private File cloneDatasourceViewsGit(String datasourceName) throws Exception {
    File targetDir = getDatasourceViewsGit(datasourceName);

    // Create datasource views bare git repo
    Repository newRepo = new FileRepository(targetDir);
    if (!targetDir.exists()) {
      newRepo.create(true);
    }

    String remoteUrl = "file://" + targetDir.getAbsolutePath();
    File tmp = getTmpDirectory();
    File localRepo = new File(tmp, "opal-" + Long.toString(System.nanoTime()));
    JGitUtils.cloneRepository(
        localRepo.getParentFile(), localRepo.getName(), remoteUrl, false, null);
    return localRepo;
  }
  /**
   * Mirrors a repository and, optionally, the server's users, and/or configuration settings from a
   * origin Gitblit instance.
   *
   * @param registration
   * @throws Exception
   */
  private void pull(FederationModel registration) throws Exception {
    Map<String, RepositoryModel> repositories = FederationUtils.getRepositories(registration, true);
    String registrationFolder = registration.folder.toLowerCase().trim();
    // confirm valid characters in server alias
    Character c = StringUtils.findInvalidCharacter(registrationFolder);
    if (c != null) {
      logger.error(
          MessageFormat.format(
              "Illegal character ''{0}'' in folder name ''{1}'' of federation registration {2}!",
              c, registrationFolder, registration.name));
      return;
    }
    File repositoriesFolder = new File(GitBlit.getString(Keys.git.repositoriesFolder, "git"));
    File registrationFolderFile = new File(repositoriesFolder, registrationFolder);
    registrationFolderFile.mkdirs();

    // Clone/Pull the repository
    for (Map.Entry<String, RepositoryModel> entry : repositories.entrySet()) {
      String cloneUrl = entry.getKey();
      RepositoryModel repository = entry.getValue();
      if (!repository.hasCommits) {
        logger.warn(
            MessageFormat.format(
                "Skipping federated repository {0} from {1} @ {2}. Repository is EMPTY.",
                repository.name, registration.name, registration.url));
        registration.updateStatus(repository, FederationPullStatus.SKIPPED);
        continue;
      }

      // Determine local repository name
      String repositoryName;
      if (StringUtils.isEmpty(registrationFolder)) {
        repositoryName = repository.name;
      } else {
        repositoryName = registrationFolder + "/" + repository.name;
      }

      if (registration.bare) {
        // bare repository, ensure .git suffix
        if (!repositoryName.toLowerCase().endsWith(DOT_GIT_EXT)) {
          repositoryName += DOT_GIT_EXT;
        }
      } else {
        // normal repository, strip .git suffix
        if (repositoryName.toLowerCase().endsWith(DOT_GIT_EXT)) {
          repositoryName = repositoryName.substring(0, repositoryName.indexOf(DOT_GIT_EXT));
        }
      }

      // confirm that the origin of any pre-existing repository matches
      // the clone url
      String fetchHead = null;
      Repository existingRepository = GitBlit.self().getRepository(repositoryName);

      if (existingRepository == null && GitBlit.self().isCollectingGarbage(repositoryName)) {
        logger.warn(
            MessageFormat.format(
                "Skipping local repository {0}, busy collecting garbage", repositoryName));
        continue;
      }

      if (existingRepository != null) {
        StoredConfig config = existingRepository.getConfig();
        config.load();
        String origin = config.getString("remote", "origin", "url");
        RevCommit commit =
            JGitUtils.getCommit(existingRepository, org.eclipse.jgit.lib.Constants.FETCH_HEAD);
        if (commit != null) {
          fetchHead = commit.getName();
        }
        existingRepository.close();
        if (!origin.startsWith(registration.url)) {
          logger.warn(
              MessageFormat.format(
                  "Skipping federated repository {0} from {1} @ {2}. Origin does not match, consider EXCLUDING.",
                  repository.name, registration.name, registration.url));
          registration.updateStatus(repository, FederationPullStatus.SKIPPED);
          continue;
        }
      }

      // clone/pull this repository
      CredentialsProvider credentials =
          new UsernamePasswordCredentialsProvider(Constants.FEDERATION_USER, registration.token);
      logger.info(
          MessageFormat.format(
              "Pulling federated repository {0} from {1} @ {2}",
              repository.name, registration.name, registration.url));

      CloneResult result =
          JGitUtils.cloneRepository(
              registrationFolderFile, repository.name, cloneUrl, registration.bare, credentials);
      Repository r = GitBlit.self().getRepository(repositoryName);
      RepositoryModel rm = GitBlit.self().getRepositoryModel(repositoryName);
      repository.isFrozen = registration.mirror;
      if (result.createdRepository) {
        // default local settings
        repository.federationStrategy = FederationStrategy.EXCLUDE;
        repository.isFrozen = registration.mirror;
        repository.showRemoteBranches = !registration.mirror;
        logger.info(MessageFormat.format("     cloning {0}", repository.name));
        registration.updateStatus(repository, FederationPullStatus.MIRRORED);
      } else {
        // fetch and update
        boolean fetched = false;
        RevCommit commit = JGitUtils.getCommit(r, org.eclipse.jgit.lib.Constants.FETCH_HEAD);
        String newFetchHead = commit.getName();
        fetched = fetchHead == null || !fetchHead.equals(newFetchHead);

        if (registration.mirror) {
          // mirror
          if (fetched) {
            // update local branches to match the remote tracking branches
            for (RefModel ref : JGitUtils.getRemoteBranches(r, false, -1)) {
              if (ref.displayName.startsWith("origin/")) {
                String branch =
                    org.eclipse.jgit.lib.Constants.R_HEADS
                        + ref.displayName.substring(ref.displayName.indexOf('/') + 1);
                String hash = ref.getReferencedObjectId().getName();

                JGitUtils.setBranchRef(r, branch, hash);
                logger.info(
                    MessageFormat.format(
                        "     resetting {0} of {1} to {2}", branch, repository.name, hash));
              }
            }

            String newHead;
            if (StringUtils.isEmpty(repository.HEAD)) {
              newHead = newFetchHead;
            } else {
              newHead = repository.HEAD;
            }
            JGitUtils.setHEADtoRef(r, newHead);
            logger.info(
                MessageFormat.format(
                    "     resetting HEAD of {0} to {1}", repository.name, newHead));
            registration.updateStatus(repository, FederationPullStatus.MIRRORED);
          } else {
            // indicate no commits pulled
            registration.updateStatus(repository, FederationPullStatus.NOCHANGE);
          }
        } else {
          // non-mirror
          if (fetched) {
            // indicate commits pulled to origin/master
            registration.updateStatus(repository, FederationPullStatus.PULLED);
          } else {
            // indicate no commits pulled
            registration.updateStatus(repository, FederationPullStatus.NOCHANGE);
          }
        }

        // preserve local settings
        repository.isFrozen = rm.isFrozen;
        repository.federationStrategy = rm.federationStrategy;

        // merge federation sets
        Set<String> federationSets = new HashSet<String>();
        if (rm.federationSets != null) {
          federationSets.addAll(rm.federationSets);
        }
        if (repository.federationSets != null) {
          federationSets.addAll(repository.federationSets);
        }
        repository.federationSets = new ArrayList<String>(federationSets);

        // merge indexed branches
        Set<String> indexedBranches = new HashSet<String>();
        if (rm.indexedBranches != null) {
          indexedBranches.addAll(rm.indexedBranches);
        }
        if (repository.indexedBranches != null) {
          indexedBranches.addAll(repository.indexedBranches);
        }
        repository.indexedBranches = new ArrayList<String>(indexedBranches);
      }
      // only repositories that are actually _cloned_ from the origin
      // Gitblit repository are marked as federated. If the origin
      // is from somewhere else, these repositories are not considered
      // "federated" repositories.
      repository.isFederated = cloneUrl.startsWith(registration.url);

      GitBlit.self().updateConfiguration(r, repository);
      r.close();
    }

    IUserService userService = null;

    try {
      // Pull USERS
      // TeamModels are automatically pulled because they are contained
      // within the UserModel. The UserService creates unknown teams
      // and updates existing teams.
      Collection<UserModel> users = FederationUtils.getUsers(registration);
      if (users != null && users.size() > 0) {
        File realmFile = new File(registrationFolderFile, registration.name + "_users.conf");
        realmFile.delete();
        userService = new ConfigUserService(realmFile);
        for (UserModel user : users) {
          userService.updateUserModel(user.username, user);

          // merge the origin permissions and origin accounts into
          // the user accounts of this Gitblit instance
          if (registration.mergeAccounts) {
            // reparent all repository permissions if the local
            // repositories are stored within subfolders
            if (!StringUtils.isEmpty(registrationFolder)) {
              if (user.permissions != null) {
                // pulling from >= 1.2 version
                Map<String, AccessPermission> copy =
                    new HashMap<String, AccessPermission>(user.permissions);
                user.permissions.clear();
                for (Map.Entry<String, AccessPermission> entry : copy.entrySet()) {
                  user.setRepositoryPermission(
                      registrationFolder + "/" + entry.getKey(), entry.getValue());
                }
              } else {
                // pulling from <= 1.1 version
                List<String> permissions = new ArrayList<String>(user.repositories);
                user.repositories.clear();
                for (String permission : permissions) {
                  user.addRepositoryPermission(registrationFolder + "/" + permission);
                }
              }
            }

            // insert new user or update local user
            UserModel localUser = GitBlit.self().getUserModel(user.username);
            if (localUser == null) {
              // create new local user
              GitBlit.self().updateUserModel(user.username, user, true);
            } else {
              // update repository permissions of local user
              if (user.permissions != null) {
                // pulling from >= 1.2 version
                Map<String, AccessPermission> copy =
                    new HashMap<String, AccessPermission>(user.permissions);
                for (Map.Entry<String, AccessPermission> entry : copy.entrySet()) {
                  localUser.setRepositoryPermission(entry.getKey(), entry.getValue());
                }
              } else {
                // pulling from <= 1.1 version
                for (String repository : user.repositories) {
                  localUser.addRepositoryPermission(repository);
                }
              }
              localUser.password = user.password;
              localUser.canAdmin = user.canAdmin;
              GitBlit.self().updateUserModel(localUser.username, localUser, false);
            }

            for (String teamname : GitBlit.self().getAllTeamnames()) {
              TeamModel team = GitBlit.self().getTeamModel(teamname);
              if (user.isTeamMember(teamname) && !team.hasUser(user.username)) {
                // new team member
                team.addUser(user.username);
                GitBlit.self().updateTeamModel(teamname, team, false);
              } else if (!user.isTeamMember(teamname) && team.hasUser(user.username)) {
                // remove team member
                team.removeUser(user.username);
                GitBlit.self().updateTeamModel(teamname, team, false);
              }

              // update team repositories
              TeamModel remoteTeam = user.getTeam(teamname);
              if (remoteTeam != null) {
                if (remoteTeam.permissions != null) {
                  // pulling from >= 1.2
                  for (Map.Entry<String, AccessPermission> entry :
                      remoteTeam.permissions.entrySet()) {
                    team.setRepositoryPermission(entry.getKey(), entry.getValue());
                  }
                  GitBlit.self().updateTeamModel(teamname, team, false);
                } else if (!ArrayUtils.isEmpty(remoteTeam.repositories)) {
                  // pulling from <= 1.1
                  team.addRepositoryPermissions(remoteTeam.repositories);
                  GitBlit.self().updateTeamModel(teamname, team, false);
                }
              }
            }
          }
        }
      }
    } catch (ForbiddenException e) {
      // ignore forbidden exceptions
    } catch (IOException e) {
      logger.warn(
          MessageFormat.format(
              "Failed to retrieve USERS from federated gitblit ({0} @ {1})",
              registration.name, registration.url),
          e);
    }

    try {
      // Pull TEAMS
      // We explicitly pull these even though they are embedded in
      // UserModels because it is possible to use teams to specify
      // mailing lists or push scripts without specifying users.
      if (userService != null) {
        Collection<TeamModel> teams = FederationUtils.getTeams(registration);
        if (teams != null && teams.size() > 0) {
          for (TeamModel team : teams) {
            userService.updateTeamModel(team);
          }
        }
      }
    } catch (ForbiddenException e) {
      // ignore forbidden exceptions
    } catch (IOException e) {
      logger.warn(
          MessageFormat.format(
              "Failed to retrieve TEAMS from federated gitblit ({0} @ {1})",
              registration.name, registration.url),
          e);
    }

    try {
      // Pull SETTINGS
      Map<String, String> settings = FederationUtils.getSettings(registration);
      if (settings != null && settings.size() > 0) {
        Properties properties = new Properties();
        properties.putAll(settings);
        FileOutputStream os =
            new FileOutputStream(
                new File(
                    registrationFolderFile, registration.name + "_" + Constants.PROPERTIES_FILE));
        properties.store(os, null);
        os.close();
      }
    } catch (ForbiddenException e) {
      // ignore forbidden exceptions
    } catch (IOException e) {
      logger.warn(
          MessageFormat.format(
              "Failed to retrieve SETTINGS from federated gitblit ({0} @ {1})",
              registration.name, registration.url),
          e);
    }

    try {
      // Pull SCRIPTS
      Map<String, String> scripts = FederationUtils.getScripts(registration);
      if (scripts != null && scripts.size() > 0) {
        for (Map.Entry<String, String> script : scripts.entrySet()) {
          String scriptName = script.getKey();
          if (scriptName.endsWith(".groovy")) {
            scriptName = scriptName.substring(0, scriptName.indexOf(".groovy"));
          }
          File file =
              new File(registrationFolderFile, registration.name + "_" + scriptName + ".groovy");
          FileUtils.writeContent(file, script.getValue());
        }
      }
    } catch (ForbiddenException e) {
      // ignore forbidden exceptions
    } catch (IOException e) {
      logger.warn(
          MessageFormat.format(
              "Failed to retrieve SCRIPTS from federated gitblit ({0} @ {1})",
              registration.name, registration.url),
          e);
    }
  }