From de7d18e02632e87a70a75574fd5adf46c4783289 Mon Sep 17 00:00:00 2001
From: Sebastian Sdorra <sebastian.sdorra@cloudogu.com>
Date: Wed, 21 Aug 2019 08:42:57 +0200
Subject: [PATCH] cancel all pending installations, if a dependency failed to
 install

---
 .../scm/plugin/DefaultPluginManager.java      | 47 ++++++++++++++-----
 .../scm/plugin/DefaultPluginManagerTest.java  | 24 ++++++++++
 2 files changed, 60 insertions(+), 11 deletions(-)

diff --git a/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java b/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java
index 77a13686c8..d670a6609c 100644
--- a/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java
+++ b/scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java
@@ -43,6 +43,7 @@ import sonia.scm.NotFoundException;
 
 //~--- JDK imports ------------------------------------------------------------
 import javax.inject.Inject;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Optional;
 import java.util.Set;
@@ -99,7 +100,7 @@ public class DefaultPluginManager implements PluginManager {
   }
 
   private <T extends Plugin> Predicate<T> filterByName(String name) {
-    return (plugin) -> name.equals(plugin.getDescriptor().getInformation().getName());
+    return plugin -> name.equals(plugin.getDescriptor().getInformation().getName());
   }
 
   private boolean isNotInstalled(AvailablePlugin availablePlugin) {
@@ -108,18 +109,42 @@ public class DefaultPluginManager implements PluginManager {
 
   @Override
   public void install(String name) {
-    if (getInstalled(name).isPresent()){
-      LOG.info("plugin {} is already installed, skipping installation", name);
-      return;
-    }
-    AvailablePlugin plugin = getAvailable(name).orElseThrow(() -> NotFoundException.notFound(entity(AvailablePlugin.class, name)));
-    Set<String> dependencies = plugin.getDescriptor().getDependencies();
-    if (dependencies != null) {
-      for (String dependency: dependencies){
-        install(dependency);
+    List<AvailablePlugin> plugins = collectPluginsToInstall(name);
+    List<PendingPluginInstallation> pendingInstallations = new ArrayList<>();
+    for (AvailablePlugin plugin : plugins) {
+      try {
+        PendingPluginInstallation pending = installer.install(plugin);
+        pendingInstallations.add(pending);
+      } catch (PluginInstallException ex) {
+        cancelPending(pendingInstallations);
+        throw ex;
       }
     }
+  }
 
-    installer.install(plugin);
+  private void cancelPending(List<PendingPluginInstallation> pendingInstallations) {
+    pendingInstallations.forEach(PendingPluginInstallation::cancel);
+  }
+
+  private List<AvailablePlugin> collectPluginsToInstall(String name) {
+    List<AvailablePlugin> plugins = new ArrayList<>();
+    collectPluginsToInstall(plugins, name);
+    return plugins;
+  }
+  private void collectPluginsToInstall(List<AvailablePlugin> plugins, String name) {
+    if (!getInstalled(name).isPresent()) {
+      AvailablePlugin plugin = getAvailable(name).orElseThrow(() -> NotFoundException.notFound(entity(AvailablePlugin.class, name)));
+
+      Set<String> dependencies = plugin.getDescriptor().getDependencies();
+      if (dependencies != null) {
+        for (String dependency: dependencies){
+          collectPluginsToInstall(plugins, dependency);
+        }
+      }
+
+      plugins.add(plugin);
+    } else {
+      LOG.info("plugin {} is already installed, skipping installation", name);
+    }
   }
 }
diff --git a/scm-webapp/src/test/java/sonia/scm/plugin/DefaultPluginManagerTest.java b/scm-webapp/src/test/java/sonia/scm/plugin/DefaultPluginManagerTest.java
index c23f9394c3..2ab111689a 100644
--- a/scm-webapp/src/test/java/sonia/scm/plugin/DefaultPluginManagerTest.java
+++ b/scm-webapp/src/test/java/sonia/scm/plugin/DefaultPluginManagerTest.java
@@ -13,6 +13,7 @@ import java.util.List;
 import java.util.Optional;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.Mockito.*;
 
 @ExtendWith(MockitoExtension.class)
@@ -153,6 +154,29 @@ class DefaultPluginManagerTest {
     verify(installer).install(review);
   }
 
+  @Test
+  void shouldRollbackOnFailedInstallation() {
+    AvailablePlugin review = createAvailable("scm-review-plugin");
+    when(review.getDescriptor().getDependencies()).thenReturn(ImmutableSet.of("scm-mail-plugin"));
+    AvailablePlugin mail = createAvailable("scm-mail-plugin");
+    when(mail.getDescriptor().getDependencies()).thenReturn(ImmutableSet.of("scm-notification-plugin"));
+    AvailablePlugin notification = createAvailable("scm-notification-plugin");
+    when(center.getAvailable()).thenReturn(ImmutableSet.of(review, mail, notification));
+
+    PendingPluginInstallation pendingNotification = mock(PendingPluginInstallation.class);
+    doReturn(pendingNotification).when(installer).install(notification);
+
+    PendingPluginInstallation pendingMail = mock(PendingPluginInstallation.class);
+    doReturn(pendingMail).when(installer).install(mail);
+
+    doThrow(new PluginChecksumMismatchException("checksum does not match")).when(installer).install(review);
+
+    assertThrows(PluginInstallException.class, () -> manager.install("scm-review-plugin"));
+
+    verify(pendingNotification).cancel();
+    verify(pendingMail).cancel();
+  }
+
   private AvailablePlugin createAvailable(String name) {
     PluginInformation information = new PluginInformation();
     information.setName(name);