Software delivers no value/revenue until it is in the hands of its users. For many businesses reducing the cycle time between an idea and usable software is critical. Usually the first iterative release contains the minimum amount of functionality providing value to the customer, thus Continuous Delivery of values is utmost importance for the competing businesses.
“Continuous Delivery”, it’s not just a deployment methodology, it’s a delivery thinking critical to doing business; is taken from the first principle of the Agile Manifesto: “Our highest priority is to satisfy the customer through early and continuous delivery of valuable software“.
Continuous Delivery (CD) is the process that moves codes from Test environment to Acceptance environment to Prod environment, taking out dependency from human being and reassign dependency on process with high degree of automation where releasing software becomes routine. CD Pipeline requires high degree of Automation as well as very high degree of configuration Management to allow code move safely through those environments ultimately into production. It requires Configuration management of everything that makes up the environment (code, data, parameters, & all the environment variables that makes the particular environment).
CD is the ability to get changes into production, or into the hands of users, safely and quickly in a sustainable way bringing developers and operations teams together (DevOps movement). Continuous Delivery makes it possible to continuously adapt software in line with user feedback, shifts in the market and changes to business strategy.
Continuous deployment and delivery has gone from controversial to commonplace. Continuous Delivery is also a deployment methodology as customers of software see ideas rapidly turn into working code that they can use every day.
The foundation for the CD approach, at least for the development team, is Continuous Integration (CI). CI keeps the entire development team in sync, removing the delays due to integration issues. CI deals with the “last mile issues,” describing how to build the deployment pipeline that turns integrated code into production software. CD offers developers a way to get back to doing smaller, more frequent releases that are more reliable, predictable and manageable.
How long would it take your organization to deploy a change that involves just one single line of code? Do you do this on a repeatable, reliable basis?” The time from deciding that you need to make a change to having it in production is known as the cycle time, and it is a vital metric for any project.
Challenge: In many organizations, cycle time is measured in weeks or months, and the release process is certainly not repeatable or reliable.
Scenario: You have a critical bug in production. It is losing money for your business every day. You know what the fix is: A one-liner in a library that is used in all three layers of your three-tier system, and a corresponding change to one database table. But the last time you released a new version of your software to production it took a weekend of working until 2 A.M.,You know the next release is going to overrun the weekend, which means the application will be down for a period during the business week.
CD solution: After extensive re-engineering, teams were able to achieve a cycle time of hours or even minutes for a critical fix. This was possible because a fully automated, repeatable, reliable process with well-understood, quantifiable risks was created for taking changes through the various stages of the build, deploy, test,
and release process.
There are certain Principles of Continuous Delivery
- Automation is the key – automate everything
- Done means “released”.
- Invest in Quality Metrics (unit test coverage, code styling, rules violations, complexity measurements, etc)
- Continuous Improvement
- Quick and sustainable release/deployment process (DevOps) for everything like code, data, DB schema, etc
- Meaningful repository – keep everything in source control & simplified revision control and software configuration management (branching)
Benefits of Continuous Delivery
- Faster time to market
- Lower cost
- Low risk releases
- Higher quality-Better products
- Happier teams
- Happier customer
Commonly used Tools for achieving Continuous Delivery
Open Source DevOps Tools
Continuous Delivery Workflow
Please also have a look at my blog on “Continuous Integration“.
@Mohammad Sami, Agile Coach
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