2019

Feature Flags in Kubernetes Applications

Feature flags are used to change the behavior of a program at runtime without forcing a restart.

Although they are essential in a native cloud environment, they cannot be implemented without significant effort on some platforms. Kubernetes has made this trivial. Here we will implement them through labels and annotations, but you can also implement them by connecting directly to the Kubernetes API Server.

Possible Use Cases

• Turn on/off a specific instance
• Turn on/off the profiling of a specific instance
• Change the logging level, to capture detailed logs during a specific event
• Change caching strategy at runtime
• Change timeouts in production
• Toggle on/off some special verification

Organizing Access Using kubeconfig Files

The kubectl command-line tool uses kubeconfig files to find the information it needs in order to choose a cluster and communicate with its API server.

What happens if the kubeconfig file of your production cluster is leaked or published by accident?

Since there is no possibility to rotate or revoke the initial kubeconfig, there is only one way to protect your infrastructure or application if the kubeconfig has leaked - delete the cluster.

Learn more on Organizing Access Using kubeconfig Files.

KubeCon Rewind: SIG Cluster API & Gardener – Managing Machines Automatically

The KubeCon + CloudNativeCon Europe buzz might be settling, but the energy from our deep dive session with the incredible folks at SIG Cluster API is still palpable! We, from the Gardener team, were absolutely thrilled to share the stage and explore the powerful, declarative world of Kubernetes cluster lifecycle management.

For those who don’t know, Gardener has been on a mission since 2017 to provide a fully managed Kubernetes experience, uniquely running customer control planes as pods within dedicated “seed” clusters, a.k.a. “Kubeception”. This approach demanded robust automation for the underlying infrastructure. To solve this, we pioneered the Machine Controller Manager, introducing the core abstractions you might recognize: Machine, MachineSet, and MachineDeployment. These concepts were born out of real-world needs to declaratively manage VMs and their lifecycles as if they were just another Kubernetes resource.

It’s exciting to see these foundational ideas embraced and extended by the wider community through Cluster API! Our joint talk was a fantastic opportunity to showcase how these abstractions, originally developed within Gardener, now form a cornerstone of Cluster API’s approach to creating, configuring, and managing Kubernetes clusters in a standardized way, across any provider. Incidentally, this also made Gardener the first adopter of the machine API.

We dove into:

• The “why” behind Cluster API – the drive to stop reinventing the wheel for cluster provisioning.
• The core API types (yes, including those familiar Machine, MachineSet, and MachineDeployment concepts!) that provide the declarative power.
• How you can bootstrap Cluster API and get it managing your clusters.
• The vibrant community and how everyone can get involved.

This collaboration isn’t just about shared code; it’s about a shared vision for a more consistent, automated, and less painful Kubernetes world. Seeing Gardener’s early innovations become part of a community-driven standard like Cluster API is a testament to the power of open source.

If you were there, thank you for the great questions and engagement! If you missed it, keep an eye out for the recording. The journey to simplify cluster management is a collective one, and we’re stoked to be building that future together with SIG Cluster API and all of you!