#!/bin/bash

function _escape() {

echo "${1//./\\.}"

}

# TODO: Not in use currently. Maybe in the future: https://github.com/docker-mailserver/docker-mailserver/pull/3484/files#r1299410851

# Replaces a string so that it can be used inside

# `sed` safely.

#

# @param ${1} = string to escape

# @output = prints the escaped string

function _escape_for_sed() {

sed -E 's/[]\/$*.^[]/\\&/g' <<< "${1:?String to escape for sed is required}"

}

# Returns input after filtering out lines that are:

# empty, white-space, comments (`#` as the first non-whitespace character)

function _get_valid_lines_from_file() {

_convert_crlf_to_lf_if_necessary "${1}"

_append_final_newline_if_missing "${1}"

grep --extended-regexp --invert-match "^\s*$|^\s*#" "${1}" || true

}

# This is to sanitize configs from users that unknowingly introduced CRLF:

function _convert_crlf_to_lf_if_necessary() {

if [[ $(file "${1}") =~ 'CRLF' ]]; then

_log 'warn' "File '${1}' contains CRLF line-endings"

if [[ -w ${1} ]]; then

_log 'debug' 'Converting CRLF to LF'

sed -i 's|\r||g' "${1}"

else

_log 'warn' "File '${1}' is not writable - cannot change CRLF to LF"

fi

fi

}

# This is to sanitize configs from users that unknowingly removed the end-of-file LF:

function _append_final_newline_if_missing() {

# Correctly detect a missing final newline and fix it:

# https://stackoverflow.com/questions/38746/how-to-detect-file-ends-in-newline#comment82380232_25749716

# https://unix.stackexchange.com/questions/31947/how-to-add-a-newline-to-the-end-of-a-file/441200#441200

# https://unix.stackexchange.com/questions/159557/how-to-non-invasively-test-for-write-access-to-a-file

if [[ $(tail -c1 "${1}" | wc -l) -eq 0 ]]; then

# Avoid fixing when the destination is read-only:

if [[ -w ${1} ]]; then

printf '\n' >> "${1}"

_log 'info' "File '${1}' was missing a final newline - this has been fixed"

else

_log 'warn' "File '${1}' is missing a final newline - it is not writable, hence it was not fixed - the last line will not be processed!"

fi

fi

}

# Provide the name of an environment variable to this function

# and it will return its value stored in /etc/dms-settings

function _get_dms_env_value() {

if [[ -f /etc/dms-settings ]]; then

grep "^${1}=" /etc/dms-settings | cut -d "'" -f 2

else

_log 'warn' "Call to '_get_dms_env_value' but '/etc/dms-settings' is not present"

return 1

fi

}

# TODO: `chown -R 5000:5000 /var/mail` has existed since the projects first commit.

# It later received a depth guard to apply the fix only when it's relevant for a dir.

# Assess if this still appropriate, it appears to be problematic for some LDAP users.

#

# `helpers/accounts.sh:_create_accounts` (mkdir, cp) appears to be the only writer to

# /var/mail folders (used during startup and change detection handling).

function _chown_var_mail_if_necessary() {

# fix permissions, but skip this if 3 levels deep the user id is already set

if find /var/mail -maxdepth 3 -a \( \! -user "${DMS_VMAIL_UID}" -o \! -group "${DMS_VMAIL_GID}" \) | read -r; then

_log 'trace' 'Fixing /var/mail permissions'

chown -R "${DMS_VMAIL_UID}:${DMS_VMAIL_GID}" /var/mail || return 1

fi

}

function _require_n_parameters_or_print_usage() {

local COUNT

COUNT=${1}

shift

[[ ${1:-} == 'help' ]] && { __usage ; exit 0 ; }

[[ ${#} -lt ${COUNT} ]] && { __usage ; exit 1 ; }

return 0

}

# NOTE: Postfix commands that read `main.cf` will stall execution,

# until the config file has not be written to for at least 2 seconds.

# After we modify the config explicitly, we can safely assume (reasonably)

# that the write stream has completed, and it is safe to read the config.

# https://github.com/docker-mailserver/docker-mailserver/issues/2985

function _adjust_mtime_for_postfix_maincf() {

if [[ $(( $(date '+%s') - $(stat -c '%Y' '/etc/postfix/main.cf') )) -lt 2 ]]; then

touch -d '2 seconds ago' /etc/postfix/main.cf

fi

}

function _reload_postfix() {

_adjust_mtime_for_postfix_maincf

postfix reload

}

# Replaces values in configuration files given a set of specific environment

# variables. The environment variables follow a naming pattern, whereby every

# variable that is taken into account has a given prefix. The new value in the

# configuration will be the one the environment variable had at the time of

# calling this function.

#

# @option --shutdown-on-error = shutdown in case an error is detected

# @param ${1} = prefix for environment variables

# @param ${2} = file in which substitutions should take place

#

# ## Example

#

# If you want to set a new value for `readme_directory` in Postfix's `main.cf`,

# you can set the environment variable `POSTFIX_README_DIRECTORY='/new/dir/'`

# (`POSTFIX_` is an arbitrary prefix, you can choose the one you like),

# and then call this function:

# `_replace_by_env_in_file 'POSTFIX_' '<PATH TO POSTFIX's main.cf>`

#

# ## Panics

#

# This function will panic, i.e. shut down the whole container, if:

#

# 1. No first and second argument is supplied

# 2. The second argument is a path to a file that does not exist

function _replace_by_env_in_file() {

if [[ -z ${1:-} ]]; then

_dms_panic__invalid_value 'first argument unset' 'utils.sh:_replace_by_env_in_file'

elif [[ -z ${2:-} ]]; then

_dms_panic__invalid_value 'second argument unset' 'utils.sh:_replace_by_env_in_file'

elif [[ ! -f ${2} ]]; then

_dms_panic__invalid_value "file '${2}' does not exist" 'utils.sh:_replace_by_env_in_file'

fi

local ENV_PREFIX=${1} CONFIG_FILE=${2}

local ESCAPED_VALUE ESCAPED_KEY

while IFS='=' read -r KEY VALUE; do

KEY=${KEY#"${ENV_PREFIX}"} # strip prefix

ESCAPED_KEY=$(sed -E 's#([\=\&\|\$\.\*\/\[\\^]|\])#\\\1#g' <<< "${KEY,,}")

ESCAPED_VALUE=$(sed -E 's#([\=\&\|\$\.\*\/\[\\^]|\])#\\\1#g' <<< "${VALUE}")

[[ -n ${ESCAPED_VALUE} ]] && ESCAPED_VALUE=" ${ESCAPED_VALUE}"

_log 'trace' "Setting value of '${KEY}' in '${CONFIG_FILE}' to '${VALUE}'"

sed -i -E "s#^${ESCAPED_KEY}[[:space:]]*=.*#${ESCAPED_KEY} =${ESCAPED_VALUE}#g" "${CONFIG_FILE}"

done < <(env | grep "^${ENV_PREFIX}")

}

# Check if an environment variable's value is zero or one. This aids in checking variables

# that act as "booleans" for enabling or disabling a service, configuration option, etc.

#

# This function will log a warning and return with exit code 1 in case the variable's value

# is not zero or one.

#

# @param ${1} = name of the ENV variable to check

function _env_var_expect_zero_or_one() {

local ENV_VAR_NAME=${1:?ENV var name must be provided to _env_var_expect_zero_or_one}

if [[ ! -v ${ENV_VAR_NAME} ]]; then

_log 'warn' "'${ENV_VAR_NAME}' is not set, but was expected to be"

return 1

fi

if [[ ! ${!ENV_VAR_NAME} =~ ^(0|1)$ ]]; then

_log 'warn' "The value of '${ENV_VAR_NAME}' (= '${!ENV_VAR_NAME}') is not 0 or 1, but was expected to be"

return 1

fi

return 0

}

# Check if an environment variable's value is an integer.

#

# This function will log a warning and return with exit code 1 in case the variable's value

# is not an integer.

#

# @param ${1} = name of the ENV variable to check

function _env_var_expect_integer() {

local ENV_VAR_NAME=${1:?ENV var name must be provided to _env_var_expect_integer}

[[ ${!ENV_VAR_NAME} =~ ^-?[0-9][0-9]*$ ]] && return 0

_log 'warn' "The value of '${ENV_VAR_NAME}' is not an integer ('${!ENV_VAR_NAME}'), but was expected to be"

return 1

}