Category: Programming

Using Ansible to provision VMs on AWS

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Using Ansible to provision VMs on AWS

I have been asked on several occasions to show how to use Ansible to provision VMs on Amazon Web Services (AWS). This is “commoditization virtualization” on demand just by running a single playbook, which is pretty cool.

Why automation in the first place?

If your reading this article and have any experience configuring A Unix/Linux/Windows server, whether it is a mail server, web server, whatever, you know how time consuming it is to:

  • Partition the disk
  • Create user accounts
  • Install software packages and updates
  • Configure the server application
  • etc…

You had to wait for the packages to install, configure and test the application to make sure it runs and that can take a few hours.

Now, that the servers are virtual and live in a cloud machine somewhere and you now have to configure more than a dozen of them… that’s a lot of time and you have better things to do. Tools like Ansible are the answer to configuring multiple machines.

Spining up VMs using AWS web console

AWS allows you to log into a web console, choose your VM image and bring them up one at a time. It will give you ssh credentials to allow you to login to the VMs you just made and from there, use Ansible to manage and configure them. Would it be nice if you could manage the provisioning of VM instances from Ansible? Yes you can…but there is a bit of work to make it work.

I will describe the way you can do it with several step script and (in another article) programmatically.

How do I know how many VMs I have in inventory?

The challenge of dynamic inventory is the program/playbook does not know what is in the inventory ahead of time. However, if we apply the cattle not pets approach and let Ansible take care of itempotents of the VMs (it won’t clobber the VMs or exceed the constraints of number of VMs that exist) then this can make our lives easier.

Without knowing the inventory, and checking it ahead of time, you are running blind.

Programmatically is the best way to manage and track dynamic inventory and use Ansibles modules to provision VMs in AWS.

Using a playbook to provision VMS.

In my opinion this is a clunky way to use Ansible.

The problem with this way is there is no clean way to see what is the current inventory that is on AWS, you have to run a separate program before running the playbook so you can see what is currently in inventory.

When this is done you end up writing three or four separate scripts to manage this process. In the long run, this becomes difficult to maintain since you have to look at other scripts to understand what is going on.
Writing maintainable code is a key principle.

Build the playbook to provision AWS cloud services.

Playbook is set to local host.

AWS keys are needed for AWS account access.

BOTO Python API libraries are installed.

Just in case you are not aware, BOTO is the API AWS uses for programmatically managing AWS services.

AWS cloud account

Log into AWS Management Console

Under user account, select “security credentials”

In the left hand column, select user

Select the security tab.

Look for security access key.

This is what you will need for boto/ansible.

Running Vagrant

I have created a Vagrant file with an Ansible playbook for managing AWS through a Linux VM created and managed by Vagrant.

First install VirtualBox then install Vagrant.

Download from Github the Vagrant Ansible AWS files.

Change into the vagrant file directory and type:

vagrant up

It will take a while for all the dependencies to be downloaded.

Once vagrant is fully up, type:

vagrant ssh

to access the shell of the vm.

Preparing for instances.

Change directory to the ansible playbook directory and modify the following files:

aws-vars.yml

and add your AWS keys.

Provisioning AWS instances.

from the shell, type:

ansible-playbook AWS-provision.yml

to start provisioning instances in AWS.

You can watch from the AWS console the instances being provisioned.

Terminating instances

from the shell, type:

ansible-playbook AWS-terminate.yml

to terminate the ec2 instances that were provisioned in your account by the provisioning playbook.

You can watch the instances terminated from the AWS console.

This is only the beginning…

With these examples, we just created self contained machines just by running an Ansible playbook. However, we can setup a virtual container network that allows you to place in a private network such items as private networks where you have access to file servers database servers an “internal” and “external” network with a “firewall”. and more complex designs.

I may cover these examples in future articles.

In the meantime, have a great day.

The Triangle of Value

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It seems like everyone wants everything these days. They want high quality products and services in the quickest amount of time at the lowest price possible. This is never the case.

I don’t recall people talking about this fundamental concept very often that is The triangle of value. It’s also known by many other names. This is a basic resource constraint when you are offering a product or service.

The triangle of value is this:

You have Time, Cost and Quality – Pick two.

You can have a low cost product very quickly but the quality suffers.

You can have a high quality product relatively quickly but it will be very expensive.

You can have a high quality product at a low cost but it will take lots of time to develop.

This is true of project management and DevOps as well. At the end of the day, these are the three elements you have to work with.

Open source products also work like this. You can have a low cost product (it’s free…so to speak) which is high quality with many features, but it gets done on donated time. It may take some time before a bug is corrected or a new features are added.

Other things that affect the “triangle of value”

Skill and Experience

Skill can reduce the amount of time it takes to make something and it can also affect quality of a product or service. Then again, you will pay more money for an individual with a higher skillset especially if you want to keep them around.

Technology

It can be something that decreases the amount of time you spend on producing a product or service. It can be in the form of automation or another catalytic process. At the end of the day, all advancements of technology are catalysts for getting more stuff out of a process. On the other hand, technology can take time and expertise to develop. This also can cost more money for better tech.

How does this understanding play into DevOps or anywhere else?

In an ideal world, you may be able to hire the brightest minds who are up to the task, have the best equipment, plenty of lead time for getting to market and an unlimited budget…but this is not the case.

It may be more like, you only could hire 2 of the 5 positions for experienced programmers (maybe your one of them) and they aren’t that bright (they just think they are), you have second hand equipment that is a few years old, your budget is a quarter of what you were promised and last week was when you had to get the project done.

That’s ok, these are the reality of the industry. You do with what you can the best you can, the same principles apply.

If you don’t have enough manpower, you make it up with overtime and finding leverage somewhere…maybe automation.

If you don’t have the latest equipment, let’s say it’s slow…you make it up by getting more of the older equipment and use them in parallel using some clever programming and networking.

If you have a short lead time, you loosen your “quality” regiment (as in hope your developers don’t make mistakes writing code by forgoing tests) to save on the time you spend in development.

DevOps CI/CD the “Holy Grail” may be a lofty goal to achieve if your resources are limited, but it is a worthwhile and doable. It may take some time to figure out how to do it and to build and train the resources to do this.

At the end of the day, what you most value is what you will get. You can’t have it all but you can choose what you can live with.

I am open to feedback and any suggestions you may have. Until then, have a good day.

Testing for DevOps – How to have 10 deploys a day versus 10 emergencies a day

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Ten deploys a day was the tech talk that started DevOps as an integrated practice for software development. However, if they simply pushed out code without checking it, then the story would have been different. Without testing the code, it would be more like 10 or more Disasters a day… A down production site would result in some serious consequences such as:

  • Loss of customers
  • Loss of confidence in the company
  • Loss of employment for all who are involved

You get the pictures. Though the use of automation is a key principle of DevOps, automation is also an efficient way to multiply human error. Without efficient testing of code, CICD would be meaningless. If you write code quickly and deploy it, BUT it’s broken code, well you defeated the purpose of having software rapidly deployed and updated. Testing of code is one of the most fundamental part of DevOps there is.

But I’m a great coder and I don’t make mistakes…(or whatever is your excuse)

Well, that may be the case, however as your software product grows and more people are touching a code, the likelyhood some form of human error (that may not be yours) will be introduced into the code. It’s bad enough when you haven’t worked on the code let’s say in a couple of weeks, you don’t remember what you did. You don’t want to be called back into work on a Friday because your code changes you created bombs out on a production system… Test for it so you can sleep soundly knowing that you have a safety net in place.

Writing tests is a fundamental practice.

The fundamentals – Vince Lombarti, who is know as the winningest coaches in football once went to the lockerroom of his players after they had a major loss from a previous season and said .“..This is a football…” Part of writing good code is writing checks or tests for your code. Unfortunately, many programmers don’t write tests for their code, especially web developers who are use to just writing and fixing it as it breaks. It has been my experience that the reason many programmers don’t test code is quite simply, they don’t know how. We’ll get you pointed the right direction.

What are the various test you can do for code?

There are hundreds of different tests you can do on software, some are appropriate and some are not appropriate for testing your software. Here are a list of some of the more common tests. For the purpose of testing in a DevOps environment, there are basically two categories of test you can do for code. I’ll put particular emphasis on what are the must have tests. We’ll cover the must have tests. We’ll touch on the other tests.

Functional Tests

These are the most basic test we need to have in place for Continuous Integration.

  • Unit testing
  • Integration testing
  • Systems testing
  • Acceptance testing

Non Functional Tests

These are also important tests but are not functional test (testing key functions in software) to have AFTER you have the core functional test in place. Here are a few non functional tests.

  • Security testing – find security holes and exploits in your code.
  • Performance testing – find out how quickly your code runs.
  • Stress testing – find out how much load your application can take before it degrades or breaks.

Behavioral driven testing

This is influenced by BDD – Behavior driven development which is at the core TDD – Test driven development where development of software is defined by very specific test cases. In the case of BDD, the tests are defined in terms of a user story. This affects how you would write unit tests and acceptance tests. Testing frameworks like cucumber support this kind of writing of user stories.

Unit testing

Every bit of function you write should (must) be unit tested. It should be the most basic test that is used with any code that goes into production.

Basic principles of unit testing.

Test the smallest testable part of an application. That is a unittest.

Write your function to handle a particular error – i.e. division by zero.

test fixture – what’s needed to perform a test

Write a test case – 1/0

Write an assertion. Unit test assertion functions are very simple, they are functions that call your function and compares the returned result or state or value. For instance if you function returns a numeric value, you may use an assertion like

functionx > 0

or

assert.greater(functionx, 0)

This is dependent on your framework or library as far as if it supports different conditions for testing assertion.

These tests are best done with a testing frameworks or assertion libaries. For java, there’s JUnit, Python uses unittest, Javascript can use JestJS, MochaJS, Jasmine.

You can read more about unit testing here.

Integration testing

This is also very important. What if the guys who are responsible for writing the database interface makes a change that the busness logic guy didn’t know about or the frontend guys didn’t know about the change in the functions for business logic. Your code justs breaks and that’s not good for your mental health. You can read more about integration testing here.

Acceptance testing

This is what your customer sees and interacts with. This is probably the most time consuming part of writing tests for. Never the less, if the customer is not able to press the “pay” button, you and your company are going to lose money…and that’s not good. Your going to catch this with a good automated testing approach. These days if your testing a web app or website, use selenium or a framework that drive selenium to test the web interface with clicks and data input values. You can record your test using the Selenium IDE in Firefox or Chrome. It will take some massaging of your recording to make a good automated acceptance test.

Depending on your testing strategy, your approach and framework you will use will vary. Regardless of your approach, I’ll always recommend unit testing your code.

Tying it in to DevOps

Continuous integration is a strategy and software testing being both a strategy for instance Behavior driven development with various frameworks as tactics such as cucumber as a framework that supports Behavior driven testing.

Without software testing and a sound testing methodology, you couldn’t have Continuous integration. That is the Holy Grail of DevOps.

I am open to any comments or suggestions to this article. Until then have a good day.

The Elephant in the room – 3 key points of DevOps – Strategy, Tactics and Implemention

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Elephant in the room?

When people talk about DevOps, most people don’t know what their talking about or usually they only know part of what is DevOps. The blind men describing an elephant is what comes to mind.

One blind man says he feels it’s like a rope. The second blind man said it’s like a thick branch of a tree. The third blind man said it’s a huge wall.

DevOps is the elephant in the room.

We tend to only “see” one part of the elephant and we view it from our own role or perspective.

For many people, the answer of what is DevOps tends to falls between these kinds of viewpoints:

  • To systems administrators, it’s about use of Automation techniques to manage many machines and deploy code (i.e.Ansible, Kubernetics).
  • To a developer, it is a consistent code development environment and automated integration system (i.e. Docker, Git).
  • To a project manager and stakeholders, it is an Agile development methodology for software and product development.

These answers are both right and wrong at the same time. This is where the understanding of Strategy and Tactics come into play. With this, you can recognize and understand the “elephant in the room” and how to use these tactics and strategies.

The Difference between Strategy and Tactics

The culture and management practices of DevOps can be looked at as the Strategy. The implementation DevOps in the form of tools and processes used are the Tactics. One is at a global level, the other is the “hands on” task(s). Strategies don’t change often. Tactics do change depending on the situation. It’s an important to understand these perspectives to understand what “DevOps” really is.

What is Strategy from the DevOps point of view?

Strategy is the plan to archive a long term goal.  DevOps may employ many different strategies.  Here are a few examples:

These strategies are NOT always going to be appropriate for your shop for a variety of reasons and may need to be modified or other alternative strategies may need to be used.   SCRUM vs Lean?  Up to you and your team.

What is Tactics from the DevOps point of view?

Tactics is the actual methodology of implementation of a strategy.  Depending on your own needs and circumstances, the tactics you chose depend on the strategy your seeking to fulfill. Here are some examples of of tactics:

  • Using a Git shared repository is a tactic for Continuous Integration .
  • Using  Kanban software and workflow is a tactic for Lean software development.
  • Using Ansible to setup standardized servers is the tactic for the “cattle not pets” strategy.
  • Having small team of five people consisting of people from Operations, Development and Quality Assurance is the tactic  for the two pizza team and break down silos strategy.

Tactics may change for different systems you manage.  For instance an MDM (Mobile Device Manager) platform would be the appropriate choice for managing Smartphones NOT Ansible or Chef and in this sort of environment, Docker may not be appropriate for development of the front end app.

Implementation is the key

Even after understating the Strategies of DevOps and developing the Tactics to implement DevOps, if people are not DOING the tasks to implement the tactics,  just doing what they always done, they don’t have a DevOps shop. People need to participate. The place to begin is with collaboration and creating an environment where there is trust and the people involved are actually carrying out the tactics as day to day activities. To get collaboration, people need to have ownership in the project and get recognition for their part. Create an environment where people are willing to take risks and are not afraid of failure. To do this, it’s important that failure is valued as part of the learning process instead of blaming people or finger pointing.  In fact back in the 70’s at IBM, Tom Watson Jr. recounts calling to his office a young executive made a $10 million dollar mistake. Expecting to be fired, the executive presented his letter of resignation. Tom Watson just shook his head:“You are certainly not leaving after we just gave you a $10 million education.” Learning from failure is part of IBM s culture, it should be part of every successful company s culture.

There is NO right way to do this

You can read books like The Phoenix Project or  The Goal (Which The Phoenix Project is based on) and apply the Theory of constraints, or  read any number of books written about DevOps.    However, the original talk they done on 2009 10+ Deploys Per Day , Allspaw and Hammond didn’t do something all that new as these concepts were done by others.  Lean manufacturing is where Kanban and Lean software development came from.   Site Reliability Engineering , which is in principle DevOps, was developed at Google around 2003, well before the Velocity 9 conference.  At Netflix,  they weren’t thinking about DevOps when they developed their “DevOps” shop.
I am of the opinion that you have to examine BOTH the STRATEGIES AND TACTICS of what worked at various organizations and what didn’t and focus on collaboration.  Building a collaborative environment that encourages ownership of a project, gives recognition and encourages people to take risks and not be afraid of failure is the key first step to creating a DevOps shop.  Doing this will make adopting  the “Elephant in the room” less intimidating and will put DevOps in your grasp.

Feel free to give me your comments and suggestions.

Until then, have a great day.

Do you Get Git? Git for source control and DevOps

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Source control is one of the core strategies for DevOps since having developers and operations team members have access to each others processes require a copy of the code and configurations available to everyone involved.
Whether you write code or just have files you continually have to revise, we need to store our files and keep copies safe.
Git provides a solution for source control and collaboration. In fact one of the largest collaborative open source platforms GitHub is built on GIT. They were recently acquired by Microsoft for over 7.5 Billion dollars.

The Problem that GIT addresses.

When I was starting out and didn’t know any better (some people say I still don’t), I would make a copy and store it in a directory. I also may store a new file with a updated name like Original.txt. I would then have a copy named Originalv2.txt Originalv3.txt as I kept making changes and updates to my file.

However, this over time became quite messy to look at and confusing after a short time.

Further, if I wanted to share this group of files with someone, I would have to tar or zip the file up and send it.
On top of this, if I’m working with someone to make changes, they would send me a file and hopefully, I add it to the right place in the project…this gets very inefficient.
This is where source control comes in.
There are many different solutions such as subversion, mercurial, etc, we’ll focus on Git.

What can Git do?

Linus Torvalds and the developers of the Linux kernel needed to replace their proprietary source control software (BitKeeper) and he made a request to the community of developers to create a source control software that had the following requirements:

Open source and free
Distributed not centralized
Able to work offline

Git is Open Source and free. Enough is said, If you need to make changes to the code to the program, you can.  Further, there is no fee to pay for the software.  Support is available from a large and active community.

Distributed not centralized. Everyone has a copy of the files. If you need to see the code that is written or a configuration file, it’s right there.

Able to work offline.  Changes can be made locally and on a central repository. You can work offline with Git. Make changes to your files and commit them both offline and on the network. Many source control systems don’t allow for offline support.

You need source control as you write code. You may make a mistake and need to roll back. Your system may be running abnormally and your files may end up corrupted… but fear not! You made a backup of that program file…or did you… Maybe its an older backup that you need to recover your code from…how far back…

This is where Git is very useful to have. You can make a local revision backup of your program.

Rather than explaining how it works, go and download a copy of Git.

Installing Git

Get git here

or use Chocolaty

$ choco install git

Git supports a variety of ways to setup a repository.
Local, HTTP/HTTPS (smart with authentication and dumb),SSH/SCP
In this article, we’ll cover local.

Setup local repository for your own files

$ git init

then

$ git add file1 file2 file3 …

or

$ git *

then

$ git commit -m ‘initial commit’

There’s more

You can upload your files to a remote repository, clone a remote repository and have this used in a DevOps environment.  It works very well with Continuous Integration/Continuous Deployment where you can setup a tool like Jenkins to start processing the code out of your repository as soon as there is a change.

For more info on Git, download the book ProGit free in e-book format.

Suggestions and ideas for using Git.
Lastly, what good is knowing about a tool without knowing how you can use it?
Many people have found other ways to use Git besides for source control for coding.
Besides using Git for making copies of code on the repository, you can use it for making
backups. People have written articles, books and distributed it using Git.
In systems administration, you can keep critical systems files using Git
I use it for my Vagrantfiles and Ansible playbooks for my systems configurations.

Let me know your comments and suggestions you may have.

Until then, have a good day.