What is Helm and how is it used in CD pipelines?

Answer

Helm is the package manager for Kubernetes. It bundles all Kubernetes resource manifests (Deployments, Services, ConfigMaps, Ingresses) for an application into a chart — a versioned, reusable package. Charts use Go templates to allow parameterization: the same chart can deploy to dev, staging, and production with different values (image tag, replica count, resource limits). In CD pipelines: the pipeline builds and pushes the Docker image, updates the image tag value, and runs helm upgrade --install my-app ./chart --values env/prod/values.yaml --set image.tag=$GIT_SHA --atomic. The --atomic flag automatically rolls back if the deployment fails health checks. Helm maintains a release history in the cluster, enabling helm rollback to any previous revision. Helm repositories (ChartMuseum, OCI registries) store versioned charts for reuse across teams.