clusterdock_setup.sh

#!/usr/bin/env bash
#
# Script which installs Docker on an Ubuntu 14.04 host and updates daemon configs.

# We hardcode which version of Docker to install to avoid potential breaking changes in new
# releases.
DOCKER_VERSION=1.11.1
# Set bridge IP to avoid conflicts with Cloudera addresses.
BRIDGE_IP="192.168.123.1/24"
# DAEMON_OPTIONS will be an array of arguments to be added to /etc/default/docker.
DAEMON_OPTIONS+=("--bip=${BRIDGE_IP}")

# Keep track of the clusterdock Docker image name since we copy from it below.
CLUSTERDOCK_IMAGE=dimaspivak/hbase:clusterdock

usage() {
  cat << __EOF

Usage: setup_docker [OPTIONS]
  -g | --graph directory   Set Docker's root directory (defaults to /var/lib/docker).
__EOF
}

parse_args() {
  until [ -z "${1}" ]; do
    case "${1}" in
      -g | --graph)
        GRAPH_DIRECTORY="${2}"
        shift 2 ;;
      *)
        usage >&2
        exit 1 ;;
    esac
  done
}

install_docker() {
  # If Docker is installed already, uninstall it.
  if command -v docker >/dev/null; then
    apt-get purge -y docker.io* lxc-docker* docker-engine*
  fi
  # Install Docker by following instructions from Docker's installation guide
  # (https://docs.docker.com/engine/installation/ubuntulinux/).
  # To use aufs on Ubuntu 14.04, we need to install the linux-image-extra package.
  LINUX_IMAGE_EXTRA_PACKAGE="linux-image-extra-$(uname -r)"
  if ! apt-get -y install "${LINUX_IMAGE_EXTRA_PACKAGE}"; then
    echo "Failed to install required package ${LINUX_IMAGE_EXTRA_PACKAGE}. Exiting..." >&2
    exit 1
  fi

  # Install Docker, exiting if any of the necessary steps (adding gpg key, updating apt sources,
  # and then actually doing the installation) fail.
  if ! apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 \
      --recv-keys 58118E89F3A912897C070ADBF76221572C52609D || \
      ! echo "deb https://apt.dockerproject.org/repo ubuntu-trusty main" > \
      /etc/apt/sources.list.d/docker.list || \
      ! apt-get update || \
      ! apt-get -o Dpkg::Options::="--force-confnew" -y install \
      docker-engine=${DOCKER_VERSION}* ; then
    echo "Docker installation failed. Exiting..." >&2
    exit 1
  fi
}

configure_docker() {
  echo "Stopping Docker daemon..."
  service docker stop

  if [ -n "${GRAPH_DIRECTORY}" ]; then
      DAEMON_OPTIONS+=("-g ${GRAPH_DIRECTORY}")
  fi

  echo "Overwriting /etc/default/docker to set DOCKER_OPTS=${DAEMON_OPTIONS[*]}.";
  cat > /etc/default/docker <<-__EOF
# Overwritten by clusterdock's setup script.
DOCKER_OPTS="${DAEMON_OPTIONS[*]}"
__EOF

  echo "Starting Docker daemon..."
  service docker start
  # Sleep for 5 seconds to make sure daemon is happy...
  sleep 5
}

write_file_from_image() {
  local IMAGE=${1}
  local FILE=${2}
  local DESTINATION=${3}
  local CONTAINER_ID=$(docker run -d "${IMAGE}")
  if docker cp "${CONTAINER_ID}:${FILE}" "${DESTINATION}"; then
    docker rm -f "${CONTAINER_ID}"
  else
    echo "Failed to copy ${FILE} from image ${IMAGE} (container ID ${CONTAINER_ID})."
    return 1
  fi
}

configure_host() {
  echo "Copying SSH key to /root/.ssh..."
  local IMAGE="${CLUSTERDOCK_IMAGE}"
  if ! write_file_from_image "${IMAGE}" \
      "/root/clusterdock/clusterdock/images/centos6.6_nodebase/ssh/id_rsa" \
      "/root/.ssh/id_rsa" || \
      ! write_file_from_image "${IMAGE}" \
      "/root/clusterdock/clusterdock/images/centos6.6_nodebase/ssh/id_rsa.pub" \
      "/root/.ssh/id_rsa.pub" || \
      ! chmod 400 /root/.ssh/id_rsa; then
    echo "Failed to copy SSH key. Exiting..." >&2
    exit 1
  fi
  if ! write_file_from_image "${IMAGE}" \
      "/root/clusterdock/clusterdock.sh" "/usr/local/bin/clusterdock.sh" || \
      ! add_file_source_to_bashrc '/usr/local/bin/clusterdock.sh'; then
    echo "Failed to add sourcing of clusterdock.sh to bashrc. Exiting..." >&2
    exit 1
  fi

  # Source clusterdock so that a user running this file gets the functions in clusterdock.sh
  # right away.
  source /usr/local/bin/clusterdock.sh
}

add_file_source_to_bashrc() {
  local FILE=${1}
  local BASHRC="/etc/bash.bashrc"

  # Only add the source if it's not already there.
  if ! grep -q "\. ${FILE}" "${BASHRC}"; then
    cat >> "${BASHRC}" << ____EOF

if [ -f ${FILE} ]; then
        . ${FILE}
fi
____EOF
  fi
}

main() {
  # Make sure only root can run our script.
  if [ $(id -u) -eq 0 ]; then
    parse_args "$@" && \
        install_docker && \
        configure_docker && \
        configure_host && \
        echo "clusterdocker setup is complete. Have fun."
  else
    echo "This script must be run as root. Exiting..." >&2
    exit 1
  fi
}

main "$@"