docs: document timeframe feature for KeptnMetric

docs/content/en/docs/implementing/evaluatemetrics.md

@@ -103,6 +103,30 @@ $ kubectl get --raw "/apis/custom.metrics.k8s.io/v1beta2/namespaces/podtato-kube
 }
 ```
 
+## Querying Metrics over a Timerange
+
+You can query metrics over a specified timeframe.
+Let's suppose you set the `range.interval` field to be `3m`,
+the Keptn Metrics Operator would query the metrics for the
+last 3 minutes which means the
+`from = currentTime - range.interval` and `to = currentTime`.
+
+The default value is set to be `5m` if the `range.interval` is not set.
+
+```yaml
+apiVersion: metrics.keptn.sh/v1alpha3
+kind: KeptnMetric
+metadata:
+  name: good-metric
+spec:
+  provider:
+    name: my-provider
+  query: "sum(kube_pod_container_resource_limits{resource='cpu'})"
+  fetchIntervalSeconds: 10
+  range:
+    interval: "3m"
+```
+
 ## Using the HorizontalPodAutoscaler
 
 Use the Kubernetes Custom Metrics API

docs/content/en/docs/yaml-crd-ref/metric.md

@@ -26,6 +26,8 @@ spec:
     name: "<named-provider>"
   query: "<query>"
   fetchIntervalSeconds: <#-seconds>
+  range:
+    interval: "<timeframe>"
 ```
 
 ## Fields
@@ -59,6 +61,9 @@ spec:
   * **query** -- String in the provider-specific query language,
     used to obtain a metric.
   * **fetchIntervalSeconds** -- Number of seconds between updates of the metric.
+  * **range**
+    * **interval** -- Timeframe for which the metric would be queried.
+    Defaults to 5m.
 
 ## Usage
 
@@ -96,6 +101,8 @@ spec:
     name: "my-provider"
   query: "sum(kube_pod_container_resource_limits{resource='cpu'})"
   fetchIntervalSeconds: 5
+  range:
+    interval: "5m"
 ```
 
 ## Files

examples/support/metrics/metric.yaml

@@ -15,5 +15,7 @@ metadata:
 spec:
   provider:
     name: my-provider
-  query: 'avg(rate(container_cpu_cfs_throttled_seconds_total{container="server", namespace="podtato-metrics"}[1m]))'
+  query: 'avg(rate(container_cpu_cfs_throttled_seconds_total{container="server", namespace="podtato-metrics"}))'
   fetchIntervalSeconds: 10
+  range:
+    interval: "1m"

metrics-operator/config/samples/metrics_v1alpha3_keptnmetric.yaml

@@ -13,3 +13,5 @@ spec:
     name: some-name
   query: "sum(kube_pod_container_resource_limits{resource='cpu'}) - sum(kube_node_status_capacity{resource='cpu'})"
   fetchIntervalSeconds: 10
+  range:
+    interval: "5m"