This is part 6 of 7 of our Helm 3 Preview: Charting Our Future blog series on library charts. You can find our previous blog post on the Helm chart dependencies here.

Helm 3 supports a class of chart called a "library chart". This is a chart that is shared by other charts, but does not create any release artifacts of its own. A library chart's templates can only declare define elements. Globally scoped non-define content is simply ignored. This allows users to re-use and share snippets of code that can be re-used across many charts, avoiding redundancy and keeping charts DRY.

This is part 5 of 7 of our Helm 3 Preview: Charting Our Future blog series about chart dependencies and some subtle differences between Helm 2 and Helm 3. (Check out our previous blog post on release management here.)

Charts that were packaged (with helm package) for use with Helm 2 can be installed with Helm 3, but the chart development workflow received an overhaul, so some changes are necessary to continue developing charts with Helm 3. One of the components that changed was the chart dependency management system.

This is part 4 of 7 of our Helm 3 Preview: Charting Our Future blog series on release management. (Check out our previous blog post on the Helm chart repositories here.

In Helm 3, an application's state is tracked in-cluster by a pair of objects:

This is part 3 of 7 of our Helm 3 Preview: Charting Our Future blog series, discussing chart repositories. (Check out our previous blog post on the gentle goodbye to Tiller here.)

At a high level, a Chart Repository is a location where Charts can be stored and shared. The Helm client packs and ships Helm Charts to a Chart Repository. Simply put, a Chart Repository is a basic HTTP server that houses an index.yaml file and some packaged charts.

This is part 2 of 7 of our Helm 3 Preview: Charting Our Future blog series. (Check out our previous blog post on the history of Helm here.)

During the Helm 2 development cycle, we introduced Tiller as part of our integration with Google's Deployment Manager. Tiller played an important role for teams working on a shared cluster - it made it possible for multiple different operators to interact with the same set of releases.

On October 15th, 2015, the project now known as Helm was born. Only one year later, the Helm community joined the Kubernetes organization as Helm 2 was fast approaching. In June 2018, the Helm community joined the CNCF as an incubating project. Fast forward to today, and Helm 3 is nearing its first alpha release.

In this series of seven blog posts over the next four weeks, I'll provide some history on Helm's beginnings, illustrate how we got where we are today, showcase some of the new features available for the first alpha release of Helm 3, and explain how we move forward from here.

We're beyond excited to share that Helm Summit EU 2019 is now official (h/t to CNCF)! Join the Helm community on September 11 - 12 in Amsterdam, The Netherlands at Pakhuis de Zwijger for our first European Helm Summit. Over the course of two days, we'll discuss all things Helm and hold tutorials, working sessions, and small group discussions with new and existing users.

Security researcher Bernard Wagner of Entersekt discovered a vulnerability in ChartMuseum, impacting all versions of ChartMuseum between ChartMuseum >=0.1.0 and < 0.8.1. A specially crafted chart could be uploaded that caused the uploaded archive to be saved outside of the intended location.

When ChartMuseum is configured for multitenancy the specially crafted chart could be uploaded to one tenant but saved in the location of another tenant. This includes overwriting a chart at a version in the other tenant.

Security researcher Bernard Wagner of Entersekt discovered a vulnerability in the Helm client, impacting all versions of Helm between Helm >=2.0.0 and < 2.12.2. Two Helm client commands may be coerced into unpacking unsafe content from a maliciously designed chart.

A specially crafted chart may be able to unpack content into locations on the filesystem outside of the chart’s path, potentially overwriting existing files.

Helm was designed with many distributed repositories in mind. Like Homebrew Taps and Debian APT repositories, Helm has the ability to add and work with many repositories. While the Helm stable and incubator repositories have been front and center from the beginning it was never our intent for these to be the only public repositories.

With this in mind, we are delighted to announce the launch of the Helm Hub. This hub provides a means for you to find charts hosted in many distributed repositories hosted by numerous people and organizations.