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December 2021 Update

New Flux releases bring more security, update GitHub integration, add support for BitBucket Server. We need your input on new Flux RFCs, upcoming events featuring Flux and more.

As the Flux family of projects and its communities are growing, we strive to inform you each month about what has already landed, new possibilities which are available for integration, and where you can get involved. Read last month’s update here.

Let’s recap what happened in November - there has been so much happening!

News in the Flux family

A flurry of Flux releases

The Flux Development team has been busy. In November they released Flux 0.21, 0.22, 0.23, and 0.24. Let’s review these one by one, so you can get the most out of Flux when you are doing the upgrade, migration or fresh installation.

0.21 brought ECDSA as the default SSH key algorithm used by flux bootstrap and all the other commands that generate SSH keys. This change was imposed by GitHub that is no longer accepting RSA SHA-1 SSH keys.

To rotate your SSH deploy keys for the repositories bootstrapped with Flux:

  • download the Flux CLI v0.21.0 binary

  • delete the deploy key secret from your cluster

    kubectl -n flux-system delete secret flux-system

    using the Flux CLI v0.21.0.

  • rerun flux bootstrap github with the same arguments as before

Flux will generate a ecdsa-sha2-nistp384 SSH key and will update the deploy key on GitHub.

0.22 introduced no breaking changes, but included these highlights:

  • Storing secrets in environment variables is no longer required, the flux bootstrap command will prompt for the GitHub/GitLab PAT when not found in env.
  • Flux adds support for ignoring manual changes made to the cluster state by disabling the server-side apply for certain resources using an annotation.
  • Improve the image automation alerting by emitting events only when changes are pushed upstream.
  • Include the updated containers URIs in the image automation alerts and events.

0.23 came with artifact integrity verification based on SHA-2 and fixes for image automation. The highlights are:

  • The format of the artifact checksum computed by source-controller changed from SHA1 to SHA256 to mitigate chosen-prefix and length extension attacks.
  • During the acquisition of an artifact, kustomize-controller and helm-controller compute its checksum and verify that it matches the checksum advertised in the Status of the Source.

And finally 0.24 comes with security updates for Alpine CVEs. We are also happy to bring you

  • New bootstrap command for Bitbucket Server and Data Center repositories (CLI).
  • Add support for self-signed certificates when bootstrapping Flux with on-prem GitHub, GitLab and BitBucket servers (CLI).
  • Improved performance when building Helm charts and introduced limits for Helm index and chart files. (source-controller).
  • Add support for Slack Apps bot alerting provider (notification-controller).

Please note that this version comes with breaking changes to Helm users. The Helm repository index.yaml max size is set to 50MiB and the chart max size is 10MiB, to change these limits see the source-controller changelog.

Support for Bitbucket Server and Data Center repositories

Big shout-out to Soulé Ba for adding Bitbucket support to Flux. This will make lots of Flux users happy. Thank you very much!

To find out how to bootstrap Flux on Bitbucket Server, please review our documentation. We love feedback, so please reach out if you have any questions or are missing anything. We are also working on support for BitBucket Cloud, for which we might need some help testing, documentation or wherever else you would like to contribute - we’d love to have you participate!

Flagger 1.16 is out

Progressive Delivery fans will be happy to hear that Flagger 1.16 comes with a new API field called primaryReadyThreshold that allows setting the percentage of pods that need to be available to consider the primary deployment as ready.

Security news

You might have heard about Flux’s security audit which was performed by ADA Logics in the last months. As discussed in the announcement, we set up a project board to track our work and have now completed over half of the identified requests with many more in flight.

Let’s talk documentation

One piece of feedback in the report was that while our Flux documentation serves its users well by e.g. showcasing many useful configuration examples, we could do an even better job by creating a more general, architectural overview of Flux and discussing the security features, assumptions and considerations users should take into account.

After talking to many people, we filed a number of issues to track this work and Scott Rigby created the landing page for Security Documentation. We already brought together quite a few notes to populate these pages more. If you want to help, please talk to Scott and the rest of us - we look forward to your questions, ideas, input and edits!

Flux’s future - we need your input

Speaking of input: we started a formal RFC process for some of the bigger improvements in Flux. This was in part due to feedback from the audit as well, but more generally something we were missing in Flux governance. So far, our process of using GitHub discussions, Slack and our weekly Dev meetings was good enough to find consensus on the bigger questions. With more integrators building on top of Flux and more diverse ways Flux is being used, we want to get the end-user experience and general assumptions right, so here is our first set of RFCs for you to consider:

We really would love your feedback on any of them!

Recent & Upcoming Events

It’s important to keep you up to date with new features and developments in Flux and provide simple ways to see our work in action and chat with our engineers.

Taming Multiple Traefik Deployments with a GitOps (Flux) Strategy

December 9, 2021 at 8am PT / 5pm CET our very own Kingdon Barrett will be presenting with Jakub Hajek from TraefikLabs. This hands-on session will include a demo on deploying Traefik on multiple clusters using Flux! Sign up here.

GitOps WG and OpenGitOps project update at KubeCon China

December 9, 2021 12:10 - 12:45 CST Scott Rigby will give an update of the GitOps Working Group and OpenGitOps project as part of the Introduction and Deep-Dive into TAG App Delivery for KubeCon/CloudNativeCon/Open Source Summit China. We are very pleased to be collaborating with these groups within the CNCF.

KubeCon/CloudNativeCon Europe 2022 CFP deadline coming up

As you all know, there’s always a KubeCon just over and the CFP deadline for the next KubeCon just coming up! That’s why we are looking for contributors, community members, organisations or integrators who would like to 1) represent Flux and 2) present on Flux, GitOps delivery and more. If you want to talk things through, have any questions or want to collaborate with us, please reach out! Deadline to submit is December 17, 2021.

More Flux Resources

We recently added a number of new resources to our Resources page. They were all from the last GitOps One-Stop Shop Event where vendors show-cased their GitOps consumer products, which were all based on top of the most recent versions of Flux.

Flux Bug Scrub

The Flux Bug Scrub in the last week of November (25th) coincided with the US Thanksgiving holiday, so it was not held. Each weekly Bug Scrub can be found (and linked Zoom details) on the calendar widget, which has now been adjusted for the end of Daylight Savings Time. Please check in on #flux or #flux-contributors for more information!

Bug Scrub is a great opportunity to talk with Flux maintainers and also a place where you can gently nudge to get our eyes on a particular bug if there is something that warrants a higher priority. There are hundreds of bugs open across Flux projects at any given time, so not all bugs can receive attention from only a dozen or so maintainers while making progress to General Availability. We rely on user feedback, including visitors at our public meetings like Bug Scrub to decide which issues are worth prioritizing.

Also a great place for volunteers to gain added context of issues and receive assignments or even a maintainer’s eye or blessings to proceed, with guidance from our GitHub triage team.

Join us for this recurring virtual meetup at 8am Eastern on Wednesday (December 1 and 15th), or at 1pm Eastern on Thursday (December 9 and January 6) – note: there will be no meeting on December 23rd due to a company-wide holiday shutdown. Find the Zoom link on the CNCF Flux Dev calendar, (subscribe), or locate the link directly on the Flux main page.

In other news

People writing about Flux

We noticed a number of new articles about Flux which we would like to share.

Joshua Zenn - Introduction to GitOps with Flux v2

This article joins the ranks of more and more upcoming news bits which firstly, explain GitOps in simple to understand terms, and secondly, walk the reader through setting up Flux. A second article to complete the series will be written soon.

Ross Fairbank - GitOps with Flux

Ross is a Platform Engineer at GiantSwarm and in his article goes into quite a bit of detail regarding the history, aims and architecture of the Flux project, particularly in its newest version.

Giantswarm blog post

The article is very nicely written - go check it out.

Michael Irwin - Compose with K8s and Flux

We are happy to see this article from a friend in our community. Michael Irwin has presented at our booth at KubeCon and is a regular on Slack and elsewhere. To set the context he starts off with

The Compose specification has slowly been used in contexts beyond running containers directly with Docker. We have ACI, ECS, and an experimental Kubernetes backend. The idea is to define your application in one spec and deploy it in a variety of manners.

The article comes with all the required steps, beautiful diagrams and a video demo. Be sure to have a look!

News from the Website and our Docs

We updated the docsy theme and hugo version in use: now we are benefiting from styling fixes, integration and many more upstream changes.

The Flux Blog overview was a bit dull. We made it more visually appealing by adding featured images for blog posts and letting the entries “breathe” more. Blog Overview

Many docs additions and fixes as well. New adopters that were added are Identinet, Omaze and Virginia Tech added.

Thanks Dennis Staiger, Gregory Vander Schueren, Jan Christoph Ebersbach, Jim Van Fleet, Kingdon Barrett, Lloyd Chang, Michael Irwin, Scott Rigby, Stefan Prodan, Valér Orlovský, Zephirin Broussard for your help!

A combined list of all Flux project maintainers is now live both in the Flux community repo, and on It’s another step into the direction of GitOps-ifying our governance.

Flux Project Facts

We are very proud of what we put together, here we want to reiterate some Flux facts - they are sort of our mission statement with Flux.

  1. 🤝 Flux provides GitOps for both apps or infrastructure. Flux and Flagger deploy apps with canaries, feature flags, and A/B rollouts. Flux can also manage any Kubernetes resource. Infrastructure and workload dependency management is built-in.
  2. 🤖 Just push to Git and Flux does the rest. Flux enables application deployment (CD) and (with the help of Flagger) progressive delivery (PD) through automatic reconciliation. Flux can even push back to Git for you with automated container image updates to Git (image scanning and patching).
  3. 🔩 Flux works with your existing tools: Flux works with your Git providers (GitHub, GitLab, Bitbucket, can even use s3-compatible buckets as a source), all major container registries, and all CI workflow providers.
  4. ☸️ Flux works with any Kubernetes and all common Kubernetes tooling: Kustomize, Helm, RBAC, and policy-driven validation (OPA, Kyverno, admission controllers) so it simply falls into place.
  5. 🤹 Flux does Multi-Tenancy (and “Multi-everything”): Flux uses true Kubernetes RBAC via impersonation and supports multiple Git repositories. Multi-cluster infrastructure and apps work out of the box with Cluster API: Flux can use one Kubernetes cluster to manage apps in either the same or other clusters, spin up additional clusters themselves, and manage clusters including lifecycle and fleets.
  6. 📞 Flux alerts and notifies: Flux provides health assessments, alerting to external systems and external events handling. Just “git push”, and get notified on Slack and other chat systems.
  7. 👍 Users trust Flux: Flux is a CNCF Incubating project and was categorised as "Adopt" on the CNCF CI/CD Tech Radar (alongside Helm).
  8. 💖 Flux has a lovely community that is very easy to work with! We welcome contributors of any kind. The components of Flux are on Kubernetes core controller-runtime, so anyone can contribute and its functionality can be extended very easily.

Over and out

If you like what you read and would like to get involved, here are a few good ways to do that:

We are looking forward to working with you.