Update/cleanup notes on how to run unbound *afer* Docker

armbian/unbound.md

@@ -90,6 +90,26 @@ systemctl start roothints.timer
 
 ```
 
+## Setup Unbound to start *after* Docker
+
+*See [here (link)](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/system_administrators_guide/sect-Managing_Services_with_systemd-Unit_Files#brid-Managing_Services_with_systemd-Extending_Unit_Config) for more details.*
+
+This is mainly here to ensure that unbound starts *after* the Docker network comes up as it's configured to listen on the Docker network. It'll fail to load/restart if the bind address isn't present when it is started.
+
+``` bash
+
+mkdir -p /etc/systemd/system/unbound.service.d/
+cat > /etc/systemd/system/unbound.service.d/00-after-docker.conf <<EOF
+[Unit]
+Requires=docker.socket docker.service
+After=docker.socket docker.service
+Restart=always
+RestartSec=5
+EOF
+systemctl daemon-reload
+
+```
+
 ## Adjust NetworkManager Config
 
 Edit ```/etc/NetworkManager/NetworkManager.conf```