Update for OpenFaaS pro health check features

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <[email protected]>

Author: alexellis

docs/openfaas-pro/retries.md

@@ -13,11 +13,13 @@ There are two primary use-cases for retrying asynchronous messages:
 
 You can install the Pro version of the queue worker by editing the values.yaml file of the [OpenFaaS chart](https://github.com/openfaas/faas-netes/tree/master/chart/openfaas).
 
+You must also set:
+
 ```yaml
-# Requires OpenFaaS Pro subscription
+openfaasPro: true
+
 queueWorkerPro:
   image: ghcr.io/openfaas/queue-worker-pro:0.1.0-rc4
-  enabled: false
   maxRetryAttempts: "10"
   maxRetryWait: "120s"
   initialRetryWait: "10s"
@@ -34,7 +36,6 @@ The `httpRetryCodes` is a comma-separated list of HTTP status codes which the qu
 
 To test the retry functionality, you can use our chaos function, which allows a function to be configured to return a canned response, or to timeout with a given duration.
 
-
 ```bash
 git clone https://github.com/alexellis/chaos-fn
 

docs/reference/workloads.md

@@ -163,14 +163,17 @@ Use of the [OpenFaaS next-gen of-watchdog](https://github.com/openfaas/of-watchd
 
 On Kubernetes is possible to run any container image as an OpenFaaS function as long as your application exposes port 8080 and has a HTTP health check endpoint.
 
-#### Custom HTTP health check
+#### Custom HTTP health checks
+
+> This feature is available for OpenFaaS Pro customers only
 
 You can specify the HTTP path of your health check and the initial check delay duration with the following annotations:
 
 * `com.openfaas.health.http.path`
 * `com.openfaas.health.http.initialDelay`
+* `com.openfaas.health.http.periodSeconds`
 
-Stack file example:
+For example, you may have a function that takes 30s to initialise, but then only needs to be checked every 5s after that.
 
 ```yaml
 functions:
@@ -180,6 +183,7 @@ functions:
     annotations:
       com.openfaas.health.http.path: "/healthz"
       com.openfaas.health.http.initialDelay: "30s"
+      com.openfaas.health.http.periodSeconds: 5s
 ``` 
 
 > Note: The initial delay value must be a valid Go duration e.g. `80s` or `3m`.