feat: Shared custom health check for multiple resources (#4212)

docs/operator-manual/health.md

@@ -36,19 +36,21 @@ metadata:
     app.kubernetes.io/name: argocd-cm
     app.kubernetes.io/part-of: argocd
 data:
-  resource.customizations.health.argoproj.io_Application: |
-    hs = {}
-    hs.status = "Progressing"
-    hs.message = ""
-    if obj.status ~= nil then
-      if obj.status.health ~= nil then
-        hs.status = obj.status.health.status
-        if obj.status.health.message ~= nil then
-          hs.message = obj.status.health.message
+  resource.customizations: |
+    argoproj.io/Application:
+      health.lua: |  
+        hs = {}
+        hs.status = "Progressing"
+        hs.message = ""
+        if obj.status ~= nil then
+          if obj.status.health ~= nil then
+            hs.status = obj.status.health.status
+            if obj.status.health.message ~= nil then
+              hs.message = obj.status.health.message
+            end
+          end
         end
-      end
-    end
-    return hs
+        return hs
 ```
 
 ## Custom Health Checks
@@ -62,34 +64,50 @@ There are two ways to configure a custom health check. The next two sections des
 
 ### Way 1. Define a Custom Health Check in `argocd-cm` ConfigMap
 
-Custom health checks can be defined in `resource.customizations.health.<group_kind>` field of `argocd-cm`. If you are using argocd-operator, this is overridden by [the argocd-operator resourceCustomizations](https://argocd-operator.readthedocs.io/en/latest/reference/argocd/#resource-customizations).
+Custom health checks can be defined in 
+```yaml
+  resource.customizations: |
+    <group/kind>:
+      health.lua: | 
+```
+field of `argocd-cm`. If you are using argocd-operator, this is overridden by [the argocd-operator resourceCustomizations](https://argocd-operator.readthedocs.io/en/latest/reference/argocd/#resource-customizations).
 
 The following example demonstrates a health check for `cert-manager.io/Certificate`.
 
 ```yaml
 data:
-  resource.customizations.health.cert-manager.io_Certificate: |
-    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 == "Ready" and condition.status == "True" then
-            hs.status = "Healthy"
-            hs.message = condition.message
-            return hs
+  resource.customizations: |
+    cert-manager.io/Certificate:
+      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 == "Ready" and condition.status == "True" then
+                hs.status = "Healthy"
+                hs.message = condition.message
+                return hs
+              end
+            end
           end
         end
-      end
-    end
 
-    hs.status = "Progressing"
-    hs.message = "Waiting for certificate"
-    return hs
+        hs.status = "Progressing"
+        hs.message = "Waiting for certificate"
+        return hs
+```
+In order to prevent duplication of the same custom health check for potentially multiple resources, it is also possible to specify a wildcard in the resource kind, like this:
+
+```yaml
+  resource.customizations: |
+    ec2.aws.crossplane.io/*:
+      health.lua: | 
+        ...
 ```
 
 The `obj` is a global variable which contains the resource. The script must return an object with status and optional message field.
@@ -139,3 +157,5 @@ tests:
 To test the implemented custom health checks, run `go test -v ./util/lua/`.
 
 The [PR#1139](https://github.com/argoproj/argo-cd/pull/1139) is an example of Cert Manager CRDs custom health check.
+
+Please note that bundled health checks with wildcards are not supported.

util/lua/lua.go

@@ -16,6 +16,7 @@ import (
 
 	appv1 "github.com/argoproj/argo-cd/v2/pkg/apis/application/v1alpha1"
 	"github.com/argoproj/argo-cd/v2/resource_customizations"
+	"github.com/argoproj/argo-cd/v2/util/glob"
 )
 
 const (
@@ -122,10 +123,24 @@ func (vm VM) ExecuteHealthLua(obj *unstructured.Unstructured, script string) (*h
 
 // GetHealthScript attempts to read lua script from config and then filesystem for that resource
 func (vm VM) GetHealthScript(obj *unstructured.Unstructured) (string, bool, error) {
+	// first, search the gvk as is in the ResourceOverrides
 	key := GetConfigMapKey(obj.GroupVersionKind())
+
 	if script, ok := vm.ResourceOverrides[key]; ok && script.HealthLua != "" {
 		return script.HealthLua, script.UseOpenLibs, nil
 	}
+
+	// if not found as is, perhaps it matches wildcard entries in the configmap
+	wildcardKey := GetWildcardConfigMapKey(vm, obj.GroupVersionKind())
+
+	if wildcardKey != "" {
+		if wildcardScript, ok := vm.ResourceOverrides[wildcardKey]; ok && wildcardScript.HealthLua != "" {
+			return wildcardScript.HealthLua, wildcardScript.UseOpenLibs, nil
+		}
+	}
+
+	// if not found in the ResourceOverrides at all, search it as is in the built-in scripts
+	// (as built-in scripts are files in folders, named after the GVK, currently there is no wildcard support for them)
 	builtInScript, err := vm.getPredefinedLuaScripts(key, healthScriptFile)
 	// standard libraries will be enabled for all built-in scripts
 	return builtInScript, true, err
@@ -333,6 +348,17 @@ func GetConfigMapKey(gvk schema.GroupVersionKind) string {
 	return fmt.Sprintf("%s/%s", gvk.Group, gvk.Kind)
 }
 
+func GetWildcardConfigMapKey(vm VM, gvk schema.GroupVersionKind) string {
+	gvkKeyToMatch := GetConfigMapKey(gvk)
+
+	for key := range vm.ResourceOverrides {
+		if glob.Match(key, gvkKeyToMatch) {
+			return key
+		}
+	}
+	return ""
+}
+
 func (vm VM) getPredefinedLuaScripts(objKey string, scriptFile string) (string, error) {
 	data, err := resource_customizations.Embedded.ReadFile(filepath.Join(objKey, scriptFile))
 	if err != nil {

util/lua/lua_test.go

@@ -126,6 +126,40 @@ func TestGetHealthScriptWithOverride(t *testing.T) {
 	assert.Equal(t, newHealthStatusFunction, script)
 }
 
+func TestGetHealthScriptWithKindWildcardOverride(t *testing.T) {
+	testObj := StrToUnstructured(objJSON)
+	vm := VM{
+		ResourceOverrides: map[string]appv1.ResourceOverride{
+			"argoproj.io/*": {
+				HealthLua:   newHealthStatusFunction,
+				UseOpenLibs: false,
+			},
+		},
+	}
+
+	script, useOpenLibs, err := vm.GetHealthScript(testObj)
+	assert.Nil(t, err)
+	assert.Equal(t, false, useOpenLibs)
+	assert.Equal(t, newHealthStatusFunction, script)
+}
+
+func TestGetHealthScriptWithGroupWildcardOverride(t *testing.T) {
+	testObj := StrToUnstructured(objJSON)
+	vm := VM{
+		ResourceOverrides: map[string]appv1.ResourceOverride{
+			"*.io/Rollout": {
+				HealthLua:   newHealthStatusFunction,
+				UseOpenLibs: false,
+			},
+		},
+	}
+
+	script, useOpenLibs, err := vm.GetHealthScript(testObj)
+	assert.Nil(t, err)
+	assert.Equal(t, false, useOpenLibs)
+	assert.Equal(t, newHealthStatusFunction, script)
+}
+
 func TestGetHealthScriptPredefined(t *testing.T) {
 	testObj := StrToUnstructured(objJSON)
 	vm := VM{}