Add ArgoCD CM for health status

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

Author: alexellis

docs/openfaas-pro/function-crd.md

@@ -130,6 +130,58 @@ $ kubectl get function/env -n openfaas-fn -o jsonpath="{.status.conditions[?(@.t
 $ kubectl get function/env -n openfaas-fn -o jsonpath="{.status.conditions[?(@.type == 'Healthy')].status}"
 ```
 
+#### ArgoCD health status
+
+Edit ArgoCD's configmap to add a custom health check for the Function CRD:
+
+```bash
+kubectl edit configmap argocd-cm -n argocd
+```
+
+```yaml
+data:
+  resource.customizations: |
+    openfaas.com/Function:
+      health.lua: |
+        hs = {}
+        if obj.status ~= nil then
+          if obj.status.conditions ~= nil then
+            for i, condition in ipairs(obj.status.conditions) do
+              if condition.type == "Ready" and condition.status == "False" then
+                hs.status = "Degraded"
+                hs.message = condition.message
+                return hs
+              end
+              if condition.type == "Stalled" and condition.status == "True" then
+                hs.status = "Degraded"
+                hs.message = condition.message
+                return hs
+              end
+              if condition.type == "Ready" and condition.status == "True" then
+                if obj.status.replicas ~= nil and obj.status.replicas > 0 then
+                  hs.status = "Healthy"
+                  hs.message = condition.message
+                else
+                  hs.status = "Suspended"
+                  hs.message = "No replicas available"
+                end
+                return hs
+              end
+            end
+          end
+        end
+
+        hs.status = "Progressing"
+        hs.message = "Waiting for Function"
+        return hs
+```
+
+ArgoCD health status:
+
+* Function can't become ready due to a missing secret => Argo status: degraded
+* Function is ready and can serve traffic to at least one Pod => Argo status: healthy
+* Function is ready (no changes need to be applied), but has been scaled down to zero replicas => Argo status: suspended
+
 ### How to generate a spec from a stack.yml
 
 If you already have functions defined in a stack.yml file, you can generate the Function resources with: