groupon/ansible-silo

#!/usr/bin/env bash
#
# Runner script which will be copied to the host and starts the actual
# container
#
# This executable is going to be mounted on the host when the container is
# called with --run and afterwards executed _on_ the host. This enables silo to
# bundle its own, very complex, docker command inside the container.
#
# Copyright (c) 2017, Groupon, Inc.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# Neither the name of GROUPON nor the names of its contributors may be
# used to endorse or promote products derived from this software without
# specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
# TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

# Make sure this is bash
# BASH_VERSION is provided by bash itself. If empty this ain't bash.
if [[ -z "${BASH_VERSION}" ]]; then
  echo "Redirecting to bash..." >&2
  self=$(readlink -f "$0")
  /bin/bash "${self}"
  exit
fi

# RUNNER_FUNCTIONS is replaced with the content of the file
# silo/runner_functions.sh. The file is not sourced as the runner file will be
# copied to the host during runtime where the runner_functions.sh is not
# available.
#{{ RUNNER_FUNCTIONS }}

#######################################
# Builds the docker command to start the container
# Globals:
#   SILO_DEBUG
#   BUNDLE_VERSION
#   SILO_DOCKER_CMD
#   SILO_IMAGE
#   SILO_IMAGE_SHORT
#   SILO_VERSION
# Arguments:
#   $@ - Anything that was passed to the script
# Returns:
#   None
#######################################
run() {
  local command docker_cmd docker_default func

  # SILO_DOCKER_CMD can be set by the user to override the default docker
  # command
  docker_default="$(command -v docker)"
  docker_cmd="${SILO_DOCKER_CMD:-${docker_default}}"
  command="${docker_cmd} run --interactive --rm"
  if [ -t 0 ]; then
    command+=" --tty"
  fi

  # SILO_IMAGE_SHORT is defined in silo/runner_functions.sh and contains the
  # basename of the Docker image. Below test checks if this is the ansible-silo
  # image or an image extending it.
  if [[ "${SILO_IMAGE_SHORT}" == "ansible-silo" ]]; then
    # Run all functions starting with silo_* and _silo_ and append their output
    # to the docker command
    while read -r func; do
      command+=" $(${func})"
    done < <(typeset -f | awk '/ \(\) $/ && !/^main / {print $1}' \
      | grep -e "^silo_" -e "^_silo_" \
      | grep -v "^silo_run")

    # SILO_VERSION is set as build parameter "v" in docker-build. It can be
    # defined by the user as environment var to run a specific ansible-silo
    # version.
    command+=" \"${SILO_IMAGE}:${SILO_VERSION}\""
  else
    # Run all functions starting with silo_* and append their output to the
    # docker command. Also functions matching the docker image name will be
    # triggered, e.g. for an image named some-image all functions starting with
    # some_image_* will be triggered.
    # shellcheck disable=SC2001
    while read -r func; do
      command+=" $(${func})"
    done < <(typeset -f \
      | awk '/ \(\) $/ && !/^main / {print $1}' \
      | grep -e "^silo_" -e "^$(echo "${SILO_IMAGE_SHORT}" \
      | sed -e "s/[^A-Za-z0-9._]/_/g")_" \
      | grep -v "^silo_run")
    # SILO_IMAGE is defined in silo/runner_functions.sh and contains the
    # name of the Docker image, including the repository path.
    # BUNDLE_VERSION is set as build parameter "v" in docker-build.
    command+=" \"${SILO_IMAGE}:{{ BUNDLE_VERSION }}\""
  fi

  for var in "$@"; do
    command+=" \"${var}\""
  done

  # SILO_DEBUG can be set by the user to enable debug output
  if [[ ! -z "${SILO_DEBUG}" ]]; then
    echo -e "Executing: ${command}\\n"
  fi

  /bin/bash -c "${command}"
}

run "$@"