updated canary CRD and query rendering

Signed-off-by: Nelson Johnstone <93178586+njohnstone2@users.noreply.github.com>

artifacts/flagger/crd.yaml

@@ -970,6 +970,11 @@ spec:
                               namespace:
                                 description: Namespace of this metric template
                                 type: string
+                          templateVariables:
+                            description: Additional variables to be used in the metrics query (key-value pairs)
+                            type: object
+                            additionalProperties:
+                              type: string
                     alerts:
                       description: Alert list for this canary analysis
                       type: array

charts/flagger/crds/crd.yaml

@@ -970,6 +970,11 @@ spec:
                               namespace:
                                 description: Namespace of this metric template
                                 type: string
+                          templateVariables:
+                            description: Additional variables to be used in the metrics query (key-value pairs)
+                            type: object
+                            additionalProperties:
+                              type: string
                     alerts:
                       description: Alert list for this canary analysis
                       type: array

kustomize/base/flagger/crd.yaml

@@ -970,6 +970,11 @@ spec:
                               namespace:
                                 description: Namespace of this metric template
                                 type: string
+                          templateVariables:
+                            description: Additional variables to be used in the metrics query (key-value pairs)
+                            type: object
+                            additionalProperties:
+                              type: string
                     alerts:
                       description: Alert list for this canary analysis
                       type: array

pkg/apis/flagger/v1beta1/canary.go

@@ -305,9 +305,9 @@ type CanaryMetric struct {
 	// +optional
 	TemplateRef *CrossNamespaceObjectReference `json:"templateRef,omitempty"`
 
-	// TemplateVariables provides a map of key/value pairs to be used on a metric template object
+	// TemplateVariables provides a map of key/value pairs that can be used to inject variables into a metric query.
 	// +optional
-	TemplateVariables map[string]string `json:"variables,omitempty"`
+	TemplateVariables map[string]string `json:"templateVariables,omitempty"`
 }
 
 // CanaryThresholdRange defines the range used for metrics validation

pkg/apis/flagger/v1beta1/zz_generated.deepcopy.go

@@ -350,6 +350,13 @@ func (in *CanaryMetric) DeepCopyInto(out *CanaryMetric) {
 		*out = new(CrossNamespaceObjectReference)
 		**out = **in
 	}
+	if in.TemplateVariables != nil {
+		in, out := &in.TemplateVariables, &out.TemplateVariables
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
 	return
 }
 
@@ -757,6 +764,13 @@ func (in *MetricTemplateList) DeepCopyObject() runtime.Object {
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *MetricTemplateModel) DeepCopyInto(out *MetricTemplateModel) {
 	*out = *in
+	if in.Variables != nil {
+		in, out := &in.Variables, &out.Variables
+		*out = make(map[string]string, len(*in))
+		for key, val := range *in {
+			(*out)[key] = val
+		}
+	}
 	return
 }
 

pkg/controller/scheduler_metrics.go

@@ -268,6 +268,8 @@ func (c *Controller) runMetricChecks(canary *flaggerv1.Canary) bool {
 			}
 
 			query, err := observers.RenderQuery(template.Spec.Query, toMetricModel(canary, metric.Interval, metric.TemplateVariables))
+			c.logger.With("canary", fmt.Sprintf("%s.%s", canary.Name, namespace)).
+				Debugf("Metric template %s.%s query: %s", metric.TemplateRef.Name, namespace, query)
 			if err != nil {
 				c.recordEventErrorf(canary, "Metric template %s.%s query render error: %v",
 					metric.TemplateRef.Name, namespace, err)

pkg/metrics/observers/render.go

@@ -26,7 +26,7 @@ import (
 )
 
 func RenderQuery(queryTemplate string, model flaggerv1.MetricTemplateModel) (string, error) {
-	t, err := template.New("tmpl").Funcs(model.TemplateFunctions()).Parse(queryTemplate)
+	t, err := template.New("tmpl").Option("missingkey=error").Funcs(model.TemplateFunctions()).Parse(queryTemplate)
 	if err != nil {
 		return "", fmt.Errorf("template parsing failed: %w", err)
 	}

pkg/metrics/observers/render_test.go

@@ -0,0 +1,82 @@
+/*
+Copyright 2020 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 observers
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	flaggerv1 "github.com/fluxcd/flagger/pkg/apis/flagger/v1beta1"
+)
+
+func Test_RenderQuery(t *testing.T) {
+	t.Run("ok_without_variables", func(t *testing.T) {
+		expected := `sum(envoy_cluster_upstream_rq{envoy_cluster_name=~"default_myapp"})`
+		templateQuery := `sum(envoy_cluster_upstream_rq{envoy_cluster_name=~"{{ namespace }}_{{ target }}"})`
+
+		model := &flaggerv1.MetricTemplateModel{
+			Name:      "standard",
+			Namespace: "default",
+			Target:    "myapp",
+			Interval:  "1m",
+		}
+
+		actual, err := RenderQuery(templateQuery, *model)
+		require.NoError(t, err)
+
+		assert.Equal(t, expected, actual)
+	})
+
+	t.Run("ok_with_variables", func(t *testing.T) {
+		expected := `delta(max by (consumer_group) (kafka_consumer_current_offset{cluster="dev", consumer_group="my_consumer"}[1m]))`
+		templateQuery := `delta(max by (consumer_group) (kafka_consumer_current_offset{cluster="{{ variables.cluster }}", consumer_group="{{ variables.consumer_group }}"}[{{ interval }}]))`
+
+		model := &flaggerv1.MetricTemplateModel{
+			Name:      "kafka_consumer_offset",
+			Namespace: "default",
+			Interval:  "1m",
+			Variables: map[string]string{
+				"cluster":        "dev",
+				"consumer_group": "my_consumer",
+			},
+		}
+
+		actual, err := RenderQuery(templateQuery, *model)
+		require.NoError(t, err)
+
+		assert.Equal(t, expected, actual)
+	})
+
+	t.Run("missing_variable_key", func(t *testing.T) {
+		templateQuery := `delta(max by (consumer_group) (kafka_consumer_current_offset{cluster="{{ variables.cluster }}", consumer_group="{{ variables.consumer_group }}"}[{{ interval }}]))`
+
+		model := &flaggerv1.MetricTemplateModel{
+			Name:      "kafka_consumer_offset",
+			Namespace: "default",
+			Interval:  "1m",
+			Variables: map[string]string{
+				"invalid":        "dev",
+				"consumer_group": "my_consumer",
+			},
+		}
+
+		_, err := RenderQuery(templateQuery, *model)
+		require.Error(t, err)
+	})
+}