fix: 🐛 fix loop and error handling in case of connection issues

✨ 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*
+.env*
+docker-compose*

CHANGELOG.md

@@ -1,10 +1,21 @@
 # Changelog
 
 
-## (unreleased)
+## 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 +44,12 @@
 
 ### 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 +58,8 @@
 
 ### 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 +1,5 @@
+FROM alpine:latest
+RUN apk update && apk add bash curl jq bind-tools
+WORKDIR /usr/src/app
+COPY . .
+CMD /bin/bash /usr/src/app/dynb.sh

README.md

@@ -11,6 +11,7 @@ IPv4 (A) and IPv6 (AAAA) record updates are supported.
 - [⚙ Configuration](#-configuration)
 - [🏃 Run](#-run)
 - [⏰ Cron](#-cron)
+- [⏰ docker](#-docker)
 <!-- /TOC -->
 
 ## ✨ Update Methods
@@ -31,7 +32,8 @@ The following update methods are currently implemented:
 
 ## 📦 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:
 
@@ -58,21 +60,23 @@ 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
+DYNB_DYN_DOMAIN=dyndns.example.com
 
-## service provider could be inwx
+## service provider could be deSEC, duckdns, dynv6, inwx
-_serviceProvider=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=
+DYNB_USERNAME=User42
-_password=
+DYNB_PASSWORD=SuperSecretPassword
+## or use a token
+DYNB_TOKEN=
 ```
 
 ## 🏃 Run
@@ -94,7 +98,14 @@ dynb --ip-mode dualstack --update-method dyndns --provider inwx --domain dyndns.
 ```
 
 ## ⏰ 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:
 ```
@@ -105,3 +116,27 @@ then enter :point_down: to run dynb every five minutes.
 */5 * * * * $HOME/.local/bin/dynb >> $HOME/.local/share/dynb/dynb-cron.log
 ```
 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.
+```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
+```

_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.sh

@@ -10,33 +10,33 @@
 ## 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=
+#DYNB_USERNAME=
-_password=
+#DYNB_PASSWORD=
 ## or use a token
-_token=
+#DYNB_TOKEN=
 
- ## TTL (time to live) for the DNS record
+## TTL (time to live) for the DNS record
- ## This setting is only relevant for API based record updates (not DnyDNS2!)
+## This setting is only relevant for API based record updates (not DnyDNS2!)
- ## minimum allowed TTL value by inwx is 300 (5 minutes)
+## minimum allowed TTL value by inwx is 300 (5 minutes)
 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
 
@@ -65,11 +65,13 @@ _response=
 _statusHostname=
 _statusUsername=
 _statusPassword=
-_version=0.0.1
+_version=0.1.1
 _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.
@@ -84,6 +86,7 @@ _debug=0
 # 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([
@@ -120,12 +123,13 @@ _arg_service_provider=
 _arg_username=
 _arg_password=
 _arg_token=
+_arg_interval=
 
 
 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 '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)"
@@ -137,6 +141,7 @@ print_help()
 	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"
 }
 
@@ -264,6 +269,14 @@ parse_commandline()
 			-t*)
 				_arg_token="${_key##-t}"
 				;;
+			--interval)
+				test $# -lt 2 && die "Missing value for the optional argument '$_key'." 1
+				_arg_interval="$2"
+				shift
+				;;
+			--interval=*)
+				_arg_interval="${_key##--interval=}"
+				;;
 			-h|--help)
 				print_help
 				exit 0
@@ -316,6 +329,14 @@ dynb --ip-mode dual --update-method dyndns --service-provider inwx --domain dynd
 EOF
 )"
 
+function loopMode() {
+  if [[ $_loopMode -eq 1 ]]; then
+    return 0
+  else
+    return 1
+  fi
+}
+
 function debugMode() {
   if [[ $_debug -eq 1 ]]; then
     return 0
@@ -336,8 +357,8 @@ function echoerr() { printf "%s\n" "$*" >&2; }
 function getMainDomain() {
   request=$( echo "{}" | \
       jq '(.method="nameserver.list")' | \
-      jq "(.params.user=\"$_username\")" | \
+      jq "(.params.user=\"$DYNB_USERNAME\")" | \
-      jq "(.params.pass=\"$_password\")"
+      jq "(.params.pass=\"$DYNB_PASSWORD\")"
     )
 
   _response=$(curl --silent  \
@@ -345,7 +366,7 @@ function getMainDomain() {
       --user-agent "$_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 "$_response" | jq --raw-output '.domain'  )
 }
@@ -353,10 +374,10 @@ function getMainDomain() {
 function fetchDNSRecords() {
   request=$( echo "{}" | \
       jq '(.method="'nameserver.info'")' | \
-      jq "(.params.user=\"$_username\")" | \
+      jq "(.params.user=\"$DYNB_USERNAME\")" | \
-      jq "(.params.pass=\"$_password\")" | \
+      jq "(.params.pass=\"$DYNB_PASSWORD\")" | \
       jq "(.params.domain=\"$_main_domain\")" | \
-      jq "(.params.name=\"$_dyn_domain\")"
+      jq "(.params.name=\"$DYNB_DYN_DOMAIN\")"
     )
 
   _response=$( curl --silent  \
@@ -405,8 +426,8 @@ function updateRecord() {
   if [[ $IP != "" ]]; then
   request=$( echo "{}" | \
       jq '(.method="nameserver.updateRecord")' | \
-      jq "(.params.user=\"$_username\")" | \
+      jq "(.params.user=\"$DYNB_USERNAME\")" | \
-      jq "(.params.pass=\"$_password\")" | \
+      jq "(.params.pass=\"$DYNB_PASSWORD\")" | \
       jq "(.params.id=\"$ID\")" | \
       jq "(.params.content=\"$IP\")" | \
       jq "(.params.ttl=\"$TTL\")"
@@ -419,7 +440,7 @@ function updateRecord() {
       --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 +452,10 @@ 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&"
+  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=$_dyn_domain&token=$_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 +473,7 @@ function dynupdate() {
       myipv6_str=ipv6
     ;;
     * )
-    echoerr "$_serviceProvider is not supported"
+    echoerr "$DYNB_SERVICE_PROVIDER is not supported"
     exit 1
     ;;
   esac
@@ -470,18 +491,18 @@ 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" \
+      --header "Authorization: Token $DYNB_TOKEN" \
-      --get --data-urlencode "hostname=$_dyn_domain" \
+      --get --data-urlencode "hostname=$DYNB_DYN_DOMAIN" \
       "${dyndns_update_url}" )
     ;;
     dynv6* | duckDNS* | duckdns* )
@@ -493,7 +514,7 @@ 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."
         return 1
@@ -528,7 +549,7 @@ function dynupdate() {
       return 1
     ;;
     notfqdn )
-      echoerr "Error: $_response: Hostname $_dyn_domain is invalid"
+      echoerr "Error: $_response: Hostname $DYNB_DYN_DOMAIN is invalid"
       return 1
     ;;
     nohost )
@@ -574,7 +595,7 @@ function checkStatus() {
       fi
     ;;
     nohost | !yours )
-      if [[ "$_statusHostname" == "$_dyn_domain" && ( "$_statusUsername" == "$_username" || $_statusUsername == "$_token" ) ]]; then
+      if [[ "$_statusHostname" == "$DYNB_DYN_DOMAIN" && ( "$_statusUsername" == "$DYNB_USERNAME" || $_statusUsername == "$DYNB_TOKEN" ) ]]; then
         echoerr "Error: Hostname supplied does not exist under specified account, enter new login credentials before performing an additional request."
         return 1
       else
@@ -583,7 +604,7 @@ function checkStatus() {
       return 0
     ;;
     badauth | 401 )
-      if [[ "$_statusUsername" == "$_username" && "$_statusPassword" == "$_password" ]]; then
+      if [[ "$_statusUsername" == "$DYNB_USERNAME" && "$_statusPassword" == "$DYNB_PASSWORD" ]]; then
         echoerr "Error: Invalid username password combination."
         return 1
       else
@@ -635,18 +656,40 @@ function checkStatus() {
 function ipHasChanged() {
   if [[ ${1} == 4 ]]; then
     remote_ip=$(getRemoteIP 4 $_ipv4_checker)
-    if [[ $_update_method == domrobot ]]; then
+    #TODO: this is doublicated code, refactor this some time
+    if [[ $? -gt 0 ]]; then
+      echoerr "IPCheck (getRemoteIP) request failed $remote_ip"
+      return 0
+    fi
+    if [[ $DYNB_UPDATE_METHOD == domrobot ]]; then
       dns_ip=$(getDNSIP A)
     else
-      dns_ip=$(dig @${_DNS_checkServer} in a +short "$_dyn_domain")
+      dig_response=$(dig @${_DNS_checkServer} in a +short "$DYNB_DYN_DOMAIN")
+      #TODO: this is doublicated code, refactor this some time
+      if [[ $dig_response == ";; connection timed out; no servers could be reached" ]]; then
+        echoerr "DNS request failed $dig_response"
+        return 0
+      fi
+      dns_ip=$dig_response
     fi
   fi
   if [[ ${1} == 6 ]]; then
     remote_ip=$(getRemoteIP 6 $_ipv6_checker)
-    if [[ $_update_method == domrobot ]]; then
+    #TODO: this is doublicated code, refactor this some time
+    if [[ $? -gt 0 ]]; then
+      echoerr "IPCheck (getRemoteIP) request failed $remote_ip"
+      return 0
+    fi
+    if [[ $DYNB_UPDATE_METHOD == domrobot ]]; then
       dns_ip=$(getDNSIP AAAA)
     else
-      dns_ip=$(dig @${_DNS_checkServer} in aaaa +short "$_dyn_domain")
+      dig_response=$(dig @${_DNS_checkServer} in aaaa +short "$DYNB_DYN_DOMAIN")
+      #TODO: this is doublicated code, refactor this some time
+      if [[ $dig_response == ";; connection timed out; no servers could be reached" ]]; then
+        echoerr "DNS request failed $dig_response"
+        return 0
+      fi
+      dns_ip=$dig_response
     fi
   fi
 
@@ -686,25 +729,55 @@ function handleParameters() {
     _debug=1
   fi
   if [[ $_arg_update_method != "" ]]; then
-    _update_method=$_arg_update_method
+    DYNB_UPDATE_METHOD=$_arg_update_method
   fi
   if [[ $_arg_ip_mode != "" ]]; then
-    _ip_mode=$_arg_ip_mode
+    DYNB_IP_MODE=$_arg_ip_mode
   fi
   if [[ $_arg_domain != "" ]]; then
-    _dyn_domain=$_arg_domain
+    DYNB_DYN_DOMAIN=$_arg_domain
   fi
   if [[ $_arg_service_provider != "" ]]; then
-    _serviceProvider=$_arg_service_provider
+    DYNB_SERVICE_PROVIDER=$_arg_service_provider
   fi
   if [[ $_arg_username != "" ]]; then
-    _username=$_arg_username
+    DYNB_USERNAME=$_arg_username
   fi
   if [[ $_arg_password != "" ]]; then
-    _password=$_arg_password
+    DYNB_PASSWORD=$_arg_password
   fi
   if [[ $_arg_token != "" ]]; then
-    _token=$_arg_token
+    DYNB_TOKEN=$_arg_token
+  fi
+  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
   return 0
 }
@@ -722,7 +795,7 @@ function checkDependencies() {
   #   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
     fi
@@ -733,11 +806,11 @@ function doUnsets() {
   unset _network_interface
   unset _DNS_checkServer
   unset _dns_records
-  unset _dyn_domain
+  unset DYNB_DYN_DOMAIN
   unset _has_getopt
   unset _help_message
   unset _INWX_JSON_API_URL
-  unset _ip_mode
+  unset DYNB_IP_MODE
   unset _ipv4_checker
   unset _ipv6_checker
   unset _is_IPv4_enabled
@@ -745,12 +818,62 @@ function doUnsets() {
   unset _main_domain
   unset _new_IPv4
   unset _new_IPv6
-  unset _password
+  unset DYNB_PASSWORD
-  unset _username
+  unset DYNB_USERNAME
-  unset _serviceProvider
+  unset DYNB_SERVICE_PROVIDER
   unset _version
 }
 
+function doUpdates() {
+  if [[ $DYNB_UPDATE_METHOD == "domrobot" ]]; then
+    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
+  fi
+
+  if [[ $DYNB_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 [[ $changed -gt 0 ]]; then
+      if checkStatus; then
+        debugMessage "checkStatus has no errors, try update"
+        if dynupdate; then
+          debugMessage "DynDNS2 update success"
+        else
+          debugMessage "Save new status after dynupdate has failed"
+          setStatus "$_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
+  fi
+}
+
 #################
 ## MAIN method ##
 #################
@@ -777,66 +900,19 @@ function dynb() {
 
   handleParameters
 
-  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
+  if loopMode; then
-    fetchDNSRecords
+    while :
-    if [[ $_is_IPv4_enabled == true ]]; then
+    do
-      ipHasChanged 4
+      doUpdates
-      if [[ $? == 1 ]]; then
+      sleep $DYNB_INTERVAL
-        updateRecord 4
+    done
-      fi
+  else
-    fi
+    doUpdates
-    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 [[ $changed -gt 0 ]]; then
-      if checkStatus; then
-        debugMessage "checkStatus has no errors, try update"
-        if dynupdate; then
-          debugMessage "DynDNS2 update success"
-        else
-          debugMessage "Save new status after dynupdate has failed"
-          setStatus "$_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
-  fi
   doUnsets
   return 0
 }

example.env

@@ -1,7 +1,21 @@
-_dyn_domain=dyndns.example.com
+###################
-_serviceProvider=inwx
+## Configuration ##
-_update_method=domrobot
+###################
-_ip_mode=dual
+
-_username=User42
+DYNB_DYN_DOMAIN=dyndns.example.com
-_password=SuperSecretPassword
+
-_token=
+## 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|