Blog
Continuous Integration

CI/CD best practices | Harness Blog

Discover CI/CD best practices to build, test, and deploy faster. Learn how to create stable pipelines with progressive delivery and real-world DevOps tips.

TL;DR

  • CI/CD best practices like frequent commits, intelligent testing, and progressive delivery help teams ship faster without sacrificing stability.
  • Standardizing pipelines with templates and automating security checks reduces risk and governance overhead as teams scale.
  • Measuring success with DORA metrics (deployment frequency, lead time, change failure rate, and MTTR) gives teams a clear benchmark for continuous improvement.
  • The right platform makes it easier to adopt and sustain these practices by encoding them into your workflows instead of relying on manual enforcement.
  • CI/CD best practices let teams deliver software faster by creating a standard way to build, test, and deploy.
  • Making small, frequent changes and using fast, reliable pipelines lowers risk and keeps builds stable.
  • The right platform helps your teams make CI/CD best practices part of their daily routine.

Modern software teams are under constant pressure to ship faster without breaking production. That’s why CI/CD best practices have become essential for high-performing DevOps organizations. Continuous integration and continuous delivery (CI/CD) help automate builds, testing, and deployments — but simply installing a pipeline tool isn’t enough. Without the right practices, pipelines become slow, flaky, and difficult to govern.

In this guide, we break down the most important CI/CD best practices for building fast, stable pipelines - from trunk-based development and intelligent test selection to progressive delivery and DORA metrics.

Implementing Continuous Integration and Continuous Delivery (CI/CD) has become a critical success factor. CI/CD enables teams to rapidly and reliably deliver high-quality software by automating the build, test, and deployment processes. However, simply adopting CI/CD is not enough; to truly reap the benefits, teams must follow best practices that ensure efficiency, reliability, and consistency. In this blog post, we'll explore key CI/CD best practices and how the Harness Software Delivery Platform can help you optimize your software delivery pipeline.

What Are CI/CD Best Practices?

CI/CD best practices are the habits that keep your pipelines fast, reliable, and predictable as your teams and systems grow. They guide how you commit and review code, build and test artifacts, deploy changes, and measure and improve the process. When teams follow the same best practices, there are fewer surprises in production, less time spent fixing deployments, and more time to deliver new features.

This guide covers the most important CI/CD best practices and explains how they help create a strong software delivery process.

  1. Commit Early, Commit Often

Making frequent, small integrations is a simple but powerful CI/CD best practice. It helps keep your pipeline fast and your main branch stable.

  • Try to merge code into the main branch often, ideally once per developer each day. This keeps merge conflicts small and helps you get feedback quickly.
  • Split your work into small, reviewable pieces that can pass tests and be deployed on their own, instead of using long, risky branches.
  • Run fast checks locally before pushing to avoid trivial red builds and wasted CI cycles.
  • Keep branches short-lived and use trunk-based development. This keeps your history clean and makes sure the main branch is always ready to release.
  • Use fast, intelligent pipelines so frequent commits do not slow anyone down. Run only the tests affected by each change.
  • Use incremental builds to cut down rebuild time. This way, developers get feedback in minutes, even when they commit often.
  • Use CI analytics to track build and test performance over time. This data helps you keep the 'commit early, commit often' approach working as your codebase grows.
  • In trunk-based development, developers integrate into the main branch at least once per day. In GitFlow-style workflows, this principle still applies — but changes are merged into short-lived feature branches that integrate back into main quickly.
  1. Get Back to Green Quickly

A green build is a happy build. In CI/CD, it's crucial to maintain a stable and reliable build process. If the build is failing, it should be the top priority to fix it. Failing not only hinders the delivery process but also erodes team confidence and productivity. Implement automated tests, linters, and code quality checks to catch issues early and ensure that the main branch remains in a deployable state.

This said, if tests are never failing and the build never turns red, you are probably not testing well enough or moving quickly enough. The occasional broken build is fine. The team simply needs to prioritize

Harness CI offers extensive testing capabilities, including automated unit, integration, and acceptance tests. With Harness's Test Intelligence feature, you can optimize your test execution by automatically identifying and running only the tests affected by code changes, saving time and resources.

  1. Build Only Once

Building artifacts multiple times across different stages of the pipeline introduces unnecessary complexity and inconsistency. Instead, adopt the practice of building once and promoting the same artifact through the various stages of testing and deployment. This ensures that the artifact being tested and deployed is the same one that was built, reducing the risk of introducing discrepancies.

Harness simplifies artifact management with centralized artifact storage. You can store and version your build artifacts in one place, ensuring the same artifact is promoted consistently through every stage of your CI/CD pipeline. This practice is often called artifact immutability, i.e., build once, then promote the exact same artifact across staging and production to prevent environment drift.

  1. Standardize Pipelines with Templates and DRY Patterns

If every team has its own one-off pipeline, CI/CD best practices will never stick. Standardization is how platform teams encode the “golden path” and keep pipelines maintainable over time. Start by identifying the common stages every service needs, such as build, unit tests, security scans, and deployment to staging and production, then capture those stages in reusable templates. Give application teams a clear extension model so they can add service-specific steps without copy-pasting entire pipelines. This DRY approach makes it easier to roll out improvements, because you change the template once instead of editing dozens of separate configurations. 

Harness pipeline templates are built for exactly this: platform engineers define the shared workflows, while product teams plug into those templates and still keep the autonomy they need.

  1. Streamline Your Tests

Slow, noisy test suites can quickly ruin CI/CD best practices by making every commit a long wait. The goal is to keep quality high and make your pipeline smart about which tests run and when.

  1. Organize your tests in layers. Start with fast unit tests, then run API or integration tests, and finish with a few end-to-end or UI tests. This way, developers get feedback in minutes instead of hours.
  2. Run fast tests early and often. Trigger unit and key integration tests on every commit, and reserve full regression suites for scheduled or pre‑release runs.
  3. Parallelize wherever you can. Split them across multiple workers or nodes so the total test time depends on your infrastructure, not just your codebase size.
  4. Continuously prune and refactor. Remove duplicate tests, fix or isolate flaky ones, and keep your suites small so you get clear, useful results.
  5. Use intelligent test selection rather than brute-force testing. Test impact analysis lets you run only the tests affected by a change, keeping coverage high and cutting pipeline time.
  6. Keep an eye on your test metrics. Use CI analytics to track test duration, failure rates, and other trends. Use this data to improve your test suites.

Most high-performing CI/CD pipelines follow the testing pyramid:

  • Many fast unit tests

  • Fewer integration tests

  • Minimal end-to-end/UI tests
  1. Secure Your CI/CD Pipeline

Security should be part of CI/CD from the start, not added at the end. Begin by keeping secrets out of source control, limiting who can change pipelines and environments, and using SSO and multi-factor authentication for access.

Next, make security checks a main part of your pipeline, not just an extra step. Add dependency scans, container image scans, and policy-as-code steps to block non-compliant changes before they go live.

Strong audit trails are another core CI/CD best practice, so you always know who deployed what, when, and where. Harness supports these practices with environment-aware RBAC, policy-as-code, and detailed deployment history, so you can move fast without losing control.

Modern CI/CD best practices include embedding SAST, DAST, container scanning, and SBOM generation directly into pipelines to support DevSecOps and supply chain security initiatives.

  1. Clean Your Environments

Consistent and reliable environments are essential for successful CI/CD. Ensure that your environments are versioned, reproducible, and disposable. Use infrastructure-as-code (IaC) practices to define and manage your environments, enabling version control and easy rollbacks. Clean up environments after each deployment to avoid configuration drift and ensure a fresh start for the next deployment.

Harness provides robust deployment and environment management capabilities. With Harness's IaCM, you can define and manage your environments using popular IaC tools like Terraform, CloudFormation, and Kubernetes manifests. Harness also supports automatic environment cleanup, keeping your environments clean and consistent.

  1. Make It the Only Way to Deploy to Production

To ensure consistency and reliability, establish your CI/CD pipeline as the sole path to production deployment. Discourage manual deployments or ad-hoc changes to production environments. By enforcing deployment through the pipeline, you maintain a standardized and auditable process, reducing the risk of human error and enabling easier rollbacks if needed.

With Harness's pipeline governance features, you can enforce policies and approvals, ensuring that only authorized changes make it to production.

  1. Release Progressively

Deploying an entire application all at once is no longer in vogue. We now understand that deploying little by little delivers a better user experience while minimizing risks. Consider deploying an application to a cluster using techniques like a Canary deployment. Canary deployments deploy the new version alongside the existing, sending only a small amount of traffic to the new one. Only after seeing that users are successful with the new version is the deployment completed, removing the old version. This approach exposes only a few users to the new version at first, helping minimize the risk and ensuring that rollback (disabling the new version) is easy.

Another approach to progressive delivery is to enable individual features separately from releasing the new version of the code. A feature management tool will allow you to first see that the new version of the code is stable, then experiment with each new feature, making sure they have the desired impact. This approach refines your CD significantly.

  1. Monitor and Measure Your Pipeline

To keep improving your CI/CD process, you need to see how your pipeline works in real situations. Track basics like how long pipelines take, where they fail most, and how often deployments succeed or need rollbacks. Use analytics to find bottlenecks, spot slow or flaky stages, and check if your changes help. Treat this as an ongoing feedback loop: review the data, pick one thing to improve, make the change, and check the results. For a more detailed view, you can add DORA metrics, which we’ll discuss next.

  1.    Measure CI/CD Health with DORA and Beyond

You can’t improve what you don’t measure, and CI/CD is no different. Start with the four DORA metrics: deployment frequency, lead time for changes, change failure rate, and mean time to recovery (MTTR). These show how fast you deliver changes, how often things go wrong, and how quickly you recover.

As you get more advanced, add other metrics like build time, test flakiness, or time waiting for approvals to find specific pipeline bottlenecks.

A key CI/CD best practice is to make these metrics visible to your team, review them often, and connect process changes to real improvements. Harness helps by showing delivery analytics from your pipelines, so you can see your metrics change as you improve.

  1. Make It a Team Effort

CI/CD isn't just a tool or a process; it's part of a DevOps culture. Get everyone involved, including developers, testers, and operations, when designing and running your CI/CD pipeline. Encourage teamwork and shared ownership so everyone helps improve the process. Offer training and support to make sure everyone understands and follows best practices.

Harness supports collaboration and teamwork through features like role-based access control (RBAC) and policy-as-code. You can define granular permissions and policies to ensure that team members have the right level of access and control over the pipeline. Harness also integrates with popular collaboration tools, making it easy to share information and work together effectively.

Practice
Why It Matters
Outcome
Small, frequent commits
Reduces merge conflicts
Faster feedback cycles
Build once, promote
Prevents artifact drift
Reliable releases
Intelligent test selection
Reduces pipeline time
Faster CI
Progressive delivery
Limits the blast radius
Safer deployments
DORA metrics tracking
Measures delivery performance
Continuous improvement

Harness Your CI/CD Potential

While following CI/CD best practices is essential, having the right tools and platform can greatly streamline and enhance your software delivery process. The Harness Software Delivery Platform streamlines software delivery so pipelines stay fast and reliable instead of becoming another source of toil. 

Harness CI accelerates builds and tests with intelligent caching, optimized cloud builds, and features like Harness Test Intelligence to prioritize the most relevant tests and shrink feedback cycles. Out-of-the-box integrations and templates minimize custom scripting and heavy configuration, so teams can onboard quickly and focus on delivering features, not wiring tools together.

Governance and compliance are built in rather than bolted on. With granular RBAC and policy-as-code, including DevOps pipeline governance,  you can enforce approvals, security scans, and compliance checks, without blocking developers.

Putting CI/CD Best Practices into Action

CI/CD best practices help teams move from fragile, unpredictable releases to a steady, reliable delivery process. By committing early and often, keeping builds green, building once, streamlining tests, securing and cleaning environments, using the pipeline for all production deployments, releasing in stages, and tracking key metrics, you build a pipeline that supports fast change. Start with one or two practices, make them habits, and add more over time. Soon, your CI/CD pipeline will be a strength, not a bottleneck.

If you want a platform that bakes these practices into your day-to-day workflows, try Harness and see how quickly your CI/CD pipeline can evolve.

Frequently Asked Questions About CI/CD Best Practices

What are the most important CI/CD best practices to start with?

If you’re just starting out, focus on a few CI/CD best practices that give the most value: commit early and often, keep the main branch ready to deploy, run automated tests on every change, and use the pipeline as the only way to reach production. Once you have these basics, you can add progressive delivery, security checks, and advanced governance without overwhelming your team.

How do CI/CD best practices change for microservices versus a monolith?

The main principles don’t change, but the impact is bigger with microservices. You need consistent templates and standards so every service uses the same process for builds, tests, and deployments. You also need better observability and progressive delivery, since one release might involve several services rolling out together instead of just one big application.

How can we speed up our pipelines without sacrificing test quality?

Start by cutting out obvious waste: remove duplicate tests, fix or isolate flaky ones, and run fast unit tests early so developers get quick feedback. Use test impact analysis and incremental builds to avoid repeating work that hasn’t changed. The goal is to keep quality high while making the pipeline smart about which tests matter for each change.

What metrics should we track to know if our CI/CD is healthy?

Start by tracking the four DORA metrics, since they show how fast and stable your process is: deployment frequency, lead time for changes, change failure rate, and MTTR. Then add a few extra metrics that fit your team’s needs, like average build time, CI queue time, or time from merge to production. Healthy pipelines have frequent, small deployments, short lead times, low failure rates, and quick recovery when things go wrong.

How do we keep CI/CD secure while still enabling fast releases?

Make security checks part of your automated pipeline, running on every change instead of being done manually at the end. Use a secret manager, limit access to CI/CD systems, and add vulnerability scans and policy-as-code rules to your pipelines. When these controls are built into the process, developers can move quickly while the pipeline enforces security and compliance.

When is it time to adopt progressive delivery and feature flags?

If deployments start to feel risky or you delay releases 'just in case,' it’s time to try progressive delivery and feature flags. Strategies like canary and blue/green deployments let you release more often by limiting the impact of each change. Feature flags let you turn features on or off without redeploying. These approaches turn big, stressful launches into smaller, safer steps that fit well with modern CI/CD.

← Previous:
Next: →

Related Resources

CI/CD for Serverless

Continuous Delivery & GitOps

CI/CD for Serverless

January 19, 2024

Dewan Ahmed

+ more
Time to Read

Ah “serverless”... the promise of running applications without worrying about servers! The term "serverless" often sparks skepticism among those rooted in traditional software development practices. The idea of handing over control over infrastructure may seem daunting, and developers might wonder if serverless is even right for their use case. My goal in this blog is to demystify serverless computing (in particular, serverless deployment) without unnecessary complexity.

Embracing Abstraction - From Infrastructure to Serverless

Evolution to SaaS and the Kubernetes Leap

The software development landscape has witnessed a fundamental transformation through the lens of abstraction. The rise of Infrastructure as a Service (IaaS) and Platform as a Service (PaaS) marked a pivotal shift, freeing engineering teams from the nitty-gritty of infrastructure concerns with the advent of Software as a Service (SaaS).

The massive adoption and growth of Kubernetes, a powerful container orchestrator, redefined how the underlying infrastructure can be abstracted away from engineers who build and deploy containerized applications. In a concise analogy, Kelsey Hightower tweeted: "Kubernetes is not the kernel; it's systemd." This emphasizes its role as a higher-level orchestrator, adept at handling the deployment, scaling, and management of containerized applications.

Serverless and FaaS: The Ultimate Abstraction

As we delve into Serverless computing, it represents the apex of abstraction, pushing the boundaries even further. Beyond Software as a Service (SaaS), Serverless encapsulates Functions as a Service (FaaS), providing a powerful tool for engineers to zero in on their code. It simplifies by abstracting away server management complexities, embracing a dynamic, event-driven model for resource efficiency.

In the realm of FaaS, a function acts as "glue code," seamlessly connecting and extending existing services. This approach utilizes a runtime framework where you deploy a compact snippet of code, not an entire container. Within this snippet, you implement a single function or override a method, specifically designed to handle incoming requests or events. Importantly, there's no need to start an HTTP Server manually.

The beauty of FaaS lies in its serverless nature, offering a straightforward developer experience where concerns about the runtime of your code fade away. Scaling is inherently built in, ensuring a seamless and hassle-free experience.

It's crucial to note that Serverless extends beyond the handling of HTTP requests. You can think of FaaS as a subset of Serverless but Serverless is not FaaS.

Benefits of Serverless Computing

Using Serverless Computing comes with some great advantages that make a difference on cost, scalability, overhead, and more in how software is delivered.

Cost Efficiency

With Serverless, you only pay for what you use, like paying for the energy you use at home. No big upfront costs for infrastructure – it's a flexible and budget-friendly way to handle computing resources.

Scalability and Flexibility

Serverless adjusts automatically to handle more or fewer tasks. When your app gets busy, it scales up. When things slow down, it scales down. This flexibility keeps your app running smoothly without wasting resources.

Simplified Development and Deployment

For developers, Serverless means less hassle with servers. You can concentrate on writing code, and when it's time to put it into action, Serverless takes care of the technical details. The burden of setting up compute infrastructure is abstracted away, letting you focus on your code without dealing with the nitty-gritty of server management.

Use Cases for Serverless Computing

Serverless computing is a flexible approach that can be applied to many different areas. Let's explore key use cases where serverless computing proves to be a valuable solution.

Auto-scaling Websites and APIs

Serverless computing is tailor-made for dynamically changing workloads. For websites and APIs with fluctuating traffic, serverless allows automatic scaling up or down based on demand. This ensures optimal performance without the need for manual intervention, making it an ideal solution for handling varying user loads.

Event Streaming

In event-driven architectures, serverless excels at processing and responding to events in real-time. By leveraging serverless capabilities, organizations can effortlessly manage event streaming, reacting promptly to changes and ensuring seamless communication between services.

Processing Events and SaaS

Serverless is a natural fit for processing events, especially in scenarios where events trigger specific actions. Integrating with Software as a Service (SaaS) applications becomes more streamlined, allowing organizations to automate tasks, synchronize data, and enhance overall workflow efficiency.

Hybrid Cloud Applications

Serverless computing seamlessly integrates with hybrid cloud models, where applications span both on-premises and cloud environments. This flexibility ensures that organizations can deploy and manage applications without being constrained by the limitations of a single hosting environment.

Internet of Things (IoT)

The scalability and event-driven nature of serverless make it an excellent choice for IoT applications. Handling data from numerous devices and responding to events in real-time is simplified, allowing for efficient processing and analysis in IoT ecosystems.

Continuous Integration and Continuous Deployment (CI/CD)

In the fast-paced landscape of software development, the ability to iterate rapidly is more crucial than ever. CI/CD pipelines play a pivotal role in enabling organizations to ship code in small, incremental updates, ensuring that bug fixes and other enhancements can be seamlessly delivered on a daily basis.

Serverless computing amplifies the power of CI/CD by automating key processes in the software development lifecycle. Code check-ins can trigger the automatic building and redeployment of websites, while pull requests (PRs) can initiate the execution of automated tests, ensuring thorough code testing before human review. This automation not only accelerates the delivery pipeline but also enhances the reliability and quality of the software being deployed.

When exploring the automation possibilities within Serverless Applications, the potential to eliminate manual tasks from the workflow becomes apparent. From triggering builds and tests to orchestrating seamless deployments, serverless computing empowers development teams to focus on coding and innovation rather than getting bogged down by manual, time-consuming tasks. This shift toward automation not only increases efficiency but also reduces the risk of human errors, ultimately contributing to a more agile and responsive development process.

The dark sides of Serverless

While Serverless computing offers a multitude of benefits and has a number of use cases, it's crucial to acknowledge that it's not a one-size-fits-all solution. Like any technology, Serverless has its own set of challenges. 

Unpredictable Costs

With rapid autoscaling comes unpredictable billing. Just as you consider factors like performance, security, and scalability, now, costs are an essential aspect of your code in serverless architecture. It's crucial for you as a developer to be aware of these costs and, importantly, to have control over them.

Portability Problems

Serverless platforms may not offer the portability freedom you imagine. While your code is portable, the triggers and scaling mechanisms are often specific to each cloud provider. For instance, the supported versions of languages may vary, impacting the migration of code across different platforms. Solutions like Kubernetes-based offerings provide some relief but come with their own set of choices and opinions.

Smells Like Infrastructure

Despite the promise of abstraction, many Serverless implementations still involve choices in infrastructure. Options like Apache OpenWhisk, Open FaaS, or KNative offer more generic serverless infrastructure but require maintenance. The rapid and sometimes unpredictable scaling of functions demands careful cluster capacity management, introducing complexities of its own.

Shifting Complexity

Serverless shifts complexity, especially in short-lived and rapidly scaling functions. While it simplifies certain aspects, the management of state becomes critical as functions may need to interact with external systems to maintain continuity. However, these challenges don't have to be insurmountable. Leveraging tools like the Serverless Framework can provide a solution by abstracting away some of the complexities. 

Your Function Has a Function

With the ease of invoking serverless functions, there's a risk of falling into the Big Ball of Mud antipattern. The rapid instantiation of "serverless containers" can lead to the inclusion of excessive logic in a single function. Advanced tools like Amazon Step Functions make orchestrating multiple functions easier but require careful design to avoid complexity pitfalls.

Cold Starts

Unlike traditional systems, Serverless introduces the concept of cold starts, where every request triggers the instantiation of a new serverless container. This is particularly critical in languages like JAVA, demanding thoughtful design and infrastructure considerations.

To mitigate this challenge, hyperscalers like AWS have introduced solutions to enhance the performance of serverless functions. For instance, AWS has introduced SnapStart for AWS Lambda functions running on Java Corretto 11. This feature significantly improves function startup performance, providing up to 10x faster initialization, without incurring additional costs.

Why CI/CD for Serverless Deployment

The principles that govern traditional production controls also apply to serverless deployment. While modifying or patching a Lambda is remarkably straightforward, similar to a traditional system, it's essential to maintain disciplined practices. Hot patching in production, even if it's relatively easy for serverless functions, raises concerns about maintaining control and adhering to Software Development Life Cycle (SDLC) principles.

Enterprises employ production controls to prevent unauthorized modifications and ensure a structured approach to changes. This discipline is equally applicable to serverless functions, and while it's tempting to make in-line modifications using tools like the AWS Lambda editor, it's crucial to integrate serverless deployment into a robust CI/CD pipeline.

A well-orchestrated CI/CD pipeline that incorporates serverless functions offers several advantages. Firstly, it extends the same level of diligence and confidence established by the SDLC and Continuous Delivery processes to serverless workloads. This ensures that modifications to serverless functions follow a systematic approach, aligning with established organizational standards.

Moreover, integrating serverless deployment into your CI/CD pipeline enhances early defect detection, increases productivity, and promotes faster release cycles. Advanced deployment strategies become feasible within a comprehensive CI/CD pipeline, including canary releases, blue-green deployments, and feature toggles, allowing for controlled testing and gradual rollouts.

By extending the CI/CD pipeline to encompass both serverless and non-serverless workloads, organizations can achieve consistency and efficiency across their entire application landscape. Utilizing a CI/CD increases early defect detection, increases productivity, and enables faster release cycles, reflecting the agility and efficiency that serverless computing promises within a disciplined development and deployment framework. This approach not only streamlines the management of serverless functions but also aligns with best practices in software delivery, promoting reliability and maintainability.

Serverless Deployment with Harness

Now that we've explored the fundamentals and nuances of serverless deployment, it's time to put theory into practice. Harness Continuous Delivery (CD) empowers you to seamlessly integrate serverless deployment into your CI/CD pipeline, ensuring a disciplined and controlled approach to managing your serverless functions.

To begin your hands-on journey and unlock the potential of Harness CD for serverless deployment, delve into our tutorials:

These comprehensive guides will walk you through the process of deploying sample functions seamlessly using Harness pipelines.

How to Implement CI/CD: Automate Builds, Testing, and Deployments in Minutes

Continuous Integration

How to Implement CI/CD: Automate Builds, Testing, and Deployments in Minutes

December 13, 2022

Pavan Belagatti

+ more
Time to Read

DevOps continues to grow in popularity among software development teams. It’s not surprising, given the benefits: a streamlined workflow leads to faster release frequency and deployment cycles, quicker bug detection, efficient rollback in case of any error, and a more productive team overall. DevOps engineers ensure that the processes and practices of code development, testing, and release are streamlined to reduce inefficiency, risk, and time to market. Coupled with continuous integration (CI) and continuous delivery (CD), DevOps helps IT organizations streamline their development process by automating manual tasks related to code deployment. Let’s explore how you can adopt CI/CD to improve your organization’s efficiency and delivery pipeline.

Continuous Integration

First, let’s take a look at what CI/CD is and what its benefits are. Although these two concepts are often discussed together, each has its own role in the software development process. 

Continuous integration is the process of automating the build and testing of code. It requires a SaaS build service (like Harness Hosted Builds) or an on-premise build server responsible for taking code from a source control system (such as Git), compiling it, and testing it to ensure it’s error-free. This helps to keep software projects on track by ensuring that errors/mistakes/bugs get spotted as soon as they occur. If a build is broken, it halts the rest of the process until it’s been fixed. As a result, the build process is much more streamlined.

Continuous Delivery & Deployment

Continuous delivery automates the release process. It ensures that code is always in a releasable state. This process includes taking the code from the build system and routing it through a staging environment to ensure it’s suitable for release. The outcome is a fully automated deployment process, which can be controlled by the team or triggered by triggers outside the team (such as when a developer pushes or commits a code to the main branch). The key difference between CI and CD is that the former is focused on building code, while the latter focuses on releasing the final product.

The below diagram depicts the difference between CI, CD, and continuous deployment.

<a href=
CI, CD, and continuous deployment">

Continuous deployment is the final and most desired stage of the CI/CD process. It’s the point at which the team can deploy the code with zero-touch automation. This is the difference between continuous delivery and deployment. When the deployment of the code is done via manual intervention, it is delivery. However, if the code is deployed in an automated fashion without any manual intervention, it is called continuous deployment. 

How to Implement CI/CD in Your Organization

Before implementing CI/CD in your organization, you should know why you are implementing it, the goal, and which metric you would like to focus on. For example, DevOps teams usually focus on four key (DORA) metrics: 

  1. Lead time for changes
  2. Change failure rate
  3. Deployment frequency
  4. Mean time to recovery

Your goal with CI/CD can also be as simple as moving away from traditional software delivery practices to cloud-native ones. This way, understanding the basics of DevOps concepts becomes very important. 

If you haven't already, you may need to adopt a version control system, implement a build system, and introduce staging environments. Once these basics are in place, you can begin the CI/CD process: 

  1. First, you’ll start with CI. This process ensures the code is tested and is clean and ready to deploy. 
  2. You can then move on to the CD part, where you’ll be able to deploy code to staging and ready for review by the team.
  3.  You can deploy the code to the production environment once everything is approved.

Next, you need to evaluate different CI/CD tools to understand which best suits your organization. Unfortunately, there are a plethora of tools that can be overwhelming to some of you. In this article, we will use a prominent CI/CD tool, Harness, to explain how CI/CD works through a simple hello world application. A well-established CI/CD pipeline also makes it easier for your team to identify areas for improvement and take action to mitigate risks that may exist in your system. It also makes it easier to implement process changes as your team grows and changes over time.

Harness CI/CD Tutorial

We will only be focusing on creating CI/CD pipelines with Harness in this tutorial. We are also a big fan of GitOps, and we have GitOps-as-a-service available at Harness to speed up your deployments. 

Software development teams that adopt a CI/CDpipeline see faster software deployments with more negligible risk and quicker bug identification and remediation. If you are new to CI/CD, it can seem like an overwhelming amount of new terms and processes to learn. But setting up a CI/CD pipeline is easier than you think. 

A CI/CD pipeline helps your team pinpoint where problems in your software are likely to occur – before they reach end users. Additionally, it allows you to release updates more frequently and spend less time testing individual components or modules before releasing them to users. Harness is a leader in CI/CD with impeccable features. Today, we will show you how to implement CI/CD in minutes with a simple setup. 

Implementing <a href=
CI/CD with Harness">

Pre-Requisites

First, we will create a simple“Hello World!” application in Node.js with a simple test case. I have already created this simple “Hello World!” application to make it easier and pushed it to GitHub. You can fork this repo to start working on it.

The Dockerfile you see in the repo will be used to build and push our application as an image to the Docker Hub. The next thing is we will build the image and push it to the Docker Hub using the command,

docker buildx build --platform=linux/arm64 --platform=linux/amd64  -t docker.io/<docker hub username>/<image name>:<tag> --push  -f ./Dockerfile .

Once the build and push are successful, you can confirm it by going to your Docker Hub account.

Docker hub confirmation

You can see the deployment.yaml file in the forked repo, which defines the deployment yaml file to help us deploy the application to our Kubernetes cluster. At this point, make sure your Kubernetes cluster is up and running.

Once everything is set, it is time to set up a Harness account to do CI/CD. Create a free Harness account and your first project. Once you sign-up at Harness, you will be presented with the new CI/CD experience and capabilities.

Add the required connectors, GitHub repo, Docker Hub and secrets, if any. Delegate in Harness is a service/software you need to install/run on the target cluster [Kubernetes cluster in our case] to connect your artifacts, infrastructure, collaboration, verification and other providers with the Harness Manager. When you set up Harness for the first time, you install a Harness Delegate.

Harness delegate menu

Select the Continuous Integration module and add the necessary stages and steps, as shown below.

Harness <a href=
CI module">

‘Test’ step set-up is done as below:

Harness <a href=
CI configure run step">

The “Push to Docker Registry” step is as below:

Push to Docker registry

Next, set up a deployment pipeline.

Add the required details in the “Service” tab.

Harness <a href=
CI service tab">

Define the environment type in the “Environment” tab.

Harness <a href=
CI environment tab">

Strategize the execution by selecting which deployment you prefer.

Select deployment method in Execution

Save everything and run the pipeline.

Run pipeline in Harness <a href=
CI">

You can see both CI and CD getting executed one by one with all the steps specified.

Congratulations! We successfully built, and tested the application code and deployed it onto our Kubernetes cluster using the Harness platform.

You can confirm this deployment by using the command kubectl get pods

kubectl command

You can see two replicas running as per our specifications on the deployment.yaml file.

Also, confirm the same by going to your Kubernetes dashboard. Since I am using Google cloud (GCP), I can see and confirm that there are two pods running.

Kubernetes dashboard

Harness platform makes it easy for developers to streamline their SDLC by leveraging the different modules available. Today we saw CI and CD modules, and Harness has a total of seven modules as of now.

Harness' seven modules

CI/CD and DevOps

CI/CD is an essential part of any DevOps strategy. It helps to automate the code review and testing process, making it easier for teams to test and deploy software. It’s also a crucial part of creating a culture of continuous improvement. It is also important to remember that CI/CD is not a magic bullet. Laying the DevOps culture(https://www.atlassian.com/team-playbook/examples/devops-culture) and methodologies are the initial steps. It is also important to remember that these processes and methodologies under DevOps are not static; they are ever-evolving and should be tweaked as needed to meet the team’s needs.

If you're interested in learning more about using Harness and intelligent software delivery, try it for free and check out our Developer Hub for more step-by-step tutorials, videos, and reference docs.

On-demand webinar: How to avoid common CI/CD problems

Get Started

Get Started with Harness AI

Try the full platform free. No module restrictions, no credit card.

Chinmay Gaikwad
Director, Product Marketing
Chinmay Gaikwad is an expert on making complex technologies - such as cloud-native solutions, Kubernetes, application security, and CI/CD pipelines - accessible and engaging for both developers and business decision-makers.
chinmay-gaikwad
Chinmay Gaikwad
https://www.linkedin.com/in/chinmay-gaikwad/