MohamedAlaa

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

ProGM

Arel Cheatsheet on Steroids

A (more) complete cheatsheet for Arel, including NamedFunction functions, raw SQL and window functions.

Tables

posts = Arel::Table.new(:posts)
posts = Post.arel_table # ActiveRecord

Table alias

coreyhaines

--colour
-I app

barmstrong

class ZendeskTicketsJob
  extend Resque::Plugins::ExponentialBackoff
  @queue = :low
  FIELDS = ['zendesk_id', 'requester_id', 'assignee_id', 'group', 'subject', 'tags', 'status', 'priority', 'via', 'ticket_type', 'created_at', 'assigned_at', 'solved_at', 'resolution_time', 'satisfaction', 'group_stations', 'assignee_stations', 'reopens', 'replies', 'first_reply_time_in_minutes', 'first_reply_time_in_minutes_within_business_hours', 'first_resolution_time_in_minutes', 'first_resolution_time_in_minutes_within_business_hours', 'full_resolution_time_in_minutes', 'full_resolution_time_in_minutes_within_business_hours', 'agent_wait_time_in_minutes', 'agent_wait_time_in_minutes_within_business_hours', 'requester_wait_time_in_minutes', 'requester_wait_time_in_minutes_within_business_hours', 'reservation_code', 'requires_manual_closing']

  def self.perform(url)
    `rm /tmp/zendesk_tickets*`
    `wget #{url} -O /tmp/zendesk_tickets.csv.zip`
    `unzip -p /tmp/zendesk_tickets.csv.zip > /tmp/zendesk_tickets.csv`
    

bastman

Docker - How to cleanup (unused) resources

Once in a while, you may need to cleanup resources (containers, volumes, images, networks) ...

delete volumes

// see: https://github.com/chadoe/docker-cleanup-volumes

$ docker volume rm $(docker volume ls -qf dangling=true)

$ docker volume ls -qf dangling=true | xargs -r docker volume rm

rushilgupta

INTRO

Concurrency is a domain I have wanted to explore for a long time because the locks and the race conditions have always intimidated me. I recall somebody suggesting concurrency patterns in golang because they said "you share the data and not the variables".

Amused by that, I searched for "concurrency in golang" and bumped into this awesome slide by Rob Pike: https://talks.golang.org/2012/waza.slide#1 which does a great job of explaining channels, concurrency patterns and a mini-architecture of load-balancer (also explains the above one-liner).

Let's dig in:

Goroutines

bokmann

# Thee will be more information here when I share the entire problem space I'm working on, but
# in short, this is preview material for my second talk in a series called "What Computer Scientists Know".
# The first talk is on recursion, and goes through several examples., leading up to a problem based
# on a simple puzzle that initial estimates based on performance of a previous puzzle would take years
# to solve on modern computers with the techniques shown in Ruby. That sets the stage for improving the
# performance of that problem with threading, concurrency, and related tuning.
#
# The second talk is on threading and concurrency, touching on algorithmic performance as well.
# Using some knowledge of the problem (board symmetry, illegal moves, etc), we reduce the problem space
# to about .5% of what we initially thought it was.  Still, the initial single threaded solution took more

dhh

# Original Rails controller and action
class EmployeesController < ApplicationController
  def create
    @employee = Employee.new(employee_params)
    
    if @employee.save
      redirect_to @employee, notice: "Employee #{@employee.name} created"
    else
      render :new
    end

franck

###############################################################################
## Monit control file
###############################################################################
##
## Comments begin with a '#' and extend through the end of the line. Keywords
## are case insensitive. All path's MUST BE FULLY QUALIFIED, starting with '/'.
##
## Below you will find examples of some frequently used statements. For 
## information about the control file, a complete list of statements and 
## options please have a look in the monit manual.

bf4

List moved

Please use https://github.com/bf4/learning to fork and pull changes.