1 files changed, 474 insertions, 0 deletions
diff --git a/console.rb b/console.rb
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+++ b/console.rb
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+#!/usr/bin/env ruby
+#
+#  console.rb: Console GUI component.
+#
+#  Copyright (C) 2011 VMware, Inc.
+# 
+#  Permission is hereby granted, free of charge, to any person obtaining a copy
+#  of this software and associated documentation files (the "Software"), to deal
+#  in the Software without restriction, including without limitation the rights
+#  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+#  copies of the Software, and to permit persons to whom the Software is
+#  furnished to do so, subject to the following conditions:
+#  
+#  The above copyright notice and this permission notice shall be included in
+#  all copies or substantial portions of the Software.
+# 
+#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+#  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+#  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+#  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+#  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+#  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+#  THE SOFTWARE.
+
+#  Apologies in advance for the state of this code, my Ruby/Tk-fu is really not
+#  up to scratch. The liberal use of $global_variables is to get things working
+#  correctly from Tk callbacks, if you know a better way to make this work
+#  please let me know.
+
+require 'tk'
+require 'ffi-rzmq'
+require 'thread'
+
+#  Convenience method to raise exception on ffi-rzmq error
+def raise_if_error(rc)
+  unless ZMQ::Util.resultcode_ok?(rc)
+    raise "ZMQ Error: #{ZMQ::Util.error_string}"
+  end
+end
+
+#  Callable on any Tk widget, adds get/set methods for mytag and mytype,
+#  allowing us to keep track of what is what when we get callback events.
+def make_taggable(widget)
+  widget.instance_eval do
+    @mytag = nil
+    @mytype = nil
+    def mytag
+      @mytag
+    end
+    def mytag=(tag)
+      @mytag = tag
+    end
+    def mytype
+      @mytype
+    end
+    def mytype=(type)
+      @mytype = type
+    end
+  end
+end
+
+#  Build out the GUI.
+def build_gui
+  $root = TkRoot.new { title "Console" }
+  $workspace = TkFrame.new($root) {
+      relief 'sunken'
+      borderwidth '2'
+    }
+  $workspace.grid :column => 0, :row => 0, :columnspan => 2, :sticky => 'nsew'
+  $buttons = TkFrame.new($root)
+  $buttons.grid :column => 0, :row => 1, :columnspan => 2, :sticky => 'nsew'
+  $start = TkButton.new($buttons) {
+      text 'Start'
+      state :disabled
+      command proc {
+        host = $selected_item.mytag
+        start_service_dialog(host)
+      }
+    }
+  $start.pack :padx => 10, :side => :left
+  $stop = TkButton.new($buttons) {
+      text 'Stop'
+      state :disabled
+      command proc {
+        service = $selected_item.mytag
+        host = $selected_item.winfo_parent.mytag
+        result = Tk::messageBox :type => :yesno,
+          :message => "Are you sure you wish to stop the service " + \
+            "'#{service}' on host '#{host}'?",
+          :icon => :question,
+          :title => "Stop service"
+        stop_service(service, host) if result == 'yes'
+      }
+    }
+  $stop.pack :padx => 10, :side => :left
+  $restart = TkButton.new($buttons) {
+      text 'Restart'
+      state :disabled
+      command proc {
+        service = $selected_item.mytag
+        host = $selected_item.winfo_parent.mytag
+        restart_service_dialog(host, service)
+      }
+    }
+  $restart.pack :padx => 10, :side => :left
+  $dns = TkButton.new($buttons) {
+      text 'Update DNS'
+      command proc {
+        update_dns_dialog()
+      }
+    }
+  $dns.pack :padx => 10, :side => :left
+  $exit = TkButton.new($buttons) {
+      text 'Exit'
+      command proc {
+        result = Tk::messageBox :type => :yesno,
+          :message => "Are you sure you want to exit?",
+          :icon => :question,
+          :title => "Confirm exit"
+        exit if result == 'yes'
+      }
+    }
+  $exit.pack :side => :left
+  $console = TkListbox.new($root) { 
+      height 10
+      width 60
+      yscrollcommand proc { |*args| $console_sb.set(*args) }
+    }
+  $console.grid :column => 0, :row => 2, :sticky => 'nwes'
+  $console_sb = TkScrollbar.new($root) {
+      orient :vertical
+      command proc { |*args| $console.yview(*args) }
+    }
+  $console_sb.grid :column => 1, :row => 2, :sticky => 'ns'
+  TkGrid.columnconfigure $root, 0, :weight => 1, :minsize => 600
+  TkGrid.rowconfigure $root, 0, :weight => 1, :minsize => 400
+end
+
+#  DNS Update dialog GUI
+def update_dns_dialog
+  w = TkToplevel.new { title "Update DNS record" }
+  w.wm_transient($root)
+  l = TkLabel.new(w) { text "Record" }
+  r = TkEntry.new(w) { width 15 }
+  r.focus
+  l2 = TkLabel.new(w) { text "Value" }
+  v = TkEntry.new(w) { width 15 }
+  ok = TkButton.new(w) {
+    text "OK"
+    command proc {
+      if r.get.length > 0 && v.get.length > 0
+        result = `./nsupdate-script #{r.get} #{v.get}`
+        result.chomp
+        console_add("Updating DNS record '#{r.get}' to value '#{v.get}': #{result}")
+        w.destroy
+      end
+      }
+    default :active
+    }
+  cancel = TkButton.new(w) { text "Cancel"; command proc { w.destroy } }
+  w.bind('Return') { ok.invoke }
+  w.bind('Escape') { cancel.invoke }
+  l.grid :column => 0, :row => 0, :padx => 10, :pady => 10
+  r.grid :column => 1, :row => 0, :padx => 10, :pady => 10
+  l2.grid :column => 0, :row => 1, :padx => 10, :pady => 10
+  v.grid :column => 1, :row => 1, :padx => 10, :pady => 10
+  ok.grid :column => 0, :row => 2, :padx => 10, :pady => 10
+  cancel.grid :column => 1, :row => 2, :padx => 10, :pady => 10
+  w.grab
+  w.tkwait
+end
+
+#  Start Service dialog GUI
+def start_service_dialog(host)
+  w = TkToplevel.new { title "Start service on #{host}" }
+  w.wm_transient($root)
+  l = TkLabel.new(w) { text "Command" }
+  e = TkEntry.new(w) { width 40 }
+  e.focus
+  ok = TkButton.new(w) {
+    text "OK"
+    command proc {
+      if e.get.length > 0
+        start_service(host, e.get)
+        w.destroy
+      end
+      }
+    default :active
+    }
+  cancel = TkButton.new(w) { text "Cancel"; command proc { w.destroy } }
+  w.bind('Return') { ok.invoke }
+  w.bind('Escape') { cancel.invoke }
+  l.grid :column => 0, :row => 0, :padx => 10, :pady => 10
+  e.grid :column => 1, :row => 0, :padx => 10, :pady => 10
+  ok.grid :column => 0, :row => 1, :padx => 10, :pady => 10
+  cancel.grid :column => 1, :row => 1, :padx => 10, :pady => 10
+  w.grab
+  w.tkwait
+end
+
+#  Restart service dialog GUI
+def restart_service_dialog(host, service)
+  w = TkToplevel.new { title "Restart service #{service} on #{host}" }
+  w.wm_transient($root)
+  l = TkLabel.new(w) { text "Command" }
+  e = TkEntry.new(w) { width 40 }
+  e.set($hosts[host][:services][service][:command])
+  e.focus
+  ok = TkButton.new(w) {
+    text "OK"
+    command proc {
+      if e.get.length > 0
+        stop_service(service, host)
+        start_service(host, e.get)
+        w.destroy
+      end
+      }
+    default :active
+    }
+  cancel = TkButton.new(w) { text "Cancel"; command proc { w.destroy } }
+  w.bind('Return') { ok.invoke }
+  w.bind('Escape') { cancel.invoke }
+  l.grid :column => 0, :row => 0, :padx => 10, :pady => 10
+  e.grid :column => 1, :row => 0, :padx => 10, :pady => 10
+  ok.grid :column => 0, :row => 1, :padx => 10, :pady => 10
+  cancel.grid :column => 1, :row => 1, :padx => 10, :pady => 10
+  w.grab
+  w.tkwait
+end
+
+#  Start service 'command' on 'host'
+def start_service(host, command)
+  console_add("Starting command '#{command}' on host #{host}");
+  s = $ctx.socket(ZMQ::PUSH)
+  rc = s.connect("tcp://#{host}:7772")
+  raise_if_error(rc)
+  rc = s.send_string("START #{command}")
+  raise_if_error(rc)
+  rc = s.close
+  raise_if_error(rc)
+end
+
+#  Stop service 'service' on 'host'
+def stop_service(service, host)
+  console_add("Stopping service: #{service} on host: #{host}")
+  s = $ctx.socket(ZMQ::PUSH)
+  rc = s.connect("tcp://#{host}:7772")
+  raise_if_error(rc)
+  rc = s.send_string("STOP #{service}")
+  raise_if_error(rc)
+  rc = s.close
+  raise_if_error(rc)
+end
+
+#  Log text to console widget
+def console_add(msg)
+  $console.insert 'end', Time.now.to_s + ' ' + msg
+  $console.yview 'end'
+end
+
+#  Select an item in the console, highlights it and updates available
+#  action buttons
+def select_item(new)
+  old = $selected_item
+  if old
+    target = old.labelwidget if old.mytype == :host
+    target = old if old.mytype == :service
+    target.background('#d9d9d9')
+  end
+  if new.mytype == :host
+    new.labelwidget.background('green')
+    $start.state(:normal)
+    $stop.state(:disabled)
+    $restart.state(:disabled)
+  elsif new.mytype == :service
+    new.background('green')
+    $start.state(:disabled)
+    $stop.state(:normal)
+    $restart.state(:normal)
+  end
+  $selected_item = new
+end
+
+#  Run periodically from Tk Timer to pull interesting messages from notifier
+#  and update the GUI accordingly.
+def update
+  begin
+    msg = ''
+    rc = 0
+    loop do
+      $semaphore.synchronize do
+        rc = $notifier_sock.recv_string(msg, ZMQ::DONTWAIT)
+      end
+      if rc < 0
+        break if ZMQ::Util.errno == ZMQ::EAGAIN
+        raise_if_error(rc)
+      end
+      if msg =~ /^WATCHDOG (\w+) (\w+) ([\w\.]+) ?(.*)?$/
+        verb = $1
+        host = $2
+        timestamp = $3.to_f
+        command = $4
+        if verb == 'ALIVE'
+          if $hosts.has_key?(host)
+            $hosts[host][:last_seen] = timestamp
+          else
+            label = TkLabel.new($workspace) { text host }
+            make_taggable(label)
+            label.mytag = host
+            label.mytype = :host
+            host_widget = TkLabelFrame.new($workspace) {
+              labelwidget label
+              width '4c'
+              height '4c'
+              relief 'raised'
+              padx 10
+              pady 10
+            }
+            make_taggable(host_widget)
+            host_widget.mytag = host
+            host_widget.mytype = :host
+            host_widget.pack :side => :left,:anchor => 'nw',
+              :padx => 10, :pady => 10
+            host_widget.cursor("hand2")
+            label.cursor("hand2")
+            label.bind("1", proc { |event|
+              host = event.widget.mytag
+              real_widget = $hosts[host][:widget]
+              select_item(real_widget)
+              console_add("Selected host: #{host}")
+              })
+            host_widget.bind("1", proc { |event|
+              select_item(event.widget)
+              console_add("Selected host: #{event.widget.mytag}")
+              })
+            $hosts[host] = {}
+            $hosts[host][:widget] = host_widget
+            $hosts[host][:services] = {}
+            $hosts[host][:last_seen] = timestamp
+            console_add("Registered host: #{host}")
+          end
+        elsif verb == 'RUNNING'
+          service = command.split()[0]
+          svcs = $hosts[host][:services]
+          if svcs.has_key?(service)
+            svcs[service][:last_seen] = timestamp
+          else
+            svcs[service] = {}
+            svcs[service][:command] = command
+            svcs[service][:last_seen] = timestamp
+            host_widget = $hosts[host][:widget]
+            service_widget = TkLabel.new(host_widget) { 
+              text service
+              padx '0.25c'
+              pady '0.25c'
+              }
+            make_taggable(service_widget)
+            service_widget.mytype = :service
+            service_widget.mytag = service
+            service_widget.pack { fill 'both' }
+            service_widget.cursor("hand2")
+            service_widget.bind("1", proc { |event|
+              select_item(event.widget)
+              console_add("Selected service: #{event.widget.mytag}")
+              })
+            svcs[service][:widget] = service_widget
+            console_add("Registered service: #{service} on host: #{host}")
+          end
+        end
+      elsif msg =~ /^VALUE (\w+) (\w+) (.*)$/
+        host = $1
+        service = $2
+        value = $3
+        if $hosts.has_key?(host) && $hosts[host][:services].has_key?(service)
+          widget = $hosts[host][:services][service][:widget]
+          widget.text(widget.mytag + "\n" + value)
+        end
+      end
+    end
+  rescue => exception
+    print exception, "\n"
+    print exception.backtrace.join("\n\t from "), "\n"
+    Process.abort
+  end
+end
+
+#  Run periodically from Tk Timer to reap dead hosts/services from GUI.
+def reaper
+  begin
+    current_time = Time.now.to_f
+    $hosts.each do |key, host|
+      if current_time - host[:last_seen] > 2
+        host[:services].each do |key, service|
+          if $selected_item == service[:widget]
+            $start.state(:disabled)
+            $stop.state(:disabled)
+            $restart.state(:disabled)
+            $selected_item = nil
+          end
+          service[:widget].destroy
+          host[:services].delete(key)
+        end
+        if $selected_item == host[:widget]
+          $start.state(:disabled)
+          $stop.state(:disabled)
+          $restart.state(:disabled)
+          $selected_item = nil
+        end
+        host[:widget].destroy
+        $hosts.delete(key)
+        console_add("Removed host: #{key}")
+      else
+        host[:services].each do |key, service|
+          if current_time - service[:last_seen] > 2
+            if $selected_item == service[:widget]
+              $start.state(:disabled)
+              $stop.state(:disabled)
+              $restart.state(:disabled)
+              $selected_item = nil
+            end
+            service[:widget].destroy
+            host[:services].delete(key)
+            console_add("Removed service: #{key}")
+          end
+        end
+      end
+    end
+  rescue => exception
+    print exception, "\n"
+    print exception.backtrace.join("\n\t from "), "\n"
+    Process.abort
+  end
+end
+
+#
+#  Main program
+#
+
+#  Globals used by GUI
+#  ZMQ context
+$ctx = ZMQ::Context.new()
+#  Currently selected item (host/service)
+$selected_item = nil
+#  Map of hosts and their services
+$hosts = {}
+
+#  Parse arguments
+unless ARGV[0]
+  print "usage: console.rb <notifier-host>\n"
+  exit 1
+end
+notifier_ep = "tcp://#{ARGV[0]}:7771"
+
+#  Create and connect to notifier socket. Synchronized to allow migration to
+#  GUI callback thread.
+$semaphore = Mutex.new
+$semaphore.synchronize do
+  $notifier_sock = $ctx.socket(ZMQ::SUB)
+  rc = $notifier_sock.setsockopt(ZMQ::SUBSCRIBE, '')
+  raise_if_error(rc)
+  rc = $notifier_sock.connect(notifier_ep)
+  raise_if_error(rc)
+end
+
+#  Build and update GUI immediately on startup
+build_gui
+update
+
+#  Setup timers and go into Tk mainloop
+#  Update GUI/reap dead objects every 500ms
+TkTimer.new(500, -1, proc { update }).start
+TkTimer.new(500, -1, proc { reaper }).start
+Tk.mainloop
+