Merge pull request #1 from freepik-company/feat/add-vars-ability

feat: Add setVar ability

README.md

@@ -148,6 +148,43 @@ spec:
 
 ```
 
+As you probably noticed in the previous example, conditions are made using vitamin Golang template
+(better known as Helm template), so **all the functions available in Helm are available here too.**
+This way you start creating wonderful policies from first minute.
+
+**Sometimes you need to store information** during conditions' evaluation that will be useful in later messages shown to the team.
+This will help your mates having meaningful messages that save time during debug.
+
+Because of that, there is a special function available in templates called `setVar`. It can be used as follows:
+
+```yaml
+apiVersion: admitik.freepik.com/v1alpha1
+kind: ClusterAdmissionPolicy
+spec:
+
+  ...
+
+  conditions:
+    - name: store-vars-for-later-usage
+      key: |
+        {{- $someDataForLater := dict "name" "example-name" "namespace" "example-namespace" -}}
+
+
+        {{/* Store your data under your desired key. You can use as many keys as needed */}}
+        {{- setVar "some_key" $someDataForLater -}}
+
+
+        {{- printf "force-condition-not-being-met" -}}
+      value: "condition-key-result"
+
+  message:
+    template: |
+      {{- $myVars := .vars -}}
+
+      {{- $someKeyInside := $myVars.some_key-}}
+
+      {{- printf "let's show some stored data: %s/%s" $someKeyInside.name $someKeyInside.namespace -}}
+```
 
 
 ## How to develop

charts/admitik/Chart.yaml

@@ -4,10 +4,10 @@ apiVersion: v2
 name: admitik
 type: application
 description: >-
-  A Helm chart for admitik, an admission controller for Kubernetes
+  A Helm chart for Admitik, an admission controller for Kubernetes
   that allow resources entrance if conditions are met (realtime)
-version: 0.1.0 # chart version
-appVersion: "0.1.0" # admitik version
+version: 0.2.0 # chart version
+appVersion: "0.2.0" # admitik version
 kubeVersion: ">=1.22.0-0" # kubernetes version
 home: https://github.com/freepik-company/admitik
 sources:

internal/template/functions.go

@@ -17,8 +17,26 @@ import (
 // for people who are already comfortable with Helm. Not all the extra functionality was added to keep this simpler.
 // Ref: https://github.com/helm/helm/blob/main/pkg/engine/funcs.go
 
-func EvaluateTemplate(templateString string, data map[string]interface{}) (result string, err error) {
+func EvaluateTemplate(templateString string, data *map[string]interface{}) (result string, err error) {
+
+	// setVar function is defined as clojure to intercept 'data'
+	// done this way as 'data' being passed as func param in later func map is not convenient
+	setVar := func(key string, value interface{}) string {
+
+		// Init data['vars'] when needed
+		vars, ok := (*data)["vars"].(map[string]interface{})
+		if !ok || vars == nil {
+			vars = make(map[string]interface{})
+			(*data)["vars"] = vars
+		}
+
+		// Store data inside
+		vars[key] = value
+		return ""
+	}
+
 	templateFunctionsMap := GetFunctionsMap()
+	templateFunctionsMap["setVar"] = setVar
 
 	// Create a Template object from the given string
 	parsedTemplate, err := template.New("main").Funcs(templateFunctionsMap).Parse(templateString)

internal/xyz/server.go

@@ -171,7 +171,7 @@ func (s *HttpServer) handleRequest(response http.ResponseWriter, request *http.R
 		// Evaluate template conditions
 		var conditionPassed []bool
 		for _, condition := range caPolicyObj.Spec.Conditions {
-			parsedKey, err := template.EvaluateTemplate(condition.Key, specificTemplateInjectedObject)
+			parsedKey, err := template.EvaluateTemplate(condition.Key, &specificTemplateInjectedObject)
 			if err != nil {
 				logger.Info(fmt.Sprintf("failed evaluating condition '%s': %s", condition.Name, err.Error()))
 				conditionPassed = append(conditionPassed, false)
@@ -183,7 +183,7 @@ func (s *HttpServer) handleRequest(response http.ResponseWriter, request *http.R
 
 		// When some condition is not met, evaluate message's template and emit a negative response
 		if slices.Contains(conditionPassed, false) {
-			parsedMessage, err := template.EvaluateTemplate(caPolicyObj.Spec.Message.Template, specificTemplateInjectedObject)
+			parsedMessage, err := template.EvaluateTemplate(caPolicyObj.Spec.Message.Template, &specificTemplateInjectedObject)
 			if err != nil {
 				logger.Info(fmt.Sprintf("failed parsing message template: %s", err.Error()))
 				return