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Wednesday, May 22, 2024

Enhancing the Bitnami Helm Charts Experience: Changelog, tags, and validation images

Bitnami has recently rolled out several initiatives aimed at enhancing the user experience with Helm charts. These improvements focus on better traceability and smoother integrations. Read on to discover the latest updates:

Improved Changelog and Tagging System

One major initiative is the enhancement of change traceability for Bitnami Helm charts. This has been achieved by introducing a file for every Helm chart and implementing git tags for every new version.

Automated Changelog Updates

With every pull request (PR) merge a new file is automatically updated to list the changes included in that specific release. This automation is powered by the conventional-changelogs-cli, eliminating the need for contributors to perform this step manually.

For example, here is what a typical file looks like. These files are excluded from the Helm charts themselves, as specified in the .helmignore file. Starting today, you will see files gradually being rolled out to every Bitnami Helm chart as new releases are produced.

Consistent Version Tagging

In addition to the changelog updates, every chart change now results in a commit tag formatted as “APP/VERSION”. An example of such a tag can be seen here: spark/9.0.4.

These enhancements are designed to assist users during the upgrade process and improve compatibility with automation tools like Renovate and GitHub Dependabot.

In the following example, we have a Helm chart (Airflow) with three dependencies: bitnami/redis, bitnami/postgresql, and bitnami/common. We will use Renovate to automatically detect and create Pull Requests every time there is a new version of these dependencies.

apiVersion: v2

appVersion: 2.9.1


- condition: redis.enabled

  name: redis

  repository: oci://

  version: 19.2.0

- condition: postgresql.enabled

  name: postgresql

  repository: oci://

  version: 15.2.0

- name: common

  repository: oci://

  version: 2.19.3

name: airflow

version: 18.1.1

Following the official Renovate installation instructions we enabled the automation in the repository

In the automated PR, we can see that it detected our helm chart:

Once this is merged, after some time we will see PRs like the following:

Checking its contents, we can see that the changelog is included in the PR description:

Warning on Replacing Default Images
We have introduced a new validation that displays warnings when default images bundled in the Helm chart are replaced. This is to let users know when the images from a Helm chart have been altered

Each Helm chart is meticulously designed, tested, and validated using a specific set of Bitnami container images across multiple platforms. Replacing these default containers can introduce several risks:

  • Degraded Security and Performance: Non-Bitnami containers may not have the same security features and optimizations, leading to potential vulnerabilities and performance issues.

  • Broken Chart Features: The Helm chart’s functionality might rely on specific configurations or tools available only in the original Bitnami containers.

  • Missing Environment Variables: Substituted containers may lack critical environment variables necessary for the Helm chart to function correctly.

  • Security: A malicious threat actor could have switched the container images and redistributed the artifact as a legit Bitnami Helm chart.

When deploying a Helm chart, if the images that Bitnami has built the Helm chart with are replaced, a warning will appear in the console to alert the user of these potential risks. We understand that some users might need to switch the container images that Bitnami has verified, but at the same time, we believe making users aware of this change is important for the reasons above.

Branch size reduction

Bitnami has recently reduced the size of certain branches related to index.yaml, as outlined in this GitHub Issue. Previously, Helm charts were distributed using the index.yaml method, which has since been replaced by OCI through DockerHub. You can find the OCI Helm charts here.

Despite the shift to OCI, index.yaml was maintained for backward compatibility. However, the sheer number of releases and commits generated by our automated test and release pipeline caused these branches to balloon in size:

  • index: 2.23 GiB

  • archive-full-index: 987.42 MiB

This significant size increase resulted in longer clone times and made life difficult for those users looking to contribute fixes or improvements.

To address this issue, we implemented automation to squash all commits in the index-related branches. This drastic size reduction has yielded the following results:

  • index: 840.41 KiB

  • archive-full-index: 1.89 MiB

These changes significantly improve the contribution experience, making it easier and faster for our community to collaborate and contribute.

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