ambari-server操作与对应的源文件

设置命令：ambari-server setup

源文件：
apache-ambari-2.4.2-src/ambari-server/src/main/python/ambari_server/serverSetup.py

1000行之后

#
# 执行ambari-server setup
# Setup the Ambari Server.
#
def setup(options):
  if options.only_silent:
    # 命令ambari-server setup已经执行，且只能执行一次
    if check_setup_already_done():
      print "Nothing was done. Ambari Setup already performed and cannot re-run setup in silent mode. Use \"ambari-server setup\" command without -s option to change Ambari setup."
      sys.exit(0)
  #设置安全先决条件
  retcode = verify_setup_allowed(options)
  if not retcode == 0:
    raise FatalException(1, None)

  #最终调用ambari-common/src/main/python/os_utils.py -> os_linux.py/os_is_root()
  #判定当前是否root用户或拥有root权限
  if not is_root():
    warn_msg = configDefaults.MESSAGE_WARN_SETUP_NOT_ROOT
    print warn_msg

  # proceed jdbc properties if they were set 如果设置它们，请继续jdbc属性
  if _check_jdbc_options(options):
    proceedJDBCProperties(options)
    return

  #SELinux
  (retcode, err) = disable_security_enhancements()
  if not retcode == 0:
    raise FatalException(retcode, err)

  #Create ambari user, if needed; 如果需要，请创建ambari用户
  (retcode, register_service, svc_user, svc_password) = check_ambari_user(options)
  if not retcode == 0:
    err = 'Failed to create user. Exiting.'
    raise FatalException(retcode, err)

  #防火墙
  print configDefaults.MESSAGE_CHECK_FIREWALL
  check_firewall()

  # proceed jdbc properties if they were set 如果设置它们，请继续jdbc属性
  if _check_jdbc_options(options):
    proceedJDBCProperties(options)

  #检测JDK
  # 在检查防火墙结束后，可以看到这句输出，开始检查JDK
  print 'Checking JDK...'
  try:
    download_and_install_jdk(options)
  except FatalException as e:
    err = 'Downloading or installing JDK failed: {0}. Exiting.'.format(e)
    raise FatalException(e.code, err)
  #完成JDK设置
  print 'Completing setup...'
  retcode = configure_os_settings()
  if not retcode == 0:
    err = 'Configure of OS settings in ambari.properties failed. Exiting.'
    raise FatalException(retcode, err)
  #开始设置数据库
  print 'Configuring database...'
  #显示数据库提示信息
  prompt_db_properties(options)

  #DB setup should be done last after doing any setup. DB设置应该在做任何设置后最后完成。

  _setup_database(options)

  #检测JDBC驱动程序
  check_jdbc_drivers(options)

  #正在提取系统视图...
  print 'Extracting system views...'
  retcode = extract_views(options)
  if not retcode == 0:
    err = 'Error while extracting system views. Exiting'
    raise FatalException(retcode, err)

  # we've already done this, but new files were created so run it one time.
  # 我们已经做到了，但是创建了新文件，所以运行它一次。
  adjust_directory_permissions(svc_user)

  service_setup(register_service, svc_user, svc_password)

启动命令：ambari-server start

源文件：
apache-ambari-2.4.2-src/ambari-server/src/main/python/ambari-server.py

100行之后

#
# 执行命令：ambari-server start
# Starts the Ambari Server.启动Ambari服务器。
# Ensures only one instance of the process is running.确保只有一个进程正在运行。
#     If this is the second instance of the process, the function fails.如果这是进程的第二个实例，函数失败。
#
@OsFamilyFuncImpl(OsFamilyImpl.DEFAULT)
def start(args):
  #先判定ambari-server是否已经运行，如果已经，则抛出异常
  status, pid = is_server_runing()
  if status:
    err = "Ambari Server is already running."
    raise FatalException(1, err)
  #ambari-server处理主程序
  server_process_main(args)

ambari-server处理主程序

源文件：ambari_server_main.py/server_process_main(args)

内容很多

ambari-server stop和ambari-server status命令

apache-ambari-2.4.2-src/ambari-server/src/main/python/ambari-server.py

#
# Stops the Ambari Server.
# 停止Ambari服务器，本质上就是执行操作系统的kill命令
#
@OsFamilyFuncImpl(OsFamilyImpl.DEFAULT)
def stop(args):
  if (args != None):
    args.exit_message = None

  status, pid = is_server_runing()

  #  status=true 说明Ambari Server处于运行态
  if status:
    try:
      #信号量SIGTERM：终止进程，软件终止信号
      os.kill(pid, signal.SIGTERM)
    except OSError, e:
      print_info_msg("Unable to stop Ambari Server - " + str(e))
      return
    pid_file_path = os.path.join(configDefaults.PID_DIR, PID_NAME)
    os.remove(pid_file_path)
    print "Ambari Server stopped"
  else:
    print "Ambari Server is not running"

#
# The Ambari Server status. Ambari服务器状态。
#
@OsFamilyFuncImpl(OsFamilyImpl.DEFAULT)
def status(args):
  args.exit_message = None
  status, pid = is_server_runing()
  #Ambari Server的pid文件
  pid_file_path = os.path.join(configDefaults.PID_DIR, PID_NAME)
  if status:
    args.exit_code = 0
    print "Ambari Server running"
    print "Found Ambari Server PID: " + str(pid) + " at: " + pid_file_path
  else:
    print "Ambari Server not running. Stale PID File at: " + pid_file_path
    args.exit_code = 3

ambari-sever设置或启动时，输入y/n

apache-ambari-2.4.2-src/ambari-server/src/main/python/ambari_server/userInput.py

#
# Gets the y/n input.
#
# return True if 'y' or False if 'n'
#
def get_YN_input(prompt, default, answer = None):
  yes = set(['yes', 'ye', 'y'])
  no = set(['no', 'n'])
  if answer is not None and answer:
    yes.update(['True', 'true'])
    no.update(['False', 'false'])

  return get_choice_string_input(prompt, default, yes, no, answer)

安装agent：yum install -y agent_XXX

apache-ambari-2.4.2-src/ambari-server/src/main/python/setupAgent.py

def installAgent(projectVersion, ret=None):

  # 在其他系统上安装（包括CentOS）
  else:
    #--nogpgcheck表示没有签名的软件包，projectVersion是HDP版本号
    Command = ["yum", "-y", "install", "--nogpgcheck", "ambari-agent-" + projectVersion]