December 3, 2017
  • Author: Karthik
  • Category: Family
December 3, 2017


  • Author: Karthik
  • Category: Family
December 3, 2017


  • Author: Karthik
  • Category: Family

Q. What is Ansible?
Ansible is developed in Python language.
It is a software tool. It is useful while deploying any application using ssh without any downtime. Using this tool one can manage and configure software applications very easily.

Q. How Ansible Works?
There are many similar automation tools available like Puppet, Capistrano, Chef, Salt, Space Walk etc, but Ansible categorize into two types of server: controlling machines and nodes.
The controlling machine, where Ansible is installed and Nodes are managed by this controlling machine over SSH. The location of nodes are specified by controlling machine through its inventory.
The controlling machine (Ansible) deploys modules to nodes using SSH protocol and these modules are stored temporarily on remote nodes and communicate with the Ansible machine through a JSON connection over the standard output.

Ansible is agent-less, that means no need of any agent installation on remote nodes, so it means there are no any background daemons or programs are executing for Ansible, when it’s not managing any nodes.

Ansible can handle 100’s of nodes from a single system over SSH connection and the entire operation can be handled and executed by one single command ‘ansible’. But, in some cases, where you required to execute multiple commands for a deployment, here we can build playbooks.
Playbooks are bunch of commands which can perform multiple tasks and each playbooks are in YAML file format.

Q.What’s the Use of Ansible.
Ansible can be used in IT Infrastructure to manage and deploy software applications to remote nodes. For example, let’s say you need to deploy a single software or multiple software to 100’s of nodes by a single command, here ansible comes into picture, with the help of Ansible you can deploy as many as applications to many nodes with one single command, but you must have a little programming knowledge for understanding the ansible scripts.

We’ve compiled a series on Ansible, title ‘Preparation for the Deployment of your IT Infrastructure with Ansible IT Automation Tool‘, through parts 1-4 and covers the following topics.

Q. How would you describe yourself in terms of what you do and how you’d like to be remembered?
Obviously I’d like to be remembered as a master of prose who forever changed the face of literature as we know it, but I’m going to have to settle for being remembered as a science fiction writer (and, more and more, critic) who wrote the occasional funny line and picked up a few awards.

Q. Why are you attracted to science and science fiction?
Early imprinting, maybe, for the science fiction. When I was quite small a family friend let me read his 1950s run of ‘Galaxy’ magazine. My favourite aunt pressed John Wyndham’s ‘The Day of the Triffids’ on me; a more terrifying great-aunt gave me G.K. Chesterton’s fantastic novels; and so on.
The incurable addiction had begun. Meanwhile, science classes just seemed to be the part of school that made most sense, and I fell in love with Pelican pop-maths titles – especially Kasner’s and Newman’s ‘Mathematics and the Imagination’ and all those books of Martin Gardner’s ‘Scientific American’ columns.

Q. Tell us about your software company and what sort of software it produced(s).
This goes back to the 1980s and the Apricot home computers, the early, pretty and non-PC-compatible ones. My pal Chris Priest and I both used them for word processing, and he persuaded me to put together a disk of utilities to improve the bundled ‘SuperWriter’ w/p, mostly written in Borland Turbo Pascal 3 and later 4: two-column printing, automated book index preparation, cleaning the crap out of the spellcheck dictionary, patching SuperWriter to produce dates in UK format, and so on.

Then I redid the index software (‘AnsibleIndex’) in CP/M for the Amstrad PCW and its Locoscript word processors. When the Apricot market collapsed, I wrote an Apricot emulator in assembler so that people could keep using their horrible but familiar old software on a PC. Eventually, in a fit of nostalgia, I collected all my columns for ‘Apricot File’ and various Amstrad PCW magazines as books unoriginally titled ‘The Apricot Files’ and ‘The Limbo Files’. (That’s probably enough self-promotion, but there’s lots more at HTTP://ANSIBLE.CO.UK/.)

Q. Describe your newsletter Ansible and who it’s aimed at.
It appears monthly and has been called the ‘Private Eye’ of science fiction, but isn’t as cruel and doesn’t (I hope) recycle old jokes quite as relentlessly. Though I feel a certain duty to list some bread-and-butter material like conventions, award winners and deaths in the field, ‘Ansible’ skips the most boring SF news – the long lists of books acquired, books published, book sales figures, major new remainders – in favour of quirkier items and poking fun at SF notables. The most popular departments quote terrible lines from published SF/fantasy and bizarre things said about SF by outsiders (‘As Others See Us’). All the back issues of ‘Ansible’ since it started in 1979 can be read online.

Q: What are the advantages of using Ansible?
The main three advantages of using this tool is,i.e. Ansible

1. Agentless
2. Very low overhead
3. Good performance

Q: So how does Ansible work? Please explain in detail?
Within the market, they are many automation tools like Puppet, Capistrano, Chef, Salt, Space Walk etc.

When it comes to Ansible, this tool is categorized into two types of servers:
1. Controlling machines
2. Nodes

Ansible is an agentless tool so it doesn’t require any mandatory installations on remote nodes. So there is no background programs that are executed while it is managing any nodes.
Ansible is able to handle a lot of nodes from a single system over SSH connection.
Playbooks are defined as a bunch of commands where they are capable of performing multiple tasks and they are in YAML file format.

Q: Do we have any Web Interface/ Rest API etc for this?
Yes, Ansible Inc makes a great efficient tool. It is easy to use.

Q: What is Ansible Tower?
Ansible is classified as a web-based solution which makes Ansible very easy to use. It is considered to be or acts like a hub for all of your automation tasks. The tower is free for usage till 10 nodes.

Q: How do change the documentation and submit it?
Usually, the documentation is kept in the main project folder in the git repository.
For complete instructions on this can be available in docs.

Q: How do you access Shell Environment Variables?
If you are just looking to access the existing variables then you can use “env” lookup plugin.
For example:
Accessing the value of Home environment variable on management machine:


Q: How can you speed up management inside in EC2?
It is not advised to manage a group of EC2 machines from your laptop.
The best way is to connect to a management node inside Ec2 first and then execute Ansible from there.

Q: How can you disable Cowsay?
If Cowsay is installed then executing your playbooks within Ansible is very smooth.
Even if you think that you want to work in a professional cow free environment, then you will have two options:
1.  Uninstall cowsay
2. Setting up value for the environment variable, like below


Q: How can you access a list of Ansible_Variables?
By default, Ansible gathers facts under machines under management. Further, these facts are accessed in Playbooks and in templates. One of the best ways to view a list of all the facts that are available in a machine, then you need to run the setup module in the ad-hoc way:

Ansible- m setup hostname

Once this statement is executed, it will print out a dictionary of all the facts that are available for that particular host. This is the best way to access the list of Ansible_variables.

Q: How can you see all the inventory variables that are defined in the host?
The best way to see all the inventory variables is by executing this command below:

Ansible - m debug- a “var=hostvars[‘hostname’]” localhost

Q: Why don’t you ship in X format?
They are several reasons for not shipping in X format. In general, it caters towards maintainability. Within the market, they are tons of different ways to ship software and it is very tedious to support all of them.

Q: What is that Ansible can do?
Ansible can do the following for us:
1. Configuration management
2. Application deployment
3. Task automation
4. IT orchestration

Q: Please define what is Ansible Galaxy?
Ansible Galaxy refers to the website Galaxy where the users will be able to share all the roles to a CLI ( Command Line interface) where the installation, creation, and managing of roles happen

Q: Do you know what language Ansible is written in?
Ansible is written in Python and PowerShell
Q: Please explain what is Red Hat Ansible?
Ansible and Ansible Tower by Red Hat, both are an end to end complete automation platforms which are capable of providing the following features or functionalities:

1. Provisioning
2. Deploying applications
3. Orchestrating workflows
4. Manage IT systems
5. Configuration of IT systems
6. Networks
7. Applications

All of these activities are dealt by Ansible where it can help the business to solve the real time business problems.

Q: Is Ansible is an open source tool?
Yes, Ansible is an open source tool which is a powerful automation software tool that one can use.

Q: Why you have to learn Ansible?
Ansible is more a tool for servers but does it have anything for networking. If you closely look into it, there is some support available in the market for networking devices. Using this tool, it will give you an overall view of your environment and also the knowledge how it works when it comes to network automation.

It is one of those tools where it is considered to be good to explore a new tool.

Q: What are Ansible server requirements?
If you are a windows user then you need to have a virtual machine in which Linux should be installed.
It requires Python 2.6 version and higher.

Q: How can you connect to other devices within Ansible?
Once, Ansible is installed and the basic setup has been completed, an inventory is created. This would be the base and one can start testing ansible. To connect to a different device then you have to use “Ping module”. This can be used as a simple connection test.

Ansible - m ping all

Q: Can you build your own modules with Ansible?
Yes, we can create or own modules within Ansible.
It is an open source tool which primarily works on Python. If you are good at programming in Python you can start creating your own modules in few hours from scratch and you don’t need to have any prior knowledge of the same.

Q: How can you find information in Ansible?
After completing the basic setup, one has to make sure to find out the module called “setup” module. Using this setup module, you will be able to find out a lot of information.

Q: What does Fact mean in Ansible?
The term “Facts” is commonly used in Ansible environment. They are described in the playbooks areas where it displays known and discovered variables about the system.  Facts are used to implement conditionals executions and also used for getting ad-hoc information of the information.

You can see all the facts via:

$ ansible all- m setup

So if you want to extract only certain part of the information then you can use “setup” module where you will have an option to filter out the output and just get hold of the fact that you are in need of.

Q: What is ask_pass in ansible?
 The ask_pass is a control in Ansible Playbook.
This controls whether ansible playbook to prompt a password by default. Usually, the default behavior is no:

It is always set to ask_pass=True

If you are using SSH keys for authentication purposes then you really don’t have to change this setting at all.

Q: Explain What is ask_sudo_pass
This control is very similar to ask_pass
The ask_sudo_pass controls the Ansible Playbook to prompt a sudo password. Usually, the default behavior is no: 

ask_sudo_pass= True

One has to make sure and change this setting where the sudo passwords are enabled most of the time.

Q: Explain what is ask_vault_pass?
Using this control we can determine whether Ansible Playbook should prompt a password for the vault password by default. As usual, the default behavior is no

ask_vault_pass= True

Q: Explain Callback_plugin in Ansible?
Callbacks are explained as a piece of code in ansible environments where get is used call a specific event and permit the notifications.

This is more sort of a developer related feature and allows low-level extensions around ansible so that they can be loaded from different locations without any problem.

Q: Explain Module utilities in Ansible? 
Ansible provides a wide variety of module utilities which help the developers while developing their own modules. The is a module which provides the main entry point for accessing the Ansible library and using those as basics one can start off working.

Q: Where is the unit testing is available in Ansible?
Unit tests for all the modules are available in .test/units/modules.
Firstly you have to setup your testing environment

Q: Explain in detail about ad-hoc command?
Well, ad-hoc commands is nothing but a command which is used to do something quickly and it is more sort of a one-time use.  Unlike, the playbook is used for a repeated actions which is something that is very useful in Ansible environment. But there might be scenarios where we want to use ad-hoc commands which can simply do the required activity and it is a nonrepetitive activity.


How do I copy files recursively onto a target host?

A) The “copy” module has a recursive parameter. However, take a look at the “synchronize” module if you want to do something more efficient for a large number of files. The “synchronize” module wraps rsync. See the module index for info on both of these modules.

Ansible Interview Questions # How do I access shell environment variables?

A) If you just need to access existing variables, use the ‘env’ lookup plugin. For example, to access the value of the HOME environment variable on the management machine:

# ...
     local_home: "{{ lookup('env','HOME') }}"

If you need to set environment variables, see the Advanced Playbooks section about environments.

Starting with Ansible 1.4, remote environment variables are available via facts in the ‘ansible_env’ variable:

{{ ansible_env.SOME_VARIABLE }}

Ansible Interview Questions # do I generate crypted passwords for the user module?

A) The mkpasswd utility that is available on most Linux systems is a great option:

mkpasswd --method=sha-512

If this utility is not installed on your system (e.g. you are using OS X) then you can still easily generate these passwords using Python. First, ensure that the Passlib password hashing library is installed:

pip install passlib

Once the library is ready, SHA512 password values can then be generated as follows:

python -c "from passlib.hash import sha512_crypt; import getpass; print sha512_crypt.using(rounds=5000).hash(getpass.getpass())"

Use the integrated Hashing filters to generate a hashed version of a password. You shouldn’t put plaintext passwords in your playbook or host_vars; instead, use Using Vault in playbooks to encrypt sensitive data.


Ansible Interview Questions # Is there a web interface / REST API / etc?

A) Yes! Ansible, Inc makes a great product that makes Ansible even more powerful and easy to use. See Ansible Tower.


Ansible Interview Questions # How do I keep secret data in my playbook?

A) If you would like to keep secret data in your Ansible content and still share it publicly or keep things in source control, see Using Vault in playbooks.

In Ansible 1.8 and later, if you have a task that you don’t want to show the results or command given to it when using -v (verbose) mode, the following task or playbook attribute can be useful:

- name: secret task
  shell: /usr/bin/do_something --value={{ secret_value }}
  no_log: True

This can be used to keep verbose output but hide sensitive information from others who would otherwise like to be able to see the output.

The no_log attribute can also apply to an entire play:

- hosts: all
  no_log: True

Though this will make the play somewhat difficult to debug. It’s recommended that this be applied to single tasks only, once a playbook is completed. Note that the use of the no_log attribute does not prevent data from being shown when debugging Ansible itself via the ANSIBLE_DEBUG environment variable.

Ansible Real Time Interview Questions And Answers

Ansible Interview Questions # When should I use {{ }}? Also, how to interpolate variables or dynamic variable names

A) A steadfast rule is ‘always use {{ }} except when when:‘. Conditionals are always run through Jinja2 as to resolve the expression, so when:failed_when: and changed_when: are always templated and you should avoid adding {{}}.

In most other cases you should always use the brackets, even if previously you could use variables without specifying (like with_ clauses), as this made it hard to distinguish between an undefined variable and a string.

Another rule is ‘moustaches don’t stack’. We often see this:

{{ somevar_{{other_var}} }}

The above DOES NOT WORK, if you need to use a dynamic variable use the hostvars or vars dictionary as appropriate:

{{ hostvars[inventory_hostname]['somevar_' + other_var] }}

Ansible Interview Questions # Why don’t you ship in X format?

A) Several reasons, in most cases it has to do with maintainability, there are tons of ways to ship software and it is a herculean task to try to support them all. In other cases there are technical issues, for example, for python wheels, our dependencies are not present so there is little to no gain.

 How do I see all the inventory vars defined for my host?

A) By running the following command, you can see vars resulting from what you’ve defined in the inventory:

ansible -m debug -a "var=hostvars['hostname']" localhost

Ansible Interview Questions # How do I loop over a list of hosts in a group, inside of a template?

A) A pretty common pattern is to iterate over a list of hosts inside of a host group, perhaps to populate a template configuration file with a list of servers. To do this, you can just access the “$groups” dictionary in your template, like this:

{% for host in groups['db_servers'] %}
    {{ host }}
{% endfor %}

If you need to access facts about these hosts, for instance, the IP address of each hostname, you need to make sure that the facts have been populated. For example, make sure you have a play that talks to db_servers:

- hosts:  db_servers
    - debug: msg="doesn't matter what you do, just that they were talked to previously."

Then you can use the facts inside your template, like this:

{% for host in groups['db_servers'] %}
   {{ hostvars[host]['ansible_eth0']['ipv4']['address'] }}
{% endfor %}

Ansible Interview Questions # How do I access a variable name programmatically?

A) An example may come up where we need to get the ipv4 address of an arbitrary interface, where the interface to be used may be supplied via a role parameter or other input. Variable names can be built by adding strings together, like so:

{{ hostvars[inventory_hostname]['ansible_' + which_interface]['ipv4']['address'] }}

The trick about going through hostvars is necessary because it’s a dictionary of the entire namespace of variables. ‘inventory_hostname’ is a magic variable that indicates the current host you are looping over in the host loop.

Ansible Interview Questions # How do I access a variable of the first host in a group?

A) What happens if we want the ip address of the first webserver in the webservers group? Well, we can do that too. Note that if we are using dynamic inventory, which host is the ‘first’ may not be consistent, so you wouldn’t want to do this unless your inventory is static and predictable. (If you are using Ansible Tower, it will use database order, so this isn’t a problem even if you are using cloud based inventory scripts).

Anyway, here’s the trick:

{{ hostvars[groups['webservers'][0]]['ansible_eth0']['ipv4']['address'] }}

Notice how we’re pulling out the hostname of the first machine of the webservers group. If you are doing this in a template, you could use the Jinja2 ‘#set’ directive to simplify this, or in a playbook, you could also use set_fact:

- set_fact: headnode={{ groups[['webservers'][0]] }}

- debug: msg={{ hostvars[headnode].ansible_eth0.ipv4.address }}

Notice how we interchanged the bracket syntax for dots – that can be done anywhere.

How do I handle python pathing not having a Python 2.X in /usr/bin/python on a remote machine?

A) While you can write ansible modules in any language, most ansible modules are written in Python, and some of these are important core ones.

By default, Ansible assumes it can find a /usr/bin/python on your remote system that is a 2.X version of Python, specifically 2.6 or higher.

Setting the inventory variable ‘ansible_python_interpreter’ on any host will allow Ansible to auto-replace the interpreter used when executing python modules.

Thus, you can point to any python you want on the system if /usr/bin/python on your system does not point to a Python 2.X interpreter.

Some Linux operating systems, such as Arch, may only have Python 3 installed by default. This is not sufficient and you will get syntax errors trying to run modules with Python 3. Python 3 is essentially not the same language as Python 2.

Python 3 support is being worked on but some Ansible modules are not yet ported to run under Python 3.0. This is not a problem though as you can just install Python 2 also on a managed host.

Do not replace the shebang lines of your python modules. Ansible will do this for you automatically at deploy time.

Ansible Interview Questions # What is the best way to make content reusable/redistributable?

A) If you have not done so already, read all about “Roles” in the playbooks documentation. This helps you make playbook content self-contained, and works well with things like git submodules for sharing content with others.

If some of these plugin types look strange to you, see the API documentation for more details about ways Ansible can be extended.

Ansible Interview Questions # Where does the configuration file live and what can I configure in it?

A) See Configuration file.

Ansible Interview Questions # How do I disable cowsay?

A) If cowsay is installed, Ansible takes it upon itself to make your day happier when running playbooks. If you decide that you would like to work in a professional cow-free environment, you can either uninstall cowsay, or set the ANSIBLE_NOCOWS environment variable:


Ansible Interview Questions # How do I see a list of all of the ansible_ variables?

A) Ansible by default gathers “facts” about the machines under management, and these facts can be accessed in Playbooks and in templates. To see a list of all of the facts that are available about a machine, you can run the “setup” module as an ad-hoc action:

ansible -m setup hostname

This will print out a dictionary of all of the facts that are available for that particular host. You might want to pipe the output to a pager.

February 11, 2015

It’s mostly an opinion: who loves Microsoft’s world will tell you that is better even for job opportunities… who prefers the rest, will say that php is better and will point you the huge amount of sites done with php (and open source cms and so on…), which are more than asp sites. Ever since Microsoft has come up with, there has been a widespread debate among programmers as to whether it is any better than the existing open source programming language of PHP.

php vs asp
php vs asp


If you were to make a search on the Internet on how loyalists of both PHP and are doing almost everything by biting each other’s heads off, you will realize how hot this debate actually is. The major contention is that Microsoft products are generally considered to be superior to other products, but then there are programmers that have been using PHP since ages and never once has it let them down. While there is acclaim for being more robust and speedier, PHP fans maintain that PHP has much better support and a very easy to understand language.


php vs asp


As the debate between PHP and rages on, it is important to make a frank comparison between the two languages, so that other developers who are not so strong in their opinions are not caught in the argument between the two.

Both are better, both are Faster and both can write any kind of program. supports a huge framework and has many built components and has a grate editing environment (Visual Studio ) through which you can easily write Asp program without worrying about case sensitivity, while PHP editing tool is work such like a notepad. For what a programmer need much strong programming knowledge and syntax.


php vs asp


php vs asp
php vs asp
php vs asp

PHP is easy to learn.  PHP has a wider community.  PHP is not too true to OOP (Object Oriented Programming).

.NET may be tricky at first for beginners.  .NET is very true to OOP.  .NET community is always up to date with the new trends and changes.

PHP can run on almost all platforms. NET will require windows with .NET framework.

PHP is better for those who feel close to PHP and have worked on it for years.  .NET is better for those who have love for windows.  It’s an individuals liking or choice of the programming language they want to use.  PHP is better in its own world and .NET is better in its own arena.

August 2, 2013



1 Higher education aspirants have many choices — from the national open university to 14 state open varsities

2 Most of the institutes will have placement cells, so finding a job will not be a problem later

3 If you apply for a course to an open learning institute, ensure they have study centres near your place

4 The location of the university’s examination centre also counts if you are unable to travel long distances. Ensure the universities have centres in your city

5 If you have applied for a regular college and are also studying from an open university, ensure that your examination dates do not clash. You will have huge problems if they do

6 Find out when the open universities schedule their personal contact programme (PCP) classes. Most of them hand out study material and get in some of their best faculty members for lectures. Missing the classes don’t make sense

7 More on PCPs: These help you network and link with other students in your programme. Peer learning in the absence of regular teachers or classes, trading notes, chatting online with the friends you’ve made in PCP classes can aid your studies

8 Language is important: If you are applying to an open university in another state, check the medium of instruction for your course





The open and distance learning (ODL) mode of study gives you a bouquet of choices – from a  pottery course, a vocational and entrepreneurial programme in beekeeping, to a qualification in sericulture and a diploma in fish processing. Whether you are a student wanting to take up a job along with an undergraduate degree, a lawyer wishing to pursue a qualification in history, a teacher with a love for plantation, an engineer aiming for an MBA, or a homemaker planning to study economics, you can follow your ambition through the ODL mode. This system gives you the flexibility and choice to join a course irrespective of who you are or where you are based.


ODL scenario
Globally, the major types of institutions/universities offering education through the ODL mode include dedicated open universities that offer programmes only through distance mode and dual style universities set up to provide correspondence courses. Another category is that of institutions offering conventional classroom-based programmes, distance education qualifications and online education.

According to RK Gupta, former member of the Distance Education Council, “Distance learning offers education at an affordable cost. There are many meritorious students who cannot afford to pursue higher education. Not everyone can study in cities like Delhi and Mumbai… a large number of students belong to remote and rural areas and cannot go to a regular college. The ODL system offers hope and opportunities to these aspirants.”

Gupta says that majorly, there are three types of students who prefer to join the ODL mode. These include those who don’t get into regular colleges, those who are working and want to pursue conventional or professional courses, and those who are otherwise eligible but cannot afford regular education.

As per the NR Madhava Menon Committee report on ODL, ODL constitutes about 21.9% of total enrolment in the conventional system. However, enrolment in technical and professional courses in the ODL system is less than 10%.

The enrolment in open universities and distance education institutions in 2009-10 was more than 36 lakh. The share of distance education increased from 2.6% in 1975-76 to 8.9% in 1985-86 and was improved to 10.7% in 1990-91 and to 20.56% in 2008-09.

Student support
When it comes to the methods and tools used to impart education, the ODL system has come a long way. From a correspondence degree based on print material to self-instructional study packages with an integrated multi-media approach, virtual learning has got a boost. The application of Information and Communication Technology (ICT) to provide flexible and cost-effective programmes has also made this system popular.

Challenges ahead
The ODL system is now growing faster compared to the conventional system. “One of the major challenges that need to be addressed is quality assurance and use of an innovative approach to impart education. Steps like providing access to video lectures by top faculty of the top institutions will solve the problem of giving access to higher education to each student. Students should also check the recognition of the institution, course material and quality of the programme before enrolling,” says Sudhanshu Bhushan, professor, higher and professional education, National University of Education Planning and Administration, who specialises in policy analysis and planning of higher education.

“The growth and access to ICT will revolutionise higher education.  E-learning modules, multimedia case studies, video tutorials need to be given a push,” he adds.

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August 2, 2013

Free Linux Console

The idea behind the website is to help all novice linux users to use the raw linux commands in its core.

As not all the students or community can buy or host a linux server.



Free internet tamil dictionary website was launched with the help of AYYA Pollachi Nasan