flynn-host.service

[Unit]
Description=Flynn layer 0
After=libvirt-bin.service networking.service
[Service]

ExecStart=/usr/local/bin/flynn-host daemon
Restart=on-failure
RestartSec=20
[Install]
WantedBy=multi-user.target

install-flynn

#!/bin/bash
#
# A script to install Flynn from a TUF repository.

FLYNN_HOST_CHECKSUM="${FLYNN_HOST_CHECKSUM:="70630744fa000b1c1f4a3913374d613baa5cd806a5b3e1d3033074ac975525681582b8afe622b75ac1f0baddb1994d1e5d72cd27b2912333ae8b91ed8d27ef33"}"

usage() {
  cat <<USAGE >&2
usage: $0 [options]

A script to install Flynn on Ubuntu 14.04.
See https://flynn.io/docs/installation/manual for further information.

OPTIONS:
  -h, --help              Show this message

  -v, --version VERSION   Install explicit VERSION (e.g. v20160512.0)

  -c, --channel CHANNEL   Fetch updates from CHANNEL (either "stable" or "nightly") [default: stable]

  --clean                 Install from a clean state (implies --remove) [DANGER: this will remove all associated data]

  --remove                Remove existing Flynn installation [DANGER: this will remove all associated data]

  --yes                   Automatic yes to prompts

  -r, --repo URL          The TUF repository to download files from [default: https://dl.flynn.io]


VARIABLES:
  FLYNN_UPDATE_CHANNEL   The release channel to fetch updates from (either "nightly" or "stable") [default: stable]
  FLYNN_VERSION          An explicit version to install (e.g. v20151104.1)
USAGE
}

main() {
  if ! is_root; then
    fail "this script must be executed as the root user"
  fi

  if ! is_ubuntu_xenial; then
    fail "this script is only compatible with Ubuntu 16.04 LTS, Xenial Xerus"
  fi

  check_installed "curl" "sha512sum"

  local install=true
  local remove=false
  local assume_yes=false
  local channel="${FLYNN_UPDATE_CHANNEL:-"stable"}"
  local repo_url

  export DEBIAN_FRONTEND=noninteractive

  while true; do
    case "$1" in
      -v | --version)
        if [[ -z "$2" ]]; then
          fail "--version requires an argument"
        fi
        export FLYNN_VERSION="$2"
        shift 2
        ;;
      -c | --channel)
        if [[ -z "$2" ]]; then
          fail "--channel requires an argument"
        fi
        channel="$2"
        shift 2
        ;;
      --clean)
        remove=true
        shift
        ;;
      --remove)
        remove=true
        install=false
        shift
        ;;
      --yes)
        assume_yes=true
        shift
        ;;
      -h | --help)
        usage
        exit 1
        ;;
      -r | --repo)
        if [[ -z "$2" ]]; then
          fail "--repo requires an argument"
        fi
        repo_url="$2"
        shift 2
        ;;
      *)
        break
        ;;
    esac
  done

  if [[ $# -ne 0 ]]; then
    usage
    exit 1
  fi

  if $remove; then
    do_remove $assume_yes
  fi

  if [[ -e "/usr/local/bin/flynn-host" ]]; then
    fail "Flynn is already installed. Run 'flynn-host update' to update to a more recent version, or use --clean to remove the existing Flynn install first"
  fi

  if ! $install; then
    exit
  fi

  repo_url="${repo_url:="https://dl.flynn.io"}"

  run apt-get update

  # install linux-headers explicitly before ubuntu-zfs to avoid skipping
  # building kernel modules due to absent kernel headers.
  info "installing linux-headers"
  run apt-get install -y "linux-headers-$(uname -r)"

  local packages=(
    "aufs-tools"
    "iptables"
    "zfsutils-linux"
  )
  if ! modprobe aufs &>/dev/null; then
    packages+=(
      "linux-image-extra-$(uname -r)"
    )
  fi
  info "installing runtime dependencies"
  run apt-get install --yes ${packages[@]}
  info "loading zfs kernel module"
  run modprobe zfs

  info "downloading flynn-host binary to tmp dir"
  local tmp="$(mktemp --directory)"
  trap "rm -rf ${tmp}" EXIT
  cd "${tmp}"
  if ! curl -fsSL -o "${tmp}/flynn-host.gz" "${repo_url}/tuf/targets/${FLYNN_HOST_CHECKSUM}.flynn-host.gz"; then
    fail "failed to download flynn-host binary from ${repo_url}"
  fi

  info "verifying flynn-host binary checksum"
  if ! echo "${FLYNN_HOST_CHECKSUM} *flynn-host.gz" | sha512sum --check --status; then
    fail "failed to verify flynn-host binary checksum!"
  fi
  run gunzip "flynn-host.gz"
  run chmod +x "flynn-host"

  info "setting release update channel to \"${channel}\""
  mkdir -p "/etc/flynn"
  echo "${channel}" > "/etc/flynn/channel.txt"

  info "downloading Flynn components"
  mkdir -p "/etc/flynn"
  run ./flynn-host download \
    --repository "${repo_url}/tuf" \
    --tuf-db     "/etc/flynn/tuf.db" \
    --config-dir "/etc/flynn" \
    --bin-dir    "/usr/local/bin"

  # install libvirt dependencies for versions before v20160711.0.
  #
  # NOTE: Uses a negative assertion so we only skip installing if we know the
  #       installed Flynn version is definitely greater than or equal to
  #       v20160711.0.
  local version="$(/usr/local/bin/flynn-host version)"
  if ! [[ "${version:1:8}" -ge "20160711" ]]; then
    info "installing extra runtime dependencies"
    run apt-get install --yes "libvirt-bin"

    info "setting libvirt defaults"
    if grep -q "^libvirt_uris=" /etc/default/libvirt-bin; then
      sed "s|^libvirt_uris=.*|libvirt_uris='qemu:///system'|" -i /etc/default/libvirt-bin
    else
      echo "libvirt_uris='qemu:///system'" >> /etc/default/libvirt-bin
    fi
  fi

  info "installing systemd job"
  cp /etc/flynn/flynn-host.service /lib/systemd/system/flynn-host.service
  systemctl enable flynn-host.service
  info "installation complete!"
}

is_root() {
  [[ $(id -u) -eq 0 ]]
}

is_ubuntu_xenial() {
  grep "Ubuntu 16.04" "/etc/os-release" &>/dev/null
}

do_remove() {
  local assume_yes=$1

  warn "*** WARNING ***"
  warn "About to stop Flynn and remove all existing data"

  if ! $assume_yes; then
    warn "Are you sure this is what you want?"
    echo -n "(yes/no): "
    while read answer; do
      case "${answer}" in
        yes) assume_yes=true; break ;;
        no)  break ;;
        *)   echo -n "Please type 'yes' or 'no': " ;;
      esac
    done
    if ! $assume_yes; then
      exit
    fi
  fi

  info "stopping flynn-host daemon"
  local status="$(systemctl is-active flynn-host)"
  if [[ "${status:0:6}" = "active" ]]; then
    run systemctl stop flynn-host
  fi

  info "killing old containers"
  sudo start-stop-daemon \
    --stop \
    --oknodo \
    --retry 5 \
    --name ".containerinit"

  info "destroying ZFS volumes"
  for path in $(grep zfs /proc/mounts | cut -d ' ' -f2); do
    run sudo umount "${path}"
  done
  if which flynn-host &>/dev/null; then
    run flynn-host destroy-volumes --include-data
  fi
  if zpool list | grep -q "flynn-default"; then
    run zpool destroy flynn-default
  fi

  info "removing Flynn files and directories"
  run rm -rf /usr/local/bin/flynn* /var/lib/flynn /etc/flynn

  info "Flynn successfully removed"
}

check_installed() {
  local missing=()

  for bin in $@; do
    if ! which "${bin}" &>/dev/null; then
      missing+=("${bin}")
    fi
  done

  if [[ ${#missing[@]} -gt 0 ]]; then
    fail "this script requires: ${missing[@]}"
  fi
}

run() {
  local cmd=$@
  info "running \"${cmd}\""
  $cmd

  local status=$?
  if [[ $status -ne 0 ]]; then
    fail "failed to run \"${cmd}\", exit status ${status}"
  fi
}

timestamp() {
  date "+%H:%M:%S.%3N"
}

info() {
  local msg=$1
  echo -e "\e[1;32m===> $(timestamp) ${msg}\e[0m"
}

warn() {
  local msg=$1
  echo -e "\e[1;33m===> $(timestamp) ${msg}\e[0m"
}

fail() {
  local msg=$1
  echo -e "\e[1;31m===> $(timestamp) ERROR: ${msg}\e[0m"
  exit 1
}

main $@