Merge branch 'ash.mckenzie/srp-refactor' into 'master'

Refactor that focuses on SRP improvements

See merge request gitlab-org/gitlab-shell!214

1 files changed, 64 insertions, 243 deletions

diff --git a/lib/gitlab_shell.rb b/lib/gitlab_shell.rb
index 78fdfe8..bd7b783 100644
--- a/lib/gitlab_shell.rb
+++ b/lib/gitlab_shell.rb
@@ -3,299 +3,120 @@ require 'pathname'
 
 require_relative 'gitlab_net'
 require_relative 'gitlab_metrics'
+require_relative 'actor'
 
-class GitlabShell # rubocop:disable Metrics/ClassLength
-  class AccessDeniedError < StandardError; end
-  class DisallowedCommandError < StandardError; end
-  class InvalidRepositoryPathError < StandardError; end
+class GitlabShell
+  API_2FA_RECOVERY_CODES_COMMAND = '2fa_recovery_codes'.freeze
 
-  GIT_COMMANDS = %w(git-upload-pack git-receive-pack git-upload-archive git-lfs-authenticate).freeze
-  GITALY_MIGRATED_COMMANDS = {
-    'git-upload-pack' => File.join(ROOT_PATH, 'bin', 'gitaly-upload-pack'),
-    'git-upload-archive' => File.join(ROOT_PATH, 'bin', 'gitaly-upload-archive'),
-    'git-receive-pack' => File.join(ROOT_PATH, 'bin', 'gitaly-receive-pack')
-  }.freeze
-  API_COMMANDS = %w(2fa_recovery_codes).freeze
-  GL_PROTOCOL = 'ssh'.freeze
+  GIT_UPLOAD_PACK_COMMAND = 'git-upload-pack'.freeze
+  GIT_RECEIVE_PACK_COMMAND = 'git-receive-pack'.freeze
+  GIT_UPLOAD_ARCHIVE_COMMAND = 'git-upload-archive'.freeze
+  GIT_LFS_AUTHENTICATE_COMMAND = 'git-lfs-authenticate'.freeze
 
-  attr_accessor :gl_id, :gl_repository, :repo_name, :command, :git_access, :git_protocol
-  attr_reader :repo_path
+  GIT_COMMANDS = [GIT_UPLOAD_PACK_COMMAND, GIT_RECEIVE_PACK_COMMAND,
+                  GIT_UPLOAD_ARCHIVE_COMMAND, GIT_LFS_AUTHENTICATE_COMMAND].freeze
+
+  Struct.new('ParsedCommand', :command, :git_access_command, :repo_name, :args)
 
   def initialize(who)
-    who_sym, = GitlabNet.parse_who(who)
-    if who_sym == :username
-      @who = who
-    else
-      @gl_id = who
-    end
     @config = GitlabConfig.new
+    @actor = Actor.new_from(who, audit_usernames: @config.audit_usernames)
   end
 
   # The origin_cmd variable contains UNTRUSTED input. If the user ran
   # ssh git@gitlab.example.com 'evil command', then origin_cmd contains
   # 'evil command'.
   def exec(origin_cmd)
-    unless origin_cmd
-      puts "Welcome to GitLab, #{username}!"
+    if !origin_cmd || origin_cmd.empty?
+      puts "Welcome to GitLab, #{actor.username}!"
       return true
     end
 
-    args = Shellwords.shellwords(origin_cmd)
-    args = parse_cmd(args)
-
-    if GIT_COMMANDS.include?(args.first)
-      GitlabMetrics.measure('verify-access') { verify_access }
-    elsif !defined?(@gl_id)
-      # We're processing an API command like 2fa_recovery_codes, but
-      # don't have a @gl_id yet, that means we're in the "username"
-      # mode and need to materialize it, calling the "user" method
-      # will do that and call the /discover method.
-      user
-    end
-
-    process_cmd(args)
-
-    true
+    parsed_command = parse_cmd(origin_cmd)
+    action = determine_action(parsed_command)
+    action.execute(parsed_command.command, parsed_command.args)
   rescue GitlabNet::ApiUnreachableError
     $stderr.puts "GitLab: Failed to authorize your Git request: internal API unreachable"
     false
-  rescue AccessDeniedError => ex
-    $logger.warn('Access denied', command: origin_cmd, user: log_username)
-
+  rescue AccessDeniedError, UnknownError => ex
+    $logger.warn('Access denied', command: origin_cmd, user: actor.log_username)
     $stderr.puts "GitLab: #{ex.message}"
     false
   rescue DisallowedCommandError
-    $logger.warn('Denied disallowed command', command: origin_cmd, user: log_username)
-
-    $stderr.puts "GitLab: Disallowed command"
+    $logger.warn('Denied disallowed command', command: origin_cmd, user: actor.log_username)
+    $stderr.puts 'GitLab: Disallowed command'
     false
   rescue InvalidRepositoryPathError
-    $stderr.puts "GitLab: Invalid repository path"
+    $stderr.puts 'GitLab: Invalid repository path'
     false
   end
 
-  protected
+  private
+
+  attr_reader :config, :actor
+
+  def parse_cmd(cmd)
+    args = Shellwords.shellwords(cmd)
 
-  def parse_cmd(args)
     # Handle Git for Windows 2.14 using "git upload-pack" instead of git-upload-pack
     if args.length == 3 && args.first == 'git'
-      @command = "git-#{args[1]}"
-      args = [@command, args.last]
+      command = "git-#{args[1]}"
+      args = [command, args.last]
     else
-      @command = args.first
+      command = args.first
     end
 
-    @git_access = @command
+    git_access_command = command
 
-    return args if API_COMMANDS.include?(@command)
+    if command == API_2FA_RECOVERY_CODES_COMMAND
+      return Struct::ParsedCommand.new(command, git_access_command, nil, args)
+    end
 
-    raise DisallowedCommandError unless GIT_COMMANDS.include?(@command)
+    raise DisallowedCommandError unless GIT_COMMANDS.include?(command)
 
-    case @command
+    case command
     when 'git-lfs-authenticate'
       raise DisallowedCommandError unless args.count >= 2
-      @repo_name = args[1]
-      case args[2]
-      when 'download'
-        @git_access = 'git-upload-pack'
-      when 'upload'
-        @git_access = 'git-receive-pack'
-      else
-        raise DisallowedCommandError
-      end
+      repo_name = args[1]
+      git_access_command = case args[2]
+                           when 'download'
+                             GIT_UPLOAD_PACK_COMMAND
+                           when 'upload'
+                             GIT_RECEIVE_PACK_COMMAND
+                           else
+                             raise DisallowedCommandError
+                           end
     else
       raise DisallowedCommandError unless args.count == 2
-      @repo_name = args.last
+      repo_name = args.last
     end
 
-    args
+    Struct::ParsedCommand.new(command, git_access_command, repo_name, args)
   end
 
-  def verify_access
-    status = api.check_access(@git_access, nil, @repo_name, @who || @gl_id, '_any', GL_PROTOCOL)
-
-    raise AccessDeniedError, status.message unless status.allowed?
-
-    self.repo_path = status.repository_path
-    @gl_repository = status.gl_repository
-    @git_protocol = ENV['GIT_PROTOCOL']
-    @gitaly = status.gitaly
-    @username = status.gl_username
-    if defined?(@who)
-      @gl_id = status.gl_id
-    end
-  end
+  def determine_action(parsed_command)
+    return Action::API2FARecovery.new(actor) if parsed_command.command == API_2FA_RECOVERY_CODES_COMMAND
 
-  def process_cmd(args)
-    return send("api_#{@command}") if API_COMMANDS.include?(@command)
-
-    if @command == 'git-lfs-authenticate'
-      GitlabMetrics.measure('lfs-authenticate') do
-        $logger.info('Processing LFS authentication', user: log_username)
-        lfs_authenticate
-      end
-      return
-    end
-
-    executable = @command
-    args = [repo_path]
-
-    if GITALY_MIGRATED_COMMANDS.key?(executable) && @gitaly
-      executable = GITALY_MIGRATED_COMMANDS[executable]
-
-      gitaly_address = @gitaly['address']
-
-      # The entire gitaly_request hash should be built in gitlab-ce and passed
-      # on as-is. For now we build a fake one on the spot.
-      gitaly_request = {
-        'repository' => @gitaly['repository'],
-        'gl_repository' => @gl_repository,
-        'gl_id' => @gl_id,
-        'gl_username' => @username,
-        'git_protocol' => @git_protocol
-      }
-
-      args = [gitaly_address, JSON.dump(gitaly_request)]
-    end
-
-    args_string = [File.basename(executable), *args].join(' ')
-    $logger.info('executing git command', command: args_string, user: log_username)
-    exec_cmd(executable, *args)
-  end
-
-  # This method is not covered by Rspec because it ends the current Ruby process.
-  def exec_cmd(*args)
-    # If you want to call a command without arguments, use
-    # exec_cmd(['my_command', 'my_command']) . Otherwise use
-    # exec_cmd('my_command', 'my_argument', ...).
-    if args.count == 1 && !args.first.is_a?(Array)
-      raise DisallowedCommandError
-    end
-
-    env = {
-      'HOME' => ENV['HOME'],
-      'PATH' => ENV['PATH'],
-      'LD_LIBRARY_PATH' => ENV['LD_LIBRARY_PATH'],
-      'LANG' => ENV['LANG'],
-      'GL_ID' => @gl_id,
-      'GL_PROTOCOL' => GL_PROTOCOL,
-      'GL_REPOSITORY' => @gl_repository,
-      'GL_USERNAME' => @username
-    }
-    if @gitaly && @gitaly.include?('token')
-      env['GITALY_TOKEN'] = @gitaly['token']
-    end
-
-    if git_trace_available?
-      env.merge!(
-        'GIT_TRACE' => @config.git_trace_log_file,
-        'GIT_TRACE_PACKET' => @config.git_trace_log_file,
-        'GIT_TRACE_PERFORMANCE' => @config.git_trace_log_file
+    GitlabMetrics.measure('verify-access') do
+      # GitlabNet#check_access will raise exception in the event of a problem
+      initial_action = api.check_access(
+        parsed_command.git_access_command,
+        nil,
+        parsed_command.repo_name,
+        actor,
+        '_any'
       )
-    end
 
-    # We use 'chdir: ROOT_PATH' to let the next executable know where config.yml is.
-    Kernel.exec(env, *args, unsetenv_others: true, chdir: ROOT_PATH)
-  end
-
-  def api
-    GitlabNet.new
-  end
-
-  def user
-    return @user if defined?(@user)
-
-    begin
-      if defined?(@who)
-        @user = api.discover(@who)
-        @gl_id = "user-#{@user['id']}"
+      case parsed_command.command
+      when GIT_LFS_AUTHENTICATE_COMMAND
+        Action::GitLFSAuthenticate.new(actor, parsed_command.repo_name)
       else
-        @user = api.discover(@gl_id)
+        initial_action
       end
-    rescue GitlabNet::ApiUnreachableError
-      @user = nil
-    end
-  end
-
-  def username_from_discover
-    return nil unless user && user['username']
-
-    "@#{user['username']}"
-  end
-
-  def username
-    @username ||= username_from_discover || 'Anonymous'
-  end
-
-  # User identifier to be used in log messages.
-  def log_username
-    @config.audit_usernames ? username : "user with id #{@gl_id}"
-  end
-
-  def lfs_authenticate
-    lfs_access = api.lfs_authenticate(@gl_id, @repo_name)
-
-    return unless lfs_access
-
-    puts lfs_access.authentication_payload
-  end
-
-  private
-
-  def continue?(question)
-    puts "#{question} (yes/no)"
-    STDOUT.flush # Make sure the question gets output before we wait for input
-    continue = STDIN.gets.chomp
-    puts '' # Add a buffer in the output
-    continue == 'yes'
-  end
-
-  def api_2fa_recovery_codes
-    continue = continue?(
-      "Are you sure you want to generate new two-factor recovery codes?\n" \
-      "Any existing recovery codes you saved will be invalidated."
-    )
-
-    unless continue
-      puts 'New recovery codes have *not* been generated. Existing codes will remain valid.'
-      return
-    end
-
-    resp = api.two_factor_recovery_codes(@gl_id)
-    if resp['success']
-      codes = resp['recovery_codes'].join("\n")
-      puts "Your two-factor authentication recovery codes are:\n\n" \
-           "#{codes}\n\n" \
-           "During sign in, use one of the codes above when prompted for\n" \
-           "your two-factor code. Then, visit your Profile Settings and add\n" \
-           "a new device so you do not lose access to your account again."
-    else
-      puts "An error occurred while trying to generate new recovery codes.\n" \
-           "#{resp['message']}"
     end
   end
 
-  def git_trace_available?
-    return false unless @config.git_trace_log_file
-
-    if Pathname(@config.git_trace_log_file).relative?
-      $logger.warn('git trace log path must be absolute, ignoring', git_trace_log_file: @config.git_trace_log_file)
-      return false
-    end
-
-    begin
-      File.open(@config.git_trace_log_file, 'a') { nil }
-      return true
-    rescue => ex
-      $logger.warn('Failed to open git trace log file', git_trace_log_file: @config.git_trace_log_file, error: ex.to_s)
-      return false
-    end
-  end
-
-  def repo_path=(repo_path)
-    raise ArgumentError, "Repository path not provided. Please make sure you're using GitLab v8.10 or later." unless repo_path
-    raise InvalidRepositoryPathError if File.absolute_path(repo_path) != repo_path
-
-    @repo_path = repo_path
+  def api
+    @api ||= GitlabNet.new
   end
 end