Continuous Delivery Tutorial: Reliable Software Release to Production

An All-embracing Guide:

We thoroughly dissected the Continuous Integration (CI) process in our previous guide. In this guide, we aerate the domains of Continuous Integration (CI) and Continuous Deployment (CD), starting with an intricate discourse on Continuous Deployment.

Dramatic transformations have been observed in software development approaches to parallel market trends and meet customer needs. The conventional waterfall approach, although sequential and structured, was inadequate in living up to customer expectations.

Suggested Reading: Prime DevOps Training Guide

The emergence of agile methodology as a solution ensures that functionality and features are rolled out at the end of brief development cycles, also known as sprints, making this approach the new standard.

However, testing the software immediately after development contributes significantly to enhancing software precision and minimizing errors, thereby taking Agile a notch higher. This strategy, also referred to as “Early Testing” or “Shift left,” is fundamental.

Consequently, merging CI and CD processes seamlessly into Agile is essential as they generate the momentum needed for software development, testing, and release.

Continuous Deployment: What is it?

Martin Fowler from ThoughtWorks defines Continuous Deployment as: “A discipline in software development where software can be deployed into production at any given time.”

From this definition, we deduce that:

• The development process of the software heavily leans on comprehensive, precise, and repetitive procedures.
• Given that the software must always be deployable, it has to be designed around the user. Achieving this requires collecting feedback from users at the initial stages.

Continuous Deployment builds on Continuous Integration to ensure users have access to the most recent code changes. This implies that developers must consistently apply their code changes triggering frequent builds. Thus, Continuous Deployment is an extension of Continuous Integration.

How to Implement Continuous Deployment

Below is a simplified high-level elucidation of the implementation of Continuous Deployment:

#1) Automation: Precision being imperative in Continuous Deployment, automation becomes a significant ingredient. It resonates with the concept of employing automated tests for repetitive activities.

Continuous Deployment extensively utilizes automation in different domains, including requisitioning requirements and deployment. The first stride towards achieving reliable Continuous Deployment is implementing automation.

#2) Version Control System: In high-paced development, different individuals may simultaneously work on the same code or project asset. A version control system is necessary to keep track of changes and oversee alterations made by team members.

#3) Collaborative Approach: Continuous Deployment enhances collaboration between developers, testers, project managers, and stakeholders breaking away from isolated work approaches, to ensure software functionality.

#4) Quality Metrics: Establishing a yardstick for success and quantifying it is a pillar in a successful Continuous Deployment process. Metrics collection and analysis shed light on issues, making problem-solving effective.

#5) DevOps: DevOps is significant in implementing Continuous Deployment. It integrates development and operations teams, smoothing out processes such as configuring, setting up environments, and deploying builds.

#6) Continuous Improvement: Continuous Deployment necessitates continuous improvement to ensure it remains relevant, easily maintainable, and efficient. Swift response to failures is crucial for sustainable success.

Tools for Deploying Continuous Deployment

Automation is at the heart of Continuous Deployment, and various tools find use in each process stage, including version control, unit testing, CI, build automation, quality checks, and more. These tools facilitate the thorough implementation of the Continuous Deployment process.

Here are the top Continuous Deployment Tool contenders:

Conceptualizing the Continuous Deployment Pipeline

The diagram below illustrates the general operation of the Continuous Deployment process:

Noteworthy points:

• Each pipeline stage from check-in to deployment into production has an arrow directing back to the previous block, underscoring the dependence of Continuous Deployment on feedback.
• New code check-in by a developer triggers the Continuous Deployment process, sparking off builds and sanity tests. If the build qualifies as a “good build,” it proceeds to the next stage of quality verification.
• The QA team carries out additional tests, including functional cross-checking, as well as non-functional load and stress tests.
• If any non-compliance or issue is flagged at any stage, it needs to be resolved for the Continuous Deployment pipeline to advance.
• After the build receives quality approval, it proceeds for deployment into production.

Quality Assurance Role in Continuous Deployment: The Essence of Continuous Testing

The critical role played by Quality Assurance in the process is evident from the Continuous Deployment pipeline. Let’s delve into what Continuous Deployment implies for QA and how it demands a fresh approach to testing.

In traditional testing models, there is usually a hiatus between the developer checking in code and the tester receiving the build containing the said code. However, Continuous Deployment sees new code frequently and consistently integrated. As a result, testing must keep pace with the “continuous” nature of the process.

How can we achieve this?

The answer is evident and has been previously suggested: Automation! Test Automation is integral to successful testing in a Continuous Deployment procedure – the greater the automation applied at all phases, the better the outcome.

Additionally, due to incremental delivery, functionality drops could occur within days, meaning that there might not be ample time for extensive test planning, and the delivered portion may lack a GUI still. Consequently, the testing approach necessitates adaptation and significant shifts.

What does this imply for testers?

The rigid barriers distinguishing developers from testers need to blur, with testers involved from the very beginning to comprehend what is being developed thoroughly and acquire the necessary skills. Similarly, developers should also possess testing skills as part of their know-how.

Pillars of Successful Continuous Deployment

#1) Adopting Analytical Reasoning and Inquiry:

Testers need to enhance their technical abilities and critically appraise the product in development. They should understand the broader context, estimate if requirements are progressing accurately, assess the environment and setup needed for testing, strategically plan distinct tests (functional, non-functional, security, accessibility). They should also maximize test automation.

#2) Crafting Test Strategy:

Designing a comprehensive test strategy incorporating different testing levels guarantees extensive coverage and roots out potential problems during development. Layered testing boosts overall quality.

#3) Ongoing Process Improvement:

In a Continuous Deployment environment, consistent improvement of testing processes is indispensable. These include optimizing communication channels, refining test scenarios, extending test coverage, adopting new test tools, and promoting overall efficiency.

#4) Technical Skill Enhancement and Efficient Test Tool Utilization:

Testers need to bolster their technical skills by understanding software architecture, code, and component interdependencies. Coding skills also prove invaluable in augmenting automation endeavors. Additionally, testers should master the use of test tools to aid automation and streamline testing in a Continuous Deployment context.

Noteworthy Benefits of Continuous Deployment

Continuous Deployment offers a plethora of benefits:

• Errors Minimized: Because code changes are integrated regularly, the likelihood of missed errors significantly decreases.
• Swift Feedback/Resolution Time: Prompt feedback results in enhanced product quality and end-user satisfaction, quickening bug resolution.
• Reduced Release Time: Continuous Deployment enables organizations to respond promptly to rapidly evolving market demands through frequent and swift releases. This significantly trims the time from idea inception to realization.

Conclusion

Employing Continuous Deployment demands a paradigm shift for organizations following the Agile process. Although it may not be easy to implement, by focusing on the benefits and being committed to the process, fruitful adoption becomes achievable.

In our ensuing article, we will delve into Continuous Integration, the underpinning of Continuous Deployment and the cornerstone of making Continuous Deployment a reality.

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