mike1011

First, setup and install monit on Ubuntu server
   ###get the latest
   sudo apt-get update
   ##install monit
   sudo apt-get install monit
   ##edit monit and add the below custom scripts
   sudo vim /etc/monit/monitrc
   ##reload and verify
   sudo monit reload
   sudo monit

mike1011

Do you have spaces in your Windows username?

1. Create a new account on Windows without a space.

#Installation

1. Download cygwin from http://cygwin.com
2. Run setup-(x86|x86_64).exe
3. Click next until selecting repo to download packages
4. Choose http://cs.vt.edu (gotta go fast), click next

mike1011

Use Case - Use Devise Confirmable module to confirm newly added organization(org) using email(association)

We want Three things to work - 
     Use confirmable - send_confirmation_instructions to send email when new org is added
     Define Routes - organization_confirmation_url, so that user can use this route to confirm the org
     Add confirmable columns inside existing organizations table, update token,timestamps on db
     
====== HERE WE START =========     
- `organization.rb`
	has_one :contact_detail ##contains email

mike1011

http://stackoverflow.com/questions/22667401/postgres-json-data-type-rails-query
http://stackoverflow.com/questions/40702813/query-on-postgres-json-array-field-in-rails

#payload: [{"kind"=>"person"}]
Segment.where("payload @> ?", [{kind: "person"}].to_json)

#data: {"interest"=>["music", "movies", "programming"]}
Segment.where("data @> ?",  {"interest": ["music", "movies", "programming"]}.to_json)
Segment.where("data #>> '{interest, 1}' = 'movies' ")
Segment.where("jsonb_array_length(data->'interest') > 1")

mike1011

######################################  UBUNTU  ###############################################

==== to search by port ======
lsof -wni tcp:3000

==== to kill by port ========
sudo kill -9 `sudo lsof -t -i:3000`
==== another way to search and kill a process using port ===
sudo lsof -i -P -n | grep 6379
sudo kill  -9 <process_id>

mike1011

Ruby and Rails Interview Questions

Ruby

• What is a class?
• What is an object?
• What is a module? Can you tell me the difference between classes and modules?
• Can you tell me the three levels of method access control for classes and modules? What do they imply about the method?
• There are three ways to invoke a method in ruby. Can you give me at least two?
• Explain this ruby idiom: a ||= b

mike1011

   To begin with, firstly create a new repository on github WITHOUT INITIALIZING it.
   
   ## clean up existing repo
   rm -rf .git
   ## re-initialize it with new .git settings
   git init
   ## firstly, dont commit any code, just create/add new sample/readme file and push it to new repo/master
   git add README.md 
   ## add newly created fresh repo
   git remote add origin [email protected]:username/my-new-master-repo.git

mike1011

========== ONLY RUBY ==========
array vs hash - ordered indexed collection
convert hash to array = h.to_a
get even/odd entries from array -> select.each_with_index { |_, i| i.even? }
get hash keys in reverse order -> Hash[h.to_a.reverse] OR hash_array.keys.reverse
---replace strings --
 value = "cat"
 # Replace string at with ote.
 value.sub!("at", "ote") // just first instance - cote
 value = value.gsub("cat", "---") //all instances globally ---

mike1011

What is Circular Dependency?
Shallow vs Deep Copy.
Array.sort() - with numbers and strings.
PUT vs PATCH
What is package-lock.json?
---ref - https://medium.com/iquii/good-practices-for-high-performance-and-scalable-node-js-applications-part-1-3-bb06b6204197
What is this? How arrow functions using it to help the binding?
Session Management in Nodejs
API Authentication in Nodejs
Default memory size in NOdejs

mike1011

DigitalOcean Rails/Ubuntu/NGINX (16.04) Setup

1. Setup
2. Swapfile
3. NGINX
4. ElasticSearch
5. RVM
6. Rails
7. Redis
8. Postgres