improve: double bracket in object template (#166)

Signed-off-by: Attila Mészáros <[email protected]>

Author: csviri

README.md

@@ -67,8 +67,8 @@ spec:
   parent:
     apiVersion: glueoperator.sample/v1  # watches all the custom resource of type WebPage
     kind: WebPage
-    statusTemplate: | # update the status of the custom resource at the end of reconciliation
-      observedGeneration: {parent.metadata.generation}
+    status:  # update the status of the custom resource at the end of reconciliation
+      observedGeneration: "{{parent.metadata.generation}}" # since it's a non-string value needs double curly brackets 
   childResources:
     - name: htmlconfigmap
       resource:

docs/reference.md

@@ -8,8 +8,31 @@ Although it is limited only to Kubernetes resources it makes it very easy to use
 
 ## Generic Notes
 
-- All templates (both object and string based) uses [Qute templating engine](https://quarkus.io/guides/qute-reference). While objects allow only
-  placeholders, you can use the full power of qute in string templates.
+ - All templates (both object and string-based) uses [Qute templating engine](https://quarkus.io/guides/qute-reference). While objects allow only
+   placeholders, you can use the full power of qute in string templates.
+        
+   ONLY for object-based templates (thus not string templates) the values can be set using the placeholder notation from Qute: 
+   ```yaml
+   value: "{string.value}" 
+   ```
+   With this standard notation, the result value will be always encoded in double quotes:
+    ```yaml
+   value: "1" 
+   ```
+   Since there is no simple way to check if the referenced value is a string or other value
+   (boolean, numeric, etc) for non-string values, user should use double brackets:
+    ```yaml
+   value: "{{nonstring.value}}" 
+   ```
+   what would result in a value without enclosed double quotes in the produced yaml:
+    ```yaml
+   value: 1 
+   ```
+   See sample [here](https://github.com/java-operator-sdk/kubernetes-glue-operator/blob/main/src/test/resources/sample/webpage/webpage.operator.yaml#L10).
+   Implementation wise, this is a preprocessor that strips the enclosed quotes and additional curly bracket
+   before it is passed to Qute.
+   In the future, we might remove such obligation by checking the type 
+   of the target value in the related schema.
 
 ## [Glue resource](https://github.com/java-operator-sdk/kubernetes-glue-operator/releases/latest/download/glues.glue-v1.yml)
 

src/main/java/io/javaoperatorsdk/operator/glue/dependent/GenericBulkDependentResource.java

@@ -29,7 +29,7 @@ public GenericBulkDependentResource(GenericTemplateHandler genericTemplateHandle
   public Map<String, GenericKubernetesResource> desiredResources(Glue primary,
       Context<Glue> context) {
 
-    var res = genericTemplateHandler.processTemplate(desiredTemplate, primary, context);
+    var res = genericTemplateHandler.processTemplate(desiredTemplate, primary, false, context);
     var desiredList = Serialization.unmarshal(res, GenericKubernetesResourceList.class).getItems();
     desiredList.forEach(r -> {
       r.getMetadata().getAnnotations()

src/main/java/io/javaoperatorsdk/operator/glue/dependent/GenericDependentResource.java

@@ -55,10 +55,10 @@ public GenericDependentResource(GenericTemplateHandler genericTemplateHandler,
   @Override
   protected GenericKubernetesResource desired(Glue primary,
       Context<Glue> context) {
+    boolean objectTemplate = desired != null;
+    var template = objectTemplate ? Serialization.asYaml(desired) : desiredTemplate;
 
-    var template = desired == null ? desiredTemplate : Serialization.asYaml(desired);
-
-    var res = genericTemplateHandler.processTemplate(template, primary, context);
+    var res = genericTemplateHandler.processTemplate(template, primary, objectTemplate, context);
     var resultDesired = Serialization.unmarshal(res, GenericKubernetesResource.class);
 
     resultDesired.getMetadata().getAnnotations()

src/main/java/io/javaoperatorsdk/operator/glue/reconciler/glue/GlueReconciler.java

@@ -195,7 +195,7 @@ private void createAndAddDependentToWorkflow(Glue primary, Context<Glue> context
     // todo test processing ns as template
     // name can reference related resources todo doc
     var targetNamespace = Utils.getNamespace(spec).map(ns -> genericTemplateHandler
-        .processTemplate(ns, primary, context));
+        .processTemplate(ns, primary, false, context));
     var resourceInSameNamespaceAsPrimary =
         targetNamespace.map(n -> n.trim().equals(primary.getMetadata().getNamespace().trim()))
             .orElse(true);
@@ -205,7 +205,7 @@ private void createAndAddDependentToWorkflow(Glue primary, Context<Glue> context
 
     if (!(dr instanceof BulkDependentResource<?, ?>)) {
       dr.setResourceDiscriminator(new GenericResourceDiscriminator(dr.getGroupVersionKind(),
-          genericTemplateHandler.processTemplate(Utils.getName(spec), primary, context),
+          genericTemplateHandler.processTemplate(Utils.getName(spec), primary, false, context),
           targetNamespace.orElse(null)));
     }
 
@@ -267,10 +267,11 @@ private void patchRelatedResourcesStatus(Context<Glue> context,
     targetRelatedResources.forEach(r -> {
       var relatedResources = Utils.getRelatedResources(primary, r, context);
 
-      var template = r.getStatusPatchTemplate() != null ? r.getStatusPatchTemplate()
-          : Serialization.asYaml(r.getStatusPatch());
+      var objectTemplate = r.getStatusPatch() != null;
+      var template =
+          objectTemplate ? Serialization.asYaml(r.getStatusPatch()) : r.getStatusPatchTemplate();
       var resultTemplate =
-          genericTemplateHandler.processTemplate(actualData, template);
+          genericTemplateHandler.processTemplate(actualData, template, objectTemplate);
       var statusObjectMap = GenericTemplateHandler.parseTemplateToMapObject(resultTemplate);
       relatedResources.forEach((n, kr) -> {
         kr.setAdditionalProperty("status", statusObjectMap);

src/main/java/io/javaoperatorsdk/operator/glue/reconciler/operator/GlueOperatorReconciler.java

@@ -144,9 +144,10 @@ private ObjectMeta glueMetadata(GlueOperator glueOperator,
     if (glueMeta != null) {
       // optimize
       var data = Map.of(PARENT_RELATED_RESOURCE_NAME, parent);
-      var glueName = genericTemplateHandler.processInputAndTemplate(data, glueMeta.getName());
+      var glueName =
+          genericTemplateHandler.processInputAndTemplate(data, glueMeta.getName(), false);
       var glueNamespace =
-          genericTemplateHandler.processInputAndTemplate(data, glueMeta.getNamespace());
+          genericTemplateHandler.processInputAndTemplate(data, glueMeta.getNamespace(), false);
       objectMetaBuilder.withName(glueName);
       objectMetaBuilder.withNamespace(glueNamespace);
     } else {

src/main/java/io/javaoperatorsdk/operator/glue/templating/GenericTemplateHandler.java

@@ -23,22 +23,31 @@ public class GenericTemplateHandler {
   private static final ObjectMapper objectMapper = new ObjectMapper();
   private static final Engine engine = Engine.builder().addDefaults().build();
 
-  public String processTemplate(Map<String, Map<?, ?>> data, String template) {
+  public String processTemplate(Map<String, Map<?, ?>> data, String template,
+      boolean objectTemplate) {
+    if (objectTemplate) {
+      template = handleDoubleCurlyBrackets(template);
+    }
     Template parsedTemplate = engine.parse(template);
     return parsedTemplate.data(data).render();
   }
 
+  private String handleDoubleCurlyBrackets(String template) {
+    template = template.replace("\"{{", "{");
+    return template.replace("}}\"", "}");
+  }
+
   public String processInputAndTemplate(Map<String, GenericKubernetesResource> data,
-      String template) {
+      String template, boolean objectTemplate) {
     Map<String, Map<?, ?>> res =
         genericKubernetesResourceDataToGenericData(data);
-    return processTemplate(res, template);
+    return processTemplate(res, template, objectTemplate);
   }
 
-  public String processTemplate(String template, Glue primary,
+  public String processTemplate(String template, Glue primary, boolean objectTemplate,
       Context<Glue> context) {
     var data = createDataWithResources(primary, context);
-    return processTemplate(data, template);
+    return processTemplate(data, template, objectTemplate);
   }
 
   private static Map<String, Map<?, ?>> genericKubernetesResourceDataToGenericData(

src/test/java/io/javaoperatorsdk/operator/glue/templating/GenericTemplateHandlerTest.java

@@ -0,0 +1,38 @@
+package io.javaoperatorsdk.operator.glue.templating;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+
+import io.fabric8.kubernetes.client.utils.Serialization;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class GenericTemplateHandlerTest {
+
+  GenericTemplateHandler templateHandler = new GenericTemplateHandler();
+
+  @Test
+  void testDoubleCurlyBrackets() {
+    var template = """
+          intValue: "{{spec.intvalue}}"
+          stringValue: "{spec.stringvalue}"
+        """;
+
+    Map<String, Map<?, ?>> data = new HashMap<>();
+
+    Map values = new HashMap();
+    values.put("intvalue", 1);
+    values.put("stringvalue", "value1");
+    data.put("spec", values);
+
+    var result = templateHandler.processTemplate(data, template, true);
+
+    Map mapResult = Serialization.unmarshal(result, Map.class);
+
+    assertEquals(1, mapResult.get("intValue"));
+    assertEquals("value1", mapResult.get("stringValue"));
+  }
+
+}

src/test/resources/sample/webpage/webpage.operator.yaml

@@ -6,8 +6,8 @@ spec:
   parent:
     apiVersion: glueoperator.sample/v1
     kind: WebPage
-    statusTemplate: |
-      observedGeneration: {parent.metadata.generation}
+    status:
+      observedGeneration: "{{parent.metadata.generation}}"
   childResources:
     - name: htmlconfigmap
       resource: