Move a bunch of interfaces and utility classes into the karyon-api

karyon3-api/build.gradle

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2015 Netflix, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+apply plugin: 'java'
+
+repositories {
+    maven { url 'https://oss.jfrog.org/libs-snapshot' }
+}
+
+dependencies {
+}
+
+eclipse {
+    classpath {
+        downloadSources = true
+        downloadJavadoc = true
+    }
+}

karyon3-core/src/main/java/com/netflix/karyon/KaryonFeature.java → karyon3-api/src/main/java/com/netflix/karyon/api/KaryonFeature.java

@@ -1,11 +1,10 @@
-package com.netflix.karyon;
+package com.netflix.karyon.api;
 
 /**
- * Base interface for all {@link Karyon} features to be implemented by an 
+ * Base interface for all Karyon features to be implemented by an 
  * enum, such as {@link KaryonFeatures}.  Each feature has an implicit
  * default value. 
  * 
- * @see Karyon
  * @author elandau
  */
 public interface KaryonFeature {

karyon3-core/src/main/java/com/netflix/karyon/KaryonFeatures.java → karyon3-api/src/main/java/com/netflix/karyon/api/KaryonFeatures.java

@@ -1,7 +1,8 @@
-package com.netflix.karyon;
+package com.netflix.karyon.api;
+
 
 /**
- * Core karyon features.  Features are configured/enabled on {@link KaryonConfiguration}
+ * Core karyon features 
  * 
  * @author elandau
  */

karyon3-core/src/main/java/com/netflix/karyon/PropertySource.java → karyon3-api/src/main/java/com/netflix/karyon/api/PropertySource.java

@@ -1,26 +1,22 @@
-package com.netflix.karyon;
+package com.netflix.karyon.api;
 
-import com.google.inject.ImplementedBy;
 
 /**
  * Very simple config interface to be used by Conditions to gain access
  * to any type of configuration.  The internal default in AutoModuleBuilder 
  * is to delegate to System properties.
  * 
- * @see PropertiesPropertySource
- * 
  * @author elandau
  * 
  */
-@ImplementedBy(DefaultPropertySource.class)
 public interface PropertySource {
     /**
      * Get the value of a property or null if not found
      * 
      * @param key
      * @return
      */
-    public String get(String key);
+    String get(String key);
 
     /**
      * Get the value of a property or default if not found
@@ -29,7 +25,7 @@ public interface PropertySource {
      * @param defaultValue
      * @return
      */
-    public String get(String key, String defaultValue);
+    String get(String key, String defaultValue);
 
     /**
      * Get a property value of a specific type
@@ -38,7 +34,7 @@ public interface PropertySource {
      * @param type
      * @return
      */
-    public <T> T get(String key, Class<T> type);
+    <T> T get(String key, Class<T> type);
 
     /**
      * Get a property value of a specific type while returning a 
@@ -49,5 +45,5 @@ public interface PropertySource {
      * @param defaultValue
      * @return
      */
-    public <T> T get(String key, Class<T> type, T defaultValue);
+    <T> T get(String key, Class<T> type, T defaultValue);
 }

karyon3-core/src/main/java/com/netflix/karyon/ServerContext.java → karyon3-api/src/main/java/com/netflix/karyon/api/ServerContext.java

@@ -1,4 +1,4 @@
-package com.netflix.karyon;
+package com.netflix.karyon.api;
 
 /**
  * Standardized set of properties 

karyon3-api/src/main/java/com/netflix/karyon/api/health/HealthCheck.java

@@ -0,0 +1,16 @@
+package com.netflix.karyon.api.health;
+
+import java.util.concurrent.CompletableFuture;
+
+/**
+ * Contract for the top level application health check.  This is the HealthCheck
+ * to be consulted when exposing a HealthCheck endpoint or for use when registering
+ * with a service registry service.
+ */
+public interface HealthCheck {
+    /**
+     * Perform a health check.
+     * @return A future on which the health check result will be emitted
+     */
+    CompletableFuture<HealthCheckStatus> check();
+}

karyon3-api/src/main/java/com/netflix/karyon/api/health/HealthCheckStatus.java

@@ -0,0 +1,32 @@
+package com.netflix.karyon.api.health;
+
+import java.util.List;
+
+/**
+ * Instance of a HealthCheck response and utility methods for creating specific statuses
+ */
+public interface HealthCheckStatus {
+    /**
+     * @return Final health check status
+     */
+    HealthState getState();
+
+    /**
+     * @return List of indicator statuses that were used to determine HealthCheck
+     */
+    List<HealthIndicatorStatus> getIndicators();
+
+    public static HealthCheckStatus create(HealthState state, List<HealthIndicatorStatus> indicators) {
+        return new HealthCheckStatus() {
+            @Override
+            public HealthState getState() {
+                return state;
+            }
+
+            @Override
+            public List<HealthIndicatorStatus> getIndicators() {
+                return indicators;
+            }
+        };
+    }
+}

karyon3-core/src/main/java/com/netflix/karyon/health/HealthIndicator.java → karyon3-api/src/main/java/com/netflix/karyon/api/health/HealthIndicator.java

@@ -1,4 +1,4 @@
-package com.netflix.karyon.health;
+package com.netflix.karyon.api.health;
 
 import java.util.concurrent.CompletableFuture;
 
@@ -50,4 +50,26 @@ public interface HealthIndicator {
      * Return the name of the health indicator.  Note that health indicators with duplicate names are allowed.
      */
     String getName();
+
+    public static HealthIndicator alwaysHealthy(String name) {
+        return memoize(name, HealthIndicatorStatus.healthy(name));
+    }
+
+    public static HealthIndicator alwaysUnhealthy(String name) {
+        return memoize(name, HealthIndicatorStatus.unhealthy(name, new Exception("Unhealthy")));
+    }
+
+    public static HealthIndicator memoize(final String name, final HealthIndicatorStatus status) {
+        return new HealthIndicator() {
+            @Override
+            public CompletableFuture<HealthIndicatorStatus> check() {
+                return CompletableFuture.completedFuture(status);
+            }
+
+            @Override
+            public String getName() {
+                return name;
+            }
+        };
+    }
 }

karyon3-core/src/main/java/com/netflix/karyon/health/HealthIndicatorRegistry.java → karyon3-api/src/main/java/com/netflix/karyon/api/health/HealthIndicatorRegistry.java

@@ -1,29 +1,12 @@
-package com.netflix.karyon.health;
+package com.netflix.karyon.api.health;
 
 import java.util.Arrays;
 import java.util.List;
 
-import com.google.inject.ImplementedBy;
-
 /**
  * Registry of active HealthIndicator's.  The HealthIndicator are used by {@link HealthCheck} to 
  * determine the application health.
- * 
- * The default registry, {@link AllHealthIndicatorRegistry} uses Guice bindings to determine the
- * list of all active indicators.  To create a curated list of {@link HealthIndicator}s regardless of 
- * Guice bindings create a binding to HealthIndicatorRegistry as follows
- * 
- * <code>
- * {@literal @}Provides
- * {@literal @}Singleton
- * HealthIndicatorRegistry getHealthIndicatorRegistry({@literal @}Named("cpu") HealthIndicator cpuIndicator, {@literal @}Named("foo") HealthIndicator fooIndicator) {
- *    return HealthIndicatorRegistry.from(cpuIndicator, fooIndicator);
- * }
- * </code>
- * 
- * @author elandau
  */
-@ImplementedBy(AllHealthIndicatorRegistry.class)
 public interface HealthIndicatorRegistry {
     /**
      * Return a list of all active health checks

karyon3-core/src/main/java/com/netflix/karyon/health/HealthIndicatorStatuses.java → karyon3-api/src/main/java/com/netflix/karyon/api/health/HealthIndicatorStatus.java

@@ -1,4 +1,4 @@
-package com.netflix.karyon.health;
+package com.netflix.karyon.api.health;
 
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
@@ -7,14 +7,45 @@
 import java.util.Map.Entry;
 
 /**
- * Utility class for creating common {@link HealthIndicatorStatus} instances
+ * Immutable health check instance returned from a {@link HealthIndicator}
  * 
+ * See {@link HealthIndicatorStatus} for utility methods to create HealthIndicatorStatus objects
  * @author elandau
- *
  */
-public final class HealthIndicatorStatuses {
+public interface HealthIndicatorStatus {
+    /**
+     * @return Map of named attributes that provide additional information regarding the health.
+     * For example, a CPU health check may return Unhealthy with attribute "usage"="90%"
+     */
+    public Map<String, Object> getAttributes();
 
-    private static final DateTimeFormatter DATE_TIME_FORMAT = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss z");
+    /**
+     * @return True if healthy or false otherwise.
+     */
+    public boolean isHealthy();
+
+    /**
+     * @return Exception providing additional information regarding the failure state.  This could be
+     * the last known exception. 
+     */
+    public String getError();
+
+    /**
+     * @return True if the status includes a error description
+     */
+    public boolean hasError();
+
+    /**
+     * @return Time when healthcheck was conducted
+     */
+    public String getTimestamp();
+
+    /**
+     * @return Name of HealthIndicator from which this status was created
+     */
+    public String getName();
+
+    static final DateTimeFormatter DATE_TIME_FORMAT = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss z");
 
     public static HealthIndicatorStatus healthy(String name) {
         return create(name, true, Collections.<String, Object>emptyMap(), null);

karyon3-core/src/main/java/com/netflix/karyon/health/HealthState.java → karyon3-api/src/main/java/com/netflix/karyon/api/health/HealthState.java

@@ -1,5 +1,8 @@
-package com.netflix.karyon.health;
+package com.netflix.karyon.api.health;
 
+/**
+ * Health state of an application
+ */
 public enum HealthState {
     Starting,
     Healthy,

karyon3-core/src/main/java/com/netflix/karyon/lifecycle/ApplicationLifecycle.java → karyon3-api/src/main/java/com/netflix/karyon/api/lifecycle/ApplicationLifecycle.java

@@ -1,6 +1,4 @@
-package com.netflix.karyon.lifecycle;
-
-import com.google.inject.ImplementedBy;
+package com.netflix.karyon.api.lifecycle;
 
 /**
  * Contract for tracking the application LifecycleState.  The application LifecycleState
@@ -64,7 +62,6 @@
  * @author elandau
  *
  */
-@ImplementedBy(LifecycleListenerApplicationLifecycle.class)
 public interface ApplicationLifecycle {
     public interface Listener {
         void onStateChanged(LifecycleState state);

karyon3-api/src/main/java/com/netflix/karyon/api/lifecycle/LifecycleState.java

@@ -0,0 +1,14 @@
+package com.netflix.karyon.api.lifecycle;
+
+/**
+ * State of an application lifecycle.  State transitions are linear as described in 
+ * the following diagram.  
+ * 
+ * {@code  O -> Starting -> Running -> Stopping -> Stopped -> (O) }
+ */
+public enum LifecycleState {
+    Starting,
+    Running,
+    Stopping,
+    Stopped
+}

karyon3-core/src/main/java/com/netflix/karyon/health/AbstractHealthIndicator.java → karyon3-api/src/main/java/com/netflix/karyon/spi/health/AbstractHealthIndicator.java

@@ -1,8 +1,11 @@
-package com.netflix.karyon.health;
+package com.netflix.karyon.spi.health;
 
 import java.util.Collections;
 import java.util.Map;
 
+import com.netflix.karyon.api.health.HealthIndicator;
+import com.netflix.karyon.api.health.HealthIndicatorStatus;
+
 public abstract class AbstractHealthIndicator implements HealthIndicator {
     private final String name;
 
@@ -37,7 +40,7 @@ public String getName() {
      */
 
     protected final HealthIndicatorStatus healthy() {
-        return HealthIndicatorStatuses.create(getName(), true, Collections.<String, Object> emptyMap(), null);
+        return HealthIndicatorStatus.create(getName(), true, Collections.<String, Object> emptyMap(), null);
     }
 
     /**
@@ -48,7 +51,7 @@ protected final HealthIndicatorStatus healthy() {
      * @return a healthy status
      */
     protected final HealthIndicatorStatus healthy(Map<String, Object> attr) {
-        return HealthIndicatorStatuses.create(getName(), true, attr, null);
+        return HealthIndicatorStatus.create(getName(), true, attr, null);
     }
 
     /**
@@ -58,7 +61,7 @@ protected final HealthIndicatorStatus healthy(Map<String, Object> attr) {
      * @return a unhealthy status
      */
     protected final HealthIndicatorStatus unhealthy() {
-        return HealthIndicatorStatuses.create(getName(), false, Collections.<String, Object> emptyMap(), null);
+        return HealthIndicatorStatus.create(getName(), false, Collections.<String, Object> emptyMap(), null);
     }
 
     /**
@@ -68,7 +71,7 @@ protected final HealthIndicatorStatus unhealthy() {
      * @return a unhealthy status
      */
     protected final HealthIndicatorStatus unhealthy(Map<String, Object> attr) {
-        return HealthIndicatorStatuses.create(getName(), false, attr, null);
+        return HealthIndicatorStatus.create(getName(), false, attr, null);
     }
 
     /**
@@ -78,7 +81,7 @@ protected final HealthIndicatorStatus unhealthy(Map<String, Object> attr) {
      * @return a unhealthy status
      */
     protected final HealthIndicatorStatus unhealthy(Throwable t) {
-        return HealthIndicatorStatuses.create(getName(), false, Collections.<String, Object> emptyMap(), t);
+        return HealthIndicatorStatus.create(getName(), false, Collections.<String, Object> emptyMap(), t);
     }
 
     /**
@@ -88,7 +91,7 @@ protected final HealthIndicatorStatus unhealthy(Throwable t) {
      * @return a unhealthy status
      */
     protected final HealthIndicatorStatus unhealthy(Map<String, Object> attr, Throwable t) {
-        return HealthIndicatorStatuses.create(getName(), false, attr, t);
+        return HealthIndicatorStatus.create(getName(), false, attr, t);
     }
 
 }