Merge pull request #708 from btimbermont/master

Added a health check

Dockerfile

@@ -39,6 +39,9 @@ RUN apt-get update \
 ADD openvpn/ /etc/openvpn/
 ADD transmission/ /etc/transmission/
 ADD tinyproxy /opt/tinyproxy/
+ADD scripts /etc/scripts/
+
+RUN chmod a+x /etc/scripts/healthcheck.sh
 
 ENV OPENVPN_USERNAME=**None** \
     OPENVPN_PASSWORD=**None** \
@@ -129,7 +132,10 @@ ENV OPENVPN_USERNAME=**None** \
     TRANSMISSION_WEB_HOME= \
     DROP_DEFAULT_ROUTE= \
     WEBPROXY_ENABLED=false \
-    WEBPROXY_PORT=8888
+    WEBPROXY_PORT=8888 \
+    HEALTH_CHECK_HOST=google.com
+
+HEALTHCHECK --interval=5m CMD /etc/scripts/healthcheck.sh
 
 # Expose port and run
 EXPOSE 9091

README.md

@@ -167,6 +167,14 @@ If TRANSMISSION_PEER_PORT_RANDOM_ON_START is enabled then it allows traffic to t
 |`UFW_EXTRA_PORTS` | Allows the comma separated list of ports through the firewall. Respects UFW_ALLOW_GW_NET. | `UFW_EXTRA_PORTS=9910,23561,443`|
 |`UFW_DISABLE_IPTABLES_REJECT` | Prevents the use of `REJECT` in the `iptables` rules, for hosts without the `ipt_REJECT` module (such as the Synology NAS). | `UFW_DISABLE_IPTABLES_REJECT=true`|
 
+### Health check option
+
+Because your VPN connection can sometimes fail, Docker will run a health check on this container every 5 minutes to see if the container is still connected to the internet. By default, this check is done by pinging google.com once. You change the host that is pinged.
+
+| Variable | Function | Example |
+|----------|----------|-------|
+| `HEALTH_CHECK_HOST` | this host is pinged to check if the network connection still works | `google.com` |
+
 ### Permission configuration options
 By default the startup script applies a default set of permissions and ownership on the transmission download, watch and incomplete directories. The GLOBAL_APPLY_PERMISSIONS directive can be used to disable this functionality.
 

scripts/healthcheck.sh

@@ -0,0 +1,22 @@
+#!/bin/sh
+# Ping uses both exit codes 1 and 2. Exit code 2 cannot be used for docker health checks,
+# therefore we use this script to catch error code 2
+HOST=$HEALTH_CHECK_HOST
+
+if [ -z "$HOST" ]
+then
+    echo "Host  not set! Set env 'HEATH_CHECK_HOST'. For now, using default google.com"
+    HOST="google.com"
+fi
+
+ping -c 1 $HOST
+STATUS=$?
+if [ $STATUS -ne 0 ]
+then
+    echo "Network is down"
+    exit 1
+fi
+
+echo "Network is up"
+exit 0
+