Enable or fix logging for HAProxy load balancer

Enable or fix logging for HAProxy load balancer

On a RedHat/CentOS server, edit the value of SYSLOGD_OPTIONS in /etc/sysconfig/syslog:

SYSLOGD_OPTIONS=”-m 0 -r”


On a Debian/Ubuntu server, edit the value of SYSLOGD in /etc/default/syslogd:

SYSLOGD=”-r”


/etc/syslog.conf:

local0.* /var/log/haproxy.log


restart syslog service to apply changes:

service syslog restart

request host, query paramters, header

登入登出轉址設計
<br />request.env['QUERY_STRING']<br />"cat=futures&sort=latest"<br /><br />#full url<br />request.url<br />#http://localhost:3000/home/<br /><br />#path<br />request.request_uri<br />"/home/"<br /><br />#host_and_port<br />request.host_with_port<br /><br />#source code http://api.rubyonrails.org/classes/ActionController/Base.html<br /> when :back<br /> if referer = request.headers["Referer"]<br /> redirect_to(referer, :status=>status)<br /> else<br /> raise RedirectBackError<br /> end<br /><br /><br />

multi-step

RoR Multi-step forms

private<br /> def get_partial_user_from_session<br /> unless @session['partial_user'].nil?<br /> @user = @session['partial_user']<br /> else<br /> @user = User.new<br /> end<br /> end<br /><br /> def save_partial_user_in_session<br /> unless @user.nil?<br /> @session['partial_user'] = @user<br /> end<br /> end<br /> <br /> # Might be a good addition to AR::Base<br /> def valid_for_attributes( model, attributes )<br /> unless model.valid?<br /> errors = model.errors<br /> our_errors = Array.new<br /> errors.each { |attr,error|<br /> if attributes.include? attr<br /> our_errors << [attr,error]<br /> end<br /> }<br /> errors.clear<br /> our_errors.each { |attr,error| errors.add(attr,error) }<br /> return false unless errors.empty?<br /> end<br /> return true<br /> end<br /><br /><br />#To ensure the errors are cleared out properly on each request add a before_filter with the following:<br /> def clear_stage_errors<br /> unless @session['partial_user'].nil?<br /> @session['partial_user'].errors.clear<br /> end<br /> end<br /><br />=begin<br />You can use<br />get_partial_user_from_session<br />and<br />save_partial_user_in_session<br />as before and after filters, respectively, so you only have to reference @user in your multi-step controller.<br />=end<br /><br />#A clean way to arrange the view is to have each step in its own partial, and set a variable such as<br />@current_stage<br />#in your controller, then in your view just do something like:<br /><%= start_form_tag({:action=> "signup"} , { :name => 'signupform' }) %><br /><%= hidden_field_tag "changeCountry" %><br /><%= hidden_field_tag "current_stage", "#{@current_stage}"%><br /><br /><h2>Registration Process</h2><br /><%= @flash['notice'] %><br /><br /><%= render_partial "#{@current_stage}" %><br /> <br /><%= end_form_tag %><br /><br /><br />#Your signup controller action could something similar to this:<br /> def signup<br /> case @request.method<br /> when :post<br /> @current_stage = @params['current_stage']<br /> if @current_stage == "stage1"<br /> @user.attributes = @params['user'] <br /> @current_stage = "stage2" if valid_for_attributes(@user,["login","attribute2"])<br /> end<br /> elsif @current_stage == "stage2"<br /> @user.attributes = @params['user'] <br /> @current_stage = "stage3" if valid_for_attributes(@user,["attribute3","attribute4"])<br /> elsif @current_stage == "stage3"<br /> @user.attributes = @params['user']<br /> <br /> if @user.save<br /> @session[:user] = User.authenticate(@user.login, @params['user']['password'])<br /> flash['notice'] = "Signup successful"<br /> redirect_to :action => "home"<br /> end<br /> end<br /> when :get<br /> @current_stage = "stage1"<br /> end<br /> end<br /><br /><br /><br />#==========================================<br />=begin<br />Comments on this post<br />bmarini posts on May 19, 2008 at 12:56<br />I took your partial validation idea and included it in AR Base<br />=end<br />module ActiveRecord<br /> module Validations<br /> module Partial<br /> def valid_for_attributes?( *attr_names )<br /> return validate_for_attributes(attr_names)<br /> end<br /> <br /> def validate_for_attributes( *attr_names )<br /> attr_names.map! {|a| a.to_s }<br /> <br /> unless valid?<br /> our_errors = Array.new<br /> errors.each { |attr,error|<br /> if attr_names.include? attr<br /> our_errors << [attr,error]<br /> end<br /> }<br /> <br /> errors.clear<br /> our_errors.each { |attr,error| errors.add(attr,error) }<br /> return false unless errors.empty?<br /> end<br /> return true<br /> end<br /> <br /> end<br /> end<br />end<br /><br />ActiveRecord::Base.class_eval do<br /> include ActiveRecord::Validations::Partial<br />end<br /><br />=begin<br />cgunther posts on Jul 02, 2009 at 11:40<br />bmarini, I think there is a bug in your code.<br /><br />When I called:<br />=end<br />@order.valid_for_attributes? 'first_name', 'last_name'<br /><br />=begin<br />It always passed validation. The error was the asterisk in front of attr_names on validate_for_attributes. It was being passed an array as the first attribute and when you run map! on it, it was converting the entire array to a single string (first_namelast_name).<br /><br />Here's the code that works for me:<br />=end<br />module ActiveRecord<br /> module Validations<br /> module Partial<br /> def valid_for_attributes?( *attr_names )<br /> return validate_for_attributes(attr_names)<br /> end<br /> <br /> def validate_for_attributes( attr_names )<br /> attr_names.map! {|a| a.to_s }<br /> <br /> unless valid?<br /> our_errors = Array.new<br /> errors.each { |attr,error|<br /> if attr_names.include? attr<br /> our_errors << [attr,error]<br /> end<br /> }<br /> <br /> errors.clear<br /> our_errors.each { |attr,error| errors.add(attr,error) }<br /> return false unless errors.empty?<br /> end<br /> return true<br /> end<br /> <br /> end<br /> end<br />end<br /><br />ActiveRecord::Base.class_eval do<br /> include ActiveRecord::Validations::Partial<br />end<br /><br /><br />#The main difference is that if you call validate_for_attributes directly, you have to pass it an array.<br /><br />#Chris Gunther

render outside your controller

Rails: Calling render() outside your Controllers
Calling Rails Render Partial in a Model or Background Task


<br /># lib/render_anywhere.rb<br /># <br /># Render templates outside of a controller or view.<br /># <br /># Simply mixin this module to your existing class, for example:<br /># <br /># class MyTemplater < ActiveRecord::Base<br /># include RenderAnywhere<br /># <br /># And you can use render() method that works the same as ActionView::Base#render<br /># <br /># obj = MyTemplater.new<br /># obj.html = obj.render :file => '/shared/header'<br /># <br /># <br />module RenderAnywhere<br /> <br /> class DummyController<br /> def logger<br /> RAILS_DEFAULT_LOGGER<br /> end<br /> def headers<br /> {}<br /> end<br /> end<br /> <br /> def render(options, assigns = {})<br /> viewer = ActionView::Base.new(Rails::Configuration.new.view_path, assigns, DummyController.new)<br /> viewer.render options<br /> end<br /> <br /> def template_exists?(path, assigns = {})<br /> viewer = ActionView::Base.new(Rails::Configuration.new.view_path, assigns, DummyController.new)<br /> viewer.pick_template_extension(path) rescue false<br /> end<br />end<br /><br />class Page < ActiveRecord::Base<br /><br /> def write_cache<br /> self.cached_content = ActionView::Base.new(Rails::Configuration.new.view_path).render(:partial => "pages/show", :locals => {:page => self})<br /> self.save<br /> end<br /><br />end

Turning web server configuration

Setting Static Asset Expires Headers with nginx and Passenger

Nginx

location ~* \.(ico|css|js|gif|jpe?g|png)(\?[0-9]+)?$ {
    expires max;
    break;
}

redirect permanent

Permanent Redirect with HTTP 301

#Apache
    RewriteCond %{HTTP_HOST}   17\.ooxx\.com [NC]
    RewriteRule ^/(.*)         http://17.ooxx.com.tw/$1 [L,R=permanent]

#Nginx
    if ($host ~* ^17.ooxx\.com) {
      rewrite ^/(.*) http://17.ooxx.com.tw/$1 permanent;
    }

META HTTP-EQUIV="refresh" 實現網頁自動跳轉

META HTTP-EQUIV="refresh" 實現網頁自動跳轉

<br />< meta http-equiv="Refresh" content="秒數; url=跳轉的文件或地址" > <br /><br />< head > <br /> < meta http-equiv="Refresh" content="3;url=http://www.haishui.net"><br />< /head > <br /><br />多個內容相似而背景不同的頁面，讓其每隔一定時間自動相互跳轉。 <br />

rails default environment

~/.bashrc

export PATH=$PATH:/opt/ruby-enterprise/bin
export RAILS_ENV=production

nginx memo

Nginx泛域名解析及Rewrite重定向普通頁面及帶參數的頁面
Nginx "how to" - Fast and Secure Web Server
Nginx Location



靜態地址重定向到帶參數的動態地址

rewrite "^(.*)/service/(.*)\.html$" $1/service.php?sid=$2 permanent;

帶參數的動態地址重定向到靜態地址

if ($query_string ~* id=(.*)) {
    set $id $1;
    rewrite "^(.*)/article.asp$" $1/article/$id.htm last;
}

舉例:
abc.domian.com/sort/2 => abc.domian.com/index.php?act=sort&name=abc&id=2

if ($host ~* (.*)\.domain\.com) {
    set $sub_name $1;
    rewrite ^/sort\/(\d+)\/?$ /index.php?act=sort&cid=$sub_name&id=$1 last;
}

Nginx Rewrite Flags
* last 相當於Apache裡的[L]標記，表示完成rewrite
* break 終止匹配, 不再匹配後面的規則
* redirect 返回302臨時重定向
* permanent 返回301永久重定向

Nginx正則表達式匹配
* ~ 為區分大小寫匹配
* ~* 為不區分大小寫匹配
* !~和!~*分別為區分大小寫不匹配及不區分大小寫不匹配

Nginx文件及目錄匹配
* -f和!-f用來判斷是否存在文件
* -d和!-d用來判斷是否存在目錄
* -e和!-e用來判斷是否存在文件或目錄
* -x和!-x用來判斷文件是否可執行

Nginx全局變量
$args
$content_length
$content_type
$document_root
$document_uri
$host
$http_user_agent
$http_cookie
$limit_rate
$request_body_file
$request_method
$remote_addr
$remote_port
$remote_user
$request_filename
$request_uri
$query_string
$scheme
$server_protocol
$server_addr
$server_name
$server_port
$uri

restart nginx

 
alias startnginx='sudo /opt/nginx/sbin/nginx' 
alias stopnginx='sudo kill `cat /opt/nginx/logs/nginx.pid `' 
alias restartnginx='stopnginx; startnginx' 

transcation

Transaction in Rails
Working with transactions in Rails
<br />transaction do<br /> first.save!<br /> second.save!<br /> third.save!<br /> fourth.save!<br />end<br /><br /> Course.transaction do<br /> @course.save!<br /> read_directory(@course.folder_title).each do |f|<br /> lo = LearningObject.new<br /> lo.course_id, lo.title = @course.id, f.gsub('_',' ')<br /> lo.save!<br /> end<br /> end<br />