disable CoreDNS if host networking is detected

Author: aptalca

README.md

@@ -291,6 +291,7 @@ Once registered you can define the dockerfile to use with `-f Dockerfile.aarch64
 
 ## Versions
 
+* **06.10.20:** - Disable CoreDNS when Host networking is detected.
 * **04.10.20:** - Allow to specify a list of names as PEERS and add ALLOWEDIPS environment variable. Also, add peer name/id to each one of the peer sections in wg0.conf. Important: Existing users need to delete `/config/templates/peer.conf` and restart
 * **27.09.20:** - Cleaning service binding example to have accurate PreDown script.
 * **06.08.20:** - Replace resolvconf with openresolv due to dns issues when a client based on this image is connected to a server also based on this image. Add IPv6 info to readme. Display kernel version in logs.

readme-vars.yml

@@ -103,6 +103,7 @@ app_setup_block: |
   
 # changelog
 changelogs:
+  - { date: "06.10.20:", desc: "Disable CoreDNS when Host networking is detected." }
   - { date: "04.10.20:", desc: "Allow to specify a list of names as PEERS and add ALLOWEDIPS environment variable. Also, add peer name/id to each one of the peer sections in wg0.conf. Important: Existing users need to delete `/config/templates/peer.conf` and restart" }
   - { date: "27.09.20:", desc: "Cleaning service binding example to have accurate PreDown script." }
   - { date: "06.08.20:", desc: "Replace resolvconf with openresolv due to dns issues when a client based on this image is connected to a server also based on this image. Add IPv6 info to readme. Display kernel version in logs." }

root/etc/cont-init.d/30-config

@@ -273,9 +273,14 @@ else
   fi
 fi
 
-# set up CoreDNS
-[[ ! -f /config/coredns/Corefile ]] && \
-  cp /defaults/Corefile /config/coredns/Corefile
+# set up or disable CoreDNS
+if ip addr show dev docker0 > /dev/null 2>&1; then
+  echo "Host networking detected, disabling CoreDNS"
+  rm -rf /etc/services.d/coredns
+else
+  [[ ! -f /config/coredns/Corefile ]] && \
+    cp /defaults/Corefile /config/coredns/Corefile
+fi
 
 # permissions
 chown -R abc:abc \