old_contents: # Microsoft Azure Linux Agent
  #
  # Copyright 2014 Microsoft Corporation
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  #
  # Requires Python 2.4+ and Openssl 1.0+
  #
  
  import azurelinuxagent.common.utils.shellutil as shellutil
  from azurelinuxagent.common.osutil.default import DefaultOSUtil
  
  class AlpineOSUtil(DefaultOSUtil):
      def __init__(self):
          super(AlpineOSUtil, self).__init__()
          self.agent_conf_file_path = '/etc/waagent.conf'
  
      def is_dhcp_enabled(self):
          return True
  
      def get_dhcp_pid(self):
          ret = shellutil.run_get_output('pidof dhcpcd', chk_err=False)
          return ret[1] if ret[0] == 0 else None
  
      def set_ssh_client_alive_interval(self):
          # Alpine will handle this.
          pass
  
      def conf_sshd(self, disable_password):
          # Alpine will handle this.
          pass
  
new_contents: # Microsoft Azure Linux Agent
  #
  # Copyright 2014 Microsoft Corporation
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  #
  # Requires Python 2.4+ and Openssl 1.0+
  #
  
  import azurelinuxagent.common.logger as logger
  import azurelinuxagent.common.utils.shellutil as shellutil
  from azurelinuxagent.common.osutil.default import DefaultOSUtil
  
  class AlpineOSUtil(DefaultOSUtil):
      def __init__(self):
          super(AlpineOSUtil, self).__init__()
          self.agent_conf_file_path = '/etc/waagent.conf'
  
      def is_dhcp_enabled(self):
          return True
  
      def get_dhcp_pid(self):
          ret = shellutil.run_get_output('pidof dhcpcd', chk_err=False)
          if ret[0] == 0:
              logger.info('dhcpcd is pid {}'.format(ret[1]))
              return ret[1].strip()
          return None
  
      def restart_if(self, ifname):
          logger.info('restarting {} (sort of, actually SIGHUPing dhcpcd)'.format(ifname))
          pid = self.get_dhcp_pid()
          if pid != None:
              ret = shellutil.run_get_output('kill -HUP {}'.format(pid))
  
      def set_ssh_client_alive_interval(self):
          # Alpine will handle this.
          pass
  
      def conf_sshd(self, disable_password):
          # Alpine will handle this.
          pass
  
subject: Add restart_if function for Alpine