feat: prepare release v4.0.1

[pb82]

Description

Prepare the v4.0.1 release, a bugfix for the broken v4.0.0 release.

The following catalog source can be used to install the Operator from OLM:

apiVersion: operators.coreos.com/v1alpha1
kind: CatalogSource
metadata:
  name: grafana-operator-manifests
  namespace: grafana
spec:
  sourceType: grpc
  image: quay.io/grafana-operator/controller-index:v4.0.1

[hubeadmin]

getting a nil pointer exception when applying datasources on a fresh install

E1012 15:16:58.902585  290186 runtime.go:78] Observed a panic: "invalid memory address or nil pointer dereference" (runtime error: invalid memory address or nil pointer dereference)
goroutine 1954 [running]:
k8s.io/apimachinery/pkg/util/runtime.logPanic(0x1658220, 0x23e19a0)
	/home/hstefans/go/pkg/mod/k8s.io/apimachinery@v0.20.2/pkg/util/runtime/runtime.go:74 +0x95
k8s.io/apimachinery/pkg/util/runtime.HandleCrash(0x0, 0x0, 0x0)
	/home/hstefans/go/pkg/mod/k8s.io/apimachinery@v0.20.2/pkg/util/runtime/runtime.go:48 +0x86
panic(0x1658220, 0x23e19a0)
	/usr/lib/golang/src/runtime/panic.go:965 +0x1b9
github.com/integr8ly/grafana-operator/controllers/grafanadatasource.(*GrafanaDatasourceReconciler).manageSuccess(0xc0002ab720, 0xc00031a580, 0x3, 0x4)
	/home/hstefans/go/src/github.com/grafana-operator/grafana-operator/controllers/grafanadatasource/datasource_controller.go:230 +0x2c9
github.com/integr8ly/grafana-operator/controllers/grafanadatasource.(*GrafanaDatasourceReconciler).reconcileDataSources(0xc0002ab720, 0xc000d3bbe8, 0xc000a4f620, 0x1a48540)
	/home/hstefans/go/src/github.com/grafana-operator/grafana-operator/controllers/grafanadatasource/datasource_controller.go:160 +0x809
github.com/integr8ly/grafana-operator/controllers/grafanadatasource.(*GrafanaDatasourceReconciler).Reconcile(0xc0002ab720, 0x1a36418, 0xc000a4f620, 0xc000f42f39, 0x7, 0xc001302000, 0x17, 0xc000a4f620, 0xc000032000, 0x16e1620, ...)
	/home/hstefans/go/src/github.com/grafana-operator/grafana-operator/controllers/grafanadatasource/datasource_controller.go:84 +0x185
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).reconcileHandler(0xc0002b1ae0, 0x1a36370, 0xc00071c900, 0x16a88a0, 0xc00043a300)
	/home/hstefans/go/pkg/mod/sigs.k8s.io/controller-runtime@v0.8.3/pkg/internal/controller/controller.go:298 +0x30d
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).processNextWorkItem(0xc0002b1ae0, 0x1a36370, 0xc00071c900, 0xc0008a8e00)
	/home/hstefans/go/pkg/mod/sigs.k8s.io/controller-runtime@v0.8.3/pkg/internal/controller/controller.go:253 +0x205
sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).Start.func1.2(0x1a36370, 0xc00071c900)
	/home/hstefans/go/pkg/mod/sigs.k8s.io/controller-runtime@v0.8.3/pkg/internal/controller/controller.go:216 +0x4a
k8s.io/apimachinery/pkg/util/wait.JitterUntilWithContext.func1()
	/home/hstefans/go/pkg/mod/k8s.io/apimachinery@v0.20.2/pkg/util/wait/wait.go:185 +0x37
k8s.io/apimachinery/pkg/util/wait.BackoffUntil.func1(0xc0008a8f50)
	/home/hstefans/go/pkg/mod/k8s.io/apimachinery@v0.20.2/pkg/util/wait/wait.go:155 +0x5f
k8s.io/apimachinery/pkg/util/wait.BackoffUntil(0xc000d3bf50, 0x1a05220, 0xc0001d8a50, 0xc00071c901, 0xc00001d380)
	/home/hstefans/go/pkg/mod/k8s.io/apimachinery@v0.20.2/pkg/util/wait/wait.go:156 +0x9b
k8s.io/apimachinery/pkg/util/wait.JitterUntil(0xc0008a8f50, 0x3b9aca00, 0x0, 0xbfc701, 0xc00001d380)
	/home/hstefans/go/pkg/mod/k8s.io/apimachinery@v0.20.2/pkg/util/wait/wait.go:133 +0x98
k8s.io/apimachinery/pkg/util/wait.JitterUntilWithContext(0x1a36370, 0xc00071c900, 0xc0004c84c0, 0x3b9aca00, 0x0, 0x1)
	/home/hstefans/go/pkg/mod/k8s.io/apimachinery@v0.20.2/pkg/util/wait/wait.go:185 +0xa6
k8s.io/apimachinery/pkg/util/wait.UntilWithContext(0x1a36370, 0xc00071c900, 0xc0004c84c0, 0x3b9aca00)
	/home/hstefans/go/pkg/mod/k8s.io/apimachinery@v0.20.2/pkg/util/wait/wait.go:99 +0x57
created by sigs.k8s.io/controller-runtime/pkg/internal/controller.(*Controller).Start.func1
	/home/hstefans/go/pkg/mod/sigs.k8s.io/controller-runtime@v0.8.3/pkg/internal/controller/controller.go:213 +0x40d
panic: runtime error: invalid memory address or nil pointer dereference [recovered]
	panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x20 pc=0x14df2e9]

will look into this a bit more

[pb82]

@HubertStefanski the exception on datasource creation should be fixed now

[hubeadmin]

LGTM!

The issue has been fixed and dashboards/datasources are successfully created