Merge pull request #3131 from ashie/win32-event-alternative-to-unix-s…

…ignal

Add win32 events alternative to unix signals

bin/fluent-ctl

@@ -0,0 +1,7 @@
+#!/usr/bin/env ruby
+
+here = File.dirname(__FILE__)
+$LOAD_PATH << File.expand_path(File.join(here, '..', 'lib'))
+require 'fluent/command/ctl'
+
+Fluent::Ctl.new.call

lib/fluent/command/ctl.rb

@@ -0,0 +1,177 @@
+#
+# Fluentd
+#
+#    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.
+#
+
+require 'optparse'
+require 'fluent/env'
+require 'fluent/version'
+if Fluent.windows?
+  require 'win32/event'
+  require 'win32/service'
+end
+
+module Fluent
+  class Ctl
+    DEFAULT_OPTIONS = {}
+
+    if Fluent.windows?
+      include Windows::ServiceConstants
+      include Windows::ServiceStructs
+      include Windows::ServiceFunctions
+
+      COMMAND_MAP = {
+        shutdown: "",
+        restart: "HUP",
+        flush: "USR1",
+        reload: "USR2",
+      }
+      WINSVC_CONTROL_CODE_MAP = {
+        shutdown: SERVICE_CONTROL_STOP,
+        # 128 - 255: user-defined control code
+        # See https://docs.microsoft.com/en-us/windows/win32/api/winsvc/nf-winsvc-controlservice
+        restart: 128,
+        flush: 129,
+        reload: SERVICE_CONTROL_PARAMCHANGE,
+      }
+    else
+      COMMAND_MAP = {
+        shutdown: :TERM,
+        restart: :HUP,
+        flush: :USR1,
+        reload: :USR2,
+      }
+    end
+
+    def initialize(argv = ARGV)
+      @argv = argv
+      @options = {}
+      @opt_parser = OptionParser.new
+      configure_option_parser
+      @options.merge!(DEFAULT_OPTIONS)
+      parse_options!
+    end
+
+    def help_text
+      text = "\n"
+      if Fluent.windows?
+        text << "Usage: #{$PROGRAM_NAME} COMMAND [PID_OR_SVCNAME]\n"
+      else
+        text << "Usage: #{$PROGRAM_NAME} COMMAND PID\n"
+      end
+      text << "\n"
+      text << "Commands: \n"
+      COMMAND_MAP.each do |key, value|
+        text << "  #{key}\n"
+      end
+      text
+    end
+
+    def usage(msg = nil)
+      puts help_text
+      if msg
+        puts
+        puts "Error: #{msg}"
+      end
+      exit 1
+    end
+
+    def call
+      if Fluent.windows?
+        if @pid_or_svcname =~ /^[0-9]+$/
+          # Use as PID
+          return call_windows_event(@command, "fluentd_#{@pid_or_svcname}")
+        end
+
+        unless call_winsvc_control_code(@command, @pid_or_svcname)
+          puts "Cannot send control code to #{@pid_or_svcname} service, try to send an event with this name ..."
+          call_windows_event(@command, @pid_or_svcname)
+        end
+      else
+        call_signal(@command, @pid_or_svcname)
+      end
+    end
+
+    private
+
+    def call_signal(command, pid)
+      signal = COMMAND_MAP[command.to_sym]
+      Process.kill(signal, pid.to_i)
+    end
+
+    def call_winsvc_control_code(command, pid_or_svcname)
+      status = SERVICE_STATUS.new
+
+      begin
+        handle_scm = OpenSCManager(nil, nil, SC_MANAGER_CONNECT)
+        FFI.raise_windows_error('OpenSCManager') if handle_scm == 0
+
+        handle_scs = OpenService(handle_scm, "fluentdwinsvc", SERVICE_STOP | SERVICE_PAUSE_CONTINUE | SERVICE_USER_DEFINED_CONTROL)
+        FFI.raise_windows_error('OpenService') if handle_scs == 0
+
+        control_code = WINSVC_CONTROL_CODE_MAP[command.to_sym]
+
+        unless ControlService(handle_scs, control_code, status)
+          FFI.raise_windows_error('ControlService')
+        end
+      rescue => e
+        puts e
+        state = status[:dwCurrentState]
+        return state == SERVICE_STOPPED || state == SERVICE_STOP_PENDING
+      ensure
+        CloseServiceHandle(handle_scs)
+        CloseServiceHandle(handle_scm)
+      end
+
+      return true
+    end
+
+    def call_windows_event(command, pid_or_svcname)
+      prefix = pid_or_svcname
+      event_name = COMMAND_MAP[command.to_sym]
+      suffix = event_name.empty? ? "" : "_#{event_name}"
+
+      begin
+        event = Win32::Event.open("#{prefix}#{suffix}")
+        event.set
+        event.close
+      rescue Errno::ENOENT => e
+        puts "Error: Cannot find the fluentd process with the event name: \"#{prefix}\""
+      end
+    end
+
+    def configure_option_parser
+      @opt_parser.banner = help_text
+      @opt_parser.version = Fluent::VERSION
+    end
+
+    def parse_options!
+      @opt_parser.parse!(@argv)
+
+      @command = @argv[0]
+      @pid_or_svcname = @argv[1] || "fluentdwinsvc"
+
+      usage("Command isn't specified!") if @command.nil? || @command.empty?
+      usage("Unknown command: #{@command}") unless COMMAND_MAP.has_key?(@command.to_sym)
+
+      if Fluent.windows?
+        usage("PID or SVCNAME isn't specified!") if @pid_or_svcname.nil? || @pid_or_svcname.empty?
+      else
+        usage("PID isn't specified!") if @pid_or_svcname.nil? || @pid_or_svcname.empty?
+        usage("Invalid PID: #{pid}") unless @pid_or_svcname =~ /^[0-9]+$/
+      end
+    end
+  end
+end
+