Prepare for Flux v2.1.0

[stefanprodan]

Flux 2.1.0 comes with new features, bug fixes and performance improvements.

📅 Target dates: 21-24 August 2023

⚠️ Breaking changes:

This release comes with breaking changes to the Flux monitoring stack (Prom+Grafana). We are leveraging kube-state-metrics CRD exporter to report Flux metrics, the Grafana dashboards shipped with Flux will target the new metrics. This will allow users to extend the Flux metrics with custom metadata such as Git branch, commit, Helm chart version, etc.

Notable changes:

• Add .spec.proxySecretRef to the GitRepository API (source-controller, image-automation-controller)
• Add .spec.certSecretRef to the HelmRepository API (source-controller)
• Add support for self-signed certs for OCI HelmRepositories (source-controller)
• Add support for OpenPGP signature verification of Git tags (source-controller)
• Perf improvements when parsing large Helm index files (source-controller)
• New kustomize.toolkit.fluxcd.io/ssa: IfNotPresent annotation for reconciling resources only when not present on the cluster. (kustomize-controller)
• Improve health checking with fail-fast behaviour by detecting stalled Kubernetes rollouts (kustomize-controller)
• Perf improvements when reconciling a Flux Kustomization with thousands of resources (kustomize-controller)
• Improve immutable error detection to work with Kubernetes CEL (kustomize-controller)
• Better load distribution when reconciling Flux objects in parallel (all controllers)
• Add support for sending alerts to Datadog (notification-controller)
• Revamp Flux Prometheus monitoring using kube-state-metrics
• Revamp the installation and bootstrap configuration documentation
• Publish docs for each Flux minor version on a dedicated subdomain

TODOs:

• Jitter requeue interval #4120
• Support for flux custom metrics #4128
• Store Helm indexes in JSON format source-controller#1178
• Helm OCI: Add support for TLS registries with self-signed certs source-controller#1097
• ocirepo: add cosign support for insecure HTTP registries source-controller#1176
• helmrepo: add .spec.certSecretRef for specifying TLS auth data source-controller#1160
• gitrepo: Add support for specifying proxy per GitRepository source-controller#1109
• gitrepo: add support for Git tag verification source-controller#1187
• add support for specified proxy in source GitRepository image-automation-controller#565
• Enable fail-fast behavior for health checks kustomize-controller#933
• Bump fluxcd/pkg/ssa to improve immutable error detection kustomize-controller#932
• Reorganise and improve the installation docs website#1573
• API docs versioning #4111
• Support Kubernetes style TLS Secrets #4137
• feat: add DataDog notification provider notification-controller#592
• e2e: Add Kubernetes v1.28.0 to conformance tests #4166
• Add --concurrent-ssa flag kustomize-controller#948
• Add IfNotPresent and Ignore SSA policies kustomize-controller#943
• oci/auth: Add support for Azure China and US Gov regions pkg#631

Release checklist:

• source-controller v1.1.0
• kustomize-controller v1.1.0
• notification-controller v1.1.0
• helm-controller: v0.36.0
• image-reflector-controller v0.30.0
• image-automation-controller v0.36.0
• flux2 v2.1.0
• terraform-provider-flux v1.1.0

Documentation:

• Publish Flux release change log to GitHub & Slack