NETOBSERV-1342: new FlowMetric API / operator-sdk scaffolding

- operator-sdk code scaffolding to create a new API called FlowMetrics
- initial implementation of the api type
- remove v1alpha1 deprecation since this is also a v1alpha1 sharing same
  package
- shrinking the deprecated flowcollector v1alpha1 alm sample to simplify
  CSV
- since v1alpha1 is imported in business code again, there was an
  import cycle with helper package=> to fix it, moving some code out of
  "helper"

Implement converting new API to FLP config

Provide some examples

Add watch, add tests, some syntax sugar

Ad omitempty

Makefile

@@ -273,13 +273,17 @@ generate-go-conversions: $(CONVERSION_GEN) ## Run all generate-go-conversions
 		--build-tag=ignore_autogenerated_core \
 		--output-file-base=zz_generated.conversion \
 		$(CONVERSION_GEN_OUTPUT_BASE) \
-		--go-header-file=./hack/boilerplate/boilerplate.generatego.txt		
+		--go-header-file=./hack/boilerplate/boilerplate.generatego.txt
 
-generate: YQ gencode manifests doc generate-go-conversions ## Run all code/file generators
+.PHONY: hack-crd-for-test
+hack-crd-for-test: YQ
 	cat ./config/crd/bases/flows.netobserv.io_flowcollectors.yaml \
 		| $(YQ) eval-all \
 		'(.spec.versions.[]|select(.name != "v1beta2").storage) = false,(.spec.versions.[]|select(.name == "v1beta2").storage) = true' \
 		> ./hack/cloned.flows.netobserv.io_flowcollectors.yaml
+	cp ./config/crd/bases/flows.netobserv.io_flowmetrics.yaml ./hack/cloned.flows.netobserv.io_flowmetrics.yaml
+
+generate: gencode manifests hack-crd-for-test doc generate-go-conversions ## Run all code/file generators
 
 .PHONY: clean-generated-conversions
 clean-generated-conversions: ## Remove files generated by conversion-gen from the mentioned dirs

PROJECT

@@ -22,4 +22,12 @@ resources:
   kind: ConfigMap
   path: k8s.io/api/core/v1
   version: v1
+- api:
+    crdVersion: v1
+    namespaced: true
+  domain: netobserv.io
+  group: flows
+  kind: FlowMetric
+  path: github.com/netobserv/network-observability-operator/api/v1alpha1
+  version: v1alpha1
 version: "3"

api/v1alpha1/doc.go

@@ -13,6 +13,4 @@ limitations under the License.
 
 // Package v1aplha1 contains the v1alpha1 API implementation.
 // +k8s:conversion-gen=github.com/netobserv/network-observability-operator/api/v1beta2
-//
-// Deprecated: This package will be removed in one of the next releases.
 package v1alpha1

api/v1alpha1/flowmetric_types.go

@@ -0,0 +1,141 @@
+/*
+Copyright 2021.
+
+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 v1alpha1
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+type MetricType string
+type FilterMatchType string
+type FlowDirection string
+
+const (
+	CounterMetric   MetricType = "Counter"
+	HistogramMetric MetricType = "Histogram"
+	// Note: we don't expose gauge on purpose to avoid configuration mistake related to gauge limitation.
+	// 99% of times, "counter" or "histogram" should be the ones to use. We can eventually revisit later.
+	MatchExact    FilterMatchType = "Exact"
+	MatchRegex    FilterMatchType = "Regex"
+	MatchPresence FilterMatchType = "Presence"
+	MatchAbsence  FilterMatchType = "Absence"
+	Egress        FlowDirection   = "Egress"
+	Ingress       FlowDirection   = "Ingress"
+	AnyDirection  FlowDirection   = "Any"
+)
+
+type MetricFilter struct {
+	// Name of the field to filter on
+	// +required
+	Field string `json:"field"`
+
+	// Value to filter on
+	// +optional
+	Value string `json:"value"`
+
+	// Type of matching to apply
+	// +kubebuilder:validation:Enum:="Exact";"Regex";"Presence";"Absence"
+	// +kubebuilder:default:="Exact"
+	MatchType FilterMatchType `json:"matchType"`
+}
+
+// FlowMetricSpec defines the desired state of FlowMetric
+// The provided API allows you to customize these metrics according to your needs.<br>
+// When adding new metrics or modifying existing labels, you must carefully monitor the memory
+// usage of Prometheus workloads as this could potentially have a high impact. Cf https://rhobs-handbook.netlify.app/products/openshiftmonitoring/telemetry.md/#what-is-the-cardinality-of-a-metric<br>
+// To check the cardinality of all NetObserv metrics, run as `promql`: `count({__name__=~"netobserv.*"}) by (__name__)`.
+type FlowMetricSpec struct {
+	// Name of the metric in Prometheus. It will be automatically prefixed with "netobserv_".
+	// +required
+	MetricName string `json:"metricName"`
+
+	// Metric type: "Counter" or "Histogram".
+	// Use "Counter" for any value that increases over time and on which you can compute a rate, such as Bytes or Packets.
+	// Use "Histogram" for any value that must be sampled independently, such as latencies.
+	// +kubebuilder:validation:Enum:="Counter";"Histogram"
+	// +required
+	Type MetricType `json:"type"`
+
+	// `valueField` is the flow field that must be used as a value for this metric. This field must hold numeric values.
+	// Leave empty to count flows rather than a specific value per flow.
+	// Refer to the documentation for the list of available fields: https://docs.openshift.com/container-platform/latest/networking/network_observability/json-flows-format-reference.html.
+	// +optional
+	ValueField string `json:"valueField,omitempty"`
+
+	// `filters` is a list of fields and values used to restrict which flows are taken into account. Oftentimes, these filters must
+	// be used to eliminate duplicates: `Duplicate:"false"` and `FlowDirection: "0"`.
+	// Refer to the documentation for the list of available fields: https://docs.openshift.com/container-platform/latest/networking/network_observability/json-flows-format-reference.html.
+	// +optional
+	Filters []MetricFilter `json:"filters"`
+
+	// `labels` is a list of fields that should be used as Prometheus labels, also known as dimensions.
+	// From choosing labels results the level of granularity of this metric, as well as the available aggregations at query time.
+	// It must be done carefully as it impacts the metric cardinality (cf https://rhobs-handbook.netlify.app/products/openshiftmonitoring/telemetry.md/#what-is-the-cardinality-of-a-metric).
+	// In general, avoid setting very high cardinality labels such as IP or MAC addresses.
+	// "SrcK8S_OwnerName" or "DstK8S_OwnerName" should be preferred over "SrcK8S_Name" or "DstK8S_Name" as much as possible.
+	// Refer to the documentation for the list of available fields: https://docs.openshift.com/container-platform/latest/network_observability/json-flows-format-reference.html.
+	// +optional
+	Labels []string `json:"labels"`
+
+	// When set to `true`, flows duplicated across several interfaces will add up in the generated metrics.
+	// When set to `false` (default), it is equivalent to adding the exact filter on `Duplicate`: `false`.
+	// +optional
+	IncludeDuplicates bool `json:"includeDuplicates,omitempty"`
+
+	// Filter for ingress, egress or any direction flows.
+	// When set to `Ingress`, it is equivalent to adding the regex filter on `FlowDirection`: `0|2`.
+	// When set to `Egress`, it is equivalent to adding the regex filter on `FlowDirection`: `1|2`.
+	// +kubebuilder:validation:Enum:="Any";"Egress";"Ingress"
+	// +kubebuilder:default:="Any"
+	// +optional
+	Direction FlowDirection `json:"direction,omitempty"`
+
+	// A list of buckets to use when `type` is "Histogram". The list must be parseable as floats. Prometheus default buckets will be used if unset.
+	// +optional
+	Buckets []string `json:"buckets,omitempty"`
+}
+
+// FlowMetricStatus defines the observed state of FlowMetric
+type FlowMetricStatus struct {
+	// INSERT ADDITIONAL STATUS FIELD - define observed state of cluster
+	// Important: Run "make" to regenerate code after modifying this file
+}
+
+//+kubebuilder:object:root=true
+//+kubebuilder:subresource:status
+
+// FlowMetric is the Schema for the flowmetrics API
+type FlowMetric struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	Spec   FlowMetricSpec   `json:"spec,omitempty"`
+	Status FlowMetricStatus `json:"status,omitempty"`
+}
+
+//+kubebuilder:object:root=true
+
+// FlowMetricList contains a list of FlowMetric
+type FlowMetricList struct {
+	metav1.TypeMeta `json:",inline"`
+	metav1.ListMeta `json:"metadata,omitempty"`
+	Items           []FlowMetric `json:"items"`
+}
+
+func init() {
+	SchemeBuilder.Register(&FlowMetric{}, &FlowMetricList{})
+}