implemented plugin installation

scm-webapp/src/main/java/sonia/scm/plugin/DefaultPluginManager.java

@@ -37,14 +37,20 @@ package sonia.scm.plugin;
 
 import com.google.common.collect.ImmutableList;
 import com.google.inject.Singleton;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import sonia.scm.NotFoundException;
 
 //~--- JDK imports ------------------------------------------------------------
 import javax.inject.Inject;
 import java.util.List;
 import java.util.Optional;
+import java.util.Set;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
+import static sonia.scm.ContextEntry.ContextBuilder.entity;
+
 /**
  *
  * @author Sebastian Sdorra
@@ -52,13 +58,17 @@ import java.util.stream.Collectors;
 @Singleton
 public class DefaultPluginManager implements PluginManager {
 
+  private static final Logger LOG = LoggerFactory.getLogger(DefaultPluginManager.class);
+
   private final PluginLoader loader;
   private final PluginCenter center;
+  private final PluginInstaller installer;
 
   @Inject
-  public DefaultPluginManager(PluginLoader loader, PluginCenter center) {
+  public DefaultPluginManager(PluginLoader loader, PluginCenter center, PluginInstaller installer) {
     this.loader = loader;
     this.center = center;
+    this.installer = installer;
   }
 
   @Override
@@ -98,6 +108,18 @@ 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);
+      }
+    }
 
+    installer.install(plugin);
   }
 }

scm-webapp/src/main/java/sonia/scm/plugin/PluginCenterDto.java

@@ -3,6 +3,7 @@ package sonia.scm.plugin;
 import com.google.common.collect.ImmutableList;
 import lombok.AllArgsConstructor;
 import lombok.Getter;
+import lombok.NoArgsConstructor;
 
 import javax.xml.bind.annotation.XmlAccessType;
 import javax.xml.bind.annotation.XmlAccessorType;
@@ -77,6 +78,8 @@ public final class PluginCenterDto implements Serializable {
 
   @XmlAccessorType(XmlAccessType.FIELD)
   @Getter
+  @NoArgsConstructor
+  @AllArgsConstructor
   static class Link {
     private String href;
   }

scm-webapp/src/main/java/sonia/scm/plugin/PluginCenterDtoMapper.java

@@ -17,8 +17,9 @@ public abstract class PluginCenterDtoMapper  {
   Set<AvailablePlugin> map(PluginCenterDto pluginCenterDto) {
     Set<AvailablePlugin> plugins = new HashSet<>();
     for (PluginCenterDto.Plugin plugin : pluginCenterDto.getEmbedded().getPlugins()) {
+      String url = plugin.getLinks().get("download").getHref();
       AvailablePluginDescriptor descriptor = new AvailablePluginDescriptor(
-        map(plugin), map(plugin.getConditions()), plugin.getDependencies()
+        map(plugin), map(plugin.getConditions()), plugin.getDependencies(), url, plugin.getSha256()
       );
       plugins.add(new AvailablePlugin(descriptor));
     }

scm-webapp/src/main/java/sonia/scm/plugin/PluginChecksumMismatchException.java

@@ -0,0 +1,7 @@
+package sonia.scm.plugin;
+
+public class PluginChecksumMismatchException extends PluginInstallException {
+  public PluginChecksumMismatchException(String message) {
+    super(message);
+  }
+}

scm-webapp/src/main/java/sonia/scm/plugin/PluginDownloadException.java

@@ -0,0 +1,7 @@
+package sonia.scm.plugin;
+
+public class PluginDownloadException extends PluginInstallException {
+  public PluginDownloadException(String message, Throwable cause) {
+    super(message, cause);
+  }
+}

scm-webapp/src/main/java/sonia/scm/plugin/PluginInstallException.java

@@ -0,0 +1,12 @@
+package sonia.scm.plugin;
+
+public class PluginInstallException extends RuntimeException {
+
+  public PluginInstallException(String message) {
+    super(message);
+  }
+
+  public PluginInstallException(String message, Throwable cause) {
+    super(message, cause);
+  }
+}

scm-webapp/src/main/java/sonia/scm/plugin/PluginInstaller.java

@@ -0,0 +1,63 @@
+package sonia.scm.plugin;
+
+import com.google.common.base.Throwables;
+import com.google.common.hash.HashFunction;
+import com.google.common.hash.Hashing;
+import com.google.common.io.ByteStreams;
+import com.google.common.io.Files;
+import sonia.scm.SCMContextProvider;
+import sonia.scm.net.ahc.AdvancedHttpClient;
+import sonia.scm.util.IOUtil;
+
+import javax.inject.Inject;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Optional;
+
+class PluginInstaller {
+
+  private final SCMContextProvider context;
+  private final AdvancedHttpClient client;
+
+  @Inject
+  public PluginInstaller(SCMContextProvider context, AdvancedHttpClient client) {
+    this.context = context;
+    this.client = client;
+  }
+
+  public void install(AvailablePlugin plugin) {
+    File file = createFile(plugin);
+    try (InputStream input = download(plugin); OutputStream output = new FileOutputStream(file)) {
+      ByteStreams.copy(input, output);
+
+      verifyChecksum(plugin, file);
+    } catch (IOException ex) {
+      throw new PluginDownloadException("failed to install plugin", ex);
+    }
+  }
+
+  private void verifyChecksum(AvailablePlugin plugin, File file) throws IOException {
+    Optional<String> checksum = plugin.getDescriptor().getChecksum();
+    if (checksum.isPresent()) {
+      String calculatedChecksum = Files.hash(file, Hashing.sha256()).toString();
+      if (!checksum.get().equalsIgnoreCase(calculatedChecksum)) {
+        throw new PluginChecksumMismatchException(
+          String.format("downloaded plugin checksum %s does not match expected %s", calculatedChecksum, checksum.get())
+        );
+      }
+    }
+  }
+
+  private InputStream download(AvailablePlugin plugin) throws IOException {
+    return client.get(plugin.getDescriptor().getUrl()).request().contentAsStream();
+  }
+
+  private File createFile(AvailablePlugin plugin) {
+    File pluginDirectory = new File(context.getBaseDirectory(), "plugins");
+    IOUtil.mkdirs(pluginDirectory);
+    return new File(pluginDirectory, plugin.getDescriptor().getInformation().getName() + ".smp");
+  }
+}