container/assets/runtime/functions

#!/bin/bash
set -e
source ${NEXTCLOUD_RUNTIME_DIR}/env-defaults

NEXTCLOUD_TEMPLATES_DIR=${NEXTCLOUD_RUNTIME_DIR}/config
NEXTCLOUD_APP_CONFIG=${NEXTCLOUD_CONFIG_DIR}/config.php
NEXTCLOUD_NGINX_CONFIG=/etc/nginx/sites-enabled/Nextcloud.conf

# Compares two version strings `a` and `b`
# Returns
#   - negative integer, if `a` is less than `b`
#   - 0, if `a` and `b` are equal
#   - non-negative integer, if `a` is greater than `b`
vercmp() {
  expr '(' "$1" : '\([^.]*\)' ')' '-' '(' "$2" : '\([^.]*\)' ')' '|' \
       '(' "$1.0" : '[^.]*[.]\([^.]*\)' ')' '-' '(' "$2.0" : '[^.]*[.]\([^.]*\)' ')' '|' \
       '(' "$1.0.0" : '[^.]*[.][^.]*[.]\([^.]*\)' ')' '-' '(' "$2.0.0" : '[^.]*[.][^.]*[.]\([^.]*\)' ')' '|' \
       '(' "$1.0.0.0" : '[^.]*[.][^.]*[.][^.]*[.]\([^.]*\)' ')' '-' '(' "$2.0.0.0" : '[^.]*[.][^.]*[.][^.]*[.]\([^.]*\)' ')'
}

# Read YAML file from Bash script
# Credits: https://gist.github.com/pkuczynski/8665367
parse_yaml() {
   local prefix=$2
   local s='[[:space:]]*' w='[a-zA-Z0-9_]*' fs=$(echo @|tr @ '\034')
   sed -ne "s|^\($s\)\($w\)$s:$s\"\(.*\)\"$s\$|\1$fs\2$fs\3|p" \
        -e "s|^\($s\)\($w\)$s:$s\(.*\)$s\$|\1$fs\2$fs\3|p" $1 |
   awk -F$fs '{
      indent = length($1)/2;
      vname[indent] = $2;
      for (i in vname) {if (i > indent) {delete vname[i]}}
      if (length($3) > 0) {
         vn=""; for (i=0; i<indent; i++) {vn=(vn)(vname[i])("_")}
         printf("%s%s%s=\"%s\"\n", "'$prefix'",vn, $2, $3);
      }
   }'
}

get_php_param() {
  local key=${1?key not specified}
  sed -n -e "s/^\(${key}=\)\(.*\)\(.*\)$/\2/p" ${NEXTCLOUD_INSTALL_DIR}/.user.ini
}

set_php_param() {
  local key=${1?key not specified}
  local value=${2?value not specified}
  local verbosity=${3:-verbose}

  local current=$(get_php_param ${key})
  if [[ "${current}" != "${value}" ]]; then
    if [[ ${verbosity} == verbose ]]; then
      echo "Setting .user.ini parameter: ${key}=${value}"
    fi
  fi

  if [[ $(sed -n -e "s/^[;]*[ ]*\(${key}\)=.*/\1/p" .user.ini) == ${key} ]]; then
    value="$(echo "${value}" | sed 's|[&]|\\&|g')"
    sed -i "s|^[;]*[ ]*${key}=.*|${key}=${value}|" ${NEXTCLOUD_INSTALL_DIR}/.user.ini
  else
    echo "${key}=${value}" >> ${NEXTCLOUD_INSTALL_DIR}/.user.ini
  fi
}

## Execute a command as NEXTCLOUD_USER
exec_as_nextcloud() {
  if [[ $(whoami) == ${NEXTCLOUD_USER} ]]; then
    $@
  else
    sudo -HEu ${NEXTCLOUD_USER} "$@"
  fi
}

occ_cli() {
  exec_as_nextcloud php occ $@
}

## Copies configuration template in ${NEXTCLOUD_TEMPLATES_DIR} to the destination as the specified USER
# $1: ownership of destination file, uses `chown`
# $2: source file
# $3: destination location
# $4: mode of destination, uses `chmod` (default: 0644)
install_template() {
  local OWNERSHIP=${1}
  local SRC=${2}
  local DEST=${3}
  local MODE=${4:-0644}
  if [[ -f ${NEXTCLOUD_TEMPLATES_DIR}/${SRC} ]]; then
    cp ${NEXTCLOUD_TEMPLATES_DIR}/${SRC} ${DEST}
  fi
  chmod ${MODE} ${DEST}
  chown ${OWNERSHIP} ${DEST}
}


## Replace placeholders with values
# $1: file with placeholders to replace
# $x: placeholders to replace
update_template() {
  local FILE=${1?missing argument}
  shift

  [[ ! -f ${FILE} ]] && return 1

  local VARIABLES=($@)
  local USR=$(stat -c %U ${FILE})
  local tmp_file=$(mktemp)
  cp -a "${FILE}" ${tmp_file}

  local variable
  for variable in ${VARIABLES[@]}; do
    # Keep the compatibilty: {{VAR}} => ${VAR}
    sed -ri "s/[{]{2}$variable[}]{2}/\${$variable}/g" ${tmp_file}
  done

  # Replace placeholders
  (
    export ${VARIABLES[@]}
    local IFS=":"; sudo -HEu ${USR} envsubst "${VARIABLES[*]/#/$}" < ${tmp_file} > ${FILE}
  )
  rm -f ${tmp_file}
}

nextcloud_finalize_database_parameters() {
  # is a mysql or postgresql database linked?
  # requires that the mysql or postgresql containers have exposed
  # port 3306 and 5432 respectively.
  if [[ -n ${MYSQL_PORT_3306_TCP_ADDR} ]]; then
    DB_TYPE=${DB_TYPE:-mysql}
    DB_HOST=${DB_HOST:-mysql}
    DB_PORT=${DB_PORT:-$MYSQL_PORT_3306_TCP_PORT}

    # support for linked sameersbn/mysql image
    DB_USER=${DB_USER:-$MYSQL_ENV_DB_USER}
    DB_PASS=${DB_PASS:-$MYSQL_ENV_DB_PASS}
    DB_NAME=${DB_NAME:-$MYSQL_ENV_DB_NAME}

    # support for linked orchardup/mysql and enturylink/mysql image
    # also supports official mysql image
    DB_USER=${DB_USER:-$MYSQL_ENV_MYSQL_USER}
    DB_PASS=${DB_PASS:-$MYSQL_ENV_MYSQL_PASSWORD}
    DB_NAME=${DB_NAME:-$MYSQL_ENV_MYSQL_DATABASE}
  elif [[ -n ${POSTGRESQL_PORT_5432_TCP_ADDR} ]]; then
    DB_TYPE=${DB_TYPE:-pgsql}
    DB_HOST=${DB_HOST:-postgresql}
    DB_PORT=${DB_PORT:-$POSTGRESQL_PORT_5432_TCP_PORT}

    # support for linked official postgres image
    DB_USER=${DB_USER:-$POSTGRESQL_ENV_POSTGRES_USER}
    DB_PASS=${DB_PASS:-$POSTGRESQL_ENV_POSTGRES_PASSWORD}
    DB_NAME=${DB_NAME:-$POSTGRESQL_ENV_POSTGRES_DB}
    DB_NAME=${DB_NAME:-$DB_USER}

    # support for linked sameersbn/postgresql image
    DB_USER=${DB_USER:-$POSTGRESQL_ENV_DB_USER}
    DB_PASS=${DB_PASS:-$POSTGRESQL_ENV_DB_PASS}
    DB_NAME=${DB_NAME:-$POSTGRESQL_ENV_DB_NAME}

    # support for linked orchardup/postgresql image
    DB_USER=${DB_USER:-$POSTGRESQL_ENV_POSTGRESQL_USER}
    DB_PASS=${DB_PASS:-$POSTGRESQL_ENV_POSTGRESQL_PASS}
    DB_NAME=${DB_NAME:-$POSTGRESQL_ENV_POSTGRESQL_DB}

    # support for linked paintedfox/postgresql image
    DB_USER=${DB_USER:-$POSTGRESQL_ENV_USER}
    DB_PASS=${DB_PASS:-$POSTGRESQL_ENV_PASS}
    DB_NAME=${DB_NAME:-$POSTGRESQL_ENV_DB}
  fi

  if [[ -z ${DB_HOST} ]]; then
    echo
    echo "ERROR: "
    echo "  Please configure the database connection."
    echo "  Cannot continue without a database. Aborting..."
    echo
    return 1
  fi

  # use default port number if it is still not set
  case ${DB_TYPE} in
    mysql) DB_PORT=${DB_PORT:-3306} ;;
    pgsql) DB_PORT=${DB_PORT:-5432} ;;
    *)
      echo
      echo "ERROR: "
      echo "  Please specify the database type in use via the DB_TYPE configuration option."
      echo "  Accepted values are \"pgsql\" or \"mysql\". Aborting..."
      echo
      return 1
      ;;
  esac

  # set default user and database
  DB_USER=${DB_USER:-root}
  DB_NAME=${DB_NAME:-nextclouddb}
}

nextcloud_finalize_php_fpm_parameters() {
  # is a nextcloud-php-fpm container linked?
  if [[ -n ${PHP_FPM_PORT_9000_TCP_ADDR} ]]; then
    NEXTCLOUD_PHP_FPM_HOST=${NEXTCLOUD_PHP_FPM_HOST:-$PHP_FPM_PORT_9000_TCP_ADDR}
    NEXTCLOUD_PHP_FPM_PORT=${NEXTCLOUD_PHP_FPM_PORT:-$PHP_FPM_PORT_9000_TCP_PORT}
  fi

  if [[ -z ${NEXTCLOUD_PHP_FPM_HOST} ]]; then
    echo
    echo "ERROR: "
    echo "  Please configure the php-fpm connection. Aborting..."
    echo
    return 1
  fi

  # use default php-fpm port number if it is still not set
  NEXTCLOUD_PHP_FPM_PORT=${NEXTCLOUD_PHP_FPM_PORT:-9000}
}

nextcloud_check_database_connection() {
  case ${DB_TYPE} in
    mysql)
      prog="mysqladmin -h ${DB_HOST} -P ${DB_PORT} -u ${DB_USER} ${DB_PASS:+-p$DB_PASS} status"
      ;;
    pgsql)
      prog=$(find /usr/lib/postgresql/ -name pg_isready)
      prog="${prog} -h ${DB_HOST} -p ${DB_PORT} -U ${DB_USER} -d ${DB_NAME} -t 1"
      ;;
  esac
  timeout=60
  while ! ${prog} >/dev/null 2>&1
  do
    timeout=$(expr $timeout - 1)
    if [[ $timeout -eq 0 ]]; then
      echo
      echo "Could not connect to database server. Aborting..."
      return 1
    fi
    echo -n "."
    sleep 1
  done
  echo
}

nextcloud_configure_database() {
  echo -n "Configuring Nextcloud::database"

  nextcloud_finalize_database_parameters
  nextcloud_check_database_connection

  if [[ -f ${NEXTCLOUD_APP_CONFIG} ]]; then
    occ_cli config:system:set dbtype --value ${DB_TYPE}
    occ_cli config:system:set dbhost --value ${DB_HOST}:${DB_PORT}
    occ_cli config:system:set dbname --value ${DB_NAME}
    occ_cli config:system:set dbuser --value ${DB_USER}
    occ_cli config:system:set dbpassword --value ${DB_PASS}
  fi
}

nextcloud_upgrade() {
  # perform installation on firstrun
  case ${DB_TYPE} in
    mysql)
      QUERY="SELECT count(*) FROM information_schema.tables WHERE table_schema = '${DB_NAME}';"
      COUNT=$(mysql -h ${DB_HOST} -P ${DB_PORT} -u ${DB_USER} ${DB_PASS:+-p$DB_PASS} -ss -e "${QUERY}")
      ;;
    pgsql)
      QUERY="SELECT count(*) FROM information_schema.tables WHERE table_schema = 'public';"
      COUNT=$(PGPASSWORD="${DB_PASS}" psql -h ${DB_HOST} -p ${DB_PORT} -U ${DB_USER} -d ${DB_NAME} -Atw -c "${QUERY}")
      ;;
  esac

  local update_version=false
  if [[ -z ${COUNT} || ${COUNT} -eq 0 ]]; then
    echo "Setting up Nextcloud for firstrun..."
    mkdir -p ${NEXTCLOUD_INSTALL_DIR}/data
    chown -R ${NEXTCLOUD_USER}: ${NEXTCLOUD_INSTALL_DIR}/data

    occ_cli maintenance:install \
      --database=${DB_TYPE} --database-host=${DB_HOST}:${DB_PORT} \
      --database-name=${DB_NAME} --database-user=${DB_USER} --database-pass=${DB_PASS} \
      --admin-user=${NEXTCLOUD_ADMIN_USER} --admin-pass=${NEXTCLOUD_ADMIN_PASSWORD} \
      --data-dir=${NEXTCLOUD_OCDATA_DIR}

    update_version=true
  else
    CACHE_VERSION=
    [[ -f ${NEXTCLOUD_CONFIG_DIR}/VERSION ]] && CACHE_VERSION=$(cat ${NEXTCLOUD_CONFIG_DIR}/VERSION)
    if [[ ${NEXTCLOUD_VERSION} != ${CACHE_VERSION} ]]; then
      ## version check, only upgrades are allowed
      if [[ -n ${CACHE_VERSION} && $(vercmp ${NEXTCLOUD_VERSION} ${CACHE_VERSION}) -lt 0 ]]; then
        echo
        echo "ERROR: "
        echo "  Cannot downgrade from Nextcloud version ${CACHE_VERSION} to ${NEXTCLOUD_VERSION}."
        echo "  Only upgrades are allowed. Please use sameersbn/nextcloud:${CACHE_VERSION} or higher."
        echo "  Cannot continue. Aborting!"
        echo
        return 1
      fi

      echo "Upgrading Nextcloud..."
      occ_cli maintenance:mode --on
      occ_cli upgrade
      occ_cli maintenance:mode --off

      update_version=true
    fi
  fi

  if [[ ${update_version} == true ]]; then
    echo -n "${NEXTCLOUD_VERSION}" | exec_as_nextcloud tee ${NEXTCLOUD_CONFIG_DIR}/VERSION >/dev/null
  fi
}

nextcloud_configure_domain() {
  echo "Configuring Nextcloud::trusted_domain..."
  occ_cli config:system:set trusted_domains 0 --value ${NEXTCLOUD_FQDN}
}

nextcloud_configure_max_upload_size() {
  echo "Configuring Nextcloud::max_upload_size..."
  set_php_param upload_max_filesize ${NEXTCLOUD_UPLOAD_MAX_FILESIZE}
  set_php_param post_max_size ${NEXTCLOUD_UPLOAD_MAX_FILESIZE}
}

nextcloud_configure_max_file_uploads() {
  echo "Configuring Nextcloud::max_file_uploads..."
  set_php_param max_file_uploads ${NEXTCLOUD_MAX_FILE_UPLOADS}
}

nginx_configure_virtualhost() {
  echo "Configuring Nextcloud virtualhost..."
  nextcloud_finalize_php_fpm_parameters
  update_template ${NEXTCLOUD_NGINX_CONFIG} \
    NEXTCLOUD_FQDN \
    NEXTCLOUD_HTTPS \
    NEXTCLOUD_PHP_FPM_HOST \
    NEXTCLOUD_PHP_FPM_PORT
}

backup_dump_database() {
  case ${DB_TYPE} in
    pgsql)
      echo "Dumping PostgreSQL database ${DB_NAME}..."
      PGPASSWORD=${DB_PASS} pg_dump --clean \
        --host ${DB_HOST} --port ${DB_PORT} \
        --username ${DB_USER} ${DB_NAME} > ${NEXTCLOUD_BACKUPS_DIR}/database.sql
      ;;
    mysql)
      echo "Dumping MySQL database ${DB_NAME}..."
      MYSQL_PWD=${DB_PASS} mysqldump --lock-tables --add-drop-table \
        --host ${DB_HOST} --port ${DB_PORT} \
        --user ${DB_USER} ${DB_NAME} > ${NEXTCLOUD_BACKUPS_DIR}/database.sql
      ;;
  esac
  chown ${NEXTCLOUD_USER}: ${NEXTCLOUD_BACKUPS_DIR}/database.sql
  exec_as_nextcloud gzip -f ${NEXTCLOUD_BACKUPS_DIR}/database.sql
}

backup_dump_directory() {
  local directory=${1}
  local dirname=$(basename ${directory})
  local extension=${2}

  echo "Dumping ${dirname}..."
  exec_as_nextcloud tar -cf ${NEXTCLOUD_BACKUPS_DIR}/${dirname}${extension} -C ${directory} .
}

backup_dump_information() {
  (
    echo "info:"
    echo "  nextcloud_version: ${NEXTCLOUD_VERSION}"
    echo "  database_adapter: $(occ_cli config:system:get dbtype)"
    echo "  created_at: $(date)"
  ) > ${NEXTCLOUD_BACKUPS_DIR}/backup_information.yml
  chown ${NEXTCLOUD_USER}: ${NEXTCLOUD_BACKUPS_DIR}/backup_information.yml
}

backup_create_archive() {
  local tar_file="$(date +%s)_nextcloud_backup.tar"

  echo "Creating backup archive: ${tar_file}..."
  exec_as_nextcloud tar -cf ${NEXTCLOUD_BACKUPS_DIR}/${tar_file} -C ${NEXTCLOUD_BACKUPS_DIR} $@
  exec_as_nextcloud chmod 0755 ${NEXTCLOUD_BACKUPS_DIR}/${tar_file}

  for f in $@
  do
    exec_as_nextcloud rm -rf ${NEXTCLOUD_BACKUPS_DIR}/${f}
  done
}

backup_purge_expired() {
  if [[ ${NEXTCLOUD_BACKUPS_EXPIRY} -gt 0 ]]; then
    echo -n "Deleting old backups... "
    local removed=0
    local now=$(date +%s)
    local cutoff=$(expr ${now} - ${NEXTCLOUD_BACKUPS_EXPIRY})
    for backup in $(ls ${NEXTCLOUD_BACKUPS_DIR}/*_nextcloud_backup.tar)
    do
      local timestamp=$(stat -c %Y ${backup})
      if [[ ${timestamp} -lt ${cutoff} ]]; then
        rm ${backup}
        removed=$(expr ${removed} + 1)
      fi
    done
    echo "(${removed} removed)"
  fi
}

backup_restore_unpack() {
  local backup=${1}
  echo "Unpacking ${backup}..."
  tar xf ${NEXTCLOUD_BACKUPS_DIR}/${backup} -C ${NEXTCLOUD_BACKUPS_DIR}
}

backup_restore_validate() {
  eval $(parse_yaml ${NEXTCLOUD_BACKUPS_DIR}/backup_information.yml backup_)

  ## version check
  if [[ $(vercmp ${NEXTCLOUD_VERSION} ${backup_info_nextcloud_version}) -lt 0 ]]; then
    echo
    echo "ERROR: "
    echo "  Cannot restore backup for version ${backup_info_nextcloud_version} on a ${NEXTCLOUD_VERSION} instance."
    echo "  You can only restore backups generated for versions <= ${NEXTCLOUD_VERSION}."
    echo "  Please use sameersbn/nextcloud:${backup_info_nextcloud_version} to restore this backup."
    echo "  Cannot continue. Aborting!"
    echo
    return 1
  fi

  ## database adapter check
  if [[ ${DB_TYPE} != ${backup_info_database_adapter} ]]; then
    echo
    echo "ERROR:"
    echo "  Your current setup uses the ${DB_TYPE} adapter, while the database"
    echo "  backup was generated with the ${backup_info_database_adapter} adapter."
    echo "  Cannot continue. Aborting!"
    echo
    return 1
  fi
  exec_as_nextcloud rm -rf ${NEXTCLOUD_BACKUPS_DIR}/backup_information.yml
}

backup_restore_database() {
  case ${DB_TYPE} in
    pgsql)
      echo "Restoring PostgreSQL database..."
      gzip -dc ${NEXTCLOUD_BACKUPS_DIR}/database.sql.gz | \
        PGPASSWORD=${DB_PASS} psql \
          --host ${DB_HOST} --port ${DB_PORT} \
          --username ${DB_USER} ${DB_NAME}
      ;;
    mysql)
      echo "Restoring MySQL database..."
      gzip -dc ${NEXTCLOUD_BACKUPS_DIR}/database.sql.gz | \
        MYSQL_PWD=${DB_PASS} mysql \
          --host ${DB_HOST} --port ${DB_PORT} \
          --user ${DB_USER} ${DB_NAME}
      ;;
    *)
      echo "Database type ${DB_TYPE} not supported."
      return 1
      ;;
  esac
  exec_as_nextcloud rm -rf ${NEXTCLOUD_BACKUPS_DIR}/database.sql.gz
}

backup_restore_directory() {
  local directory=${1}
  local dirname=$(basename ${directory})
  local extension=${2}

  echo "Restoring ${dirname}..."
  files=($(shopt -s nullglob;shopt -s dotglob;echo ${directory}/*))
  if [[ ${#files[@]} -gt 0 ]]; then
    exec_as_nextcloud mv ${directory} ${directory}.$(date +%s)
  else
    exec_as_nextcloud rm -rf ${directory}
  fi
  exec_as_nextcloud mkdir -p ${directory}
  exec_as_nextcloud tar -xf ${NEXTCLOUD_BACKUPS_DIR}/${dirname}${extension} -C ${directory}
  exec_as_nextcloud rm -rf ${NEXTCLOUD_BACKUPS_DIR}/${dirname}${extension}
}

install_configuration_templates() {
  echo "Installing configuration templates..."
  if [[ -d /etc/nginx/sites-enabled && ! -f ${NEXTCLOUD_NGINX_CONFIG} ]]; then
    install_template root: nginx/Nextcloud.conf ${NEXTCLOUD_NGINX_CONFIG} 0644
    update_template ${NEXTCLOUD_NGINX_CONFIG} NEXTCLOUD_INSTALL_DIR
  fi
}

initialize_datadir() {
  echo "Initializing datadir..."
  chmod 0755 ${NEXTCLOUD_DATA_DIR}
  chown ${NEXTCLOUD_USER}: ${NEXTCLOUD_DATA_DIR}

  # create ocdata directory
  mkdir -p ${NEXTCLOUD_OCDATA_DIR}
  chown -R ${NEXTCLOUD_USER}: ${NEXTCLOUD_OCDATA_DIR}
  chmod -R 0750 ${NEXTCLOUD_OCDATA_DIR}

  # create config directory
  mkdir -p ${NEXTCLOUD_CONFIG_DIR}
  chown -R ${NEXTCLOUD_USER}: ${NEXTCLOUD_CONFIG_DIR}
  chmod -R 0750 ${NEXTCLOUD_CONFIG_DIR}

  # create backups directory
  mkdir -p ${NEXTCLOUD_BACKUPS_DIR}
  chmod -R 0755 ${NEXTCLOUD_BACKUPS_DIR}
  chown -R ${NEXTCLOUD_USER}: ${NEXTCLOUD_BACKUPS_DIR}

  # symlink to config/config.php -> ${NEXTCLOUD_APP_CONFIG}
  ln -sf ${NEXTCLOUD_APP_CONFIG} ${NEXTCLOUD_INSTALL_DIR}/config/config.php
}

initialize_system() {
  initialize_datadir
  install_configuration_templates
}

configure_nextcloud() {
  echo "Configuring Nextcloud..."
  nextcloud_configure_database
  nextcloud_upgrade
  nextcloud_configure_domain
  nextcloud_configure_max_upload_size
  nextcloud_configure_max_file_uploads

  if [[ -f ${NEXTCLOUD_APP_CONFIG} ]]; then
    occ_cli maintenance:mode --quiet --off
  fi
}

configure_nginx() {
  echo "Configuring nginx..."
  nginx_configure_virtualhost
}

backup_create() {
  echo -n "Checking database connection"
  nextcloud_finalize_database_parameters
  nextcloud_check_database_connection

  occ_cli maintenance:mode --on
  backup_dump_database
  backup_dump_directory ${NEXTCLOUD_CONFIG_DIR} .tar.gz
  backup_dump_directory ${NEXTCLOUD_OCDATA_DIR} .tar
  backup_dump_information
  backup_create_archive backup_information.yml database.sql.gz config.tar.gz ocdata.tar
  backup_purge_expired
  occ_cli maintenance:mode --off
}

backup_restore() {
  local tar_file=
  local interactive=true
  for arg in $@
  do
    if [[ $arg == BACKUP=* ]]; then
      tar_file=${arg##BACKUP=}
      interactive=false
      break
    fi
  done

  # user needs to select the backup to restore
  if [[ $interactive == true ]]; then
    num_backups=$(ls ${NEXTCLOUD_BACKUPS_DIR}/*_nextcloud_backup.tar | wc -l)
    if [[ $num_backups -eq 0 ]]; then
      echo "No backups exist at ${NEXTCLOUD_BACKUPS_DIR}. Cannot continue."
      return 1
    fi

    echo
    for b in $(ls ${NEXTCLOUD_BACKUPS_DIR} | grep _nextcloud_backup.tar | sort -r)
    do
      echo "‣ $b (created at $(date --date="@${b%%_nextcloud_backup.tar}" +'%d %b, %G - %H:%M:%S %Z'))"
    done
    echo

    read -p "Select a backup to restore: " tar_file

    if [[ -z ${tar_file} ]]; then
      echo "Backup not specified. Exiting..."
      return 1
    fi
  fi

  if [[ ! -f ${NEXTCLOUD_BACKUPS_DIR}/${tar_file} ]]; then
    echo "Specified backup does not exist. Aborting..."
    return 1
  fi

  echo -n "Checking database connection"
  nextcloud_finalize_database_parameters
  nextcloud_check_database_connection

  backup_restore_unpack ${tar_file}
  backup_restore_validate
  backup_restore_database
  backup_restore_directory ${NEXTCLOUD_CONFIG_DIR} .tar.gz
  backup_restore_directory ${NEXTCLOUD_OCDATA_DIR} .tar
}