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A curated list of AWS resources to prepare for the AWS Certifications

A curated list of awesome AWS resources you need to prepare for the all 5 AWS Certifications. This gist will include: open source repos, blogs & blogposts, ebooks, PDF, whitepapers, video courses, free lecture, slides, sample test and many other resources.

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Index:

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#Cookbooks
+ A cookbook is the fundamental unit of configuration and policy distribution when using Chef
+ Cookbook contains
  1. Recipes
  1. Attribute Files
  1. File distributions
  1. Templates
  1. Any extensions to Chef such as libraries and custom resources    

+ Chef cookbook defines a scenario. For example, in case of an Apache cookbook

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#Understanding Chef Recipes and Run Lists
+ Recipes are a collection of resources, defined and written using patterns. 
+ Helper code, such as loops and if statements, can be written around those resources to help customize the configurations of specific nodes. For example, if or case statements around package names.
+ Recipe is the most fundamental configuration element within the organization
+ A recipe is created using Ruby
+ must define everything that is required to configure part of a system
+ Recipe stored in a cookbook
+ May be included in a recipe(include_recipe)
+ May use the results of a search query and read the contents of a data bag
+ May have a dependency on one (or more) recipes

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+Terminal log:
        C:\Users\shinidharan\Documents\GitHub> ssh [email protected]
        Warning: Permanently added '54.86.131.236' (ECDSA) to the list of known hosts
        [email protected]'s password:
        Last login: Wed Jan  4 05:06:13 2017 from c-76-104-43-10.hsd1.va.comcast.net
        [user@gsmurali1 ~]$ vim learn.rb
        [user@gsmurali1 ~]$ cat learn.rb
        package 'apache' do
                package_name 'httpd'
        end

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[root@gsmurali1 user]# vim learn.rb
[root@gsmurali1 user]# cat learn.rb
package 'apache' do
end

This is the pre-convergence checks; to check ruby syntax and chef syntax
------------------------------------------------------------------------

[root@gsmurali1 user]# ruby -c learn.rb
Syntax OK

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Convergence
*Pre-convergence - Phase before a node is configured. Lint tests, foodcritic
*Convergence - Tests the defined resources to ensure they are in the desired state,"Providers' are what do the work (yum, apt-get etc.,) to enforce the desired configuration
*Post-Convergence - Occurs after the Chef convergence - Run tests that verifies a node is in the desired state of configuration/ Unit testing

Chef can be run over and over again without changing configurations if configurations are already in place (Idempotency)

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Configure user 'user' for sudo access and change root password and user password
* use passwd command to change passwords for user and root
Add user 'user' to sudo
*  usermod -g wheel user
Download chef development kit
* go to https://downloads.chef.io/chefdk/1.1.16 and copy url for RHEL - https://packages.chef.io/files/stable/chefdk/1.1.16/el/7/chefdk-1.1.16-1.el7.x86_64.rpm
wget the above link in the server to download the software
Install using the command - sudo rpm -ivh chefdk-1.1.16-1.el7.x86_64.rpm
To verify installation, type 'sudo chef-client --local-mode' (running chef-client in local mode)

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#!/bin/bash
yum install httpd -y
/sbin/chkconfig --levels 235 httpd on
service httpd start
instanceId=$(curl http://169.254.169.254/latest/meta-data/instance-id)
region=$(curl http://169.254.169.254/latest/dynamic/instance-identity/document | grep region | awk -F\" '{print $4}')
echo "<h1>$instanceId</h1>" > /var/www/html/index.html
aws ec2 create-tags --resources "$instanceId" --tags Key=Name,Value="PROD-$instanceId" --region "$region"

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aws elb create-load-balancer \
--load-balancer-name MyELB \
--listeners Protocol=TCP,LoadBalancerPort=80,InstanceProtocol=TCP,InstancePort=80 \
--subnets subnet-46e6506c subnet-57b8010f \
--scheme internet-facing \
--security-groups sg-aec570d4

aws autoscaling create-launch-configuration \
--launch-configuration-name MyLC \
--key-name virginia \

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aws autoscaling put-lifecycle-hook \
--lifecycle-hook-name scale-out-hook \
--auto-scaling-group-name MyASG \
--lifecycle-transition autoscaling:EC2_INSTANCE_LAUNCHING

aws autoscaling complete-lifecycle-action \
--lifecycle-action-result CONTINUE \
--instance-id i-0680775fb68bc97a5 \
--lifecycle-hook-name scale-out-hook \
--auto-scaling-group-name MyASG