#200: Initial crash loop prevention for custom resources

- Extend the resource clients for app definitions, sessions, and
workspaces to be able to handle the status subresource.
- Add basic status for our CRDs to track handling state of the operator
- Prevent crashloops by never handling resources that are in error or
handling state. The latter indicates an unexcepted crash during handling
(e.g. NPE).
- NOTE: The previous step was only dony for LAZY handlers. EAGER
handlers did not change
- Exemplary sub steps for volume claim an attachment for workspace
resources
- Increase resource versions for all CRs
- Move API, KIND, and CRD_NAME constants from Spec to resource classes
(e.g. from SessionSpec to Session) because they belong to the resource
itself. This became apparent when adding the Status to the resources

Note: Status handling can probably be refactored to be a bit cleaner and
make use of better code-reuse.

Part of #200

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/client/AppDefinitionResourceClient.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (C) 2022 EclipseSource and others.
+ * Copyright (C) 2022-2023 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -18,7 +18,8 @@
 import org.eclipse.theia.cloud.common.k8s.resource.AppDefinition;
 import org.eclipse.theia.cloud.common.k8s.resource.AppDefinitionSpec;
 import org.eclipse.theia.cloud.common.k8s.resource.AppDefinitionSpecResourceList;
+import org.eclipse.theia.cloud.common.k8s.resource.AppDefinitionStatus;
 
-public interface AppDefinitionResourceClient
-	extends CustomResourceClient<AppDefinitionSpec, AppDefinition, AppDefinitionSpecResourceList> {
+public interface AppDefinitionResourceClient extends
+	CustomResourceClient<AppDefinitionSpec, AppDefinitionStatus, AppDefinition, AppDefinitionSpecResourceList> {
 }

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/client/CustomResourceClient.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (C) 2022 EclipseSource and others.
+ * Copyright (C) 2022-2023 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -18,32 +18,49 @@
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.function.Consumer;
 import java.util.stream.Collectors;
 
 import org.eclipse.theia.cloud.common.k8s.resource.UserScopedSpec;
 
 import io.fabric8.kubernetes.api.model.KubernetesResourceList;
 import io.fabric8.kubernetes.client.CustomResource;
 
-public interface CustomResourceClient<S, T extends CustomResource<S, Void>, L extends KubernetesResourceList<T>>
+public interface CustomResourceClient<SPEC, STATUS, T extends CustomResource<SPEC, STATUS>, L extends KubernetesResourceList<T>>
 	extends ResourceClient<T, L> {
 
-    T create(String correlationId, S spec);
+    T create(String correlationId, SPEC spec);
 
-    default Optional<S> spec(String name) {
+    default Optional<SPEC> spec(String name) {
 	return get(name).map(T::getSpec);
     }
 
+    default Optional<STATUS> status(String name) {
+	return get(name).map(T::getStatus);
+    }
+
     default List<T> list(String user) {
 	return list().stream().filter(item -> Objects.equals(UserScopedSpec.getUser(item.getSpec()), user))
 		.collect(Collectors.toList());
     }
 
-    default List<S> specs() {
+    default List<SPEC> specs() {
 	return list().stream().map(item -> item.getSpec()).collect(Collectors.toList());
     }
 
-    default List<S> specs(String user) {
+    default List<SPEC> specs(String user) {
 	return list(user).stream().map(item -> item.getSpec()).collect(Collectors.toList());
     }
+
+    default boolean updateStatus(String correlationId, T resource, Consumer<STATUS> editOperation) {
+	trace(correlationId, "Update Status of " + resource);
+	final String name = resource.getMetadata().getName();
+	return (editStatus(correlationId, name, res -> {
+	    STATUS status = Optional.ofNullable(res.getStatus()).orElse(createDefaultStatus());
+	    res.setStatus(status);
+	    editOperation.accept(status);
+	}) != null);
+    }
+
+    STATUS createDefaultStatus();
 }

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/client/DefaultAppDefinitionResourceClient.java

@@ -18,6 +18,7 @@
 import org.eclipse.theia.cloud.common.k8s.resource.AppDefinition;
 import org.eclipse.theia.cloud.common.k8s.resource.AppDefinitionSpec;
 import org.eclipse.theia.cloud.common.k8s.resource.AppDefinitionSpecResourceList;
+import org.eclipse.theia.cloud.common.k8s.resource.AppDefinitionStatus;
 
 import io.fabric8.kubernetes.api.model.ObjectMeta;
 import io.fabric8.kubernetes.client.NamespacedKubernetesClient;
@@ -42,4 +43,9 @@ public AppDefinition create(String correlationId, AppDefinitionSpec spec) {
 	return operation().create(appDefinition);
     }
 
+    @Override
+    public AppDefinitionStatus createDefaultStatus() {
+	return new AppDefinitionStatus();
+    }
+
 }

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/client/DefaultSessionResourceClient.java

@@ -22,6 +22,7 @@
 import org.eclipse.theia.cloud.common.k8s.resource.Session;
 import org.eclipse.theia.cloud.common.k8s.resource.SessionSpec;
 import org.eclipse.theia.cloud.common.k8s.resource.SessionSpecResourceList;
+import org.eclipse.theia.cloud.common.k8s.resource.SessionStatus;
 import org.eclipse.theia.cloud.common.util.TheiaCloudError;
 
 import io.fabric8.kubernetes.api.model.ObjectMeta;
@@ -102,4 +103,9 @@ public boolean reportActivity(String correlationId, String name) {
 	}) != null;
     }
 
+    @Override
+    public SessionStatus createDefaultStatus() {
+	return new SessionStatus();
+    }
+
 }

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/client/DefaultWorkspaceResourceClient.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (C) 2022 EclipseSource and others.
+ * Copyright (C) 2022-2023 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -20,6 +20,7 @@
 import org.eclipse.theia.cloud.common.k8s.resource.Workspace;
 import org.eclipse.theia.cloud.common.k8s.resource.WorkspaceSpec;
 import org.eclipse.theia.cloud.common.k8s.resource.WorkspaceSpecResourceList;
+import org.eclipse.theia.cloud.common.k8s.resource.WorkspaceStatus;
 import org.eclipse.theia.cloud.common.util.TheiaCloudError;
 
 import io.fabric8.kubernetes.api.model.ObjectMeta;
@@ -88,4 +89,9 @@ protected boolean isWorkspaceComplete(String correlationId, WorkspaceSpec create
 	}
 	return false;
     }
+
+    @Override
+    public WorkspaceStatus createDefaultStatus() {
+	return new WorkspaceStatus();
+    }
 }

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/client/ResourceClient.java

@@ -62,6 +62,15 @@ default T edit(String correlationId, String name, Consumer<T> consumer) {
 	return resource.edit(JavaUtil.toUnary(consumer));
     }
 
+    default T editStatus(String correlationId, String name, Consumer<T> consumer) {
+	trace(correlationId, "Edit status of" + name);
+	Resource<T> resource = resource(name);
+	if (resource.get() == null) {
+	    return null;
+	}
+	return resource.editStatus(JavaUtil.toUnary(consumer));
+    }
+
     Optional<T> loadAndCreate(String correlationId, String yaml, Consumer<T> customization);
 
     default Optional<T> loadAndCreate(String correlationId, String yaml) {

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/client/SessionResourceClient.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (C) 2022 EclipseSource and others.
+ * Copyright (C) 2022-2023 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -20,8 +20,10 @@
 import org.eclipse.theia.cloud.common.k8s.resource.Session;
 import org.eclipse.theia.cloud.common.k8s.resource.SessionSpec;
 import org.eclipse.theia.cloud.common.k8s.resource.SessionSpecResourceList;
+import org.eclipse.theia.cloud.common.k8s.resource.SessionStatus;
 
-public interface SessionResourceClient extends CustomResourceClient<SessionSpec, Session, SessionSpecResourceList> {
+public interface SessionResourceClient
+	extends CustomResourceClient<SessionSpec, SessionStatus, Session, SessionSpecResourceList> {
     Session launch(String correlationId, SessionSpec spec, long timeout, TimeUnit unit);
 
     default Session launch(String correlationId, SessionSpec spec, int timeout) {

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/client/WorkspaceResourceClient.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (C) 2022 EclipseSource and others.
+ * Copyright (C) 2022-2023 EclipseSource and others.
  *
  * This program and the accompanying materials are made available under the
  * terms of the Eclipse Public License v. 2.0 which is available at
@@ -20,14 +20,14 @@
 import org.eclipse.theia.cloud.common.k8s.resource.Workspace;
 import org.eclipse.theia.cloud.common.k8s.resource.WorkspaceSpec;
 import org.eclipse.theia.cloud.common.k8s.resource.WorkspaceSpecResourceList;
+import org.eclipse.theia.cloud.common.k8s.resource.WorkspaceStatus;
 
 public interface WorkspaceResourceClient
-	extends CustomResourceClient<WorkspaceSpec, Workspace, WorkspaceSpecResourceList> {
+	extends CustomResourceClient<WorkspaceSpec, WorkspaceStatus, Workspace, WorkspaceSpecResourceList> {
 
     Workspace launch(String correlationId, WorkspaceSpec spec, long timeout, TimeUnit unit);
 
     default Workspace launch(String correlationId, WorkspaceSpec spec) {
 	return launch(correlationId, spec, 1, TimeUnit.MINUTES);
     }
-
 }

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/resource/AppDefinition.java

@@ -25,13 +25,16 @@
 import io.fabric8.kubernetes.model.annotation.Singular;
 import io.fabric8.kubernetes.model.annotation.Version;
 
-@Version("v6beta")
+@Version("v8beta")
 @Group("theia.cloud")
 @Singular("appdefinition")
 @Plural("appdefinitions")
-public class AppDefinition extends CustomResource<AppDefinitionSpec, Void> implements Namespaced {
+public class AppDefinition extends CustomResource<AppDefinitionSpec, AppDefinitionStatus> implements Namespaced {
 
     private static final long serialVersionUID = 8749670583218521755L;
+    public static final String API = "theia.cloud/v8beta";
+    public static final String KIND = "AppDefinition";
+    public static final String CRD_NAME = "appdefinitions.theia.cloud";
 
     @Override
     public String toString() {

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/resource/AppDefinitionSpec.java

@@ -22,10 +22,6 @@
 @JsonDeserialize()
 public class AppDefinitionSpec {
 
-    public static final String API = "theia.cloud/v6beta";
-    public static final String KIND = "AppDefinition";
-    public static final String CRD_NAME = "appdefinitions.theia.cloud";
-
     @JsonProperty("name")
     private String name;
 

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/resource/AppDefinitionStatus.java

@@ -0,0 +1,23 @@
+/********************************************************************************
+ * Copyright (C) 2023 EclipseSource and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+package org.eclipse.theia.cloud.common.k8s.resource;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+
+@JsonDeserialize
+public class AppDefinitionStatus extends ResourceStatus {
+
+}

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/resource/OperatorStatus.java

@@ -0,0 +1,30 @@
+/********************************************************************************
+ * Copyright (C) 2022 EclipseSource and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+package org.eclipse.theia.cloud.common.k8s.resource;
+
+/**
+ * Constant values to describe resource handling.
+ */
+public interface OperatorStatus {
+
+    String NEW = "NEW";
+
+    String ERROR = "ERROR";
+
+    String HANDLING = "HANDLING";
+
+    String HANDLED = "HANDLED";
+}

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/resource/ResourceStatus.java

@@ -0,0 +1,44 @@
+/********************************************************************************
+ * Copyright (C) 2023 EclipseSource and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+package org.eclipse.theia.cloud.common.k8s.resource;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+public abstract class ResourceStatus {
+
+    @JsonProperty()
+    private String operatorStatus;
+
+    @JsonProperty()
+    private String operatorMessage;
+
+    public String getOperatorStatus() {
+	return operatorStatus;
+    }
+
+    public void setOperatorStatus(String operatorStatus) {
+	this.operatorStatus = operatorStatus;
+    }
+
+    public String getOperatorMessage() {
+	return operatorMessage;
+    }
+
+    public void setOperatorMessage(String operatorMessage) {
+	this.operatorMessage = operatorMessage;
+    }
+
+}

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/resource/Session.java

@@ -1,5 +1,5 @@
 /********************************************************************************
- * Copyright (C) 2022 EclipseSource, Lockular, Ericsson, STMicroelectronics and 
+ * Copyright (C) 2022-2023 EclipseSource, Lockular, Ericsson, STMicroelectronics and 
  * others.
  *
  * This program and the accompanying materials are made available under the
@@ -25,13 +25,16 @@
 import io.fabric8.kubernetes.model.annotation.Singular;
 import io.fabric8.kubernetes.model.annotation.Version;
 
-@Version("v4beta")
+@Version("v5beta")
 @Group("theia.cloud")
 @Singular("session")
 @Plural("sessions")
-public class Session extends CustomResource<SessionSpec, Void> implements Namespaced {
+public class Session extends CustomResource<SessionSpec, SessionStatus> implements Namespaced {
 
     private static final long serialVersionUID = 4518092300237069237L;
+    public static final String API = "theia.cloud/v5beta";
+    public static final String KIND = "Session";
+    public static final String CRD_NAME = "sessions.theia.cloud";
 
     @Override
     public String toString() {

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/resource/SessionSpec.java

@@ -28,10 +28,6 @@
 @JsonDeserialize()
 public class SessionSpec implements UserScopedSpec {
 
-    public static final String API = "theia.cloud/v4beta";
-    public static final String KIND = "Session";
-    public static final String CRD_NAME = "sessions.theia.cloud";
-
     @JsonProperty("name")
     private String name;
 

java/common/org.eclipse.theia.cloud.common/src/main/java/org/eclipse/theia/cloud/common/k8s/resource/SessionStatus.java

@@ -0,0 +1,23 @@
+/********************************************************************************
+ * Copyright (C) 2023 EclipseSource and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+package org.eclipse.theia.cloud.common.k8s.resource;
+
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+
+@JsonDeserialize
+public class SessionStatus extends ResourceStatus {
+
+}