轉：Setting up an SSL secured Webserver with CentOS

在apache裡建https就這麼簡單...

1. Getting the required software

   yum install mod_ssl openssl

2. Generate a self-signed certificate

   # Generate private key 
   openssl genrsa -out ca.key 1024 
   
   # Generate CSR 
   openssl req -new -key ca.key -out ca.csr
   
   # Generate Self Signed Key
   openssl x509 -req -days 365 -in ca.csr -signkey ca.key -out ca.crt
   
   # Copy the files to the correct locations
   cp ca.crt /etc/pki/tls/certs
   cp ca.key /etc/pki/tls/private/ca.key
   cp ca.csr /etc/pki/tls/private/ca.csr

3. Setting up the virtual hosts
   

   #vim /etc/httpd/conf.d/ssl.conf
   -----------------------------
   #將<virtualhost>裡的內容修改為以下...
   <virtualhost *:443>
       SSLEngine on
       SSLCertificateFile /etc/pki/tls/certs/ca.crt
       SSLCertificateKeyFile /etc/pki/tls/private/ca.key
       <Directory /var/www/vhosts/yoursite.com/httpsdocs>
           AllowOverride All
       </Directory>
       DocumentRoot /var/www/vhosts/yoursite.com/httpsdocs
       ServerName yoursite.com
   </VirtualHost>

4. Configuring the firewall

   yum install mod_ssl openssl

Reference

• Setting up an SSL secured Webserver with CentOS

mysql存日期該用什麼data type

mysql存日期的data type有好幾種type，用int存秒數也是一種
一直很猶疑要用哪一種，想法是byte越少越好
所以整理了一下

Type	Storage(Bytes)	Minimum Value(Signed/Unsigned)	Maximum Value(Signed/Unsigned)
DATE	3 bytes
TIME	3 bytes
DATETIME	8 bytes
TIMESTAMP	4 bytes
YEAR	1 bytes
INT	4	-2147483648	2147483647

所以我想... 利用INT存比較快吧...
created date就用int來存秒數，轉換日期就利用FROM_UNIXTIME(seconds)
last updated date就用timestamp來存，反正一樣大，而且會自動更新
References

• Data Type Storage Requirements

active record使用memcached

一直用sql當memcached的key跑的順順的
不過最近在用ci在開發，發現用的active record不知抓什麼來當key
研究了一下，發現有last_query()可取出sql string
不過又看了一下發現是先execute後，才會有的query

而cache當然是要跑之前做，不然就沒有意義了
又serach了一下，發現有_compile_select()
差別當然在有執行跟沒執行，以下是片斷程式碼
有引用tomschlick寫好給ci用的memcached-library

 $key = $this->db->_compile_select();
$this->load->library('Memcached_library','','memcached');
$results = $this->memcached->get($key);

// If the key does not exist it could mean the key was never set or expired
if ($results) 
     echo 'hit';
else{
     echo 'miss';
     $results = $this->db->get()->row_array();
     $this->memcached->add($key, $results);
}

不過每個有用db的程式這樣寫太麻煩了
原本想改寫ci的db driver，看起來有點麻煩，先求有吧
所以先簡單的寫在helper裡，有空再來研究改寫driver

_compile_select());
        $ci = & get_instance();
        $ci->load->library('Memcached_library','','memcached');
        $results = $ci->memcached->get($key);

        // If the key does not exist it could mean the key was never set or expired
        if ($results) {

                $ci->fb->info('[memcache] hit', "info");
        }else{

                $ci->fb->warn('[memcache] miss', "memcached");
                $results = $db->get()->row_array();
                $ci->memcached->add($key, $results);
        }

        $db->_reset_select();  //clear sql query string
        return $results;
}

References Getting CodeIgniter Active Record's current SQL code

檢查遠端的檔案是否存在

這方法還不錯，只回傳header，不看body

function remoteFileExists($url) {
    $curl = curl_init($url);

    //don't fetch the actual page, you only want to check the connection is ok
    curl_setopt($curl, CURLOPT_NOBODY, true);

    //do request
    $result = curl_exec($curl);

    $ret = false;

    //if request did not fail
    if ($result !== false) {
        //if request was ok, check response code
        $statusCode = curl_getinfo($curl, CURLINFO_HTTP_CODE);  

        if ($statusCode == 200) {
            $ret = true;   
        }
    }

    curl_close($curl);

    return $ret;
}

$exists = remoteFileExists('http://stackoverflow.com/favicon.ico');
if ($exists) {
    echo 'file exists';
} else {
    echo 'file does not exist';   
}

Reference

• How can one check to see if a remote file exists using PHP?

CodeIgniter - db active record常用指令

• basic
  
  • 取得config中，名為group_one的db

    $DB1 = $this->load->database('group_one', TRUE); //給true才會產生實體給$DB1
    $this->db->select('title')->from('mytable')->where('id', $id)->limit(10, 20);
    

    p.s. 給true才會回傳個db object
  • 取sql string
    • last_query()
      執行的過程中，最後的一個sql query string
    • _compile_select()
      目前sql條件的sql query string，尚未實際執行
• select

  $this->db->select('title, content, date'); //不下的話就是*
  $query = $this->db->get('mytable');
  foreach ($query->result() as $row)
  {
      echo $row->title;
  }
  

• from、join

  $this->db->from('mytable');

  $this->db->select('*');
  $this->db->from('blogs');
  $this->db->join('comments', 'comments.id = blogs.id');
  
  $query = $this->db->get();
  
  // Produces:
  // SELECT * FROM blogs
  // JOIN comments ON comments.id = blogs.id

• where 

  //法1.
  $query = $this->db->get_where('mytable', array('id' => $id), $limit, $offset);
  $this->db->or_where('id >', $id);  // Produces: WHERE name != 'Joe' OR id > 50
  
  //法2
  $this->db->select('title')->from('mytable')->where('id', $id);
  

• insert
新增欄位為now()的方法

$data = array (
   'customer_id'=> $customer_id,
   'total' => $totalprice
  );
  $this->db->set('order_date', 'NOW()', FALSE);
  $this->db->insert('omc_orders', $data);

Reference

• Connecting to your Database
• Active Record Class

FirePHP

FireBug用久了，做php時，也很想要有這樣的好物
用過之後，覺得真的是超~~~~~~~~~~~~~~方便.......感動到想哭...
不過其他如ie要查時就... 無言了...

除了直接跟php搭外
還可以跟php的framework搭
[PHP] 好用 Debug PHP 工具 FirePHP for FireFox on CodeIgniter
這篇教學很完整，不再複製貼上了

• CodeIgniter
• Zend
  

  require_once('Zend/Log.php');
  require_once('Zend/Log/Writer/Firebug.php');
  
  $writer = new Zend_Log_Writer_Firebug();
  $logger = new Zend_Log($writer);
  
  $logger->info('info message');
  $logger->warn('warning message');
  $logger->err('error message');

讓config可以控制要不要輸出log

• 配置config文件
  在application/config/目录下找到config.php，增加如下一行内容：
  

  $config['enable_firephp'] = true;

• libraries/firephp.php文件
  

  $CI = & get_instance();
  if($CI->config->item('enable_firephp'))
     define('ENABLE_FIREPHP', true);
  else
     define('ENABLE_FIREPHP', false);
  

• 每個class裡，使用firephp
  

  $this->fb->setEnabled(ENABLE_FIREPHP);
  $logger->info('info message');

References

• [PHP] 好用 Debug PHP 工具 FirePHP for FireFox on CodeIgniter
• 在Codeigniter中使用FirePHP进行调试