Merge pull request #3 from cytopia/release-0.10

REL-0.10 Adding injectable custom DNS resolver

Dockerfile

@@ -13,7 +13,7 @@ LABEL \
 	image="bind" \
 	vendor="cytopia" \
 	license="MIT" \
-	build-date="2017-05-10"
+	build-date="2017-05-24"
 
 
 ###

README.md

@@ -1,6 +1,6 @@
 # Bind Docker
 
-<small>**Latest build:** 2017-05-10</small>
+<small>**Latest build:** 2017-05-24</small>
 
 [![Build Status](https://travis-ci.org/cytopia/docker-bind.svg?branch=master)](https://travis-ci.org/cytopia/docker-bind) [![](https://images.microbadger.com/badges/version/cytopia/bind.svg)](https://microbadger.com/images/cytopia/bind "bind") [![](https://images.microbadger.com/badges/image/cytopia/bind.svg)](https://microbadger.com/images/cytopia/bind "bind") [![](https://images.microbadger.com/badges/license/cytopia/bind.svg)](https://microbadger.com/images/cytopia/bind "bind")
 
@@ -32,6 +32,7 @@
 | DEBUG_COMPOSE_ENTRYPOINT | bool | `0` | Show shell commands executed during start.<br/>Value: `0` or `1` |
 | WILDCARD_DOMAIN | string | `` | Specify a wild-card domain to add during startup.<br/>Example: `WILDCARD_DOMAIN=example.com` or `WILDCARD_DOMAIN=local` or `WILDCARD_DOMAIN=loc`<br/>**Note:** `$WILDCARD_ADDRESS` must also be specified. |
 | WILDCARD_ADDRESS | string | `` | Specify to which IP address the wild-card domain should point to.<br/>Example: `WILDCARD_ADDRESS=192.168.0.1`<br/>**Note:** $WILDCARD_DOMAIN` must also be specidied. |
+| DNS_FORWARDER | string| `` | Specify a comma separated list of IP addresses as custom DNS resolver. This is useful if your LAN already has a DNS server which adds custom/internal domains and you still want to keep them in this DNS server<br/>Example: `DNS_FORWARDER=8.8.8.8,8.8.4.4` |
 
 ### Default mount points
 
@@ -81,6 +82,21 @@ $ docker run -i \
     -t cytopia/bind
 ```
 
+**4. Add wildcard Domain (TLD) and use your corporate DNS server as resolver**
+
+* `loc` and all its subdomains (such as: `hostname.loc`) will point to `192.168.0.1`:
+* Your corporate DNS servers are `10.0.15.1` and `10.0.15.2`
+
+```bash
+$ docker run -i \
+    -p 127.0.0.1:53:53 \
+    -p 127.0.0.1:53/udp:53/udp \
+    -e WILDCARD_DOMAIN=loc \
+    -e WILDCARD_ADDRESS=192.168.0.1 \
+	-e DNS_FORWARDER=10.0.15.1,10.0.15,2 \
+    -t cytopia/bind
+```
+
 ## Version
 
 BIND 9.9.5

scripts/docker-entrypoint.sh

@@ -174,6 +174,55 @@ else
 fi
 
 
+###
+### Add custom forwarder IP's
+###
+if ! set | grep '^DNS_FORWARDER=' >/dev/null 2>&1; then
+	log "warn" "\$DNS_FORWARDER not set."
+	log "warn" "No custom DNS server will be used as forwarder"
+else
+
+	# To be pupulated
+	_forwarders_block=""
+
+	# Transform into newline separated forwards:
+	#   x.x.x.x\n
+	#   y.y.y.y\n
+	_forwards="$( echo "${DNS_FORWARDER}" | sed 's/[[:space:]]*//g' | sed 's/,/\n/g' )"
+
+	# loop over them
+	IFS='
+	'
+	for ip in ${_forwards}; do
+		if ! isip "${ip}"; then
+			log "err" "DNS_FORWARDER error: not a valid IP address: ${ip}"
+			exit 1
+		fi
+
+		if [ "${_forwarders_block}" = "" ]; then
+			_forwarders_block="\t\t${ip};"
+		else
+			_forwarders_block="${_forwarders_block}\n\t\t${ip};"
+		fi
+	done
+
+	if [ "${_forwarders_block}" = "" ]; then
+		log "err" "DNS_FORWARDER error: variable specified, but no IP addresses found."
+		exit 1
+	fi
+
+	log "info" "Adding custom DNS forwarder: ${DNS_FORWARDER}"
+
+	# forwarders {
+	#     x.x.x.x;
+	#     y.y.y.y;
+	# };
+	_forwarders_block="\tforwarders {\n${_forwarders_block}\n\t};"
+
+	run "sed -i'' 's/^};$/${_forwarders_block}\n};/' /etc/bind/named.conf.options"
+fi
+
+
 
 ###
 ### Start