Add new configuration parameter waitForInitialLoad to the `Breakerb…

…oxConfiguration`. This allows a user to block Dropwizard from starting for a period of time while waiting for initial `Breakerbox` configurations to be fetched. This avoids situations where you could be running with defaults or local configurations where they deviate or differ a lot from whatever `Breakerbox` has. Also, we should be applying `Breakerbox` configurations after local ones.

README.md

@@ -295,11 +295,13 @@ breakerbox:
   urls: http://breakerbox.yourcompany.com:8080/archaius/{service}
   initialDelay: 0s
   delay: 60s
+  waitForInitialLoad: 0s
 ```
 
 -   `urls` is a list of comma-deliminated list of urls for where to pull tenacity configurations. This will pull override configurations for all dependency keys for requested service.
 -   `initialDelay` how long before the first poll for newer configuration executes.
 -   `delay` the ongoing schedule to poll for newer configurations.
+-   `waitForInitialLoad` is the amount of item to block Dropwizard from starting while waiting for `Breakerbox` configurations.
 
 ![Breakerbox Dashboard](http://yammer.github.io/tenacity/breakerbox_latest.png)
 ![Breakerbox Configure](http://yammer.github.io/tenacity/breakerbox_configure.png)

pom.xml

@@ -69,6 +69,17 @@
         </repository>
     </distributionManagement>
 
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>com.github.tomakehurst</groupId>
+                <artifactId>wiremock</artifactId>
+                <scope>test</scope>
+                <version>${wiremock.version}</version>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+
     <repositories>
         <repository>
             <id>jcenter.bintray.com</id>
@@ -83,6 +94,7 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+        <wiremock.version>2.7.1</wiremock.version>
     </properties>
 
     <profiles>

tenacity-core/pom.xml

@@ -61,5 +61,15 @@
             <artifactId>mockito-core</artifactId>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.hamcrest</groupId>
+            <artifactId>hamcrest-core</artifactId>
+            <version>1.3</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>com.github.tomakehurst</groupId>
+            <artifactId>wiremock</artifactId>
+        </dependency>
     </dependencies>
 </project>

tenacity-core/src/main/java/com/yammer/tenacity/core/config/BreakerboxConfiguration.java

@@ -4,9 +4,6 @@
 
 import javax.validation.Valid;
 import javax.validation.constraints.NotNull;
-import java.util.Objects;
-
-import static com.google.common.base.Preconditions.checkNotNull;
 
 public class BreakerboxConfiguration {
     @NotNull @Valid
@@ -18,54 +15,44 @@ public class BreakerboxConfiguration {
     @NotNull @Valid
     private Duration delay = Duration.seconds(60);
 
-    public BreakerboxConfiguration() { /* Jackson */ }
+    @NotNull @Valid
+    private Duration waitForInitialLoad = Duration.milliseconds(0);
 
-    public BreakerboxConfiguration(String urls, Duration initialDelay, Duration delay) {
-        this.urls = checkNotNull(urls);
-        this.initialDelay = checkNotNull(initialDelay);
-        this.delay = checkNotNull(delay);
-    }
+    public BreakerboxConfiguration() { /* Jackson */ }
 
     public String getUrls() {
         return urls;
     }
 
-    public Duration getInitialDelay() {
-        return initialDelay;
-    }
-
-    public Duration getDelay() {
-        return delay;
-    }
-
     public void setUrls(String urls) {
         this.urls = urls;
     }
 
+    public Duration getInitialDelay() {
+        return initialDelay;
+    }
+
     public void setInitialDelay(Duration initialDelay) {
         this.initialDelay = initialDelay;
     }
 
+    public Duration getDelay() {
+        return delay;
+    }
+
     public void setDelay(Duration delay) {
         this.delay = delay;
     }
 
-    @Override
-    public int hashCode() {
-        return Objects.hash(urls, initialDelay, delay);
+    public Duration getWaitForInitialLoad() {
+        return waitForInitialLoad;
+    }
+
+    public void setWaitForInitialLoad(Duration waitForInitialLoad) {
+        this.waitForInitialLoad = waitForInitialLoad;
     }
 
-    @Override
-    public boolean equals(Object obj) {
-        if (this == obj) {
-            return true;
-        }
-        if (obj == null || getClass() != obj.getClass()) {
-            return false;
-        }
-        final BreakerboxConfiguration other = (BreakerboxConfiguration) obj;
-        return Objects.equals(this.urls, other.urls)
-                && Objects.equals(this.initialDelay, other.initialDelay)
-                && Objects.equals(this.delay, other.delay);
+    public boolean isWaitForInitialLoad() {
+        return waitForInitialLoad.getQuantity() > 0;
     }
 }

tenacity-core/src/main/java/com/yammer/tenacity/core/properties/ArchaiusPropertyRegister.java

@@ -7,11 +7,17 @@
 import com.netflix.config.PolledConfigurationSource;
 import com.netflix.config.sources.URLConfigurationSource;
 import com.yammer.tenacity.core.config.BreakerboxConfiguration;
+import io.dropwizard.util.Duration;
 import org.apache.commons.configuration.Configuration;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.concurrent.CountDownLatch;
+
 public class ArchaiusPropertyRegister {
+    private static final Logger LOGGER = LoggerFactory.getLogger(ArchaiusPropertyRegister.class);
+
+
     private static class TenacityPollingScheduler extends FixedDelayPollingScheduler {
         private static final Logger LOGGER = LoggerFactory.getLogger(TenacityPollingScheduler.class);
 
@@ -32,14 +38,33 @@ public void register(BreakerboxConfiguration breakerboxConfiguration) {
         if (breakerboxConfiguration.getUrls().isEmpty()) {
             return;
         }
+
+        final TenacityPollingScheduler tenacityPollingScheduler = new TenacityPollingScheduler(
+                Ints.checkedCast(breakerboxConfiguration.getInitialDelay().toMilliseconds()),
+                Ints.checkedCast(breakerboxConfiguration.getDelay().toMilliseconds()),
+                true);
+
+        final CountDownLatch countDownLatch = new CountDownLatch(1);
+
+        if (breakerboxConfiguration.isWaitForInitialLoad()) {
+            tenacityPollingScheduler.addPollListener((eventType, lastResult, exception) -> countDownLatch.countDown());
+        }
+
         final DynamicConfiguration dynConfig = new DynamicConfiguration(
                 new URLConfigurationSource(breakerboxConfiguration.getUrls().split(",")),
-                new TenacityPollingScheduler(
-                        Ints.checkedCast(breakerboxConfiguration.getInitialDelay().toMilliseconds()),
-                        Ints.checkedCast(breakerboxConfiguration.getDelay().toMilliseconds()),
-                        true));
+                tenacityPollingScheduler);
 
         ConfigurationManager.getConfigInstance();
         ConfigurationManager.loadPropertiesFromConfiguration(dynConfig);
+
+        if (breakerboxConfiguration.isWaitForInitialLoad()) {
+            final Duration duration = breakerboxConfiguration.getWaitForInitialLoad();
+            try {
+                final boolean success = countDownLatch.await(duration.getQuantity(), duration.getUnit());
+                LOGGER.info("Breakerbox initial configuration load: {}", success ? "SUCCESS" : "FAILURE");
+            } catch (Exception err) {
+                LOGGER.warn("Failed waiting for Breakerbox initial load", err);
+            }
+        }
     }
 }

tenacity-core/src/main/java/com/yammer/tenacity/core/properties/TenacityPropertyRegister.java

@@ -28,11 +28,11 @@ public TenacityPropertyRegister(Map<TenacityPropertyKey, TenacityConfiguration>
     }
 
     public void register() {
-        archaiusPropertyRegister.register(breakerboxConfiguration);
         final AbstractConfiguration configInstance = ConfigurationManager.getConfigInstance();
         for (Map.Entry<TenacityPropertyKey, TenacityConfiguration> entry : configurations.entrySet()) {
             registerConfiguration(entry.getKey(), entry.getValue(), configInstance);
         }
+        archaiusPropertyRegister.register(breakerboxConfiguration);
     }
 
     public static void registerCircuitForceOpen(TenacityPropertyKey key) {

tenacity-core/src/test/java/com/yammer/tenacity/tests/ArchaiusPropertyRegisterBlockStartupTest.java

@@ -0,0 +1,107 @@
+package com.yammer.tenacity.tests;
+
+import com.github.tomakehurst.wiremock.junit.WireMockRule;
+import com.google.common.io.Resources;
+import com.google.common.primitives.Ints;
+import com.yammer.tenacity.core.bundle.TenacityBundleBuilder;
+import com.yammer.tenacity.core.bundle.TenacityBundleConfigurationFactory;
+import com.yammer.tenacity.core.config.BreakerboxConfiguration;
+import com.yammer.tenacity.core.config.TenacityConfiguration;
+import com.yammer.tenacity.core.properties.StringTenacityPropertyKeyFactory;
+import com.yammer.tenacity.core.properties.TenacityPropertyKey;
+import com.yammer.tenacity.core.properties.TenacityPropertyKeyFactory;
+import com.yammer.tenacity.testing.TenacityTestRule;
+import io.dropwizard.Application;
+import io.dropwizard.Configuration;
+import io.dropwizard.setup.Bootstrap;
+import io.dropwizard.setup.Environment;
+import io.dropwizard.testing.junit.DropwizardAppRule;
+import org.junit.BeforeClass;
+import org.junit.ClassRule;
+import org.junit.Rule;
+import org.junit.Test;
+
+import javax.validation.Valid;
+import javax.validation.constraints.NotNull;
+import java.time.Duration;
+import java.util.Collections;
+import java.util.Map;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+
+import static com.github.tomakehurst.wiremock.client.WireMock.*;
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class ArchaiusPropertyRegisterBlockStartupTest {
+    @ClassRule
+    public static final WireMockRule wireMockRule = new WireMockRule(55789);
+
+    @Rule
+    public TenacityTestRule tenacityTestRule = new TenacityTestRule();
+
+    @Rule
+    public final DropwizardAppRule<AppConfiguration> rule = new DropwizardAppRule<>(
+            App.class, Resources.getResource("waitForInitialLoadApp.yml").getPath());
+
+    private static class AppConfiguration extends Configuration {
+        @NotNull @Valid
+        private BreakerboxConfiguration breakerbox;
+
+        public BreakerboxConfiguration getBreakerbox() {
+            return breakerbox;
+        }
+    }
+
+    public static class App extends Application<AppConfiguration> {
+        public static void main(String[] args) throws Exception {
+            new TenacityConfiguredBundleBuilderTest.TenacityBundleApp().run(args);
+        }
+
+        final CountDownLatch startedLatch = new CountDownLatch(1);
+
+        @Override
+        public void initialize(Bootstrap<AppConfiguration> bootstrap) {
+            bootstrap.addBundle(TenacityBundleBuilder
+                    .<AppConfiguration>newBuilder()
+                    .configurationFactory(new TenacityBundleConfigurationFactory<AppConfiguration>() {
+                        @Override
+                        public Map<TenacityPropertyKey, TenacityConfiguration> getTenacityConfigurations(AppConfiguration applicationConfiguration) {
+                            return Collections.emptyMap();
+                        }
+
+                        @Override
+                        public TenacityPropertyKeyFactory getTenacityPropertyKeyFactory(AppConfiguration applicationConfiguration) {
+                            return new StringTenacityPropertyKeyFactory();
+                        }
+
+                        @Override
+                        public BreakerboxConfiguration getBreakerboxConfiguration(AppConfiguration applicationConfiguration) {
+                            return applicationConfiguration.getBreakerbox();
+                        }
+                    })
+                    .build());
+        }
+
+        @Override
+        public void run(AppConfiguration configuration, Environment environment) throws Exception {
+            startedLatch.countDown();
+        }
+    }
+
+    @BeforeClass
+    public static void init() {
+        wireMockRule.stubFor(get(urlEqualTo("/archaius/test"))
+                .willReturn(aResponse()
+                        .withFixedDelay(Ints.checkedCast(Duration.ofSeconds(2).toMillis()))
+                        .withStatus(200)));
+    }
+
+
+    @Test
+    public void waitingForInitialLoadBlocksDropwizardFromStarting() throws Exception {
+        assertThat(((App)rule.getApplication()).startedLatch.await(5, TimeUnit.SECONDS)).isTrue();
+
+        verify(getRequestedFor(urlMatching("/archaius/test")));
+    }
+
+}

tenacity-core/src/test/resources/waitForInitialLoadApp.yml

@@ -0,0 +1,13 @@
+server:
+  applicationConnectors:
+    - type: http
+      port: 0
+  adminConnectors:
+    - type: http
+      port: 0
+
+breakerbox:
+  urls: http://127.0.0.1:55789/archaius/test
+  initialDelay: 0s
+  delay: 60s
+  waitForInitialLoad: 5s