Fix issue in watchdog - not reading false config overrides.

watchdog/README.md

@@ -25,13 +25,35 @@ ENV fprocess="/bin/cat"
 CMD ["fwatchdog"]
 ```
 
+**Implementing the a healthcheck**
+
+Docker swarm will keep your function out of the DNS-RR / IPVS pool if the task (container) is not healthy.
+
+Here is an example of the `echo` function implementing a healthcheck with a 5-second checking interval.
+
+```
+FROM functions/alpine
+
+ENV fprocess="cat /etc/hostname"
+
+HEALTHCHECK --interval=5s CMD [ -e /tmp/.lock ] || exit 1
+```
+
+The watchdog process creates a .lock file in `/tmp/` on starting its internal Golang HTTP server. `[ -e file_name ]` is shell to check if a file exists.
+
+Swarm tutorial on Healthchecks:
+
+ * [Test-drive Docker Healthcheck in 10 minutes](http://blog.alexellis.io/test-drive-healthcheck/)
+
+
 **Environmental overrides:**
 
 A number of environmental overrides can be added for additional flexibility and options:
 
 | Option                 | Usage             |
 |------------------------|--------------|
-| `fprocess`     | The process to invoke for each function call. This must be a UNIX binary and accept input via STDIN and output via STDOUT.  |
+| `fprocess`             | The process to invoke for each function call. This must be a UNIX binary and accept input via STDIN and output via STDOUT.  |
 | `marshal_requests`     | Instead of re-directing the raw HTTP body into your fprocess, it will first be marshalled into JSON. Use this if you need to work with HTTP headers |
-| `write_timeout`     | HTTP timeout for writing a response body from your function  |
-| `read_timeout`     | HTTP timeout for reading the payload from the client caller  |
+| `write_timeout`        | HTTP timeout for writing a response body from your function  |
+| `read_timeout`         | HTTP timeout for reading the payload from the client caller  |
+| `suppress_lock`        | The watchdog will attempt to write a lockfile to /tmp/ for swarm healthchecks - set this to true to disable behaviour. |