feat: throw new MissingCRDException when CRD validation fails

This is useful for processes that observe the controller registration
(the quarkus extension, for example) to know more specifically what
happened instead of using a generic OperatorException.

Author: metacosm

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/MissingCRDException.java

@@ -0,0 +1,32 @@
+package io.javaoperatorsdk.operator;
+
+public class MissingCRDException extends OperatorException {
+  private final String crdName;
+  private final String specVersion;
+
+  public String getCrdName() {
+    return crdName;
+  }
+
+  public String getSpecVersion() {
+    return specVersion;
+  }
+
+  public MissingCRDException(String crdName, String specVersion) {
+    super();
+    this.crdName = crdName;
+    this.specVersion = specVersion;
+  }
+
+  public MissingCRDException(String crdName, String specVersion, String message) {
+    super(message);
+    this.crdName = crdName;
+    this.specVersion = specVersion;
+  }
+
+  public MissingCRDException(String crdName, String specVersion, String message, Throwable cause) {
+    super(message, cause);
+    this.crdName = crdName;
+    this.specVersion = specVersion;
+  }
+}

operator-framework-core/src/main/java/io/javaoperatorsdk/operator/Operator.java

@@ -115,17 +115,22 @@ public <R extends CustomResource> void register(
       final String controllerName = configuration.getName();
 
       // check that the custom resource is known by the cluster if configured that way
-      final CustomResourceDefinition crd;
+      final CustomResourceDefinition crd; // todo: check proper CRD spec version based on config
       if (configurationService.checkCRDAndValidateLocalModel()) {
         final var crdName = configuration.getCRDName();
+        final var specVersion = "v1";
         crd = k8sClient.apiextensions().v1().customResourceDefinitions().withName(crdName).get();
         if (crd == null) {
-          throw new OperatorException(
+          throw new MissingCRDException(
+              crdName,
+              specVersion,
               "'"
                   + crdName
-                  + "' CRD was not found on the cluster, controller "
+                  + "' "
+                  + specVersion
+                  + " CRD was not found on the cluster, controller '"
                   + controllerName
-                  + " cannot be registered");
+                  + "' cannot be registered");
         }
 
         // Apply validations that are not handled by fabric8