Install Jenkins on Ubuntu 16.04

1. Introduction

2. Step by Step

2.1. Prerequisites

2.1.a. Check Memory available

• 1 GB of RAM minimum; 
• 4 GB desired;

2.1.b. System Update

$ sudo apt-get update

2.2. Install Jenkins

$ wget -q -O - https://pkg.jenkins.io/debian/jenkins-ci.org.key | sudo apt-key add -
OK
$ cat /etc/apt/sources.list.d/jenkins.list
deb http://pkg.jenkins.io/debian-stable binary/
$ sudo apt-get update

2.3. Upgrade Jenkins version ( optional )

$ sudo apt-get update
$ sudo apt-get install jenkins

2.4. Cheking services

$ # Ubuntu/Debian (different from CentOs/Fedora) usually starts software after installation
$ # Jenkins will be started as a deamon service named 'jenkins'
$ # See /etc/init.d/jenkins for more details. Log file will be placed in /var/log/jenkins/jenkins.log.
$ # Config parameters like JENKINS_HOME and etc, will be captured on /etc/default/jenkins
$ # By default, Jenkins listen on port 8080. Edit /etc/default/jenkins to change port
$ # To start-stop-status service do: sudo service jenkins stop; sudo service jenkins start; sudo service jenkins status

2.5. Check/allow firewall rules

a) Check firewall status - Inactive? Great nothing to do

$ sudo ufw status
Status: inactive

b) Check firewall status - Active? add rule to allows Jenkins port

$ sudo ufw status
Status: active
:
8080                       ALLOW       Anywhere
:
$ sudo ufw allow 8080

2.6. Setting up Jenkins 

a) Access Jenkins interface on browser and you'll see "Unlock Jenkins screen"

• http://localhost:8080

$ sudo cat /var/lib/jenkins/secrets/initialAdminPassword

+------------------------------------------------+
| Unlock Jenkins                                 |
|    :       :                                   |
| /var/lib/jenkins/secrets/initialAdminPassword  |
| Administrator password                         | 
| [                   ]                          | <- paste here
+------------------------------------------------+

b) Install suggested plugins 

+------------------------------------------------+
| Customize Jenkins                              |
| +------------------+                           |
| |Install Suggested |                           |
| | Pluggins         |                           | <- click button
| +------------------+                           |
+------------------------------------------------+

c) Create first admin user

+------------------------------------------------+
| Create first admin user                        |
|   Username: [admin]                            |
|   Password: [admin]                            |
+------------------------------------------------+

3. References

• https://wiki.jenkins.io/display/JENKINS/Installing+Jenkins+on+Ubuntu
• https://www.digitalocean.com/community/tutorials/how-to-install-jenkins-on-ubuntu-16-04
• https://vexxhost.com/resources/tutorials/how-to-install-configure-and-use-jenkins-on-ubuntu-14-04/

Manipulating text files on linux

1. Introdução

This post gathers information about how to manipulates text files on linux systems.

2. Referências

• http://terminalroot.com.br/2015/07/30-exemplos-do-comando-sed-com-regex.html

How to Increase the size of a Linux LVM by adding a new disk

1. Introduction

This post olny gathers information about how to increase size linux LVM.

2. References

* https://www.rootusers.com/how-to-increase-the-size-of-a-linux-lvm-by-adding-a-new-disk/

DOCKER Faq, HowTo, Referece, Sample Install Run PostgreSQL in a Docker

1. Introduction

This post gathers information about PostgreSQL and Docker.

2. Step-by-Step

2.1. Ensure Docker, Docker Compose are working

# docker --version
Docker version 17.03.1-ce, build c6d412e
# docker-compose --version
docker-compose version 1.11.2, build dfed245

2.2. Install a PostgreSQL Docker

• Determining PostgreSQL Docker Version to install

# psql --version
psql (PostgreSQL) 9.6.3

• Pull docker image versions

# docker pull postgres:9.6.3-alpine
# docker pull postgres:9.6.3

• Run PostgreSQL Docker Image in background - database instance

# docker run --name postgres-01 -e POSTGRES_PASSWORD=mysecretpassword -d postgres:9.6.3-alpine
# docker run --name postgres-02 -e POSTGRES_PASSWORD=mysecretpassword -d postgres:9.6.3

• Check both Docker process images running 

# docker ps
CONTAINER ID        IMAGE                   COMMAND                  CREATED             STATUS              PORTS               NAMES
676278f9f054        postgres:9.6.3          "docker-entrypoint..."   7 seconds ago       Up 7 seconds        5432/tcp            postgres-02
0d93213e347e        postgres:9.6.3-alpine   "docker-entrypoint..."   12 seconds ago      Up 11 seconds       5432/tcp            postgres-01

• Stop Docker instance "postgres-02"

# docker stop postgres-02
# docker kill postgres-02

• Run PostgreSQL psql command line, linked to running instance "postgres-01", using interative mode. Interate with application saying the password "mysecretpassword"

# docker run --name postgres-psql-01 -it --rm --link postgres-01:postgres postgres psql -h postgres-01 -U postgres:9.6.3-alpine
Password for user postgres: mysecretpassword
psql (9.6.3)
Type "help" for help.

postgres=# select current_date;
    date
------------
 2017-06-03

(1 row)

postgres=# \q

• Run PostgreSQL plsql command line, linked to running instance "postgres-01", using interative mode, using password in command line

3. References

• https://hub.docker.com/_/postgres/
• https://docs.docker.com/compose/rails/
• http://blog.kontena.io/rails-5-and-docker/
• https://stackoverflow.com/questions/29600369/starting-and-populating-a-postgres-container-in-docker
• https://github.com/kiasaki/docker-alpine-postgres/issues/18

RAILS Faq, HowTo, Reference, Sample Setup a Rails App With Apache and Passenger on CentOS 6

1. Introduction

This post gathers information about how to setup RAILS APP with Apache and Passenger on CentOS 6.

2. Step-by-Steyp

• Step#1: First of all, mantain your linux so up-to-date

# yum update

• Step#2: Install Apache

# yum install httpd

• Step#3: Install apache

# yum install httpd curl-devel httpd-devel

• Step#4:  Get Apache to start on boot:

# chkconfig httpd on

• Step#5: Install Phusion Passenger and dependency packages

# gem install passenger
# yum install curl-devel httpd-devel

• Step#6: Compile the environment:

# passenger-install-apache2-module

• Step#7 Edit the Apache config file in etc/httpd/conf/httpd.conf 

Uncomment the line containing NameVirtualHost *:80 towards the end
Paste the output from (Step#6 Compile environment) anywhere at the end of the file, eg:

# vim etc/httpd/conf/httpd.conf

LoadModule passenger_module /usr/local/rvm/gems/ruby-2.1.1/gems/passenger-4.0.41/buildout/apache2/mod_passenger.so

PassengerRoot /usr/local/rvm/gems/ruby-2.1.1/gems/passenger-4.0.41

PassengerDefaultRuby /usr/local/rvm/gems/ruby-2.1.1/wrappers/ruby

<VirtualHost *:80>

 ServerName 1.2.3.4 # www.whatever.com

 DocumentRoot /var/www/rails/public # the path to your rails app

 <Directory /var/www/rails/public>

 AllowOverride all

 Options -MultiViews

 </Directory>

</VirtualHost>

3. References

https://www.digitalocean.com/community/tutorials/how-to-setup-a-rails-4-app-with-apache-and-passenger-on-centos-6
https://stackoverflow.com/questions/5584759/start-rails-server-automatically-after-boot

RAILS Faq HowTo Reference Sample Using scopes on Rails to Filter index page and Re-display filter inputs

1. Introduction

This post gathers information about FAQ-Frequently Asked Question, How To, technical document references and samples about these RAILS topics.

• Using scopes on Rails to Filter index page and Re-display filter inputs

2. FAQ, HOWTO, REFERENCES, SAMPLES, etc

2.1. Create model scopes for each filter condition

# vim app/models/cluster_config.rb

class ClusterConfig < ApplicationRecord

  include Filterable

  scope :cluster_config, -> (id) { where id: id}

  scope :cluster_status, -> (cluster_status_id) { where cluster_status_id: cluster_status_id}

  scope :cluster_environment_type, -> (cluster_environment_type_id) { where cluster_environment_type_id: cluster_environment_type_id}

  scope :cluster_content_type, -> (cluster_content_type_id) { where cluster_content_type_id: cluster_content_type_id}

end

2.2. Implement generic filter on model concerns

# vim app/models/concerns/filterable.rb

module Filterable

  extend ActiveSupport::Concern

  module ClassMethods

    def filter(filtering_params)

      results = self.where(nil)

      filtering_params.each do |key, value|

        results = results.public_send(key, value) if value.present?

      end

      results

    end

  end

end

2.3. Implement filter on index controller

# vim app/controllers/cluster_configs_controller.rb

class ClusterConfigsController < ApplicationController

  before_action :set_cluster_config, only: [:show, :edit, :update, :destroy]

    :

  def index

    @cluster_configs = ClusterConfig.filter(params.slice(:cluster_config, :cluster_status, :cluster_environment_type, :cluster_content_type)).paginate(page: params[:page], per_page: 20)

  end

    :

  private

    def set_cluster_config

      @cluster_config = ClusterConfig.find(params[:id])

    end

    :

    def cluster_config_params

      params.require(:cluster_config).permit(:cluster_status_id, :cluster_environment_type_id, :cluster_content_type_id, :url_rest_service, :db_host, :db_port, :db_name, :dt_created, :dt_delivered, :obs)

    end

end

2.4. Implement filter on index viewer

# vim app/views/cluster_configs/index.html.erb

<h3>Filter by:</h3>

<%= form_for cluster_configs_path do %>

<div>

  Id: <%= text_field_tag 'cluster_config', '' %>

  Status Massa: <%= select("cluster_status", "cluster_status", ClusterStatus.all.map {|a| [a.cluster_status, a.id] }, { include_blank: true }) %>

  Environment Type: <%= select("cluster_environment_type", "cluster_environment_type", ClusterEnvironmentType.all.map {|a| [a.cluster_environment_type, a.id] }, { include_blank: true }) %>

  Content Type: <%= select("cluster_content_type", "cluster_content_type", ClusterContentType.all.map {|a| [a.cluster_content_type, a.id] }, { include_blank: true }) %>

  <br><br>

  <%= submit_tag 'Filter' %>

  <br><br>

</div>

<% end %>

2.5. Erro

Error when "Filter" submit button

ActionController::ParameterMissing in ClusterConfigsController#create

  param is missing or the value is empty: cluster_config

  Extracted source (around line #73):

    72: def cluster_config_params

    73:    params.require(:cluster_config).permit(:cluster_status_id, :cluster_environment_type_id, :cluster_content_type_id, :url_rest_service, :db_host, :db_port, :db_name, :dt_created, :dt_delivered, :obs)

    74: end

Request

Parameters:

{"utf8"=>"✓",

 "authenticity_token"=>"BF22bYvS/UXHOgeLLXeindCqWeXj41w/MxPE93cNoLBnaGwMhdC+HOuvvc6TCoteFHTsyyCZsoxO2j0kA4q/yA==",

 "cluster_config"=>"",

 "cluster_status"=>{"cluster_status"=>""},

 "cluster_environment_type"=>{"cluster_environment_type"=>""},

 "cluster_content_type"=>{"cluster_content_type"=>""},

 "commit"=>"Filter"}

3. References

• http://www.justinweiss.com/articles/search-and-filter-rails-models-without-bloating-your-controller/
• https://stackoverflow.com/questions/6903339/rails-filter-index-page-and-re-display-filter-inputs
• https://stackoverflow.com/questions/19199994/rails-4-filter-index-via-collection-select-values-in-a-form-on-index-action
• https://stackoverflow.com/questions/6462956/rails-select-tag-setting-include-blank-and-selecting-a-default-value

RAILS Faq HowTo Reference Sample Bootstrap Navbar with RAILS

1. Introduction

This post gathers information about FAQ-Frequently Asked Question, How To, technical document references and samples about these RAILS topics.
* Bootstrap Navbar with RAILS

2. FAQ, HOWTO, REFERENCES, SAMPLES, etc

2.1. Bootstrap Navbar with RAILS

a) HOWTO

a.1) Setp #1: Find Gemfile configuration

•  Open rubygems and search for "bootstrap-sass"

https://rubygems.org/
[ bootstrap-sass ] | Search

You should be redirect to https://rubygems.org/gems/bootstrap-sass
Copy gemfile command on the left corner, something like "gem 'bootstrap-sass', '~> 3.3', '>= 3.3.7'"
Edit ./Gemfile on your project root and add bootstrap-sass

a.2) Setp #2: Configure your project Gemfile

$ cd ~/myrailsproject
$ vim Gemfile
  :
# Josemarsilva - 2017-05-19 - http://www.rubydoc.info/gems/bootstrap-sass/3.3.7#a-ruby-on-rails
gem 'bootstrap-sass', '~> 3.3', '>= 3.3.7'
gem 'sass-rails', '~> 5.0'

a.3) Setp #3: Configure your project Gemfile and 

# bundle install

a.4) Step #4: Hide default "application.css" and configure "application.scss"

# mv  app/assets/stylesheets/application.css app/assets/stylesheets/application.css.hidden-by-bootstrap
# vim app/assets/stylesheets/application.scss
+----------------------------------------------------------------------------------------+
|// "bootstrap-sprockets" must be imported before "bootstrap" and "bootstrap/variables"  |
|$icon-font-path: "bootstrap-sass/assets/fonts/bootstrap/";                              |
|@import "bootstrap-sprockets";                                                          |
|@import "bootstrap";                                                                    |
+----------------------------------------------------------------------------------------+

a.5) Step #5: configure "application.js"

# vim app/assets/javascripts/application.js
+----------------------------------------------------------------------------------------+
|// JosemarSilva 2017-05-19 http://www.rubydoc.info/gems/bootstrap-sass/3.3.7            |
|//= require bootstrap                                                                   |
|//= require jquery                                                                      |
|//= require jquery_ujs                                                                  |
|//= require turbolinks                                                                  |
|//= require bootstrap-sprockets                                                         |
|//= require_tree .                                                                      |
+----------------------------------------------------------------------------------------+

a.6) Step #6: configure "app/views/layouts/application.html.erb"

# vim app/views/layouts/application.html.erb
+-------------------------------------------------------------------------------------------------+
|<!DOCTYPE html>                                                                                  |
|<html>                                                                                           |
|  <head>                                                                                         |
|    :                                                                                            |
|    <%= csrf_meta_tags %>                                                                        |
|    <%= stylesheet_link_tag    'application', media: 'all', 'data-turbolinks-track': 'reload' %> |
|    <%= javascript_include_tag 'application', 'data-turbolinks-track': 'reload' %>               |
|    :                                                                                            |
|  </head>                                                                                        |
|    :                                                                                            |
|  <body>                                                                                         |
|    :                                                                                            |
|    <%= render '/staticpages/header' %>                                                          |
|    :                                                                                            |
|    <div class="container">                                                                      |
|      <%= yield %>                                                                               |
|    </div>                                                                                       |
|    :                                                                                            |
|  </body>                                                                                        |
|</html>                                                                                          |
+-------------------------------------------------------------------------------------------------+

a.7) Step #7: configure Navbar on header part template using bootstrap

• Open Bootstrap Navbar documentation and copy example

http://getbootstrap.com/components/#navbar

• Paste example into '_header.html.erb' part

# vim app/views/staticpages/_header.html.erb
+-------------------------------------------------------------------------------------------------+
| <nav class="navbar navbar-default">                                                             |
|  <div class="container-fluid">                                                                  |
|    <!-- Brand and toggle get grouped for better mobile display -->                              |
|    <div class="navbar-header">                                                                  |
|       :                                                                                         |
|      <ul class="nav navbar-nav navbar-right">                                                   |
|       :                                                                                         |
|      </ul>                                                                                      |
|    </div><!-- /.navbar-collapse -->                                                             |
|  </div><!-- /.container-fluid -->                                                               |
|</nav>                                                                                           |
+-------------------------------------------------------------------------------------------------+

b) REFERENCES

• https://www.youtube.com/watch?v=g_azQO53Mzs
• http://getbootstrap.com/components/
• http://www.rubydoc.info/gems/bootstrap-sass/3.3.7
• https://launchschool.com/blog/integrating-rails-and-bootstrap-part-1