Creating a dummy process in linux with a process name for testing and other purpose

bash -c 'exec -a ProcessName sleep 1000000' &

nagios https proxy monitoring plugin or Bash website monitoring script

#!/bin/bash

if [ $# -eq 0 ]
  then
    echo "No arguments supplied"
fi

if [ $# -eq 1  ]
then

output=`curl  -x 10.11.10.10:3128 -L $1 -m 10 -o /dev/null || echo "Website_down"`

if [ "$output" == "Website_down" ] ; then

echo "Website is down CRITICAL  "
exit 2

else

echo "Website_up $1  OK"
exit 0
fi

fi

Adding client certificate file using chef data bags

Below is just an example 

logstash_cert_secret = Chef::EncryptedDataBagItem.load_secret("/etc/chef/secrets/logstash_client_key")

logstash_certs = Chef::EncryptedDataBagItem.load("certs", "logstash_client", logstash_cert_secret)

directory "/etc/pki/tls/certs/" do

  action :create

  mode "0755"

  owner "root"

  group "root"

end

file "/etc/pki/tls/certs/logstash_client.crt" do

  action :create

  mode "0644"

  owner "root"

  group "root"

  content logstash_certs["crt"].join("")

  end

Search and replace in all files in a current directory

grep -rl 'pc961' ./|xargs sed -i 's/pc961/pc/g'

Ansible define a basic windows hosts

[windows]

10.10.10.120

[windows:vars]

ansible_connection=winrm

ansible_ssh_user=Administrator

ansible_ssh_pass=AdminPa$$

Three basic Git commands

1) git add -A

git add -A is equivalent to  git add .; git add -u.

git add .  ( This will add all files but does not remove files )
git add -u ( This will add only changes but will not add any new files created )

So we use

git add -A ( this will take care of both the commands )

2) git commit -m “Commit changes text ex: I have added new function xyz to the file”

3) git push origin  


example of branch name : develop


Another 3 frequently used commands include :

git pull
git status 
git merge origin/Branchname

Installing configuring Ansible and deploying haproxy playbook

  Basic installation 

sudo yum install ansible (or) sudo pip install ansible

Configuring your hosts file with inventory 

cat /etc/ansible/hosts 

[haproxy]

10.0.184.12   



[all_servers:vars]

ansible_connection=ssh 

ansible_user=root

ansible_ssh_private_key_file=/Users/home/yoursshkey.pem


I have only one server in my inventory where i will be setting up an haproxy 
For easy management we will be writing common variables under [all_servers:vars]


When we run ansible play books hosts will be picked from the above inventory file 

Example : hosts: haproxy  ( this will run on all servers under haproxy )

Now test servers doing a ping ( ping in ansible will connect to the server using ssh )

 ansible haproxy -m ping


10.0.184.12 | SUCCESS => {


    "changed": false, 


    "ping": "pong"


}


Then Download ready made packages from ansible galaxy 
https://galaxy.ansible.com/devops/haproxy/
Also download dependencies that will configure EPEL repositories
https://galaxy.ansible.com/sfromm/epel/
Then create a common playbook for both the roles main.yml




- hosts: haproxy

  roles:

     - { role: devops.epel }





- hosts: haproxy

  roles:

     - role: devops.haproxy

       haproxy_stats:

         name: 'global_monitor'

         ip: "{{ ansible_default_ipv4.address }}"

         port: '38888'

         stats:

           enabled: True

           hide_version: true

           uri: /slb_stats_url

           realm: Welcome\ to\ slb\ monitor

           auth: admin:admin

           refresh: 2s

       haproxy_frontends:

       - name: 'fe-testsite'

         ip: '{{ ansible_default_ipv4.address }}'

         port: '80'

         maxconn: '1000'

         default_backend: 'be-testsite'

       haproxy_backends:

       - name: 'be-testsite'

         description: 'testsite'

         servers:

           - name: 'be-testsite-01'

             ip: '192.168.1.100'

sh-3.2# ansible-playbook main.yml 

PLAY [haproxy] *****************************************************************

TASK [setup] *******************************************************************
ok: [10.0.184.12]

TASK [devops.epel : Installs python dependencies] ******************************
changed: [10.0.184.12] => (item=[u'libselinux-python'])

TASK [devops.epel : Disable SElinux] *******************************************
changed: [10.0.184.12]

TASK [devops.epel : create EPEL yum repository] ********************************
changed: [10.0.184.12]

TASK [devops.epel : import EPEL GPG key] ***************************************
changed: [10.0.184.12]

PLAY [haproxy] *****************************************************************

TASK [setup] *******************************************************************
ok: [10.0.184.12]

TASK [devops.haproxy : Include OS-specific variables.] *************************
ok: [10.0.184.12]

TASK [devops.haproxy : Installs haproxy as well as socat for socket api.] ******
changed: [10.0.184.12] => (item=[u'haproxy', u'socat'])

TASK [devops.haproxy : Ensure HAProxy is started and enabled on boot.] *********
changed: [10.0.184.12]

TASK [devops.haproxy : Ensure chroot directory exists.] ************************
ok: [10.0.184.12]

TASK [devops.haproxy : Create directory for the frontend] **********************
changed: [10.0.184.12]

TASK [devops.haproxy : Empty the folder if not already empty] ******************
changed: [10.0.184.12]

TASK [devops.haproxy : Build up the frontends] *********************************
[DEPRECATION WARNING]: Using bare variables is deprecated. Update your playbooks so that the environment value uses the full variable syntax ('{{haproxy_frontends}}').
This feature will be
removed in a future release. Deprecation warnings can be disabled by setting deprecation_warnings=False in ansible.cfg.
changed: [10.0.184.12] => (item={u'ip': u'10.0.184.12', u'maxconn': u'1000', u'default_backend': u'be-testsite', u'port': u'80', u'name': u'fe-testsite'})

TASK [devops.haproxy : Create directory for the backends] **********************
changed: [10.0.184.12]

TASK [devops.haproxy : Empty the folder if not already empty] ******************
changed: [10.0.184.12]

TASK [devops.haproxy : Build up the backends] **********************************
[DEPRECATION WARNING]: Using bare variables is deprecated. Update your playbooks so that the environment value uses the full variable syntax ('{{haproxy_backends}}').
This feature will be
removed in a future release. Deprecation warnings can be disabled by setting deprecation_warnings=False in ansible.cfg.
changed: [10.0.184.12] => (item={u'servers': [{u'ip': u'192.168.1.100', u'name': u'be-testsite-01'}], u'description': u'testsite', u'name': u'be-testsite'})

TASK [devops.haproxy : Create directory for the listen sections] ***************
changed: [10.0.184.12]

TASK [devops.haproxy : Empty the folder if not already empty] ******************
changed: [10.0.184.12]

TASK [devops.haproxy : Build up the listen sections] ***************************
skipping: [10.0.184.12] => (item=haproxy_listen)

TASK [devops.haproxy : Create directory for the userlists] *********************
changed: [10.0.184.12]

TASK [devops.haproxy : Empty the folder if not already empty] ******************
changed: [10.0.184.12]

TASK [devops.haproxy : Build up the userlist sections] *************************
skipping: [10.0.184.12] => (item=haproxy_userlists)

TASK [devops.haproxy : Create  the compiled folder] ****************************
changed: [10.0.184.12]

TASK [devops.haproxy : Empty the folder if not already empty] ******************
changed: [10.0.184.12]

TASK [devops.haproxy : Build up the global config] *****************************
changed: [10.0.184.12]

TASK [devops.haproxy : Build up the default config] ****************************
changed: [10.0.184.12]

TASK [devops.haproxy : Build up the stats config] ******************************
changed: [10.0.184.12]

TASK [devops.haproxy : Assemble the frontends configuration file] **************
changed: [10.0.184.12]

TASK [devops.haproxy : Assemble the backends configuration file] ***************
changed: [10.0.184.12]

TASK [devops.haproxy : Assemble the listen sections configuration file] ********
changed: [10.0.184.12]

TASK [devops.haproxy : Assemble the userlists sections configuration file] *****
changed: [10.0.184.12]

TASK [devops.haproxy : Assemble the final configuration file] ******************
changed: [10.0.184.12]

RUNNING HANDLER [devops.haproxy : restart haproxy] *****************************
changed: [10.0.184.12]

PLAY RECAP *********************************************************************
10.0.184.12                : ok=31   changed=27   unreachable=0    failed=0




This is just a test deployment that will forward request to background test server 192.168.1.100