Announcing Flux 2.5 GA blog post

Signed-off-by: Stefan Prodan <stefan.prodan@gmail.com>

content/en/blog/2025-02-20-announcing-flux-v2.5.0/index.md

@@ -0,0 +1,215 @@
+---
+author: Stefan Prodan
+date: 2025-02-20 12:00:00+00:00
+title: Announcing Flux 2.5 GA
+description: "We are thrilled to announce the release of Flux v2.5.0! Here you will find highlights of new features and improvements in this release."
+url: /blog/2025/02/flux-v2.5.0/
+tags: [announcement]
+resources:
+- src: "**.{png,jpg}"
+  title: "Image #:counter"
+---
+
+We are thrilled to announce the release of [Flux v2.5.0](https://github.com/fluxcd/flux2/releases/tag/v2.5.0)!
+In this post, we will highlight some of the new features and improvements included in this release.
+
+![](featured-image.png)
+
+## Highlights
+
+Flux v2.5 marks a significant milestone in the project's evolution, we have integrated Common Expression Language (CEL)
+with the Flux controllers to enable long-awaited features such as custom health checks and webhook receiver filters.
+Moreover, we have added support for GitHub App authentication, custom event metadata for notifications and Flux CLI helpers
+for troubleshooting Flux resources.
+
+In ecosystem news, the [Flux Operator](https://github.com/controlplaneio-fluxcd/flux-operator) v0.14 release brings
+one of the most requested features: deploy app code and/or config changes made in a GitHub Pull Request
+or GitLab Merge Request to an ephemeral environment for testing and validation.
+
+The Flux Operator has the ability to create, update and delete application instances on-demand based
+on the [ResourceSet](https://fluxcd.control-plane.io/operator/resourcesets/introduction/)
+definitions and Pull/Merge Requests state.
+
+For more details on how to use the ephemeral environments feature, see the following guides:
+
+- [Ephemeral Environments for GitHub Pull Requests](https://fluxcd.control-plane.io/operator/resourcesets/github-pull-requests/)
+- [Ephemeral Environments for GitLab Merge Requests](https://fluxcd.control-plane.io/operator/resourcesets/gitlab-merge-requests/)
+
+### Health Checks for Custom Resources
+
+In this release, we have extended the Flux [Kustomization](/flux/components/kustomize/kustomizations/) API
+with support for defining custom health checks using Common Expression Language (CEL).
+The health checks are used to verify the readiness of the resources managed by Flux and are a key feature
+for ensuring that the desired state of the cluster is achieved.
+
+While Flux performs a series of built-in health checks for Kubernetes core resources, the new feature
+allows users to teach Flux how to check the health of Kubernetes custom resources.
+This is particularly useful for custom resources that do not subscribe to the Kubernetes API conventions
+or for resources that require additional logic to determine if they reached the desired state.
+
+A common use case for custom health checks is to verify the status of `Cluster` objects reconciled by
+the [Cluster API](https://cluster-api.sigs.k8s.io/) controllers. When Flux is used to manage a fleet
+of Kubernetes clusters, the health checks can be used to ensure that the clusters are ready before
+deploying cluster addons and applications.
+
+Example of a Kustomization with a custom health check for Cluster API:
+
+```yaml
+apiVersion: kustomize.toolkit.fluxcd.io/v1
+kind: Kustomization
+metadata:
+  name: prod-clusters
+  namespace: infra
+spec:
+  interval: 30m
+  retryInterval: 5m
+  prune: true
+  sourceRef:
+    kind: GitRepository
+    name: fleet
+  path: "./production"
+  timeout: 15m
+  wait: true
+  healthCheckExprs:
+    - apiVersion: cluster.x-k8s.io/v1beta1
+      kind: Cluster
+      failed: "status.conditions.filter(e, e.type == 'Ready').all(e, e.status == 'False')"
+      current: "status.conditions.filter(e, e.type == 'Ready').all(e, e.status == 'True')"
+```
+
+The above example configures Flux to wait for all the `Cluster` objects to reach the Ready state
+before proceeding with the reconciliation of other Kustomizations that have a
+[dependsOn](/flux/components/kustomize/kustomizations/#dependencies) relationship
+defined for the `prod-clusters`.
+
+We have published a [health check library](/flux/guides/health-checks/) that contains CEL
+expressions for popular custom resources. The library is community-maintained, and we encourage
+users to contribute new health checks.
+
+Other kustomize-controller improvements include:
+
+- Fine-grained control of garbage collection with [.spec.deletionPolicy](https://fluxcd.io/flux/components/kustomize/kustomizations/#deletion-policy).
+- SOPS support for decryption of Kubernetes secrets generated by Kustomize components.
+
+### GitHub App Authentication for Git Repositories
+
+Starting with Flux v2.5, you can configure source-controller and image-automation-controller
+to authenticate against GitHub repositories using a GitHub App installation.
+
+Instead of relying on personal access tokens or SSH keys that require manual rotation,
+you can now configure Flux to authenticate against GitHub repositories using an identity
+that is not tied to a specific user account.
+
+We have added a new command to the Flux CLI that can be used to create the Kubernetes Secret
+required for the GitHub App authentication.
+
+```shell
+flux create secret githubapp github-auth \
+  --app-id=1 \
+  --app-installation-id=2 \
+  --app-private-key=~/private-key.pem  
+```
+
+The Kubernetes Secret generated by the above command can be referenced in a `GitRepository`
+and `ImageUpdateAutomation` with `.spec.secretRef.name`.
+
+For more details on how to configure the GitHub App authentication, see the
+[GitRepository API documentation](https://fluxcd.io/flux/components/source/gitrepositories/#github).
+
+### Custom event metadata for notifications
+
+Starting with Flux v2.5, users can enrich the metadata of the events sent by the notification-controller
+by adding annotations on the Flux `Kustomization` and `HelmRelease` resources.
+The metadata is included in the notifications sent to the configured providers, such as Slack, Microsoft Teams, etc.,
+and can be used to provide additional context about a particular application or environment.
+
+One highly requested feature was the ability to include the image tag in the notifications send when
+Flux image automation updates the container image tag in HelmRelease values.
+
+Example of a HelmRelease with custom event metadata containing the image tag:
+
+```yaml
+apiVersion: helm.toolkit.fluxcd.io/v2
+kind: HelmRelease
+metadata:
+  name: my-app
+  namespace: apps
+  annotations:
+    event.toolkit.fluxcd.io/image: docker.io/org/my-app:1.0.0 # {"$imagepolicy": "apps:my-app"}
+spec:
+  chart:
+    spec:
+      chart: my-app
+      sourceRef:
+        kind: HelmRepository
+        name: podinfo
+  values:
+    image:
+      tag: 1.0.0  # {"$imagepolicy": "apps:my-app:tag"}
+```
+
+When the image automation updates the `my-app` HelmRelease with a new image tag e.g. `1.0.1`,
+the notification sent after the Helm release upgrade will include `image: docker.io/org/my-app:1.0.1`
+in message body.
+
+For more details on how to configure custom event metadata, see the
+[Alert API documentation](https://fluxcd.io/flux/components/notification/alerts/#event-metadata-from-object-annotations).
+
+Other notifications improvements include:
+
+- The notification-controller is now capable of updating
+  [Git commit statuses](https://fluxcd.io/flux/cheatsheets/oci-artifacts/#git-commit-status-updates)
+  from events about Kustomizations that consume OCIRepositories.
+- The [Receiver API](https://fluxcd.io/flux/components/notification/receivers/#filtering-reconciled-objects-with-cel)
+  now supports filtering the declared resources that match a given Common Expression Language (CEL) expression.
+
+### CLI Improvements
+
+To help users troubleshoot Flux, we've added a new `flux debug` command the following subcommands:
+
+- `flux debug kustomization --show-vars` used to inspect the final variables values by merging the Flux `Kustomization`
+  inline vars with the vars coming from Kubernetes ConfigMaps/Secrets.
+- `flux debug helmrelease --show-values` used to inspect the final Helm values by merging the `HelmRelease`
+  inline values with the values coming from Kubernetes ConfigMaps/Secrets.
+
+Note that these commands will print sensitive information if Kubernetes Secrets are referenced in
+the Flux `Kustomization` or `HelmRelease` resources.
+
+Other CLI improvements include:
+
+- A new command was added, `flux create secret githubapp` that can be used to generate a Kubernetes Secret
+  for GitHub App authentication.
+- The `flux create source git` command now supports the `--provider=github` flag to configure GitHub App authentication
+  for Git repositories.
+
+## Supported Versions
+
+Flux v2.2 has reached end-of-life and is no longer supported.
+
+Flux v2.5 supports the following Kubernetes versions:
+
+| Distribution | Versions         |
+|:-------------|:-----------------|
+| Kubernetes   | 1.30, 1.31, 1.32 |
+| OpenShift    | 4.17             |
+
+{{% alert color="info" title="Enterprise support" %}}
+Note that the CNCF Flux project offers support only for the latest
+three minor versions of Kubernetes.
+
+Backwards compatibility with older versions of Kubernetes and OpenShift is offered by vendors
+such as [ControlPlane](https://control-plane.io/enterprise-for-flux-cd/) that provide
+enterprise support for Flux.
+{{% /alert %}}
+
+## Over and out
+
+If you have any questions, or simply just like what you read and want to get involved,
+here are a few good ways to reach us:
+
+- Join our [upcoming dev meetings](https://fluxcd.io/community/#meetings).
+- Join the [Flux mailing list](https://lists.cncf.io/g/cncf-flux-dev) and let us know what you need help with.
+- Talk to us in the #flux channel on [CNCF Slack](https://slack.cncf.io/).
+- Join the [planning discussions](https://github.com/fluxcd/flux2/discussions).
+- Follow [Flux on Twitter](https://twitter.com/fluxcd), or join the
+  [Flux LinkedIn group](https://www.linkedin.com/groups/8985374/).