📝 change default dns server setting

✨ add man page

.pre-commit-config.yaml

@@ -0,0 +1,11 @@
+repos:
+  - repo: https://github.com/syntaqx/git-hooks
+    rev: v0.0.17
+    hooks:
+    - id: shellcheck
+    - id: shfmt
+      args: 
+        - "-l" # list files whose formatting differs from shfmt's
+        - "-i 2" # indent: 0 for tabs (default), >0 for number of spaces
+        - "-ci" # switch cases will be indented
+        - "-w" # write result to file instead of stdout

CHANGELOG.md

@@ -1,6 +1,34 @@
 # Changelog
 
 
+## (unreleased)
+
+### Documentation
+
+* :memo: update README.md. [Eduard Veit]
+
+### Other
+
+* :recycle: normalizing pre-commit configuration to a top-level map. [Eduard Veit]
+
+* :recycle: refactorings. [Eduard Veit]
+
+* Feature: :sparkles: add pre-commit git hook for shellcheck. [Eduard Veit]
+
+* Refactor: :recycle: remove unused help message. [Eduard Veit]
+
+
+## 0.1.2 (2021-04-23)
+
+### Documentation
+
+* :memo: document environment variables. [Eduard Veit]
+
+### Other
+
+* :recycle: refactor: method extractions and other beautifications. [Eduard Veit]
+
+
 ## 0.1.1 (2021-04-23)
 
 ### Fix

README.md

@@ -11,7 +11,7 @@ IPv4 (A) and IPv6 (AAAA) record updates are supported.
 - [⚙ Configuration](#-configuration)
 - [🏃 Run](#-run)
 - [⏰ Cron](#-cron)
-- [⏰ docker](#-docker)
+- [🐟 docker](#-docker)
 <!-- /TOC -->
 
 ## ✨ Update Methods
@@ -140,3 +140,18 @@ services:
       - DYNB_PASSWORD=SuperSecretPassword
       - DYNB_INTERVAL=60
 ```
+## environment variables
+| variable              | default value   | description                                   |
+| --------------------- | --------------- | --------------------------------------------- |
+| DYNB_DYN_DOMAIN       | undefined       | required; `dyndns.example.com`                |
+| DYNB_SERVICE_PROVIDER | undefined       | required; `deSEC`, `duckdns`, `dynv6`, `inwx` |
+| DYNB_UPDATE_METHOD    | undefined       | required; `dyndns` or `domrobot` (with inwx)  |
+| DYNB_IP_MODE          | undefined       | required; `4`, `6` or `64` for both           |
+| DYNB_USERNAME         | undefined       | the requirement depends on your provider and the update method |
+| DYNB_PASSWORD         | undefined       | the requirement depends on your provider and the update method |
+| DYNB_TOKEN            | undefined       | the requirement depends on your provider and the update method |
+| DYNB_INTERVAL         | undefined       | without this setting the script/docker container will run one time and exits |
+| DYNB_DEBUG            | undefined       | more console outputs |
+| DYNB_IPv4_CHECK_SITE  | api64.ipify.org | You need a website or Web-API that outputs your remote IP |
+| DYNB_IPv6_CHECK_SITE  | api64.ipify.org | You need a website or Web-API that outputs your remote IP |
+| DYNB_DNS_CHECK_SERVER | undefined       | If you are using a local DNS Resolver/Server make sure it answers with the public answer or set another server |

dynb-parsing-template.m4

@@ -0,0 +1,24 @@
+#!/bin/bash
+
+# m4_ignore(
+echo "This is just a script template for argbash, not the script." >&2
+exit 11  #)Created by argbash-init v2.10.0
+# Rearrange the order of options below according to what you would like to see in the help message.
+# ARG_OPTIONAL_BOOLEAN([version],[v],[outputs the client version],[off])
+# ARG_OPTIONAL_BOOLEAN([link],[l],[links to your script at ~/.local/bin/dynb],[off])
+# ARG_OPTIONAL_BOOLEAN([reset],[r],[deletes the client blocking status file],[off])
+# ARG_OPTIONAL_BOOLEAN([debug],[],[enables debug mode],[off])
+# ARG_OPTIONAL_SINGLE([update-method],[m],[choose if you want to use DynDNS2 or the DomRobot RPC-API],[])
+# ARG_OPTIONAL_SINGLE([ip-mode],[i],[updates type A (IPv4) and AAAA (IPv6) records],[])
+# ARG_OPTIONAL_SINGLE([domain],[d],[set the domain you want to update],[])
+# ARG_OPTIONAL_SINGLE([service-provider],[s],[set your provider in case you are using DynDNS2],[])
+# ARG_OPTIONAL_SINGLE([username],[u],[depends on your selected update method and your provider],[])
+# ARG_OPTIONAL_SINGLE([password],[p],[depends on your selected update method and your provider],[])
+# ARG_OPTIONAL_SINGLE([token],[t],[depends on your selected update method and your provider],[])
+# ARG_OPTIONAL_SINGLE([interval],[],[choose the seconds interval to run the script in a loop, minimum is 60],[])
+# ARG_HELP([DynB - dynamic DNS update script for bash])
+# ARGBASH_GO
+
+# [ <-- needed because of Argbash
+
+# ] <-- needed because of Argbash

dynb-parsing.sh

@@ -0,0 +1,297 @@
+#!/bin/bash
+
+# Created by argbash-init v2.10.0
+# Rearrange the order of options below according to what you would like to see in the help message.
+# ARG_OPTIONAL_BOOLEAN([version],[v],[outputs the client version],[off])
+# ARG_OPTIONAL_BOOLEAN([link],[l],[links to your script at ~/.local/bin/dynb],[off])
+# ARG_OPTIONAL_BOOLEAN([reset],[r],[deletes the client blocking status file],[off])
+# ARG_OPTIONAL_BOOLEAN([debug],[],[enables debug mode],[off])
+# ARG_OPTIONAL_SINGLE([update-method],[m],[choose if you want to use DynDNS2 or the DomRobot RPC-API],[])
+# ARG_OPTIONAL_SINGLE([ip-mode],[i],[updates type A (IPv4) and AAAA (IPv6) records],[])
+# ARG_OPTIONAL_SINGLE([domain],[d],[set the domain you want to update],[])
+# ARG_OPTIONAL_SINGLE([service-provider],[s],[set your provider in case you are using DynDNS2],[])
+# ARG_OPTIONAL_SINGLE([username],[u],[depends on your selected update method and your provider],[])
+# ARG_OPTIONAL_SINGLE([password],[p],[depends on your selected update method and your provider],[])
+# ARG_OPTIONAL_SINGLE([token],[t],[depends on your selected update method and your provider],[])
+# ARG_OPTIONAL_SINGLE([interval],[],[choose the seconds interval to run the script in a loop, minimum is 60],[])
+# ARG_HELP([DynB - dynamic DNS update script for bash])
+# ARGBASH_GO()
+# needed because of Argbash --> m4_ignore([
+### START OF CODE GENERATED BY Argbash v2.10.0 one line above ###
+# Argbash is a bash code generator used to get arguments parsing right.
+# Argbash is FREE SOFTWARE, see https://argbash.io for more info
+
+
+# # When called, the process ends.
+# Args:
+# 	$1: The exit message (print to stderr)
+# 	$2: The exit code (default is 1)
+# if env var _PRINT_HELP is set to 'yes', the usage is print to stderr (prior to $1)
+# Example:
+# 	test -f "$_arg_infile" || _PRINT_HELP=yes die "Can't continue, have to supply file as an argument, got '$_arg_infile'" 4
+die()
+{
+	local _ret="${2:-1}"
+	test "${_PRINT_HELP:-no}" = yes && print_help >&2
+	echo "$1" >&2
+	exit "${_ret}"
+}
+
+
+# Function that evaluates whether a value passed to it begins by a character
+# that is a short option of an argument the script knows about.
+# This is required in order to support getopts-like short options grouping.
+begins_with_short_option()
+{
+	local first_option all_short_options='vlrmidsupth'
+	first_option="${1:0:1}"
+	test "$all_short_options" = "${all_short_options/$first_option/}" && return 1 || return 0
+}
+
+# THE DEFAULTS INITIALIZATION - OPTIONALS
+_arg_version="off"
+_arg_link="off"
+_arg_reset="off"
+_arg_debug="off"
+_arg_update_method=
+_arg_ip_mode=
+_arg_domain=
+_arg_service_provider=
+_arg_username=
+_arg_password=
+_arg_token=
+_arg_interval=
+
+
+# Function that prints general usage of the script.
+# This is useful if users asks for it, or if there is an argument parsing error (unexpected / spurious arguments)
+# and it makes sense to remind the user how the script is supposed to be called.
+print_help()
+{
+	printf '%s\n' "DynB - dynamic DNS update script for bash"
+	printf 'Usage: %s [-v|--(no-)version] [-l|--(no-)link] [-r|--(no-)reset] [--(no-)debug] [-m|--update-method <arg>] [-i|--ip-mode <arg>] [-d|--domain <arg>] [-s|--service-provider <arg>] [-u|--username <arg>] [-p|--password <arg>] [-t|--token <arg>] [--interval <arg>] [-h|--help]\n' "$0"
+	printf '\t%s\n' "-v, --version, --no-version: outputs the client version (off by default)"
+	printf '\t%s\n' "-l, --link, --no-link: links to your script at ~/.local/bin/dynb (off by default)"
+	printf '\t%s\n' "-r, --reset, --no-reset: deletes the client blocking status file (off by default)"
+	printf '\t%s\n' "--debug, --no-debug: enables debug mode (off by default)"
+	printf '\t%s\n' "-m, --update-method: choose if you want to use DynDNS2 or the DomRobot RPC-API (no default)"
+	printf '\t%s\n' "-i, --ip-mode: updates type A (IPv4) and AAAA (IPv6) records (no default)"
+	printf '\t%s\n' "-d, --domain: set the domain you want to update (no default)"
+	printf '\t%s\n' "-s, --service-provider: set your provider in case you are using DynDNS2 (no default)"
+	printf '\t%s\n' "-u, --username: depends on your selected update method and your provider (no default)"
+	printf '\t%s\n' "-p, --password: depends on your selected update method and your provider (no default)"
+	printf '\t%s\n' "-t, --token: depends on your selected update method and your provider (no default)"
+	printf '\t%s\n' "--interval: choose the seconds interval to run the script in a loop, minimum is 60 (no default)"
+	printf '\t%s\n' "-h, --help: Prints help"
+}
+
+
+# The parsing of the command-line
+parse_commandline()
+{
+	while test $# -gt 0
+	do
+		_key="$1"
+		case "$_key" in
+			# The version argurment doesn't accept a value,
+			# we expect the --version or -v, so we watch for them.
+			-v|--no-version|--version)
+				_arg_version="on"
+				test "${1:0:5}" = "--no-" && _arg_version="off"
+				;;
+			# We support getopts-style short arguments clustering,
+			# so as -v doesn't accept value, other short options may be appended to it, so we watch for -v*.
+			# After stripping the leading -v from the argument, we have to make sure
+			# that the first character that follows coresponds to a short option.
+			-v*)
+				_arg_version="on"
+				_next="${_key##-v}"
+				if test -n "$_next" -a "$_next" != "$_key"
+				then
+					{ begins_with_short_option "$_next" && shift && set -- "-v" "-${_next}" "$@"; } || die "The short option '$_key' can't be decomposed to ${_key:0:2} and -${_key:2}, because ${_key:0:2} doesn't accept value and '-${_key:2:1}' doesn't correspond to a short option."
+				fi
+				;;
+			# See the comment of option '--version' to see what's going on here - principle is the same.
+			-l|--no-link|--link)
+				_arg_link="on"
+				test "${1:0:5}" = "--no-" && _arg_link="off"
+				;;
+			# See the comment of option '-v' to see what's going on here - principle is the same.
+			-l*)
+				_arg_link="on"
+				_next="${_key##-l}"
+				if test -n "$_next" -a "$_next" != "$_key"
+				then
+					{ begins_with_short_option "$_next" && shift && set -- "-l" "-${_next}" "$@"; } || die "The short option '$_key' can't be decomposed to ${_key:0:2} and -${_key:2}, because ${_key:0:2} doesn't accept value and '-${_key:2:1}' doesn't correspond to a short option."
+				fi
+				;;
+			# See the comment of option '--version' to see what's going on here - principle is the same.
+			-r|--no-reset|--reset)
+				_arg_reset="on"
+				test "${1:0:5}" = "--no-" && _arg_reset="off"
+				;;
+			# See the comment of option '-v' to see what's going on here - principle is the same.
+			-r*)
+				_arg_reset="on"
+				_next="${_key##-r}"
+				if test -n "$_next" -a "$_next" != "$_key"
+				then
+					{ begins_with_short_option "$_next" && shift && set -- "-r" "-${_next}" "$@"; } || die "The short option '$_key' can't be decomposed to ${_key:0:2} and -${_key:2}, because ${_key:0:2} doesn't accept value and '-${_key:2:1}' doesn't correspond to a short option."
+				fi
+				;;
+			# See the comment of option '--version' to see what's going on here - principle is the same.
+			--no-debug|--debug)
+				_arg_debug="on"
+				test "${1:0:5}" = "--no-" && _arg_debug="off"
+				;;
+			# We support whitespace as a delimiter between option argument and its value.
+			# Therefore, we expect the --update-method or -m value.
+			# so we watch for --update-method and -m.
+			# Since we know that we got the long or short option,
+			# we just reach out for the next argument to get the value.
+			-m|--update-method)
+				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+				_arg_update_method="$2"
+				shift
+				;;
+			# We support the = as a delimiter between option argument and its value.
+			# Therefore, we expect --update-method=value, so we watch for --update-method=*
+			# For whatever we get, we strip '--update-method=' using the ${var##--update-method=} notation
+			# to get the argument value
+			--update-method=*)
+				_arg_update_method="${_key##--update-method=}"
+				;;
+			# We support getopts-style short arguments grouping,
+			# so as -m accepts value, we allow it to be appended to it, so we watch for -m*
+			# and we strip the leading -m from the argument string using the ${var##-m} notation.
+			-m*)
+				_arg_update_method="${_key##-m}"
+				;;
+			# See the comment of option '--update-method' to see what's going on here - principle is the same.
+			-i|--ip-mode)
+				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+				_arg_ip_mode="$2"
+				shift
+				;;
+			# See the comment of option '--update-method=' to see what's going on here - principle is the same.
+			--ip-mode=*)
+				_arg_ip_mode="${_key##--ip-mode=}"
+				;;
+			# See the comment of option '-m' to see what's going on here - principle is the same.
+			-i*)
+				_arg_ip_mode="${_key##-i}"
+				;;
+			# See the comment of option '--update-method' to see what's going on here - principle is the same.
+			-d|--domain)
+				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+				_arg_domain="$2"
+				shift
+				;;
+			# See the comment of option '--update-method=' to see what's going on here - principle is the same.
+			--domain=*)
+				_arg_domain="${_key##--domain=}"
+				;;
+			# See the comment of option '-m' to see what's going on here - principle is the same.
+			-d*)
+				_arg_domain="${_key##-d}"
+				;;
+			# See the comment of option '--update-method' to see what's going on here - principle is the same.
+			-s|--service-provider)
+				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+				_arg_service_provider="$2"
+				shift
+				;;
+			# See the comment of option '--update-method=' to see what's going on here - principle is the same.
+			--service-provider=*)
+				_arg_service_provider="${_key##--service-provider=}"
+				;;
+			# See the comment of option '-m' to see what's going on here - principle is the same.
+			-s*)
+				_arg_service_provider="${_key##-s}"
+				;;
+			# See the comment of option '--update-method' to see what's going on here - principle is the same.
+			-u|--username)
+				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+				_arg_username="$2"
+				shift
+				;;
+			# See the comment of option '--update-method=' to see what's going on here - principle is the same.
+			--username=*)
+				_arg_username="${_key##--username=}"
+				;;
+			# See the comment of option '-m' to see what's going on here - principle is the same.
+			-u*)
+				_arg_username="${_key##-u}"
+				;;
+			# See the comment of option '--update-method' to see what's going on here - principle is the same.
+			-p|--password)
+				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+				_arg_password="$2"
+				shift
+				;;
+			# See the comment of option '--update-method=' to see what's going on here - principle is the same.
+			--password=*)
+				_arg_password="${_key##--password=}"
+				;;
+			# See the comment of option '-m' to see what's going on here - principle is the same.
+			-p*)
+				_arg_password="${_key##-p}"
+				;;
+			# See the comment of option '--update-method' to see what's going on here - principle is the same.
+			-t|--token)
+				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+				_arg_token="$2"
+				shift
+				;;
+			# See the comment of option '--update-method=' to see what's going on here - principle is the same.
+			--token=*)
+				_arg_token="${_key##--token=}"
+				;;
+			# See the comment of option '-m' to see what's going on here - principle is the same.
+			-t*)
+				_arg_token="${_key##-t}"
+				;;
+			# See the comment of option '--update-method' to see what's going on here - principle is the same.
+			--interval)
+				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+				_arg_interval="$2"
+				shift
+				;;
+			# See the comment of option '--update-method=' to see what's going on here - principle is the same.
+			--interval=*)
+				_arg_interval="${_key##--interval=}"
+				;;
+			# See the comment of option '--version' to see what's going on here - principle is the same.
+			-h|--help)
+				print_help
+				exit 0
+				;;
+			# See the comment of option '-v' to see what's going on here - principle is the same.
+			-h*)
+				print_help
+				exit 0
+				;;
+			*)
+				_PRINT_HELP=yes die "FATAL ERROR: Got an unexpected argument '$1'" 1
+				;;
+		esac
+		shift
+	done
+}
+
+# Now call all the functions defined above that are needed to get the job done
+parse_commandline "$@"
+
+# OTHER STUFF GENERATED BY Argbash
+
+### END OF CODE GENERATED BY Argbash (sortof) ### ])
+# [ <-- needed because of Argbash
+
+
+# vvv  PLACE YOUR CODE HERE  vvv
+
+# PUT YOUR CODE HERE
+
+# ^^^  TERMINATE YOUR CODE BEFORE THE BOTTOM ARGBASH MARKER  ^^^
+
+# ] <-- needed because of Argbash