Mac OS X Server Samba Crash

My Mac pro shutdown because power cut last night.

Today. Windows user can ping me by computer name. But they can’t visit my share folder. There are some error in log:

Samba: ERROR: failed to setup guest info.

When I open /etc/smb.conf. I found it’s blank file. OK! So. To fix this:

1
sudo cp -p /etc/smb.conf.template /etc/smb.conf

Then it works.

Objective-C 笔记

声明一个类需要两个文件, 接口(.h)和实现(.m).

接口(interface)更像是”声明”, 协议(protocol)才是起到”接口”的作用.

类方法用加号(+), 实例方法用减号(-).

1
2
+ alloc;
- init;

引用类型带星号(*).

1
(NSString *) name

方法名包括参数名.

1
2
3
4
// 方法名: setWidth:andHeight:   参数: width, height
- (void)setWidth:(float)width andHeight:(float)height;
// 调用写法
[receiver setWidth:1.0 andHeight:2.0];

super是关键字; self是变量名, 可以被覆盖.

“类采纳了某协议”, 翻译过来就是:”类实现了某接口”. “协议采纳另个协议”, 翻译过来就是:”接口继承”.

1
2
3
4
5
6
7
8
9
// Formatter采纳了Formatting和Prettifying两个协议 
@interface Formatter : NSObject < Formatting, Prettifying >
@end

// 协议采纳协议
@protocol Paging < Formatting >

// 使用协议类型表示实例变量
id <Formatting> anObject;

属性声明的格式.

1
2
3
4
@property(这里是一些特性, 例如readonly/retain/copy) 类型 名称;

// IBOutlet的意思是把属性暴露给Interface Builder设计器
@property (nonatomic, retain) IBOutlet NSButton *myButton;

如何在XCode中使用Interface Builder设计器里的对象.

在设计器里选中对象, 切换到Connections标签, 从Referencing Outlets里扯一条线连接到Controller上, 然后选择实例变量名.

数据源委托到控制器.

对于需要集合数据类型作为数据源的界面元素, 会把dataSource连接到控制器上, 然后由控制器采纳数据源协议并实现方法. 这与以往所见的大不相同, 如果有两个数据源该怎么办?

关于#pragma. 是用于XCode识别代码的标记, 被编译器忽略.

方法分类:

1
#pragma mark 采纳UIPickerDataSource协议

白空格:

1
#pragma mark -

压制未使用变量警告:

1
#pragma unused(unusedVar)

只有井底之蛙才会觉得 Web Inspector 复制了 Firebug

一个部落格饶有兴致的介绍Chrome6.0dev中的开发人员工具, 也就是Web Inspector. 博主谦虚的口吻是清晰可见的, 然而急躁的国人仍然在回复中丝毫不客气, 含蓄的骂着”兰州烧饼”, 还说”对Firebug的复制品无爱”.

谁让咱是个爱钻牛角尖的人咧! 我偏要挖一挖历史:

有据可查的Firebug历史:
https://addons.mozilla.org/en-US/firefox/addon/1843/versions/?page=2#version-0.2

有据可查的Web Inspector历史:
http://webkit.org/blog/41/introducing-the-web-inspector/

看看吧, 相隔4天, 哪里谈得上谁复制谁.

如果偏要说复制品, 倒是可以看看这篇文章:
http://antennasoft.net/robcee/2010/05/14/inspector-landing/

A Lazy Usage for Factory Girl

Factory girl let us product model instance feel luck. But for me(a lazy boy). I wanna write shorter that standard way.

So a… Look code below. I’m lazy to explain.

spec/factories.rb
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
class F
  class << self
    {:a => :attributes_for, :b => :build, :c => :create, :d => :define, :s => :stub, :* => :sequence, :+ => :next}.each do |k,v|
      delegate v, :to => Factory
      alias_method k, v
    end
  end
end

F.d :user do |u|
  u.name "foo"
  u.full_name "福娃"
  u.password "0"
end

F.* :foos do |n|
  "foo_#{n}"
end
spec/models/user_spec.rb
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
require "spec_helper"

describe User do
  after do
    User.delete_all
  end

  it "should valid" do
    F.b(:user).should be_valid
  end

  it "should save success" do
    F.c(:user).should_not be_new_record
    User.all.should be_one
  end

  it "should product some foos" do
    F.+(:foos).should eql "foo_1"
    (F + :foos).should eql "foo_2"
  end
end

When Rails Ujs Met Chrome Frame

Rails ujs let us use other javascript frameworks (like jQuery) in our project. That’s cool.

jQuery

Here is an article about top 10 javascript frameworks by google. He use a way (an easy way) to sort these frameworks. Search “javascript frameworks” in Google. You can see that the default rails javascript frameworks prototype is not the most popular one now.

I’m working on a small project for my company by rails and jQuery. The newest rails3 use many html5 features. So I decide let user use a modern browser to use my web page. Otherwise IE6 will kill me. How to switch smoothly? I found chrome frame has beta yesterday!

Someone said that they hate the web page of xxx-browser only. But wait! I use this in my company only! Didn’t you saw those enterprise-level soft let you install their plugin?

Make an IE-only page is easy. Make an IE-except page is easier. lol

Chrome frame show my html5 page (maybe). It’s beautiful than IE. But it cannot works when I send ajax request.

For example I write a link like this:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
    <!-- Rails html5 templete -->
    <%= link_to "Add user", new_user_path, :remote => true %>

    <!-- Will product -->
    <a href="/users/new" data-remote="true">Add user</a>

Rails handle these link with data-remote by rails.js, It cancel click event, make a ajax request, then trigger ajax:success event back.

    #!javascript
    // Live is new method in jQuery 1.4+.
    $('a[data-confirm]').live('click', function () { ... });

    // When user click the link. jQuery will handle it and send a ajax request.
    $.ajax({
    	url: "/users/new",
    	dataType: "script",
    	...
    });

But chrome frame look like send a incorrect request to rails. Check the log of rails, I found this line:

Processing by UsersController#new as */*

The right process method is JS because the data type is script. I have test IE FF Chrome and Safari on win and mac. Only chrome frame has this issus.

I think I should fix this at client side. When I try to get navigator.userAgent by javascript. I found it has the same value as chrome stand-alone.

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) AppleWebKit/533.4 (KHTML, like Gecko) Chrome/5.0.375.62 Safari/533.4

But rails could detect the right user agent:

Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727) chromeframe/5.0.375.62

Oh! Javascript don’t know it’s running in chrome frame, so it can do anything. Rails know it’s processing the request from chrome frame, but it don’t know that’s a ajax request.

After a minute. I decide let rails tell javascript: “u r working for chrome frame.”

application.html.erb
1
2
3
4
5
6
<!-- Hold it in application.html.erb or ur own default layout. for this example put in navigator. -->
<% if @win_ie_with_chromeframe %>
<script>
navigator.chromeframe = true;
</script>
<% end -%>
application_controller.rb
1
2
3
4
5
6
7
8
# Detect chrome frame in application_controller.rb
before_filter :chromeframe_detect

protected
def chromeframe_detect
  ua = request.user_agent
  @win_ie_with_chromeframe = ua =~ /Windows NT/ and ua =~ /MSIE (\d+)/ and $1.to_i < 9 and ua =~ /chromeframe/
end

And then hack $.ajax. In fact I have three things need fix.

  • Chrome frame cannot send PUT DELETE verb.
  • Append .js to url tell rails I’m a JS request.
  • jQuery will try parse the result as JSON when dataType is script. If it got html. You will see an error: “Uncaught SyntaxError: Unexpected token <”.
application.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
//BUGFIX: Chromeframe miss some features.
(function($) {
  $.oldAjax = $.ajax;

  $.ajax = function(o) {
    // I can't detect it by navigator.userAgent. So I set it on server side.
    if (navigator.chromeframe) {
      // Chromeframe can't send DELETE and PUT verb.
      if (o.type == "DELETE") {
        o.type = "POST";
        o.data = "_method=delete";
      } else if (o.type == "PUT") {
        o.type = "POST";
        o.data += "&_method=put";
      }
    }

    // Chromeframe send incorrect ajax type make rails process the request by */*. The right way is JS. I try many way to avoid this. But I can do this with append .js to url only.
    if (o.dataType == "script" && !/\.js$/.test(o.url)) {
      o.url += ".js";
      // Webkit try parse result to json then raise a syntax error when receive html. It appear in inspector only and user can't see that except u r a developer. The url(end of .js) has told rails how to process my request. So I set dataType as text because I need respondText only. I can parse json myself.
      o.dataType = "text";
    }

    $.oldAjax(o);
  };
});

Mac 服务器 Servermgrd 崩溃

首先说一下背景:

我们平常用Server Admin来管理MacOSX Server时, 是通过图形界面与一个叫servermgrd的后台进程沟通交换数据的, 它由LaunchCtl启动/System/Library/LaunchDaemon/com.apple.servermgrd.plist实现开机自动运行, 侦听端口311.

事实上servermgrd是一个Web服务器, 我们的Server Admin是通过HTTP的方式实现远程管理的(即便你在本机使用). 你可以在本机上打开https://localhost:311印证这一点.

不得不说servermgrd的启动依赖太多东西, 修复的过程让我意识到许多服务的配置都会间接的导致servermgrd崩溃. 我认为这会导致许多不便, 问题的根源是servermgrd不能尝试去修复你的配置, 但至少应该兼容这些未包括在图形界面上或不正确的配置, 例如当配置Apache的时候用户自己打开配置文件加入的参数Server Admin是不会碰的. 总之, 不应该崩溃, 因为它一旦崩溃, Server Admin就无法修改, 这真的很尴尬.

我的Mac Pro运行着Mac OS X Server 10.6.3. 在一次运行Gateway Setup Assistant失败后, 遭遇了servermgrd不能启动的尴尬局面. Console里显示servermgrd不能启动的原因是”Segmentation fault”.

May 12 14:20:39 mes servermgrd[7658]: servermgr_ipfilter:ipfw config:Notice:Flushed IPv4 rules
May 12 14:20:39 mes servermgrd[7658]: servermgr_ipfilter:ipfw config:Notice:Flushed IPv6 rules
May 12 14:20:39 mes com.apple.launchd[1] (com.apple.servermgrd[7658]): Job appears to have crashed: Segmentation fault
May 12 14:20:39 mes com.apple.launchd[1] (com.apple.servermgrd): Throttling respawn: Will start in 9 seconds
May 12 14:20:39 mes com.apple.ReportCrash.Root[7607]: 2010-05-12 14:20:39.824 ReportCrash[7607:440b] Saved crash report for servermgrd[7658] version ??? (???) to /Library/Logs/DiagnosticReports/servermgrd_2010-05-12-142039_localhost.crash

我尝试着google各种可能的关键词, 发现servermgrd不能启动的原因真的太多了. 许多问题都没有答案, 解决办法往往是重装系统.

没有了Server Admin这个图形化的工具, 其实我们还有serveradmin这个shell工具, 它不需要与后端通讯, 只是用起来有点不方便.

我是在运行向导时出现的问题, 因此我将目标锁定在NAT服务. (说起来容易, 其实到此为止我已经浪费了大半天的时间了.)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
# 查看NAT服务配置
sudo serveradmin settings nat
nat:reverse = no
nat:unregistered_only = yes
nat:same_ports = yes
nat:natportmap_interface = "en0"
nat:log = yes
nat:clamp_mss = yes
nat:dynamic = yes
nat:log_denied = no
nat:use_sockets = yes
nat:proxy_only = no
nat:enable_natportmap = yes
nat:interface = ""
nat:deny_incoming = no

看到了没? NAT的接口竟然指向了空字符串.

nat:interface = ""

修复方法:

1
2
3
4
5
6
7
8
9
# 试着改回正常值
sudo serveradmin settings nat:natportmap_interface = "en1"
nat:natportmap_interface = "en1"
sudo serveradmin settings nat:interface = "en0"
nat:interface = "en0"

# 等10秒看看servermgrd起来没
ps aux | grep servermgrd | grep -v grep
root      7687   0.0  0.2  2577788  38484   ??  Ss    2:20PM   0:03.57 servermgrd -x

顺便跟着乔老爷子起哄, BS一下Adobe.

起死回生的Server Admin再一次尝试连接时, 会出奇的慢, 似乎在重置着自己的配置. 等了N久后显示 Server Admin wants to use the PrivateEncryptedDatak keychain, 并且提示我输入密码, 可是怎么输也不对.

你有没有觉得 PrivateEncryptedDatak 很眼生, 它是谁呀? Google后发现它是Adobe Air的一个示例程序生成的Keychain. Adobe suck!

删了它, 没事的, 反正就一Demo.

位置: ~/Library/Application Support/Adobe/AIR/ELS/com.adobe.demo.RememberMe/

如果你有洁癖, 就继续打开Keychain - Edit - Keychain List. 把那里面的也删除了.