15 Jan 2021 5 min read github

Why Trunk-Based Development Is More Effective with Kubernetes: A Deep Dive into Modern Software Practices

In recent years, software development teams have increasingly turned to Kubernetes and Trunk-Based Development (TBD) to accelerate their deployment processes, reduce complexity, and build more resilient systems. These tools and practices align perfectly to meet the demands of modern software delivery — but what makes them so effective together?

In this blog post, we’ll explore why trunk-based development paired with Kubernetes provides superior benefits compared to traditional GitFlow or branch-based models, backed by insights from the 2016 and 2017 DORA (DevOps Research and Assessment) reports.

What is Trunk-Based Development?

Trunk-based development is a software development practice where developers work on a single shared branch (often called "trunk" or "main"). Instead of creating long-lived feature branches, developers commit their code frequently — often multiple times a day — directly to the trunk. This approach prioritizes small, incremental changes and ensures that the main branch is always in a deployable state.

What is GitFlow?

GitFlow is a branching model introduced by Vincent Driessen in 2010. It promotes a more structured, isolated development process with multiple long-lived branches, such as:

Feature branches for new developments,
Release branches for preparing production releases,
Hotfix branches for urgent fixes.

While GitFlow provides structure and discipline, it has inherent challenges, especially as projects grow in size and complexity.

The Challenges of GitFlow and Long-Lived Branches

While GitFlow is widely used and has its merits, it introduces several bottlenecks, especially in fast-moving teams. Here are some of the common drawbacks:

1. Complexity in Managing Multiple Branches

As a team grows and more features are developed in parallel, managing multiple branches becomes a task fraught with complexity. It requires a clear and rigid workflow to ensure that changes in feature branches don’t conflict with the release or hotfix branches.

2. Merge Conflicts and Integration Delays

Long-lived feature branches can diverge significantly from the main branch. When it comes time to merge, these branches are often difficult to integrate, leading to significant merge conflicts. This delay can lead to integration hell, where the effort to merge branches overwhelms the development process, causing slowdowns and frustration.

3. Outdated Code

Feature branches can become outdated quickly, especially in fast-moving teams where the trunk evolves rapidly. This disconnect can lead to more work for developers to bring their feature up to date with the main branch, further increasing merge conflict risk and slowing development.

4. Slower Feedback Loops

Long-lived branches mean developers aren’t getting immediate feedback on the impact of their changes. In contrast, trunk-based development encourages frequent commits, enabling a continuous feedback loop that improves the quality and speed of code delivery.

The Benefits of Trunk-Based Development with Kubernetes

Now that we’ve identified the challenges of GitFlow, let’s see how combining trunk-based development with Kubernetes can resolve these issues and lead to more efficient software delivery.

1. Fast and Frequent Deployments

Kubernetes is designed for continuous delivery and automates the deployment process. By coupling Kubernetes’ rolling updates feature with trunk-based development, development teams can deploy changes quickly and safely. As each commit is small and frequent, integration with Kubernetes ensures that the latest code is always tested and deployed in the most efficient manner.

With trunk-based development, developers don’t need to wait until a feature is fully complete to begin testing and deployment. This rapid iteration ensures that small bugs can be identified and resolved quickly, leading to higher software quality.

2. Reduced Complexity and Merge Conflicts

One of the most significant challenges of GitFlow is managing the complexity of multiple branches. With trunk-based development, teams are working on a single branch. The simplicity of this model reduces the overhead associated with branching and merging. Kubernetes makes it easier to manage microservices and containers independently, so developers can deploy individual services even if they’re part of a larger codebase. This helps prevent integration issues and ensures the system remains stable.

3. Continuous Integration and Continuous Delivery (CI/CD)

Both trunk-based development and Kubernetes align with the principles of Continuous Integration and Continuous Delivery. Trunk-based development ensures that code is integrated into the main branch frequently, while Kubernetes provides the infrastructure needed to automate the build, testing, and deployment processes. Together, they enable a fully automated pipeline, reducing the risk of human error and ensuring that new code reaches production quickly and reliably.

4. Easier Rollbacks and Failures Recovery

Kubernetes’ self-healing and rollbacks make it easy to quickly revert any deployment that may cause problems. With trunk-based development, if something goes wrong, there’s no need to track down a complex chain of merges and feature branches. The problem can be identified and corrected in a matter of minutes, ensuring minimal disruption.

5. Better Scalability and Flexibility

Kubernetes allows teams to scale applications seamlessly and independently. This flexibility means that teams can deploy parts of their application without waiting for the entire system to be ready, which is especially important for microservices architectures. Coupled with trunk-based development, the small and frequent changes ensure that every microservice is deployed and scaled efficiently without the long waiting periods associated with GitFlow.

Insights from the DORA Reports

The 2016 and 2017 DORA reports provide valuable insights into DevOps performance and the practices that lead to high-performing teams. Key findings from the reports include:

High Deployment Frequency: Teams that integrate code frequently (at least once per day) and deploy continuously outperform teams with longer release cycles.
Faster Lead Time: High-performing teams have significantly reduced lead times from development to production.
Fewer Failures: Continuous integration and delivery (CI/CD) practices, which are foundational to trunk-based development, lead to fewer deployment failures and faster recovery times.
Security and Quality: High performers prioritize security and automated testing, which are key practices when using both trunk-based development and Kubernetes.

These findings align perfectly with the benefits of combining trunk-based development with Kubernetes. High deployment frequency, faster lead times, and automated testing ensure teams are moving fast without sacrificing quality or security.

Real-World Examples of Trunk-Based Development and Kubernetes in Action

Google: Google uses trunk-based development along with its internal Kubernetes-based system (Borg) to manage its infrastructure. Their focus on small, incremental changes enables them to deploy at scale with low friction.
Shopify: Shopify adopted Kubernetes to scale its applications more efficiently. The company practices trunk-based development to continuously deploy changes and optimize their infrastructure.
Monzo: The UK-based digital bank Monzo uses Kubernetes for managing its microservices and practices trunk-based development for quick iteration and deployment. They’ve shared in their engineering blogs that this combination has been critical to their ability to scale rapidly.

Conclusion

Trunk-based development, paired with Kubernetes, has become the modern standard for high-performance software delivery. By reducing complexity, shortening feedback loops, and enabling continuous integration and delivery, these practices allow teams to deploy frequently, recover quickly, and scale efficiently. The insights from the DORA reports support the shift towards continuous, small changes as the key to high performance.

While GitFlow and long-lived branches may work in some cases, they don’t align as well with the demands of rapid iteration, microservices, and automation. For teams looking to stay ahead in the fast-paced world of modern software development, trunk-based development and Kubernetes are the way forward.

Let me know if you would like any further edits or additional details for this blog post!