Categories

• lessons 1
• linux 73
• cronjob 5
• rails 102
• design 4
• css 13
• capistrano 16
• deployment 16
• thin 2
• nginx 11
• ruby 44
• rbenv 1
• rspec 8
• test 12
• installation 3
• spring 1
• guard 1
• virtualbox 3
• angularjs 1
• js 17
• frameworks 1
• sysops 27
• fedora 5
• nodejs 3
• sublime 6
• activerecord 15
• i18n 1
• imagemagick 1
• postgresql 15
• html 3
• ssl 4
• rsync 1
• ckeditor 3
• refinerycms 1
• git 17
• server 7
• configuration 3
• ssh 10
• file 1
• regexp 2
• monit 3
• bash 30
• windows 7
• iptables 3
• security 7
• selinux 3
• logging 2
• monitoring 4
• journalctl 2
• fail2ban 3
• debug 3
• random 1
• best-practices 3
• compression 1
• delayed_job 4
• bootstrap 5
• tables 1
• video 1
• byobu 1
• sinatra 2
• sqlserver 1
• google-analytics 1
• sse 1
• ftp 1
• I18n 1
• nestacms 1
• string 1
• rvm 5
• factorygirl 1
• pundit 2
• jquery 2
• clustering 1
• mina 3
• kernel 1
• GeoHash 1
• maps 3
• dropbox 2
• glibc 1
• rest 1
• vagrant 3
• google 2
• hacks 1
• system 1
• networking 1
• benchmarking 2
• jbuilder 1
• mini-profiler 1
• process 2
• presenters 1
• turbolinks 1
• Ruby 1
• markdown 1
• sharetribe 1
• exceptions 1
• class_eval 1
• instance_eval 1
• define_method 1
• extend 1
• mailchimp 1
• metaprogramming 1
• letsencrypt 1
• refactor 1
• oop 3

lessons

• Jekyll Introduction

linux

• How to print linux distro name
• List Linux machine reboots
• Difference between &, disown, NOHUP
• Useful bash commands
• Mount shared folder in windows into linux
• IPTABLES updating
• Finding and copying files keeping folder structure
• Deshabilitar descarga automatica de updates en Fedora
• Developer's machine setup
• While Loop in bash
• WRK: HTTP BENCHMARKING TOOL
• Useful networking commands
• Traverse folders recursively and replace 1st line of text files
• Substitute 1st line
• Print gateway IP addr
• Security limits
• How to execute script/command at boot time
• Get and set default target
• Find ports used by tcp for services imap3 and imaps
• Find files by name and delete them
• Find files by name and copy them
• Duplicate files with another extension
• Add line to text files that contains some pattern
• sshd config
• Linux useful commands
• How to check glibc version in Linux
• How to change timezone in Linux
• How to find and colour a pattern in a text file with grep
• Text files manipulation in Linu
• Reduce cpu load during deployment controlling the niceness of linux processes
• How to connect a usb memory stick to linux
• ftp server in fedora
• Folders size
• Boot and GRUB
• nmap - Network mapper
• Keep pinging until host is known
• Scheduling jobs with cron
• Linux monitoring tools - load average
• Monitoring Linux system with TOP
• Background and foreground processes, managing and scheduling
• Working with compression
• Deploying with Capistrano: warning: setlocale: LC_CTYPE: Can not change locale
• IPTables
• Prevent YUM from updating the kernel
• sshd config
• SELinux
• Security
• Firewalld and iptables
• Autossh
• Bash initialisation files
• Linux System info
• SSH passwordless authentication with public key
• 4 Steps to Perform SSH Login Without Password Using ssh-keygen & ssh-copy-id
• SSH Agent
• Force SSH do not use key and ask for password
• Types of linux shells
• Check if it's a login shell
• About users and groups
• rsync to download backup from server
• Bash
• Search patterns in a file
• Report or delete repeated lines in sorted file
• Extract strings from a file
• Count lines, words in a file
• Copy standard output to a file
• Change characters inside a file
• Sort file contents
• Combine file contents
• Text/file manipulation
• Linux
• bash aliases
• Whenever gem
• cronjob

cronjob

• Scheduling jobs with cron
• Background and foreground processes, managing and scheduling
• Execute model's method in command console or with a cronjob
• Whenever gem
• cronjob

rails

• PostgreSQL geometric types
• PG citext type: case-insensitive text
• devise_token_auth with an existing Rails application
• Smart way to fetch a value from a hash (array) giving a default value if key is missing
• Testing sanitization of user entries
• Rescue + else
• Pass block to before_action filter
• Move uniqueness validation with scope to database constraint
• HashWithIndiferentAccess
• DB Schema with uuids
• Add sensible data in secrets file
• Rails performance considerations
• How to execute a ruby script outside project root folder
• Avoid HTML comments in view templates as these are viewable to clients
• How to validate only when updating record
• Search and Filter Rails Models Without Bloating Your Controller
• Rails 'presence' vs 'present?'
• Extend vs include
• 7 Patterns to Refactor Fat ActiveRecord Models
• Metaprogramming in Rails
• Scope of a range of dates
• How to include helpers in views directly
• How to pass url to view and call it with parameters
• Model callbacks vs object responsability
• instalación ShareTribe en local
• How to render html from controller action responding to pdf format
• Dynamic Rails error pages
• Use Rails url helpers inside a module
• Rails time in time_zone
• Rails constraints to limit mime types responses
• Ejemplo JBuilder
• Automated Tasks with Rake
• ActiveRecord query with regexp
• Devise and user default scope
• Rails routes constraints
• How to eliminate values from params hash that are not valid option keys
• Scope with aggregate functions on associations
• Rails load js scripts per controller
• Rails extend vs include
• How to use assset helpers in a controller
• How to set defaults options for rails server command
• How to downgrade a gem in Rails
• How to call class methods from instance methods
• Custom devise mails
• Use namespacing to make REST controllers
• Rails helper to create links
• Nested layouts in Rails
• How to create new rails app using rvm
• How to include subfolders in assets
• Good reasons to replace db/schema.rb with db/structure.sql
• How to list all notes in code
• Rails routes en web
• Config to log request parameters
• How to solve RVM ERROR GEM_PATH NOT SET
• Rake assets:precompile error with EXECJS runtime error
• What is needed to precompile assets locally?
• List models
• How to pass a method to a partial
• How to filter registers whose has many association is empty
• How to export data in a seeds data file format
• Get table names inside a database
• Feeding data with a custom seed file
• How to pass messages from model to controller
• Faster Capistrano
• Remember selected tab using bootstrap toogle pills in rails and localstorage
• How to open a popup from Rails
• How to load Google fonts with SSL
• How to clear session variables in Rails
• Change model validation error message
• CKEditor toolbars configuration in Rails
• ActiverRecord update possibillities in Rails 4
• Multiple has_many associations beetween same tables
• Rails text helpers
• Server-Sent Events with Rails 4
• Specify order in has_many association
• SQL Server with Rails
• Check_box_tag for collections
• Rails binstubs vs bundler binstubs
• Create nondigest versions of all ckeditor digest assets
• Execute model's method in command console or with a cronjob
• Execute JS and submit form
• Do not install gems documentation
• Seed data from a file
• SSL in local development
• REFINERY CMS clean install
• Rake task to feed the database
• Mark some photos with a boolean field to be included in a carrousel
• Do not bundle install on new app creation
• Date and DateTime differences
• rake db:migrate fails with unitialized constant CKEditor
• Proxy HTTPS requests to a HTTP backend with NGINX
• Conditionally add css class
• HABTM association migration
• Simple user authentification
• Rails
• New app
• Email configuration
• Eager load
• Custom logger
• Activer record associations
• Rake tasks
• Whenever gem

design

• CSS tables
• Bootstrap - hidden columns
• Advanced CSS
• PSD to HTML

css

• How to hide exceeding text in CSS
• CSS Selectors
• CSS Centering
• Grep to find duplicated css
• Non-Transparent Elements Inside Transparent Elements
• Centering vertically with CSS
• Perfect Full Page Background Image
• Centering Percentage Width/Height Elements
• Beveled class in CSS
• CSS tables
• Numbering sections and paragraphs with CSS
• Conditionally add css class
• Advanced CSS

capistrano

• Capistrano task to open rails console
• What is needed to precompile assets locally?
• Faster Capistrano
• Capistrano formatted output prettyfied with Airbrush
• Capistrano & whenever
• sudo: no tty present and no askpass program specified
• Capistrano environment variables
• Capistrano deployment workflow
• Deploying with Capistrano: warning: setlocale: LC_CTYPE: Can not change locale
• Capistrano shell environments variables
• Understanding SSHKit
• Tailing log files with Capistrano 3
• Deploy branches with Capistrano
• Capistrano deploy to different instances on same cloud provider
• Staging
• Capistrano

deployment

• Prepare destination to deploy with mina
• Upload shared gitignored files with mina
• Implement MINA for deploying in existing app
• Reduce cpu load during deployment controlling the niceness of linux processes
• Capistrano & whenever
• sudo: no tty present and no askpass program specified
• Capistrano environment variables
• Capistrano deployment workflow
• Deploying with Capistrano: warning: setlocale: LC_CTYPE: Can not change locale
• Using Chef to provision a Rails and Postgres server
• Tailing log files with Capistrano 3
• Deploy branches with Capistrano
• Capistrano deploy to different instances on same cloud provider
• Staging
• Deployment
• Capistrano

thin

• Thin server configuration file
• Deployment

nginx

• Nginx redirection routes
• How to block php requests in Nginx
• Allowing Nginx to use a Puma/Unicorn UNIX socket with SELinux
• SELinux issues with nginx
• How to solve 'Failed to read PID from file /run/nginx.pid: Invalid argument' error in Nginx
• Nginx netstat
• SSL certificate issued by Let's Encrypt with new Certbot client
• Nginx server config by direct IP instead domain server
• Proxy HTTPS requests to a HTTP backend with NGINX
• nginx
• Deployment

ruby

• Ruby send vs __send__
• Smart way to fetch a value from a hash (array) giving a default value if key is missing
• Rescue + else
• Add watermark with CarrierWave
• sockets in Ruby
• How to execute a ruby script outside project root folder
• Prepend module to avoid monkey patching classes
• Sandi Metz' Rules For Developers
• How to limit value asignation
• How to create status methods
• Extend vs include
• Metaprogramming in Rails
• Ruby functions with optional parameters
• Metaprogramming Ruby
• Mastering Ruby exceptions
• How to create table of content in markdown file
• How to check process is running from its pid number, in Ruby
• About presenters (view objects)
• 6 Ways to Run Shell Commands in Ruby
• The % notation in ruby
• Execute shell commands from ruby
• Encode string for url in ruby
• Ejemplo JBuilder
• Convert seconds to d h m
• Default values, required arguments, keyword arguments and splats in Ruby
• 4 Simple Memoization Patterns in Ruby (and One Gem)
• How to merge arrays in Ruby
• How to call class methods from instance methods
• Use namespacing to make REST controllers
• Rails helper to create links
• Five Ruby Methods You Should Be Using
• Retry when rescue from error
• Get random array element
• Humanize seconds in Ruby
• Sum array elements in Ruby
• Get an array of one field of each record in ruby
• Best method to sort an array in ruby
• nil? vs empty? vs blank?
• Read text files
• Date and DateTime differences
• Conditionally add css class
• Ruby
• Custom logger
• rbenv

rbenv

• rbenv

rspec

• How to test inside a controller test that a model receives a message
• Aggregate failures with RSpec
• RSpec improvements in speed with focus
• Stop spec_helper from being loaded multiple times
• Test Pundit policies with RSpec
• How to test actions that redirect to request.referer
• Sorcery & RSpec
• RSpec

test

• Testing sanitization of user entries
• Stub vs query
• Usar devise current_user en tests
• Aggregate failures with RSpec
• How to test policy scopes
• Stop spec_helper from being loaded multiple times
• Test Pundit policies with RSpec
• How to test actions that redirect to request.referer
• How to create a bunch of records with FactoryGirl
• Sorcery & RSpec
• Spring & Guard
• RSpec

installation

• Install Fedora in VirtualBox VM
• Setting up development environment
• Ruby, Node, Rails on Ubuntu 14.04

spring

• Spring & Guard

guard

• Spring & Guard

virtualbox

• Add a new disk to Virtualbox machine
• Mount a Virtualbox shared folder
• VirtualBox

angularjs

• AngularJS

js

• 12 extremely useful hacks for JavaScript
• How to prevent zooming to much in Google Maps API
• How to move the viewport in JS
• How to fix at top some element as it is scrolled up
• Detecting scroll position with JS
• How to detect screen movement reaching top
• How to add event listeners in JS
• JavaScript Debounce Function
• How to convert a string into date in JS
• JS debugging techniques and tricks
• Preventing data loss when leaving page with onbeforeunload event
• Execute JS and submit form
• Input field validation in JS
• node.js installation
• Javascript
• Calculate week number in JS
• AngularJS

frameworks

• AngularJS

sysops

• Protect images downloading
• How to prevent bots indexing images folder or file
• Checklists for Software Development
• How to manually detect and ban the attacker ips
• How to block php requests in Nginx
• SysAdmin strace for tracing rake assets precompilation
• Developer's machine setup
• How to put colors in LESS
• WRK: HTTP BENCHMARKING TOOL
• How to execute script/command at boot time
• Get and set default target
• How to change timezone in Linux
• Reduce cpu load during deployment controlling the niceness of linux processes
• How to connect a usb memory stick to linux
• Folders size
• Byobu
• nmap - Network mapper
• Background and foreground processes, managing and scheduling
• sudo: no tty present and no askpass program specified
• Fail2ban
• System logging review with journalctl
• SSHD Logging
• HOST fingerprint
• Creating server in DreamHost.com
• Thin server configuration file
• Terminal configuration in Kitty Putty
• bash aliases

fedora

• Install Fedora in VirtualBox VM
• Types of linux shells
• Check if it's a login shell
• About users and groups
• fedora

nodejs

• Rake assets:precompile error with EXECJS runtime error
• NODEJS installation in Fedora
• node.js installation

sublime

• Sublime shortcuts
• How to use regex in sublime to find posts by category
• Sublime Pluggin for ERB templates
• How to change sidebar font size in SublimeText3
• Change sidebar font size in Sublime
• Sublime Text 3

activerecord

• How to validate only when updating record
• 7 Patterns to Refactor Fat ActiveRecord Models
• Scope of a range of dates
• Belongs_to through association
• ActiveRecord query with regexp
• Config to log request parameters
• How to filter registers whose has many association is empty
• Get table names inside a database
• Feeding data with a custom seed file
• Change model validation error message
• ActiverRecord update possibillities in Rails 4
• Multiple has_many associations beetween same tables
• Specify order in has_many association
• Eager load
• Activer record associations

i18n

• I18n

imagemagick

• Image upload with ImageMagick

postgresql

• PostgreSQL geometric types
• PostgreSQL console
• PG citext type: case-insensitive text
• How to use pgBadger to extract information from PostrgeSQL logs
• How to install and activate statistics in PostgreSQL
• PostgreSQL issue on Centos 7
• Finding active sessions or connections in PostgreSQL
• How to get last registers of each group in PostgreSQL
• Postgres service
• Postgresql installation
• Change Postgres port on Fedora
• Automatic postgresql database backup
• PostgreSQL recommended configuration
• Restore postgresql database
• PostgreSQL

html

• Several submit actions in same form
• Centering vertically with CSS
• Numbering sections and paragraphs with CSS

ssl

• SSL certificate issued by Let's Encrypt with new Certbot client
• How to load Google fonts with SSL
• SSL in local development
• Proxy HTTPS requests to a HTTP backend with NGINX

rsync

• rsync to download backup from server

ckeditor

• CKEditor toolbars configuration in Rails
• Create nondigest versions of all ckeditor digest assets
• rake db:migrate fails with unitialized constant CKEditor

refinerycms

• REFINERY CMS clean install

git

• Resolve merge conflicts
• Checkout a file from another branch
• Squash my last X commits together using Git
• How to remove a file from git commits
• Git Interactive Rebase, Squash, Amend and Other Ways of Rewriting History
• GIT log with dates
• GIT list tags with dates
• GIT coloured prompt
• Increase team productivity reviewing pull requests locally. How to git pull remote pull requests
• How to untrack a folder locally in git and push to production without deleting it
• GIT REBASE: Move one branch ahead
• List branches ordered by date
• Move a local branch to the head
• Undo last commit and push
• Checkout only some file from origin/master
• Resolve a conflict and test a remote branch in local machine before merging
• Discard local changes and rever local master to origin

server

• Protect images downloading
• How to prevent bots indexing images folder or file
• System logging review with journalctl
• SSHD Logging
• HOST fingerprint
• Creating server in DreamHost.com
• Thin server configuration file

configuration

• Change sidebar font size in Sublime
• Nginx server config by direct IP instead domain server
• Thin server configuration file

ssh

• sshd config
• SSH, SSH-AGENT and security
• SSHD Logging
• sshd config
• Autossh
• Autostart ssh agent
• SSH passwordless authentication with public key
• 4 Steps to Perform SSH Login Without Password Using ssh-keygen & ssh-copy-id
• SSH Agent
• Force SSH do not use key and ask for password

file

• Read text file

regexp

• ActiveRecord query with regexp
• Regular expressions

monit

• start stop delayed_job with monit
• Monitoring delayed jobs with monit
• Monit - system monitorization tool

bash

• How to check process is running from its pid number, in bash
• Useful bash commands
• Execute shell commands from ruby
• Finding and copying files keeping folder structure
• GIT coloured prompt
• Filter files by date with bash
• How to put colors in LESS
• While Loop in bash
• Useful networking commands
• Traverse folders recursively and replace 1st line of text files
• Substitute 1st line
• Print gateway IP addr
• Find ports used by tcp for services imap3 and imaps
• Find files by name and delete them
• Find files by name and copy them
• Duplicate files with another extension
• Add line to text files that contains some pattern
• Bash colors
• Random numbers generator
• Hide standard output
• Creating temporary files and folders
• String manipulation in Bash
• Redirecting errors in Bash
• Loops in Bash
• Debug mode in Bash
• Case statement in Bash
• Boolean comparision in Bash
• sudo: no tty present and no askpass program specified
• Autostart ssh agent
• Bash initialisation files

windows

• Let download files from links in Outlook mail messages overriding system restrictions
• Ping a range of addresses in MSDOS
• Mount shared folder in windows into linux
• Recursively travers folders and change file name
• How to create a photo video with music
• W8-W10 no reconoce CD/DVD-ROM
• Calculate checksum on Windows

iptables

• IPTABLES updating
• IPTables
• Firewalld and iptables

security

• devise_token_auth with an existing Rails application
• Avoid HTML comments in view templates as these are viewable to clients
• How to manually detect and ban the attacker ips
• IPTABLES updating
• Fail2ban
• HOST fingerprint
• Security

selinux

• Allowing Nginx to use a Puma/Unicorn UNIX socket with SELinux
• SELinux issues with nginx
• SELinux

logging

• System logging review with journalctl
• SSHD Logging

monitoring

• Keep pinging until host is known
• Background and foreground processes, managing and scheduling
• System logging review with journalctl
• SSHD Logging

journalctl

• List Linux machine reboots
• System logging review with journalctl

fail2ban

• How to manually detect and ban the attacker ips
• How to print status of all Fail2ban jails
• Fail2ban

debug

• JS debugging techniques and tricks
• Redirecting errors in Bash
• Debug mode in Bash

random

• Random numbers generator

best-practices

• Checklists for Software Development
• Delayed job best practices
• 67WEBS Procedures handbook

compression

• Working with compression

delayed_job

• start stop delayed_job with monit
• Delayed job best practices
• Monitoring delayed jobs with monit
• Scheduling jobs with cron

bootstrap

• MediaQuery for Bootstrap Collapse Menu Button
• Bootstrap Glyphicons
• Remember selected tab using bootstrap toogle pills in rails and localstorage
• How to load Glyphicons with Bootstrap when they are not being shown
• Bootstrap - hidden columns

tables

• CSS tables

video

• How to create a photo video with music

byobu

• Byobu

sinatra

• Start Sinatra or NestaCMS application
• Push notifications with Sinatra

sqlserver

• SQL Server with Rails

google-analytics

• Google analytics in Rails

sse

• Server-Sent Events with Rails 4

ftp

• ftp server in fedora

I18n

• Change model validation error message

nestacms

• Start Sinatra or NestaCMS application

string

• How to convert a string into date in JS

rvm

• New app with RVM
• RVM hook to binstubs
• List gems in RVM gemsets
• How to create new rails app using rvm
• How to solve RVM ERROR GEM_PATH NOT SET

factorygirl

• How to create a bunch of records with FactoryGirl

pundit

• How to test policy scopes
• Test Pundit policies with RSpec

jquery

• How to pass all input fields of a form to a http request with jQuery
• How to fill a DOM list/dropdown list in jquery

clustering

• Cluster array - group adjacent values

mina

• Prepare destination to deploy with mina
• Upload shared gitignored files with mina
• Implement MINA for deploying in existing app

kernel

• Retry when rescue from error

GeoHash

• GeoHash

maps

• How to prevent zooming to much in Google Maps API
• How to fit bounds in Google Maps
• Cluster-icons-for-maps

dropbox

• Upload files to dropbox with dropbox_uploader
• DROPBOX command line in linux

glibc

• How to check glibc version in Linux

rest

• Use namespacing to make REST controllers

vagrant

• How to use scp command with Vagrant machine
• Vagrant
• Upgrade Guest Additions in Vagrant box

google

• How to prevent zooming to much in Google Maps API
• How to fit bounds in Google Maps

hacks

• 12 extremely useful hacks for JavaScript

system

• Security limits

networking

• Nginx netstat

benchmarking

• Benchmarking in ruby
• WRK: HTTP BENCHMARKING TOOL

jbuilder

• Ejemplo JBuilder

mini-profiler

• Mini profiler in staging

process

• How to check process is running from its pid number, in Ruby
• How to check process is running from its pid number, in bash

presenters

• About presenters (view objects)

turbolinks

• Disable turbolinks in specific links

Ruby

• How to check if a process is running in Ruby

markdown

• How to create table of content in markdown file

sharetribe

• instalación ShareTribe en local

exceptions

• Mastering Ruby exceptions

class_eval

• Metaprogramming Ruby

instance_eval

• Metaprogramming Ruby

define_method

• Metaprogramming Ruby

extend

• Metaprogramming Ruby

mailchimp

• Cómo he creado una campaña de correo Mailchimp

metaprogramming

• Metaprogramming in Rails

letsencrypt

• Remove domains from letsencrypt

refactor

• 7 Patterns to Refactor Fat ActiveRecord Models

oop

• Prepend module to avoid monkey patching classes
• Sandi Metz' Rules For Developers
• How to create status methods