Set Kubernetes 1.31 as min supported version

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

.github/workflows/conformance.yaml

@@ -19,7 +19,7 @@ jobs:
       matrix:
         # Keep this list up-to-date with https://endoflife.date/kubernetes
         # Build images with https://github.com/fluxcd/flux-benchmark/actions/workflows/build-kind.yaml
-        KUBERNETES_VERSION: [1.31.5, 1.32.1, 1.33.1]
+        KUBERNETES_VERSION: [1.31.5, 1.32.1, 1.33.0]
       fail-fast: false
     steps:
       - name: Checkout
@@ -169,7 +169,7 @@ jobs:
     strategy:
       matrix:
         # Keep this list up-to-date with https://endoflife.date/red-hat-openshift
-        OPENSHIFT_VERSION: [ 4.17.0-okd, 4.18.0-okd ]
+        OPENSHIFT_VERSION: [ 4.18.0-okd ]
       fail-fast: false
     steps:
       - name: Checkout

.github/workflows/e2e-bootstrap.yaml

@@ -32,8 +32,8 @@ jobs:
           cluster_name: kind
           # The versions below should target the newest Kubernetes version
           # Keep this up-to-date with https://endoflife.date/kubernetes
-          node_image: ghcr.io/fluxcd/kindest/node:v1.31.0-amd64
-          kubectl_version: v1.31.0
+          node_image: ghcr.io/fluxcd/kindest/node:v1.33.0-amd64
+          kubectl_version: v1.32.0
       - name: Setup Kustomize
         uses: fluxcd/pkg/actions/kustomize@7e9c75bbb6a47b08c194edefa11d1c436e5bdd9e # main
       - name: Setup yq

.github/workflows/e2e.yaml

@@ -40,8 +40,8 @@ jobs:
           config: .github/kind/config.yaml # disable KIND-net
           # The versions below should target the oldest supported Kubernetes version
           # Keep this up-to-date with https://endoflife.date/kubernetes
-          node_image: ghcr.io/fluxcd/kindest/node:v1.30.9-amd64
-          kubectl_version: v1.30.9
+          node_image: ghcr.io/fluxcd/kindest/node:v1.31.5-amd64
+          kubectl_version: v1.32.0
       - name: Setup Calico for network policy
         run: |
           kubectl apply -f https://raw.githubusercontent.com/projectcalico/calico/v3.27.3/manifests/calico.yaml

cmd/flux/check.go

@@ -60,7 +60,7 @@ type checkFlags struct {
 }
 
 var kubernetesConstraints = []string{
-	">=1.30.0-0",
+	">=1.31.0-0",
 }
 
 var checkArgs checkFlags

cmd/flux/testdata/check/check_pre.golden

@@ -1,3 +1,3 @@
 ► checking prerequisites
-✔ Kubernetes {{ .serverVersion }} >=1.30.0-0
+✔ Kubernetes {{ .serverVersion }} >=1.31.0-0
 ✔ prerequisites checks passed