Prevent Styx from starting when initial origins configuration fails t…

…o load.

Origins reload command to return 500 Internal Server Error (as opposed to 400 Bad Request)
when the origins file failed to reload.

components/proxy/src/main/java/com/hotels/styx/admin/tasks/OriginsReloadCommandHandler.java

@@ -1,5 +1,5 @@
 /**
- * Copyright (C) 2013-2017 Expedia Inc.
+ * Copyright (C) 2013-2018 Expedia Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -72,6 +72,8 @@ private void reload(Subscriber<? super HttpResponse> subscriber) {
                         } else if (result.outcome() == UNCHANGED) {
                             subscriber.onNext(okResponse(format("Origins were not reloaded because %s.\n", result.message())));
                             subscriber.onCompleted();
+                        } else {
+                            subscriber.onError(mapError(result));
                         }
                     } else {
                         subscriber.onNext(errorResponse(exception));
@@ -81,6 +83,14 @@ private void reload(Subscriber<? super HttpResponse> subscriber) {
                 });
     }
 
+    private Throwable mapError(Registry.ReloadResult result) {
+        if (result.cause().isPresent()) {
+            return new RuntimeException(result.cause().get());
+        } else {
+            return new RuntimeException("Reload failure");
+        }
+    }
+
     private HttpResponse okResponse(String content) {
         return response(OK)
                 .contentType(PLAIN_TEXT_UTF_8)

components/proxy/src/main/java/com/hotels/styx/proxy/backends/file/FileBackedBackendServicesRegistry.java

@@ -37,6 +37,7 @@
 import static com.google.common.base.Throwables.propagate;
 import static com.hotels.styx.api.io.ResourceFactory.newResource;
 import static com.hotels.styx.client.applications.BackendServices.newBackendServices;
+import static com.hotels.styx.infrastructure.Registry.Outcome.FAILED;
 import static java.lang.String.format;
 import static java.util.Objects.requireNonNull;
 
@@ -102,7 +103,12 @@ protected CompletableFuture<Void> startService() {
             return x;
         }
         return this.fileBackedRegistry.reload()
-                .thenAccept(result -> logReloadAttempt("Initial load", result));
+                .thenApply(result -> logReloadAttempt("Initial load", result))
+                .thenAccept(result -> {
+                    if (result.outcome() == FAILED) {
+                        throw new RuntimeException(result.cause().orElse(null));
+                    }
+                });
     }
 
     @Override
@@ -125,7 +131,7 @@ private ReloadResult logReloadAttempt(String reason, ReloadResult outcome) {
         String fileName = this.fileBackedRegistry.fileName();
         if (outcome.outcome() == Outcome.RELOADED || outcome.outcome() == Outcome.UNCHANGED) {
             LOGGER.info("Backend services reloaded. reason='{}', {}, file='{}'", new Object[]{reason, outcome.message(), fileName});
-        } else if (outcome.outcome() == Outcome.FAILED) {
+        } else if (outcome.outcome() == FAILED) {
             LOGGER.error("Backend services reload failed. reason='{}', {}, file='{}'",
                     new Object[]{reason, outcome.message(), fileName, outcome.cause().get()});
         }

components/proxy/src/test/java/com/hotels/styx/proxy/backends/file/FileBackedBackendServicesRegistryTest.java

@@ -31,6 +31,7 @@
 import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionException;
+import java.util.concurrent.ExecutionException;
 
 import static ch.qos.logback.classic.Level.ERROR;
 import static ch.qos.logback.classic.Level.INFO;
@@ -192,8 +193,9 @@ public void serviceStarts_logsInfoWhenReloadSucceeds() throws Exception {
         ));
     }
 
-    @Test
-    public void serviceStarts_logsInfoWhenReloadFails() throws Exception {
+    @Test(expectedExceptions = ExecutionException.class,
+            expectedExceptionsMessageRegExp = "java.lang.RuntimeException: java.lang.RuntimeException: something went wrong")
+    public void serviceStarts_failsToStartWhenReloadFails() throws Exception {
         FileBackedRegistry<BackendService> delegate = mock(FileBackedRegistry.class);
         when(delegate.fileName()).thenReturn("/monitored/origins.yml");
         when(delegate.reload()).thenReturn(
@@ -203,14 +205,32 @@ public void serviceStarts_logsInfoWhenReloadFails() throws Exception {
 
         registry = new FileBackedBackendServicesRegistry(delegate);
         registry.startService().get();
+    }
 
-        assertThat(log.lastMessage(), is(
-                loggingEvent(
-                        ERROR,
-                        "Backend services reload failed. reason='Initial load', md5-hash: 9034890345289043, Failed to load file, file='/monitored/origins.yml'",
-                        RuntimeException.class,
-                        "something went wrong")
-        ));
+    @Test
+    public void serviceStarts_logsInfoWhenReloadFails() {
+        FileBackedRegistry<BackendService> delegate = mock(FileBackedRegistry.class);
+        when(delegate.fileName()).thenReturn("/monitored/origins.yml");
+        when(delegate.reload()).thenReturn(
+                completedFuture(failed(
+                        "md5-hash: 9034890345289043, Failed to load file",
+                        new RuntimeException("something went wrong"))));
+
+        registry = new FileBackedBackendServicesRegistry(delegate);
+
+        try {
+            registry.startService().get();
+        } catch (Throwable any) {
+              // pass
+        } finally {
+            assertThat(log.lastMessage(), is(
+                    loggingEvent(
+                            ERROR,
+                            "Backend services reload failed. reason='Initial load', md5-hash: 9034890345289043, Failed to load file, file='/monitored/origins.yml'",
+                            RuntimeException.class,
+                            "something went wrong")
+            ));
+        }
     }
 
     @Test

system-tests/e2e-suite/src/test/scala/com/hotels/styx/admin/OriginsReloadCommandSpec.scala

@@ -19,8 +19,8 @@ import java.nio.file.StandardCopyOption.REPLACE_EXISTING
 import java.nio.file.{Files, Paths}
 
 import com.google.common.io.Files.createTempDir
-import com.hotels.styx.api.HttpRequest
-import com.hotels.styx.api.messages.HttpResponseStatus.BAD_REQUEST
+import com.hotels.styx.api.HttpRequest.Builder.post
+import com.hotels.styx.api.messages.HttpResponseStatus.INTERNAL_SERVER_ERROR
 import com.hotels.styx.proxy.backends.file.FileBackedBackendServicesRegistry
 import com.hotels.styx.support.ResourcePaths.fixturesHome
 import com.hotels.styx.support.configuration._
@@ -44,16 +44,16 @@ class OriginsReloadCommandSpec extends FunSpec
   val styxOriginsFile = Paths.get(tempDir.toString, "origins.yml")
   var styxServer: StyxServer = _
 
-  it("Responds with BAD_REQUEST when the origins cannot be read") {
+  it("Responds with INTERNAL_SERVER_ERROR when the origins cannot be read") {
     val fileBasedBackendsRegistry = FileBackedBackendServicesRegistry.create(styxOriginsFile.toString)
     styxServer = StyxConfig().startServer(fileBasedBackendsRegistry)
 
     styxServer.isRunning should be(true)
 
     Files.copy(originsNok, styxOriginsFile, REPLACE_EXISTING)
 
-    val resp = decodedRequest(HttpRequest.Builder.post(styxServer.adminURL("/admin/tasks/origins/reload")).build())
-    resp.status() should be(BAD_REQUEST)
+    val resp = decodedRequest(post(styxServer.adminURL("/admin/tasks/origins/reload")).build())
+    resp.status() should be(INTERNAL_SERVER_ERROR)
 
     BackendService.fromJava(fileBasedBackendsRegistry.get().asScala.head) should be(
       BackendService(