prevent flux install from overriding bootrapped cluster

Signed-off-by: Somtochi Onyekwere <somtochionyekwere@gmail.com>

cmd/flux/cluster_info.go

@@ -0,0 +1,87 @@
+/*
+Copyright 2023 The Flux authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"context"
+	"fmt"
+
+	apiextensionsv1 "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
+	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	kustomizev1 "github.com/fluxcd/kustomize-controller/api/v1"
+	sourcev1 "github.com/fluxcd/source-controller/api/v1"
+)
+
+// bootstrapLabels are labels put on a resource by kustomize-controller. These labels on the CRD indicates
+// that flux has been bootstrapped.
+var bootstrapLabels = []string{
+	fmt.Sprintf("%s/name", kustomizev1.GroupVersion.Group),
+	fmt.Sprintf("%s/namespace", kustomizev1.GroupVersion.Group),
+}
+
+// fluxClusterInfo contains information about an existing flux installation on a cluster.
+type fluxClusterInfo struct {
+	// bootstrapped indicates that Flux was installed using the `flux bootstrap` command.
+	bootstrapped bool
+	// managedBy is the name of the tool being used to manage the installation of Flux.
+	managedBy string
+	// version is the Flux version number in semver format.
+	version string
+}
+
+// getFluxClusterInfo returns information on the Flux installation running on the cluster.
+// If the information cannot be retrieved, the boolean return value will be false.
+// If an error occurred, the returned error will be non-nil.
+//
+// This function retrieves the GitRepository CRD from the cluster and checks it
+// for a set of labels used to determine the Flux version and how Flux was installed.
+func getFluxClusterInfo(ctx context.Context, c client.Client) (fluxClusterInfo, bool, error) {
+	var info fluxClusterInfo
+	crdMetadata := &metav1.PartialObjectMetadata{
+		TypeMeta: metav1.TypeMeta{
+			APIVersion: apiextensionsv1.SchemeGroupVersion.String(),
+			Kind:       "CustomResourceDefinition",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name: fmt.Sprintf("gitrepositories.%s", sourcev1.GroupVersion.Group),
+		},
+	}
+	if err := c.Get(ctx, client.ObjectKeyFromObject(crdMetadata), crdMetadata); err != nil {
+		if errors.IsNotFound(err) {
+			return info, false, nil
+		}
+		return info, false, err
+	}
+
+	info.version = crdMetadata.Labels["app.kubernetes.io/version"]
+
+	var present bool
+	for _, l := range bootstrapLabels {
+		_, present = crdMetadata.Labels[l]
+	}
+	if present {
+		info.bootstrapped = true
+	}
+
+	if manager, ok := crdMetadata.Labels["app.kubernetes.io/managed-by"]; ok {
+		info.managedBy = manager
+	}
+	return info, true, nil
+}