a few more stylistic changes in the lamp_haproxy module

lamp_haproxy/README.md

@@ -1,12 +1,10 @@
-Lamp Stack + load balancer(haproxy) + add/remove nodes from cluster + Serial Rolling update of webserserver
-----------------------------------------------------------------------------------------------------------
+LAMP Stack + HAProxy: Example Playbooks
+-----------------------------------------------------------------------------
 
-This example is an extension of the simple lamp deployment, In this example we deploy a lampstack with a LoadBalancer in front.
-This also has the capability to add/remove nodes from the deployment. It also includes examples to do a rolling update of a stack
-without affecting the service.
+This example is an extension of the simple LAMP deployment. Here we'll deploy a web server with an HAProxy load balancer in front. This set of playbooks also have the capability to dynamically add and remove web server nodes from the deployment. It also includes examples to do a rolling update of a stack without affecting the service.
 
 ###Setup Entire Site.
-Firstly we setup the entire stack, configure the 'hosts' inventory file to include the names of your hosts on which the stack would be deployed.
+First we configure the entire stack by listing our hosts in the 'hosts' inventory file, grouped by their purpose:
 
 		[webservers]
 		web3
@@ -16,26 +14,32 @@ Firstly we setup the entire stack, configure the 'hosts' inventory file to inclu
 		[lbservers]
 		lbserver
 
-After which we execute the following command to deploy the site.
+After which we execute the following command to deploy the site:
 
 	ansible-playbook -i hosts site.yml
 
-The deployment can be verified by accessing the webpage." lynx http://<ip-of-lb>:8888. multiple access should land you up in different webservers.
+The deployment can be verified by accessing the IP address of your load balnacer host in a web browser: http://<ip-of-lb>:8888. Reloading the page should have you hit different webservers.
 
-###Remove a node from the cluster.
-Removal of a node from the cluster would be as simple as executing the following command:
+###Remove a Node
 
-	ansible-playbook -i hosts playbooks/remove_webservers.yml  --limit=web2
+Removal of a node from the cluster is as simple as executing the following command:
+
+	ansible-playbook -i hosts playbooks/remove_webservers.yml --limit=web2
+
+###Add a Node
 
-###Adding a node to the cluster.
 Adding a node to the cluster can be done by executing the following command:
  
-	ansible-playbook -i hosts playbooks/add_webservers.yml  --limit=web2
+	ansible-playbook -i hosts playbooks/add_webservers.yml --limit=web2
+
+###Rolling Update
+
+Rolling updates are the preferred way to update the web server software or deployed application, since the load balancer can be dynamically configured to take the hosts to be updated out of the pool. This will keep the service running on other servers so that the users are not interrupted.
+
+In this example the hosts are updated in serial fashion, which means
+that only one server will be updated at one time. If you have a lot of web server hosts, this behaviour can be changed by setting the 'serial' keyword in webservers.yml file.
 
-###Rolling update of the entire site or  a single hosts
-Rolling updates are the preffered way to do an update as this wont affect the end users, In this example the hosts are updated in serial fashion, which means
-that only one server would be updated at one time, this behaviour can be changed by setting the 'serial' keyword in webservers.yml file.
-Once the code has been updated in the repository which can be defined in the group_vars/all file, execute the following command:
+Once the code has been updated in the source repository for your application which can be defined in the group_vars/all file, execute the following command:
 
 	 ansible-playbook -i hosts playbooks/rolling_update.yml
 

lamp_haproxy/group_vars/all

@@ -1,5 +1,5 @@
 ---
-# varialbles here would be applicable to all groups
+# Variables here are applicable to all host groups
 
 httpd_port: 80
 ntpserver: 192.168.1.2

lamp_haproxy/group_vars/dbservers

@@ -1,5 +1,6 @@
 ---
-# The variables file used by the playbooks in the dbservers group, these dont have to be imported by vars_files: these are autopopulated.
+# The variables file used by the playbooks in the dbservers group.
+# These don't have to be explicitly imported by vars_files: they are autopopulated.
 
 mysqlservice: mysqld
 mysql_port: 3306

lamp_haproxy/group_vars/lbservers

@@ -1,18 +1,19 @@
 ---
-# File for the HAproxy configuration
+# Variables for the HAproxy configuration
 
-# Supports http and tcp, for ssl smtp etc.. use tcp
+# HAProxy supports "http" and "tcp". For SSL, SMTP, etc, use "tcp".
 mode: http
 
-# port on which the lb should listen
+# Port on which HAProxy should listen
 listenport: 8888
 
-# A name for the proxy daemon, this would be the suffix in the logs.
+# A name for the proxy daemon, this wil be the suffix in the logs.
 daemonname: myapplb
 
-# Balancing Algorithm Avalilable options: roundrobin,source,leastconn,source,uri
-# (if persistance is required use source)
+# Balancing Algorithm. Available options:
+# roundrobin, source, leastconn, source, uri
+# (if persistance is required use, "source")
 balance: roundrobin 
 
-# Which Ethernet interface on which the load balancer should listen
+# Ethernet interface on which the load balancer should listen
 iface: eth0

lamp_haproxy/group_vars/webservers

@@ -1,5 +1,5 @@
 ---
-# File for the web server configuration
+# Variables for the web server configuration
 
-# Which Ethernet interface on which the web server should listen
+# Ethernet interface on which the web server should listen
 iface: eth0

lamp_haproxy/playbooks/add_webservers.yml

@@ -1,5 +1,5 @@
 ---
-# This Playbook adds  a webserver into the the web cluster
+# This Playbook adds a webserver into the the web cluster
 
 - hosts: webservers
   user: root

lamp_haproxy/playbooks/db.yml

@@ -1,5 +1,5 @@
 ---
-# This playbook deploys mysql and configures database on the db node/nodes  
+# This playbook deploys MySQL and configures the database on the db node(s)
 
 - hosts: dbservers
   user: root

lamp_haproxy/playbooks/haproxy.yml

@@ -1,5 +1,5 @@
 ---
-#PlayBook for haproxy operations
+# Playbook for HAProxy operations
 
 - hosts: lbservers
   user: root

lamp_haproxy/playbooks/remove_webservers.yml

@@ -1,6 +1,7 @@
 ---
-# This Playbook removes a  webserver from  the pool serialy.
-
+# This playbook removes a webserver from the pool serially.
+# Change the value of serial: to adjust the number of servers
+# to be removed at a time.
 
 - hosts: webservers
   user: root

lamp_haproxy/playbooks/rolling_update.yml

@@ -1,5 +1,6 @@
 ---
-# This Playbook does a rolling update of the code for all webservers serially (one at a time). Change the value of serial: to adjust the number of server to be updated.
+# This Playbook does a rolling update of the code for all webservers serially (one at a time).
+# Change the value of serial: to adjust the number of server to be updated.
 
 - hosts: webservers
   user: root

lamp_haproxy/playbooks/web.yml

@@ -1,5 +1,5 @@
 ---
-# This Playbook deploys the WebServers with httpd and the code.
+# This playbook deploys the webservers with httpd and the code.
 
 - hosts: webservers
   user: root

lamp_haproxy/roles/common/handlers/main.yml

@@ -1,5 +1,5 @@
 ---
-# Handler to handle common notifications
+# Handlers for common notifications
 
 - name: restart ntp
   service: name=ntpd state=restarted

lamp_haproxy/roles/common/tasks/main.yml

@@ -1,5 +1,5 @@
 ---
-# This playbook contains common plays that would be run on all Nodes.
+# This playbook contains common plays that will run on all nodes.
 
 - name: Install ntp 
   yum: name=ntp state=present
@@ -18,8 +18,4 @@
   get_url: url=http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm dest=/tmp/ force=yes
 
 - name: Install EPEL RPM
-#  command: rpm -Uvh --force /tmp/epel-release-6-8.noarch.rpm
   yum: name=/tmp/epel-release-6-8.noarch.rpm state=installed
-
-- name: Clean up
-  command: rm -f /tmp/epel-release-6-8.noarch.rpm

lamp_haproxy/roles/db/tasks/main.yml

@@ -1,5 +1,5 @@
 ---
-# This playbook will install mysql and create db user and give permissions.
+# This playbook will install MySQL and create db user and give permissions.
 
 - name: Install Mysql package
   action: yum pkg=$item state=installed
@@ -24,7 +24,6 @@
   lineinfile: dest=/etc/sysconfig/iptables state=present regexp="$mysql_port" insertafter="^:OUTPUT " line="-A INPUT -p tcp  --dport $mysql_port -j  ACCEPT"
   notify: restart iptables
 
-
 - name: Create Application Database
   mysql_db: name=$dbname state=present
 

lamp_haproxy/roles/haproxy/handlers/main.yml

@@ -1,5 +1,5 @@
 ---
-# Handlers for the HAproxy
+# Handlers for HAproxy
 
 - name: restart haproxy
   service: name=haproxy state=restarted
@@ -7,5 +7,3 @@
 - name: reload haproxy
   service: name=haproxy state=reloaded
 
- 
-

lamp_haproxy/roles/haproxy/tasks/main.yml

@@ -1,5 +1,5 @@
 ---
-# This PlayBook Installs the HAProxy and configures it.
+# This playbook installs HAProxy and configures it.
 
 - name: Download and install haproxy and socat
   yum: name=$item state=installed

lamp_haproxy/roles/haproxy/templates/haproxy.cfg.j2.bck

@@ -1,36 +0,0 @@
-global
-    log         127.0.0.1 local2 
-
-    chroot      /var/lib/haproxy
-    pidfile     /var/run/haproxy.pid
-    maxconn     4000
-    user        root
-    group       root
-    daemon
-
-    # turn on stats unix socket
-    stats socket /var/lib/haproxy/stats level admin
-
-defaults
-    mode                    {{ mode }}
-    log                     global
-    option                  httplog
-    option                  dontlognull
-    option http-server-close
-    option forwardfor       except 127.0.0.0/8
-    option                  redispatch
-    retries                 3
-    timeout http-request    10s
-    timeout queue           1m
-    timeout connect         10s
-    timeout client          1m
-    timeout server          1m
-    timeout http-keep-alive 10s
-    timeout check           10s
-    maxconn                 3000
-
-backend app
-    {% for host in groups['lbservers'] %}
-    	listen {{ daemonname }} {{ hostvars[host].ansible_eth0.ipv4.address }}:{{ listenport }}
-    {% endfor %}
-    balance     {{ balance }}

lamp_haproxy/roles/web/handlers/main.yml

@@ -1,5 +1,5 @@
 ---
-# Handler for the webtier
+# Handler for the web tier
 
 - name: restart iptables
   service: name=iptables state=restarted

lamp_haproxy/roles/web/tasks/add_to_lb.yml

@@ -1,5 +1,5 @@
 ---
-# This Playbook does utility stuff's like adding a webserver into the pool, etc..
+# This Playbook handles the addition of a web server to the pool.
 
 - name: Add server to LB
   lineinfile: dest=/etc/haproxy/haproxy.cfg state=present regexp="${ansible_hostname}" line="server ${ansible_hostname} ${hostvars.{$inventory_hostname}.ansible_$iface.ipv4.address}:${httpd_port}"

lamp_haproxy/roles/web/tasks/copy_code.yml

@@ -4,7 +4,5 @@
 - name: Copy the code from repository
   git: repo=${repository} dest=/var/www/html/
 
-
-- name: Create's the index.php file 
+- name: Create the index.php file 
   template: src=../roles/web/templates/index.php.j2 dest=/var/www/html/index.php
-  

lamp_haproxy/roles/web/tasks/install_httpd.yml

@@ -9,7 +9,6 @@
    - php-mysql
    - libsemanage-python
    - libselinux-python
-  
 
 - name: insert iptables rule for httpd
   lineinfile: dest=/etc/sysconfig/iptables state=present regexp="$httpd_port" insertafter="^:OUTPUT " line="-A INPUT -p tcp  --dport $httpd_port -j  ACCEPT"

lamp_haproxy/roles/web/tasks/remove_from_lb.yml

@@ -1,9 +1,9 @@
 ---
-# This Playbook does utility stuff's like adding a webserver into the pool, etc..
+# This playbook handles the removal of a webserver from the pool.
 
 - name: Remove the code from server
   command: rm -rf /var/www/html/*
-  
+
 - name: Remove server from LB
   lineinfile: dest=/etc/haproxy/haproxy.cfg state=absent regexp="${ansible_hostname}" 
   delegate_to: $item

lamp_haproxy/roles/web/tasks/utils.yml

@@ -1,39 +0,0 @@
----
-# This Playbook does utility stuff's like adding a webserver into the pool, etc..
-
-- name: Add server to LB
-  lineinfile: dest=/etc/haproxy/haproxy.cfg state=present regexp="${ansible_hostname}" line="server ${ansible_hostname} ${hostvars.{$inventory_hostname}.ansible_$iface.ipv4.address}:${httpd_port}"
-  delegate_to: ${lbserver}
-  register: last_run
-  tags: add
-   
-- name: Reload the haproxy
-  service: name=haproxy state=reloaded
-  delegate_to: ${lbserver}
-  only_if: ${last_run.changed}
-  tags: add
-
-- name: Remove the code from server
-  command: rm -rf /var/www/html/*
-  tags: remove
-  
-- name: Remove server from LB
-  lineinfile: dest=/etc/haproxy/haproxy.cfg state=absent regexp="${ansible_hostname}" 
-  delegate_to: $item
-  with_items: ${groups.lbservers}}
-  register: last_run
-  tags: remove
-
-- name: disable the server in haproxy
-  shell: echo "disable server myapplb/${ansible_hostname}" | socat stdio /var/lib/haproxy/stats
-  delegate_to: $item
-  with_items: ${groups.lbservers}}
-  tags:  remove
-
-- name: Remove the httpd package
-  yum: name=httpd state=absent
-  tags: remove
-
-
-
- 

lamp_haproxy/roles/web/templates/index.php.j2

@@ -7,7 +7,7 @@
   <a href=http://{{ hostvars[inventory_hostname]['ansible_' + iface].ipv4.address }}/index.html>Homepage</a>
  </br>
 <?php 
- Print "Hello, World! I am configured in Ansible and i am : ";
+ Print "Hello, World! I am a web server deployed using Ansible and I am : ";
  echo exec('hostname');
  Print  "</BR>";
 ?>