doc: 📝 update CHANGELOG.md

✨ add man page

.dockerignore

@@ -0,0 +1,9 @@
+**/.env
+**/.dockerignore
+**/.docker-compose.debug.yml
+**/.docker-compose.yml
+**/.git
+**/.gitignore
+**/.gitchangelog.rc
+man/man.rst
+man/man-defs.rst

.gitignore

@@ -1 +1,2 @@
 .env*
+docker-compose*

.pre-commit-config.yaml

@@ -0,0 +1,17 @@
+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
+  - repo: https://github.com/executablebooks/mdformat
+    rev: 0.7.9
+    hooks:
+    - id: mdformat
+      additional_dependencies:
+      - mdformat-gfm # GitHub Flavored Markdown support

CHANGELOG.md

@@ -1,10 +1,79 @@
 # Changelog
 
 
-## (unreleased)
+## 0.2.0 (2021-09-24)
 
 ### New
 
+* :sparkles: enable parameter extensions for `docker run --interactive` [Eduard Veit]
+
+* :sparkles: add pre-commit hooks for markdown. [Eduard Veit]
+
+* :sparkles: change git hooks and add shfmt. [Eduard Veit]
+
+* :sparkles: add pre-commit git hook for shellcheck. [Eduard Veit]
+
+### Changes
+
+* :wrench: remove md-toc from pre-commit. [Eduard Veit]
+
+* :wrench: handle dns server selection. [Eduard Veit]
+
+### Documentation
+
+* :memo: update CHANGELOG.md. [Eduard Veit]
+
+* :memo: document docker parameters. [Eduard Veit]
+
+* :memo: change default dns server setting. [Eduard Veit]
+
+* :memo: update CHANGELOG. [Eduard Veit]
+
+* :memo: update README.md. [Eduard Veit]
+
+### Other
+
+* :art: lint README.md. [Eduard Veit]
+
+* :art: add shfmt params to pre-commit check. [Eduard Veit]
+
+* :art: fix shell style. [Eduard Veit]
+
+* :recycle: seperate parsing logic. [Eduard Veit]
+
+* :recycle: normalizing pre-commit configuration to a top-level map. [Eduard Veit]
+
+* :recycle: refactorings. [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
+
+* :bug: fix loop and error handling in case of connection issues. [Eduard Veit]
+
+
+## 0.1.0 (2021-04-22)
+
+### New
+
+* :sparkles: add Dockerfile. [Eduard Veit]
+
+* :sparkles: add loop mode. [Eduard Veit]
+
 * :sparkles: add support for Duck DNS as DynDNS2 provider. [Eduard Veit]
 
 * :sparkles: add support for deSEC as DynDNS2 provider. [Eduard Veit]
@@ -33,6 +102,12 @@
 
 ### Documentation
 
+* :memo: document example of an docker-compose.yml file. [Eduard Veit]
+
+* :memo: document loop mode and dig as requirement. [Eduard Veit]
+
+* :memo: update example of .env in README.md. [Eduard Veit]
+
 * :memo: add CHANGELOG.md. [Eduard Veit]
 
 * :memo: add example.env. [Eduard Veit]
@@ -41,6 +116,8 @@
 
 ### Other
 
+* :recycle: refactor: rename environment variables. [Eduard Veit]
+
 * :recycle: refactor, fix and debug error handling. [Eduard Veit]
 
 * :recycle: refactor main code. [Eduard Veit]

Dockerfile

@@ -0,0 +1,12 @@
+FROM alpine:latest
+RUN \
+apk update \
+&& \
+apk add \
+bash \
+curl \
+jq \
+bind-tools
+WORKDIR /usr/src/app
+COPY . .
+ENTRYPOINT ["/bin/bash", "/usr/src/app/dynb.sh"]

README.md

@@ -1,8 +1,11 @@
 # 🔃 DynB
+
 DynB - dynamic DNS update script, written in bash
 
 IPv4 (A) and IPv6 (AAAA) record updates are supported.
+
 <!-- TOC -->
+
 - [✨ Update Methods](#-update-methods)
   - [APIs](#apis)
   - [DynDNS2](#dyndns2)
@@ -11,46 +14,54 @@ IPv4 (A) and IPv6 (AAAA) record updates are supported.
 - [⚙ Configuration](#-configuration)
 - [🏃 Run](#-run)
 - [⏰ Cron](#-cron)
+  - [loop mode](#loop-mode)
+  - [crontab](#crontab)
+- [🐟 docker](#-docker)
+- [environment variables](#environment-variables)
+
 <!-- /TOC -->
 
 ## ✨ Update Methods
+
 The following update methods are currently implemented:
 
 ### APIs
 
-* INWX.com Domrobot JSON-RPC-API  
+- INWX.com Domrobot JSON-RPC-API\
   Limitations:
   - minimum TTL is 300 (5 minutes)
 
 ### DynDNS2
 
-* INWX.com  
-* deSEC.io (dedyn.io)  
-* DuckDNS.org  
-* dynv6.com  
+- INWX.com
+- deSEC.io (dedyn.io)
+- DuckDNS.org
+- dynv6.com
 
 ## 📦 Requirements
 
-* `curl` - The minimum requirement for running DynDNS2 operations
+- `curl` - The minimum requirement for all API requests.
+- `dig` - You can get it by installing `dnsutils` (debian/ubuntu/ArchLinux), `bind-utils` (CentOS/RHEL), `bind-tools` (Alpine)
 
 also essential if you are using other APIs:
 
-* `jq` - Command-line JSON processor
+- `jq` - Command-line JSON processor
 
 ## 🚀 Installation
 
 Download the latest release
 
 or simply clone this repo
-```
+
+```shell
 git clone https://github.com/EV21/dynb.git
 ```
 
 If you want to add the script to you PATH, run :point_down:
-```
+
+```shell
 bash dynb.sh --link
 ```
-This convenience function only works if `util-linux` is installed on your system.
 
 ## ⚙ Configuration
 
@@ -58,51 +69,118 @@ You can use a config in form of an `.env` file.
 Or you can just use CLI parameters.
 
 Create `.env` in the app root directory or at `~/.local/share/dynb/.env`.
-```
-_dyn_domain=dyndns.example.com
 
-## service provider could be inwx
-_serviceProvider=inwx
+```bash
+DYNB_DYN_DOMAIN=dyndns.example.com
+
+## service provider could be deSEC, duckdns, dynv6, inwx
+DYNB_SERVICE_PROVIDER=inwx
 
 ## update method options: domrobot, dyndns
-_update_method=domrobot
+DYNB_UPDATE_METHOD=domrobot
 
 ## ip mode could be either: 4, 6 or dual for dualstack
-_ip_mode=dual
+DYNB_IP_MODE=64
 
 ## If you are using the DomRobot RPC-API enter your credentials for the web interface login here
 ## If you are using the DynDNS2 protocol enter your credentials here
-_username=
-_password=
+DYNB_USERNAME=User42
+DYNB_PASSWORD=SuperSecretPassword
+## or use a token
+DYNB_TOKEN=
 ```
 
 ## 🏃 Run
 
 If you have a config file just run :point_down:
-```
+
+```bash
 dynb
 ```
-Alternatively you can use parameters if your system meets the relevant requirements. This example shows the long form parameter, there are also short ones.  
+
+Alternatively you can use parameters if your system meets the relevant requirements. This example shows the long form parameter, there are also short ones.\
 Call the help function :point_down:
-```
+
+```bash
 dynb --help
 ```
-```
+
+```bash
 dynb --ip-mode dualstack --update-method domrobot --domain dyndns.example.com --username user42 --password SuperSecretPassword
 ```
-```
+
+```bash
 dynb --ip-mode dualstack --update-method dyndns --provider inwx --domain dyndns.example.com --username user42 --password SuperSecretPassword
 ```
 
 ## ⏰ Cron
-To automatically call the script you can use cron.
+
+To automatically call the script you can use either crontab or the script can also run in a loop mode.
+
+### loop mode
+
+Just use the parameter `--interval 60` or the environment variable `DYNB_INTERVAL=60` so the script will check every 60 seconds if it needs to do an update.
+
+### crontab
 
 execute :point_down:
-```
+
+```bash
 crontab -e
 ```
+
 then enter :point_down: to run dynb every five minutes.
-```
+
+```bash
 */5 * * * * $HOME/.local/bin/dynb >> $HOME/.local/share/dynb/dynb-cron.log
 ```
+
+alternative with docker and parameters::
+
+```bash
+*/5 * * * * docker run --interactive --tty --rm --network host ev21/dynb:latest --ip-mode 64 --update-method domrobot --domain dyndns.example.com --username user42 --password SuperSecretPassword
+```
+
 Note, cron typically does not use the users PATH variable.
+
+## 🐟 docker
+
+This is an example of a `docker-compose.yml` file. If you are using IPv6 make sure the routing works properly with your docker container. Note: [IPv6 networking](https://docs.docker.com/config/daemon/ipv6/) is only supported on Docker daemons running on Linux hosts.
+
+```yaml
+version: '3.4'
+
+services:
+  dynb:
+    image: ev21/dynb
+    container_name: dynb
+    network_mode: host
+    build:
+      context: .
+      dockerfile: ./Dockerfile
+    environment:
+      - DYNB_DYN_DOMAIN=dyndns.example.com
+      - DYNB_SERVICE_PROVIDER=inwx
+      - DYNB_UPDATE_METHOD=dyndns
+      - DYNB_IP_MODE=64
+      - DYNB_USERNAME=User42
+      - 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.sh

@@ -12,10 +12,10 @@ _dynb_sh ()
 	COMPREPLY=()
 	cur="${COMP_WORDS[COMP_CWORD]}"
 	prev="${COMP_WORDS[COMP_CWORD-1]}"
-	all_long_opts="--version --link --reset --debug --update-method --ip-mode --domain --service-provider --username --password --token --help "
+	all_long_opts="--version --link --reset --debug --update-method --ip-mode --domain --service-provider --username --password --token --interval --help "
 	all_short_opts="-v -l -r -m -i -d -s -u -p -t -h "
 	case "$prev" in
-		--update-method|-m|--ip-mode|-i|--domain|-d|--service-provider|-s|--username|-u|--password|-p|--token|-t)
+		--update-method|-m|--ip-mode|-i|--domain|-d|--service-provider|-s|--username|-u|--password|-p|--token|-t|--interval)
 			COMPREPLY=( $(compgen -o bashdefault -o default -- "${cur}") )
 			return 0
 			;;
@@ -37,5 +37,5 @@ _dynb_sh ()
 	esac
 
 }
-complete -F _dynb_sh dynb.sh dynb
+complete -F _dynb_sh dynb.sh
 ### END OF CODE GENERATED BY Argbash (sortof) ### ])

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

dynb.sh

@@ -10,23 +10,23 @@
 ## Configuration ##
 ###################
 
-_dyn_domain=
+#DYNB_DYN_DOMAIN=
 
 ## service provider could be deSEC, duckdns, dynv6, inwx
-_serviceProvider=
+#DYNB_SERVICE_PROVIDER=
 
 ## update method options: domrobot, dyndns
-_update_method=
+#DYNB_UPDATE_METHOD=
 
 ## ip mode could be either: 4, 6 or dual for dualstack
-_ip_mode=
+#DYNB_IP_MODE=
 
 ## If you are using the DomRobot RPC-API enter your credentials for the web interface login here
 ## If you are using the DynDNS2 protocol enter your credentials here
-_username=
-_password=
+#DYNB_USERNAME=
+#DYNB_PASSWORD=
 ## or use a token
-_token=
+#DYNB_TOKEN=
 
 ## TTL (time to live) for the DNS record
 ## This setting is only relevant for API based record updates (not DnyDNS2!)
@@ -36,12 +36,12 @@ TTL=300
 ## The IP-Check sites (some sites have different urls for v4 and v6)
 ## Pro tip: use your own ip check server for privacy
 ## it could be as simple as that...
-## create an index.php with <?php echo $_SERVER['REMOTE_ADDR']; ?>
+## create an index.php with <?php echo $_SERVER'REMOTE_ADDR'; ?>
 _ipv4_checker=api64.ipify.org
 _ipv6_checker=api64.ipify.org
 
 ## An exernal DNS check server prevents wrong info from local DNS servers/resolvers
-_DNS_checkServer=1.1.1.1
+_DNS_checkServer=
 
 ## if you are actively using multiple network interfaces you might want to specify this
 ## normally the default value is okay
@@ -65,257 +65,22 @@ _response=
 _statusHostname=
 _statusUsername=
 _statusPassword=
-_version=0.0.1
+_version=0.1.2
 _userAgent="DynB/$_version github.com/EV21/dynb"
 _configFile=$HOME/.local/share/dynb/.env
 _statusFile=/tmp/dynb.status
 _debug=0
+_minimum_looptime=60
+_loopMode=0
 
-# 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_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
-
-
-die()
-{
-	local _ret="${2:-1}"
-	test "${_PRINT_HELP:-no}" = yes && print_help >&2
-	echo "$1" >&2
-	exit "${_ret}"
-}
-
-
-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=
-
-
-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>] [-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' "-h, --help: Prints help"
-}
-
-
-parse_commandline()
-{
-	while test $# -gt 0
-	do
-		_key="$1"
-		case "$_key" in
-			-v|--no-version|--version)
-				_arg_version="on"
-				test "${1:0:5}" = "--no-" && _arg_version="off"
-				;;
-			-v*)
-				_arg_version="on"
-				_next="${_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."
+function loopMode() {
+  if [[ $_loopMode -eq 1 ]]; then
+    return 0
+  else
+    return 1
   fi
-				;;
-			-l|--no-link|--link)
-				_arg_link="on"
-				test "${1:0:5}" = "--no-" && _arg_link="off"
-				;;
-			-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
-				;;
-			-r|--no-reset|--reset)
-				_arg_reset="on"
-				test "${1:0:5}" = "--no-" && _arg_reset="off"
-				;;
-			-r*)
-				_arg_reset="on"
-				_next="${_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
-				;;
-			--no-debug|--debug)
-				_arg_debug="on"
-				test "${1:0:5}" = "--no-" && _arg_debug="off"
-				;;
-			-m|--update-method)
-				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
-				_arg_update_method="$2"
-				shift
-				;;
-			--update-method=*)
-				_arg_update_method="${_key##--update-method=}"
-				;;
-			-m*)
-				_arg_update_method="${_key##-m}"
-				;;
-			-i|--ip-mode)
-				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
-				_arg_ip_mode="$2"
-				shift
-				;;
-			--ip-mode=*)
-				_arg_ip_mode="${_key##--ip-mode=}"
-				;;
-			-i*)
-				_arg_ip_mode="${_key##-i}"
-				;;
-			-d|--domain)
-				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
-				_arg_domain="$2"
-				shift
-				;;
-			--domain=*)
-				_arg_domain="${_key##--domain=}"
-				;;
-			-d*)
-				_arg_domain="${_key##-d}"
-				;;
-			-s|--service-provider)
-				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
-				_arg_service_provider="$2"
-				shift
-				;;
-			--service-provider=*)
-				_arg_service_provider="${_key##--service-provider=}"
-				;;
-			-s*)
-				_arg_service_provider="${_key##-s}"
-				;;
-			-u|--username)
-				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
-				_arg_username="$2"
-				shift
-				;;
-			--username=*)
-				_arg_username="${_key##--username=}"
-				;;
-			-u*)
-				_arg_username="${_key##-u}"
-				;;
-			-p|--password)
-				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
-				_arg_password="$2"
-				shift
-				;;
-			--password=*)
-				_arg_password="${_key##--password=}"
-				;;
-			-p*)
-				_arg_password="${_key##-p}"
-				;;
-			-t|--token)
-				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
-				_arg_token="$2"
-				shift
-				;;
-			--token=*)
-				_arg_token="${_key##--token=}"
-				;;
-			-t*)
-				_arg_token="${_key##-t}"
-				;;
-			-h|--help)
-				print_help
-				exit 0
-				;;
-			-h*)
-				print_help
-				exit 0
-				;;
-			*)
-				_PRINT_HELP=yes die "FATAL ERROR: Got an unexpected argument '$1'" 1
-				;;
-		esac
-		shift
-	done
 }
 
-parse_commandline "$@"
-
-# OTHER STUFF GENERATED BY Argbash
-
-### END OF CODE GENERATED BY Argbash (sortof) ### ])
-# [ <-- needed because of Argbash
-
-# The generated argbash help message does not look as nice as this:
-_help_message="$(cat << 'EOF'
-dynb - dynamic DNS update script for bash
-
-Usage
-=====
-dynb [options]
-
--h, --help                                displays this help message
---version                                 outputs the client version
---link                                    links to your script at ~/.local/bin/dynb
---reset                                   deletes the client blocking status file
-
-Configuration options
----------------------
--i | --ip-mode [ 4 | 6 | dual ]           updates type A (IPv4) and AAAA (IPv6) records
--m | --update-method [dyndns | domrobot]  choose if you want to use DynDNS2 or the DomRobot RPC-API
--s | --service-provider inwx              set your provider in case you are using DynDNS2
--d | --domain "dyndns.example.com"        set the domain you want to update
--u | --username "user42"                  depends on your selected update method and your provider
--p | --password "SuperSecretPassword"     depends on your selected update method and your provider
--t | --token "YourProviderGivenToken"     depends on your selected update method and your provider
-
-##### examples #####
-dynb --ip-mode dual --update-method domrobot --domain dyndns.example.com --username user42 --password SuperSecretPassword
-dynb --ip-mode dual --update-method dyndns --service-provider inwx --domain dyndns.example.com --username user42 --password SuperSecretPassword
-EOF
-)"
-
 function debugMode() {
   if [[ $_debug -eq 1 ]]; then
     return 0
@@ -324,42 +89,55 @@ function debugMode() {
   fi
 }
 
+function infoMessage() {
+  echo "$(logtime) INFO: $*"
+}
+
 function debugMessage() {
   if debugMode; then
-    echo "Debug: $*"
+    echo "$(logtime) DEBUG: $*"
   fi
 }
 
-function echoerr() { printf "%s\n" "$*" >&2; }
+function errorMessage() { printf "$(logtime) ERROR: %s\n" "$*" >&2; }
+
+function logtime() {
+  LOGTIME=$(date "+%Y-%m-%d %H:%M:%S")
+  echo "[$LOGTIME]"
+}
 
 # The main domain as an identifier for the dns zone is required for the updateRecord call
 function getMainDomain() {
-  request=$( echo "{}" | \
-      jq '(.method="nameserver.list")' | \
-      jq "(.params.user=\"$_username\")" | \
-      jq "(.params.pass=\"$_password\")"
+  request=$(
+    echo "{}" |
+      jq '(.method="nameserver.list")' |
+      jq "(.params.user=\"$DYNB_USERNAME\")" |
+      jq "(.params.pass=\"$DYNB_PASSWORD\")"
   )
 
-  _response=$(curl --silent  \
+  _response=$(
+    curl --silent \
       "$_interface_str" \
       --user-agent "$_userAgent" \
       --header "Content-Type: application/json" \
       --request POST $_INWX_JSON_API_URL \
-      --data "$request" | jq ".resData.domains[] | select(inside(.domain=\"$_dyn_domain\"))"
+      --data "$request" | jq ".resData.domains[] | select(inside(.domain=\"$DYNB_DYN_DOMAIN\"))"
   )
   _main_domain=$(echo "$_response" | jq --raw-output '.domain')
 }
 
 function fetchDNSRecords() {
-  request=$( echo "{}" | \
-      jq '(.method="'nameserver.info'")' | \
-      jq "(.params.user=\"$_username\")" | \
-      jq "(.params.pass=\"$_password\")" | \
-      jq "(.params.domain=\"$_main_domain\")" | \
-      jq "(.params.name=\"$_dyn_domain\")"
+  request=$(
+    echo "{}" |
+      jq '(.method="'nameserver.info'")' |
+      jq "(.params.user=\"$DYNB_USERNAME\")" |
+      jq "(.params.pass=\"$DYNB_PASSWORD\")" |
+      jq "(.params.domain=\"$_main_domain\")" |
+      jq "(.params.name=\"$DYNB_DYN_DOMAIN\")"
   )
 
-  _response=$( curl --silent  \
+  _response=$(
+    curl --silent \
       "$_interface_str" \
       --user-agent "$_userAgent" \
       --header "Content-Type: application/json" \
@@ -387,8 +165,18 @@ function getDNSIP() {
 # 2. param: IP check server address
 # result to stdout
 function getRemoteIP() {
+  if [[ -n $_DNS_checkServer ]]; then
     curl --silent "$_interface_str" --user-agent "$_userAgent" \
-    --ipv"${1}" --dns-servers 1.1.1.1 --location "${2}"
+      --ipv"${1}" --dns-servers "$_DNS_checkServer" --location "${2}"
+  else
+    curl --silent "$_interface_str" --user-agent "$_userAgent" \
+      --ipv"${1}" --location "${2}"
+  fi
+  # shellcheck disable=2181
+  if [[ $? -gt 0 ]]; then
+    errorMessage "IPCheck (getRemoteIP ${1}) request failed"
+    exit 1
+  fi
 }
 
 # requires parameter
@@ -403,23 +191,25 @@ function updateRecord() {
     IP=$_new_IPv6
   fi
   if [[ $IP != "" ]]; then
-  request=$( echo "{}" | \
-      jq '(.method="nameserver.updateRecord")' | \
-      jq "(.params.user=\"$_username\")" | \
-      jq "(.params.pass=\"$_password\")" | \
-      jq "(.params.id=\"$ID\")" | \
-      jq "(.params.content=\"$IP\")" | \
+    request=$(
+      echo "{}" |
+        jq '(.method="nameserver.updateRecord")' |
+        jq "(.params.user=\"$DYNB_USERNAME\")" |
+        jq "(.params.pass=\"$DYNB_PASSWORD\")" |
+        jq "(.params.id=\"$ID\")" |
+        jq "(.params.content=\"$IP\")" |
         jq "(.params.ttl=\"$TTL\")"
     )
 
-  _response=$(curl --silent  \
+    _response=$(
+      curl --silent \
         "$_interface_str" \
         --user-agent "$_userAgent" \
         --header "Content-Type: application/json" \
         --request POST $_INWX_JSON_API_URL \
         --data "$request"
     )
-     echo -e "$(echo "$_response" | jq --raw-output '.msg')\n Domain: $_dyn_domain\n new IPv${1}: $IP"
+    echo -e "$(echo "$_response" | jq --raw-output '.msg')\n Domain: $DYNB_DYN_DOMAIN\n new IPv${1}: $IP"
   fi
 }
 
@@ -431,10 +221,10 @@ function dynupdate() {
 
   INWX_DYNDNS_UPDATE_URL="https://dyndns.inwx.com/nic/update?"
   DESEC_DYNDNS_UPDATE_URL="https://update.dedyn.io/?"
-  DUCKDNS_DYNDNS_UPDATE_URL="https://www.duckdns.org/update?domains=$_dyn_domain&token=$_token&"
-  DYNV6_DYNDNS_UPDATE_URL="https://dynv6.com/api/update?zone=$_dyn_domain&token=$_token&"
+  DUCKDNS_DYNDNS_UPDATE_URL="https://www.duckdns.org/update?domains=$DYNB_DYN_DOMAIN&token=$DYNB_TOKEN&"
+  DYNV6_DYNDNS_UPDATE_URL="https://dynv6.com/api/update?zone=$DYNB_DYN_DOMAIN&token=$DYNB_TOKEN&"
 
-  case $_serviceProvider in
+  case $DYNB_SERVICE_PROVIDER in
     inwx* | INWX*)
       dyndns_update_url=$INWX_DYNDNS_UPDATE_URL
       ;;
@@ -452,7 +242,7 @@ function dynupdate() {
       myipv6_str=ipv6
       ;;
     *)
-    echoerr "$_serviceProvider is not supported"
+      errorMessage "$DYNB_SERVICE_PROVIDER is not supported"
       exit 1
       ;;
   esac
@@ -470,22 +260,23 @@ function dynupdate() {
   debugMessage "Update URL was: $dyndns_update_url"
 
   ## request ##
-  case $_serviceProvider in
+  case $DYNB_SERVICE_PROVIDER in
     inwx* | INWX*)
       _response=$(curl --silent "$_interface_str" \
         --user-agent "$_userAgent" \
-      --user "$_username":"$_password" \
+        --user "$DYNB_USERNAME":"$DYNB_PASSWORD" \
         "${dyndns_update_url}")
       ;;
     deSEC* | desec* | dedyn*)
       _response=$(curl --silent "$_interface_str" \
         --user-agent "$_userAgent" \
-      --header "Authorization: Token $_token" \
-      --get --data-urlencode "hostname=$_dyn_domain" \
+        --header "Authorization: Token $DYNB_TOKEN" \
+        --get --data-urlencode "hostname=$DYNB_DYN_DOMAIN" \
         "${dyndns_update_url}")
       ;;
     dynv6* | duckDNS* | duckdns*)
-      _response=$(curl --silent "$_interface_str" \
+      _response=$(
+        curl --silent "$_interface_str" \
           --user-agent "$_userAgent" \
           "${dyndns_update_url}"
       )
@@ -493,66 +284,66 @@ function dynupdate() {
   esac
 
   case $_response in
-    good* | OK* )
+    good* | OK* | "addresses updated")
       if [[ $_response == "good 127.0.0.1" ]]; then
-        echoerr "Error: $_response: Request ignored."
+        errorMessage "$_response: Request ignored."
         return 1
       else
-        echo "$_response: The DynDNS update has been executed."
+        infoMessage "$_response: The DynDNS update has been executed."
         _errorCounter=0
         return 0
       fi
       ;;
     nochg*)
-      echo "$_response: Nothing has changed, IP addresses are still up to date."
+      infoMessage "$_response: Nothing has changed, IP addresses are still up to date."
       return 1
       ;;
     abuse)
-      echoerr "Error: $_response: Username is blocked due to abuse."
+      errorMessage "$_response: Username is blocked due to abuse."
       return 1
       ;;
     badauth | 401)
-      echoerr "Error: $_response: Invalid username password combination."
+      errorMessage "$_response: Invalid username password combination."
       return 1
       ;;
     badagent)
-      echoerr "Error: $_response: Client disabled. Something is very wrong!"
+      errorMessage "$_response: Client disabled. Something is very wrong!"
       return 1
       ;;
     !donator)
-      echoerr "Error: $_response: An update request was sent, including a feature that is not available to that particular user such as offline options."
+      errorMessage "$_response: An update request was sent, including a feature that is not available to that particular user such as offline options."
       return 1
       ;;
     !yours)
-      echoerr "Error: $_response: The domain does not belong to your user account"
+      errorMessage "$_response: The domain does not belong to your user account"
       return 1
       ;;
     notfqdn)
-      echoerr "Error: $_response: Hostname $_dyn_domain is invalid"
+      errorMessage "$_response: Hostname $DYNB_DYN_DOMAIN is invalid"
       return 1
       ;;
     nohost)
-      echoerr "Error: $_response: Hostname supplied does not exist under specified account, enter new login credentials before performing an additional request."
+      errorMessage "$_response: Hostname supplied does not exist under specified account, enter new login credentials before performing an additional request."
       return 1
       ;;
     numhost)
-      echoerr "Error: $_response: Too many hostnames have been specified for this update"
+      errorMessage "$_response: Too many hostnames have been specified for this update"
       return 1
       ;;
     dnserr)
-      echoerr "Error: $_response: There is an internal error in the dyndns update system. Retry update no sooner than 30 minutes."
+      errorMessage "$_response: There is an internal error in the dyndns update system. Retry update no sooner than 30 minutes."
       return 1
       ;;
     911 | 5*)
-      echoerr "Error: $_response: A fatal error on provider side such as a database outage. Retry update no sooner than 30 minutes."
+      errorMessage "$_response: A fatal error on provider side such as a database outage. Retry update no sooner than 30 minutes."
       return 1
       ;;
     *)
       if [[ "$_response" == "$_status" ]]; then
-        echoerr "Error: An unknown response code has been received. $_response"
+        errorMessage "An unknown response code has been received. $_response"
         return 1
       else
-        echoerr "Error: unknown respnse code: $_response"
+        errorMessage "unknown respnse code: $_response"
         return 0
       fi
       ;;
@@ -568,14 +359,14 @@ function checkStatus() {
   case $_status in
     nochg*)
       if [[ _errorCounter -gt 1 ]]; then
-        echoerr "Error: The update client was spamming unnecessary update requests, something might be wrong with your IP-Check site."
-        echoerr "Fix your config an then delete $_statusFile"
+        errorMessage "The update client was spamming unnecessary update requests, something might be wrong with your IP-Check site."
+        errorMessage "Fix your config an then delete $_statusFile or restart your docker container"
         return 1
       fi
       ;;
     nohost | !yours)
-      if [[ "$_statusHostname" == "$_dyn_domain" && ( "$_statusUsername" == "$_username" || $_statusUsername == "$_token" ) ]]; then
-        echoerr "Error: Hostname supplied does not exist under specified account, enter new login credentials before performing an additional request."
+      if [[ "$_statusHostname" == "$DYNB_DYN_DOMAIN" && ("$_statusUsername" == "$DYNB_USERNAME" || $_statusUsername == "$DYNB_TOKEN") ]]; then
+        errorMessage "Hostname supplied does not exist under specified account, enter new login credentials before performing an additional request."
         return 1
       else
         rm "$_statusFile"
@@ -583,8 +374,8 @@ function checkStatus() {
       return 0
       ;;
     badauth | 401)
-      if [[ "$_statusUsername" == "$_username" && "$_statusPassword" == "$_password" ]]; then
-        echoerr "Error: Invalid username password combination."
+      if [[ "$_statusUsername" == "$DYNB_USERNAME" && "$_statusPassword" == "$DYNB_PASSWORD" ]]; then
+        errorMessage "Invalid username password combination."
         return 1
       else
         rm "$_statusFile"
@@ -592,19 +383,19 @@ function checkStatus() {
       return 0
       ;;
     badagent)
-      echoerr "Error: Client is deactivated by provider."
+      errorMessage "Client is deactivated by provider."
       echo "Fix your config and then manually remove $_statusFile to reset the client blockade."
       echo "If it still fails file an issue at github or try another client :)"
       return 1
       ;;
     !donator)
-      echoerr "Error: An update request was sent, including a feature that is not available to that particular user such as offline options."
+      errorMessage "An update request was sent, including a feature that is not available to that particular user such as offline options."
       echo "Fix your config and then manually remove $_statusFile to reset the client blockade"
       echo "If it still fails file an issue at github or try another client :)"
       return 1
       ;;
     abuse)
-      echoerr "Error: Username is blocked due to abuse."
+      errorMessage "Username is blocked due to abuse."
       echo "Fix your config and then manually remove $_statusFile to reset the client blockade"
       echo "If it still fails file an issue at github or try another client :)"
       return 1
@@ -612,7 +403,7 @@ function checkStatus() {
     911 | 5*)
       delta=$(($(date +%s) - _eventTime))
       if [[ $delta -lt 1800 ]]; then
-        echoerr "$_status: The provider currently has an fatal error. DynB will wait for next update until 30 minutes have passed since last request, $(date --date=@$delta -u +%M) minutes already passed."
+        errorMessage "$_status: The provider currently has an fatal error. DynB will wait for next update until 30 minutes have passed since last request, $(date --date=@$delta -u +%M) minutes already passed."
         return 1
       else
         rm "$_statusFile"
@@ -621,7 +412,7 @@ function checkStatus() {
       ;;
     *)
       if [[ _errorCounter -gt 1 ]]; then
-        echoerr "Error: An unknown response code has repeatedly been received. $_response"
+        errorMessage "An unknown response code has repeatedly been received. $_response"
         return 1
       else
         return 0
@@ -633,30 +424,48 @@ function checkStatus() {
 # requires parameter
 # 1. param: 4 or 6 for IP version
 function ipHasChanged() {
-  if [[ ${1} == 4 ]]; then
+  case ${1} in
+    4)
       remote_ip=$(getRemoteIP 4 $_ipv4_checker)
-    if [[ $_update_method == domrobot ]]; then
+      if [[ $DYNB_UPDATE_METHOD == domrobot ]]; then
         dns_ip=$(getDNSIP A)
       else
-      dns_ip=$(dig @${_DNS_checkServer} in a +short "$_dyn_domain")
-    fi
-  fi
-  if [[ ${1} == 6 ]]; then
-    remote_ip=$(getRemoteIP 6 $_ipv6_checker)
-    if [[ $_update_method == domrobot ]]; then
-      dns_ip=$(getDNSIP AAAA)
+        if [[ -n $_DNS_checkServer ]]; then
+          dig_response=$(dig @"${_DNS_checkServer}" in a +short "$DYNB_DYN_DOMAIN")
         else
-      dns_ip=$(dig @${_DNS_checkServer} in aaaa +short "$_dyn_domain")
+          dig_response=$(dig in a +short "$DYNB_DYN_DOMAIN")
         fi
+        if [[ $dig_response == ";; connection timed out; no servers could be reached" ]]; then
+          errorMessage "DNS request failed $dig_response"
+          return 0
+        fi
+        dns_ip=$dig_response
       fi
-
-  if [[ ${1} == 4 ]]; then
       _new_IPv4=$remote_ip
       debugMessage "New IPv4: $_new_IPv4 old was: $dns_ip"
+      ;;
+    6)
+      remote_ip=$(getRemoteIP 6 $_ipv6_checker)
+      if [[ $DYNB_UPDATE_METHOD == domrobot ]]; then
+        dns_ip=$(getDNSIP AAAA)
       else
+        if [[ -n $_DNS_checkServer ]]; then
+          dig_response=$(dig @"${_DNS_checkServer}" in aaaa +short "$DYNB_DYN_DOMAIN")
+        else
+          dig_response=$(dig in aaaa +short "$DYNB_DYN_DOMAIN")
+        fi
+        if [[ $dig_response == ";; connection timed out; no servers could be reached" ]]; then
+          errorMessage "DNS request failed $dig_response"
+          return 0
+        fi
+        dns_ip=$dig_response
+      fi
       _new_IPv6=$remote_ip
       debugMessage "New IPv6: $_new_IPv6 old was: $dns_ip"
-  fi
+      ;;
+    *) ;;
+
+  esac
 
   if [[ "$remote_ip" == "$dns_ip" ]]; then
     return 0
@@ -670,41 +479,94 @@ function ipHasChanged() {
 ################
 
 function handleParameters() {
+  # shellcheck disable=SC2154
   if [[ $_arg_version == "on" ]]; then
     echo $_version
     exit 0
   fi
+  # shellcheck disable=SC2154
   if [[ $_arg_link == "on" ]]; then
     ln --verbose --symbolic "$(realpath "$0")" "$HOME/.local/bin/dynb"
     exit 0
   fi
+  # shellcheck disable=SC2154
   if [[ $_arg_reset == "on" ]]; then
     rm --verbose "$_statusFile"
     exit 0
   fi
+  # shellcheck disable=SC2154
   if [[ $_arg_debug == "on" ]]; then
     _debug=1
   fi
+  # shellcheck disable=SC2154
   if [[ $_arg_update_method != "" ]]; then
-    _update_method=$_arg_update_method
+    DYNB_UPDATE_METHOD=$_arg_update_method
   fi
+  # shellcheck disable=SC2154
   if [[ $_arg_ip_mode != "" ]]; then
-    _ip_mode=$_arg_ip_mode
+    DYNB_IP_MODE=$_arg_ip_mode
   fi
+  # shellcheck disable=SC2154
   if [[ $_arg_domain != "" ]]; then
-    _dyn_domain=$_arg_domain
+    DYNB_DYN_DOMAIN=$_arg_domain
   fi
+  # shellcheck disable=SC2154
   if [[ $_arg_service_provider != "" ]]; then
-    _serviceProvider=$_arg_service_provider
+    DYNB_SERVICE_PROVIDER=$_arg_service_provider
   fi
+  # shellcheck disable=SC2154
   if [[ $_arg_username != "" ]]; then
-    _username=$_arg_username
+    DYNB_USERNAME=$_arg_username
   fi
+  # shellcheck disable=SC2154
   if [[ $_arg_password != "" ]]; then
-    _password=$_arg_password
+    DYNB_PASSWORD=$_arg_password
   fi
+  # shellcheck disable=SC2154
   if [[ $_arg_token != "" ]]; then
-    _token=$_arg_token
+    DYNB_TOKEN=$_arg_token
+  fi
+  # shellcheck disable=SC2154
+  if [[ $_arg_interval != "" ]]; then
+    DYNB_INTERVAL=$_arg_interval
+  fi
+
+  if [[ -z $DYNB_INTERVAL ]]; then
+    _loopMode=0
+  elif [[ $DYNB_INTERVAL -lt _minimum_looptime ]]; then
+    DYNB_INTERVAL=$_minimum_looptime
+    _loopMode=1
+  else
+    _loopMode=1
+  fi
+  if [[ $_network_interface != "" ]]; then
+    _interface_str="--interface $_network_interface"
+  fi
+
+  if [[ $DYNB_IP_MODE == d* ]]; then
+    _is_IPv4_enabled=true
+    _is_IPv6_enabled=true
+  fi
+  if [[ $DYNB_IP_MODE == *4* ]]; then
+    _is_IPv4_enabled=true
+  fi
+  if [[ $DYNB_IP_MODE == *6* ]]; then
+    _is_IPv6_enabled=true
+  fi
+
+  if [[ $DYNB_DEBUG == true ]]; then
+    _debug=1
+  fi
+  # shellcheck disable=SC2154
+  if [[ -n $DYNB_IPv4_CHECK_SITE ]]; then
+    _ipv4_checker=$DYNB_IPv4_CHECK_SITE
+  fi
+  # shellcheck disable=SC2154
+  if [[ -n $DYNB_IPv6_CHECK_SITE ]]; then
+    _ipv6_checker=$DYNB_IPv6_CHECK_SITE
+  fi
+  if [[ -n $DYNB_DNS_CHECK_SERVER ]]; then
+    _DNS_checkServer=$DYNB_DNS_CHECK_SERVER
   fi
   return 0
 }
@@ -714,30 +576,31 @@ function handleParameters() {
 ##################
 
 function checkDependencies() {
-  ## If there will be more general dependencies use a loop
-  # for i in curl and some other stuff; do
-  #   if ! command -v $i >/dev/null 2>&1; then
-  #     echoerr "Error: could not find \"$i\", DynB depends on it. "
-  #     exit 1
-  #   fi
-  # done
+  failCounter=0
+  for i in curl dig; do
+    if ! command -v $i >/dev/null 2>&1; then
+      errorMessage "could not find \"$i\", DynB depends on it. "
+      ((failCounter++))
+    fi
+  done
   [[ -x $(command -v jq 2>/dev/null) ]] || {
-    if [[ $_update_method != dyndns* ]]; then
+    if [[ $DYNB_UPDATE_METHOD != dyndns* ]]; then
       echo "This script depends on jq and it is not available." >&2
-      exit 1
+      ((failCounter++))
     fi
   }
+  if [[ failCounter -gt 0 ]]; then
+    exit 1
+  fi
 }
 
 function doUnsets() {
   unset _network_interface
   unset _DNS_checkServer
   unset _dns_records
-  unset _dyn_domain
   unset _has_getopt
   unset _help_message
   unset _INWX_JSON_API_URL
-  unset _ip_mode
   unset _ipv4_checker
   unset _ipv6_checker
   unset _is_IPv4_enabled
@@ -745,18 +608,84 @@ function doUnsets() {
   unset _main_domain
   unset _new_IPv4
   unset _new_IPv6
-  unset _password
-  unset _username
-  unset _serviceProvider
   unset _version
+  unset DYNB_DYN_DOMAIN
+  unset DYNB_USERNAME
+  unset DYNB_PASSWORD
+  unset DYNB_TOKEN
+  unset DYNB_SERVICE_PROVIDER
+  unset DYNB_IP_MODE
+  unset DYNB_INTERVAL
+  unset DYNB_IPv4_CHECK_SITE
+  unset DYNB_IPv6_CHECK_SITE
+  unset DYNB_DNS_CHECK_SERVER
+  unset DYNB_DEBUG
+}
+
+function doDomrobotUpdates() {
+  getMainDomain
+  fetchDNSRecords
+  if [[ $_is_IPv4_enabled == true ]]; then
+    ipHasChanged 4
+    if [[ $? == 1 ]]; then
+      updateRecord 4
+    else
+      debugMessage "Skip IPv4 record update, it is already up to date"
+    fi
+  fi
+  if [[ $_is_IPv6_enabled == true ]]; then
+    ipHasChanged 6
+    if [[ $? == 1 ]]; then
+      updateRecord 6
+    else
+      debugMessage "Skip IPv6 record update, it is already up to date"
+    fi
+  fi
+}
+
+function doDynDNS2Updates() {
+  changed=0
+  if [[ $_is_IPv4_enabled == true ]]; then
+    ipHasChanged 4
+    ((changed += $?))
+  fi
+  if [[ $_is_IPv6_enabled == true ]]; then
+    ipHasChanged 6
+    ((changed += $?))
+  fi
+  if [[ $changed -gt 0 ]]; then
+    if checkStatus; then
+      debugMessage "checkStatus has no errors, try update"
+      if dynupdate; then
+        debugMessage "DynDNS2 update success"
+      else
+        debugMessage "Save new status after dynupdate has failed"
+        setStatus "$_response" "$(date +%s)" $((_errorCounter += 1)) "$DYNB_DYN_DOMAIN" "${DYNB_USERNAME}" "${DYNB_PASSWORD}${DYNB_TOKEN}"
+      fi
+    else
+      debugMessage "Skip DynDNS2 update, checkStatus fetched previous error."
+    fi
+  else
+    debugMessage "Skip DynDNS2 update, IPs are up to date or there is a connection problem"
+  fi
+}
+
+function doUpdates() {
+  if [[ $DYNB_UPDATE_METHOD == "domrobot" ]]; then
+    doDomrobotUpdates
+  fi
+
+  if [[ $DYNB_UPDATE_METHOD == "dyndns" ]]; then
+    doDynDNS2Updates
+  fi
 }
 
 #################
 ## MAIN method ##
 #################
 function dynb() {
-  ## parameters and checks
-  checkDependencies
+  # shellcheck disable=SC1091,SC1090
+  source "$(dirname "$(realpath "$0")")/dynb-parsing.sh"
 
   # shellcheck source=.env
   if test -f "$_configFile"; then
@@ -775,68 +704,19 @@ function dynb() {
     source "$_statusFile"
   fi
 
+  ## parameters and checks
   handleParameters
+  checkDependencies
 
-  if [[ $_network_interface != "" ]]; then
-    _interface_str="--interface $_network_interface"
-  fi
-
-  if [[ $_ip_mode == d* ]]; then
-    _is_IPv4_enabled=true
-    _is_IPv6_enabled=true
-  fi
-  if [[ $_ip_mode == *4* ]]; then
-    _is_IPv4_enabled=true
-  fi
-  if [[ $_ip_mode == *6* ]]; then
-    _is_IPv6_enabled=true
-  fi
-
-  ## execute operations
-
-  if [[ $_update_method == "domrobot" ]]; then
-    getMainDomain
-    fetchDNSRecords
-    if [[ $_is_IPv4_enabled == true ]]; then
-      ipHasChanged 4
-      if [[ $? == 1 ]]; then
-        updateRecord 4
-      fi
-    fi
-    if [[ $_is_IPv6_enabled == true ]]; then
-      ipHasChanged 6
-      if [[ $? == 1 ]]; then
-        updateRecord 6
-      fi
-    fi
-  fi
-
-  if [[ $_update_method == "dyndns" ]]; then
-    changed=0
-    if [[ $_is_IPv4_enabled == true ]]; then
-      ipHasChanged 4
-      (( changed += $? ))
-    fi
-    if [[ $_is_IPv6_enabled == true ]]; then
-      ipHasChanged 6
-      (( changed += $? ))
-    fi
-    if [[ $changed -gt 0 ]]; then
-      if checkStatus; then
-        debugMessage "checkStatus has no errors, try update"
-        if dynupdate; then
-          debugMessage "DynDNS2 update success"
+  if loopMode; then
+    while :; do
+      doUpdates
+      sleep $DYNB_INTERVAL
+    done
   else
-          debugMessage "Save new status after dynupdate has failed"
-          setStatus "$_response" "$(date +%s)" $(( _errorCounter += 1 )) "$_dyn_domain" "${_username}" "${_password}${_token}"
-        fi
-      else
-        debugMessage "Skip DynDNS2 update, checkStatus fetched previous error."
-      fi
-    else
-      debugMessage "Skip DynDNS2 update, IPs are up to date"
-    fi
+    doUpdates
   fi
+
   doUnsets
   return 0
 }

example.env

@@ -1,7 +1,21 @@
-_dyn_domain=dyndns.example.com
-_serviceProvider=inwx
-_update_method=domrobot
-_ip_mode=dual
-_username=User42
-_password=SuperSecretPassword
-_token=
+###################
+## Configuration ##
+###################
+
+DYNB_DYN_DOMAIN=dyndns.example.com
+
+## service provider could be deSEC, duckdns, dynv6, inwx
+DYNB_SERVICE_PROVIDER=inwx
+
+## update method options: domrobot, dyndns
+DYNB_UPDATE_METHOD=domrobot
+
+## ip mode could be either: 4, 6 or dual for dualstack
+DYNB_IP_MODE=64
+
+## If you are using the DomRobot RPC-API enter your credentials for the web interface login here
+## If you are using the DynDNS2 protocol enter your credentials here
+DYNB_USERNAME=User42
+DYNB_PASSWORD=SuperSecretPassword
+## or use a token
+DYNB_TOKEN=

man/dynb.1

@@ -1,6 +1,6 @@
 .\" Man page generated from reStructuredText.
 .
-.TH MAN 1 "2021-04-03" "" ""
+.TH MAN 1 "2021-04-21" "" ""
 .SH NAME
 man \- DynB - dynamic DNS update script for bash
 .
@@ -32,7 +32,7 @@ level margin: \\n[rst2man-indent\\n[rst2man-indent-level]]
 ..
 .SH SYNOPSIS
 .sp
-\fBman  [\-\-version] [\-\-link] [\-\-reset] [\-\-debug] [\-\-update\-method UPDATE\-METHOD] [\-\-ip\-mode IP\-MODE] [\-\-domain DOMAIN] [\-\-service\-provider SERVICE\-PROVIDER] [\-\-username USERNAME] [\-\-password PASSWORD] [\-\-token TOKEN] [\-\-help]\fP
+\fBman  [\-\-version] [\-\-link] [\-\-reset] [\-\-debug] [\-\-update\-method UPDATE\-METHOD] [\-\-ip\-mode IP\-MODE] [\-\-domain DOMAIN] [\-\-service\-provider SERVICE\-PROVIDER] [\-\-username USERNAME] [\-\-password PASSWORD] [\-\-token TOKEN] [\-\-interval INTERVAL] [\-\-help]\fP
 .SH DESCRIPTION
 .sp
 IPv4 (A) and IPv6 (AAAA) record updates are supported.
@@ -97,6 +97,11 @@ e.g. SuperSecretPassword
 depends on your selected update method and your provider.
 .sp
 YourProviderGivenToken
+.TP
+.BI \-\-interval \ INTERVAL
+choose the seconds interval to run the script in a loop, minimum is 60.
+.sp
+
 .TP
 .B \-h\fP,\fB  \-\-help
 Prints help.

man/man-defs.rst

@@ -30,4 +30,6 @@
 
 .. |OPTION_TOKEN| replace:: YourProviderGivenToken
 
+.. |OPTION_INTERVAL| replace:: \
+
 .. |OPTION_HELP| replace:: \

man/man.rst

@@ -11,7 +11,7 @@ DynB - dynamic DNS update script for bash
 -----------------------------------------
 
 :Author: |AUTHOR|
-:Date:   2021-04-03
+:Date:   2021-04-21
 :Version: |VERSION|
 :Manual section: |MAN_SECTION|
 
@@ -19,7 +19,7 @@ DynB - dynamic DNS update script for bash
 SYNOPSIS
 ========
 
-``man  [--version] [--link] [--reset] [--debug] [--update-method UPDATE-METHOD] [--ip-mode IP-MODE] [--domain DOMAIN] [--service-provider SERVICE-PROVIDER] [--username USERNAME] [--password PASSWORD] [--token TOKEN] [--help]``
+``man  [--version] [--link] [--reset] [--debug] [--update-method UPDATE-METHOD] [--ip-mode IP-MODE] [--domain DOMAIN] [--service-provider SERVICE-PROVIDER] [--username USERNAME] [--password PASSWORD] [--token TOKEN] [--interval INTERVAL] [--help]``
 
 
 DESCRIPTION
@@ -79,6 +79,10 @@ ARGUMENTS
 
                                                           |OPTION_TOKEN|
 
+--interval INTERVAL                                       choose the seconds interval to run the script in a loop, minimum is 60.
+
+                                                          |OPTION_INTERVAL|
+
 -h, --help                                                Prints help.
 
                                                           |OPTION_HELP|