_denv_entrypoint

#!/bin/sh
# SPDX-License-Identifier: GPL-3.0-only
#
# This file is part of the denv project: https://github.com/tomeichlersmith/denv
#
# Copyright (C) 2021 denv contributors
#
# denv is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License version 3
# as published by the Free Software Foundation.
#
# denv is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with denv; if not, see <http://www.gnu.org/licenses/>.

# POSIX
set -o errexit
set -o nounset

# Assumptions on the configuration of the container running this script
# 1. The denv workspace is mounted to the home directory and HOME is defined
# 2. Some other denv environment variables are defined
#     DENV_RUNNER, DENV_IMAGE, DENV_NAME
# 3. Optional environment variables should be defined for the container
#    if they are defined for denv (e.g. DENV_DEBUG, DENV_INFO)

if [ -n "${DENV_DEBUG+x}" ]; then
  set -o xtrace
fi

if [ -n "${DENV_INFO+x}" ]; then
  _denv_info() {
    printf "\033[32;1m INFO: \033[0m\033[32m%s\n" "$1"
    shift
    while [ "$#" -gt "0" ]; do
      printf '       %s\n' "$1"
      shift
    done
    printf "\033[0m"
  }
else
  _denv_info() {
    :
  }
fi

# print each argument on its own line with the first line
# prefixed with "ERROR: ".
_denv_error() {
  printf >&2 "\033[1;31mERROR: \033[0m\033[31m%s\n" "$1"
  shift
  while [ "$#" -gt "0" ]; do
    printf >&2 "       %s\n" "$1"
    shift
  done
  printf >&2 "\033[0m"
}

# we have some variables that necessarily are defined outside this script
# shellcheck disable=SC2154
if [ -z "${DENV_RUNNER+x}" ] || [ -z "${DENV_IMAGE+x}" ] || [ -z "${DENV_NAME+x}" ] || [ -z "${HOME+x}" ]; then
  _denv_error "The necessary environment variables have not been passed into the runner." \
    "_denv_entrypoint should only be run within a container launced by denv."
  exit 1
fi

if [ -d "${HOME}/.denv" ] && [ ! -f "${HOME}/.denv/skel-init" ]; then
  # If we do not have profile files in the home, we should copy the
  # skeleton files, if present.
  # Ensure we copy only if the dotfile is not already present.
  if [ -d "/etc/skel" ]; then
    skel_files="$(find /etc/skel/ -type f || :)"
    for skel_file in ${skel_files}; do
      base_file_name=$(basename "${skel_file}")
      skel_file_path=$(dirname "${skel_file}")
      file_path_for_home=${skel_file_path#/etc/skel}
  
      if [ -n "${file_path_for_home}" ] &&
        [ ! -d "${HOME}/${file_path_for_home:+"${file_path_for_home}"}" ]; then
        mkdir -p "${HOME}/${file_path_for_home:+"${file_path_for_home}"/}"
      fi
  
      if [ ! -f "${HOME}/${file_path_for_home:+"${file_path_for_home}"/}${base_file_name}" ] &&
        [ ! -L "${HOME}/${file_path_for_home:+"${file_path_for_home}"/}${base_file_name}" ]; then
        cp "${skel_file}" "${HOME}/${file_path_for_home:+"${file_path_for_home}"/}${base_file_name}"
      fi
    done
  fi

  if [ -f "${HOME}/.bashrc" ]; then
    if [ "${DENV_RUNNER}" = "singularity" ] || [ "${DENV_RUNNER}" = "apptainer" ]; then
      # for apptainer/singularity runners
      {
        echo "# apptainer/singularity set the environment varible PROMPT_COMMAND"
        echo "# to overwrite PS1 with a container-specific prompt, we undo that"
        echo "# overwwriting here to allow the '.bashrc'-generated prompt to persist"
        echo "# https://github.com/tomeichlersmith/denv/issues/3"
        echo "unset PROMPT_COMMAND"
      } >> "${HOME}/.bashrc"
    fi
  fi
  touch "${HOME}/.denv/skel-init"
fi

# use a login shell to give users an opportunity to update env variables
# via the ~/.profile file if desired
sh -lc "$*"