DevOps is the combination of application development
and operations, which minimizes or eliminates the disconnect between
software developers who build applications and systems administrators
who keep infrastructure running.
Why is DevOps important?
When the Agile methodology is properly used to develop software, a new
bottleneck often appears during the frequent deployment
and operations phases. New updates and fixes are produced so fast in each
sprint that infrastructure teams can be overwhelmed with deployments and
push back on the pace of delivery. To alleviate some of these issues,
application developers are asked to work closely with operations folks to
automate the delivery of code from development to production.
DevOps tooling resources
DevOps cannot be performed with tools alone, but having the right tools
to augment the culture and processes is important to successful software
delivery. The following resources discuss both Python-specific and general
tools and services for DevOps environments.
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DevOps: Python tools to get started
is a presentation slideshow that explains that while DevOps is a culture,
it can be supported by tools such as Fabric, Jenkins, BuildBot and Git
which when used properly can enable continuous software delivery.
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For an Atlassian-centric perspective on tooling, take a look at
this guide on how to
choose the right DevOps tools
which is biased towards their tools but still has some good insight
such as using automated testing to provide immediate awareness of
defects that require fixing.
General DevOps resources
The following resources give advice and approaches for building the right
teams, culture, processes and tools into software development organizations.
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DevOps vs. Platform Engineering
considers DevOps to be an ad hoc approach to developing software while
building a platform is a strict contract. I see this as "DevOps is a
process", while a "platform is code". Running code is better than any
organizational process.
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The open source
PagerDuty Incident Response guide is the
amazing result from their company taking the practices they use to keep
their services running and putting them out for other developers to consume.
Highly recommended.
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Introduction to DevOps and Software Delivery Performance
explains the four key delivery metrics of Delivery Lead Time,
Deployment Frequency, Time to Restore Service, and Change Fail Rate,
and then gives a high-level overview of technical, process and
cultural capabilities that impact these metrics.
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Operations for software developers for beginners
gives advice to developers who have never done operations work and
been on call for outages before in their career. The advantage of DevOps
is greater ownership for developers who built the applications running
in production. The disadvantage of course is the greater ownership
also leads to much greater responsibility when something breaks!
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Google's
Site Reliability Engineering (SRE) book
is free online and required reading for understanding the practices and
principles behind keeping the largest websites alive. Note though that
some of the advice in the book will be considered controversial at more
stodgy traditional organizations that have done operations differently
for a long time. There is also
a wonderful interview with Ben Treynor,
one of the authors of the book, that contains additional information.
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The Increment, Stripe's fantastic digital and
print magazine, has
an issue dedicated to being on-call
which discusses many DevOps-related topics such as what happens when
your pager goes off, ownership and how startups can be different from
large companies with their incident responses.
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Why are we racing to DevOps?
is a very high level summary of the benefits of DevOps to IT organizations.
It's not specific to Python and doesn't dive into the details, but it's
a decent start for figuring out why IT organizations consider DevOps the
hot new topic after adopting an Agile development methodology.
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SRE vs. DevOps: competing standards or close friends?
covers Google's take on how Site Reliability Engineering (SRE) fits
with the DevOps world. Roughly speaking, SRE is more closely aligned with
metrics and how to operate infrastructure and applications, rather than
the broader principles embodied by the DevOps philosophy.
What do you want to learn next about deployments?
I've built a Python web app, now how do I deploy it?
Can I automate testing and deployments for my app?
How do I go about testing my Python code?