdir -p /mnt/ephemeral
    mount /mnt/ephemeral

    mkdir -p /mnt/ephemeral/kubernetes

    move_docker="/mnt/ephemeral"
    move_kubelet="/mnt/ephemeral/kubernetes"
  elif [[ ${docker_storage} == "devicemapper" || ${docker_storage} == "aufs" ]]; then
    # We always use LVM, even with one device
    # In devicemapper mode, Docker can use LVM directly
    # Also, fewer code paths are good
    echo "Using LVM2 and ext4"
    apt-get install --yes lvm2

    # Don't output spurious "File descriptor X leaked on vgcreate invocation."
    # Known bug: e.g. Ubuntu #591823
    export LVM_SUPPRESS_FD_WARNINGS=1

    for block_device in ${block_devices}; do
      pvcreate ${block_device}
    done
    vgcreate vg-ephemeral ${block_devices[@]}

    if [[ ${docker_storage} == "devicemapper" ]]; then
      # devicemapper thin provisioning, managed by docker
      # This is the best option, but it is sadly broken on most distros
      # Bug: https://github.com/docker/docker/issues/4036

      # 95% goes to the docker thin-pool
      lvcreate -l 95%VG --thinpool docker-thinpool vg-ephemeral

      DOCKER_OPTS="${DOCKER_OPTS} --storage-opt dm.thinpooldev=/dev/mapper/vg--ephemeral-docker--thinpool"
      # Note that we don't move docker; docker goes direct to the thinpool
    else
      # aufs

      # Create a docker lv, use docker on it
      # 95% goes to the docker thin-pool
      release=`lsb_release -c -s`
      if [[ "${release}" != "wheezy" ]] ; then
        lvcreate -l 95%VG --thinpool docker-thinpool vg-ephemeral

        THINPOOL_SIZE=$(lvs vg-ephemeral/docker-thinpool -o LV_SIZE --noheadings --units M --nosuffix)
        lvcreate -V${THINPOOL_SIZE}M -T vg-ephemeral/docker-thinpool -n docker
      else
        # Thin provisioning not supported by Wheezy
        echo "Detected wheezy; won't use LVM thin provisioning"
        lvcreate -l 95%VG -n docker vg-ephemeral
      fi

      mkfs -t ext4 /dev/vg-ephemeral/docker
      mkdir -p /mnt/ephemeral/docker
      echo "/dev/vg-ephemeral/docker  /mnt/ephemeral/docker  ext4  noatime  0 0" >> /etc/fstab
      mount /mnt/ephemeral/docker
      move_docker="/mnt/ephemeral"
    fi

    # Remaining 5% is for kubernetes data
    # TODO: Should this be a thin pool?  e.g. would we ever want to snapshot this data?
    lvcreate -l 100%FREE -n kubernetes vg-ephemeral
    mkfs -t ext4 /dev/vg-ephemeral/kubernetes
    mkdir -p /mnt/ephemeral/kubernetes
    echo "/dev/vg-ephemeral/kubernetes  /mnt/ephemeral/kubernetes  ext4  noatime  0 0" >> /etc/fstab
    mount /mnt/ephemeral/kubernetes

    move_kubelet="/mnt/ephemeral/kubernetes"
  else
    echo "Ignoring unknown DOCKER_STORAGE: ${docker_storage}"
  fi
fi


if [[ ${docker_storage} == "btrfs" ]]; then
  DOCKER_OPTS="${DOCKER_OPTS} -s btrfs"
elif [[ ${docker_storage} == "aufs-nolvm" || ${docker_storage} == "aufs" ]]; then
  # Install aufs kernel module
  apt-get install --yes linux-image-extra-$(uname -r)

  DOCKER_OPTS="${DOCKER_OPTS} -s aufs"
elif [[ ${docker_storage} == "devicemapper" ]]; then
  DOCKER_OPTS="${DOCKER_OPTS} -s devicemapper"
else
  echo "Ignoring unknown DOCKER_STORAGE: ${docker_storage}"
fi

if [[ -n "${move_docker}" ]]; then
  # Move docker to e.g. /mnt
  if [[ -d /var/lib/docker ]]; then
    mv /var/lib/docker ${move_docker}/
  fi
  mkdir -p ${move_docker}/docker
  ln -s ${move_docker}/docker /var/lib/docker
  DOCKER_ROOT="${move_docker}/docker"
  DOCKER_OPTS="${DOCKER_OPTS} -g ${DOCKER_ROOT}"
fi

if [[ -n "${move_kubelet}" ]]; then
  # Move /var/lib/kubelet to e.g. /mnt
  # (the backing for empty-dir volumes can use a lot of space!)
  if [[ -d /var/lib/kubelet ]]; then
    mv /var/lib/kubelet ${move_kubelet}/
  fi
  mkdir -p ${move_kubelet}/kubelet
  ln -s ${move_kubelet}/kubelet /var/lib/kubelet
  KUBELET_ROOT="${move_kubelet}/kubelet"
fi



mkdir -p /etc/salt/minion.d
echo "master: $SALT_MASTER" > /etc/salt/minion.d/master.conf


cat <<EOF >/etc/salt/minion.d/grains.conf
grains:
  roles:
    - kubernetes-pool
  cbr-cidr: 10.123.45.0/30
  cloud: aws
EOF

if [[ -z "${HOSTNAME_OVERRIDE}" ]]; then
  HOSTNAME_OVERRIDE=`curl --silent curl http://169.254.169.254/2007-01-19/meta-data/local-hostname`
fi

if [[ -n "${HOSTNAME_OVERRIDE}" ]]; then
  cat <<EOF >>/etc/salt/minion.d/grains.conf
  hostname_override: "${HOSTNAME_OVERRIDE}"
EOF
fi

if [[ -n "${DOCKER_OPTS}" ]]; then
  cat <<EOF >>/etc/salt/minion.d/grains.conf
  docker_opts: '$(echo "$DOCKER_OPTS" | sed -e "s/'/''/g")'
EOF
fi

if [[ -n "${DOCKER_ROOT}" ]]; then
  cat <<EOF >>/etc/salt/minion.d/grains.conf
  docker_root: '$(echo "$DOCKER_ROOT" | sed -e "s/'/''/g")'
EOF
fi

if [[ -n "${KUBELET_ROOT}" ]]; then
  cat <<EOF >>/etc/salt/minion.d/grains.conf
  kubelet_root: '$(echo "$KUBELET_ROOT" | sed -e "s/'/''/g")'
EOF
fi

install-salt

service salt-minion start