Merge pull request #380 from carsonoid/issue-324-carsonoid

Allow metrics to be defined as `namespaced: false`

pkg/config/config.go

@@ -58,6 +58,8 @@ type ResourceMapping struct {
 	// Overrides specifies exceptions to the above template, mapping label names
 	// to group-resources
 	Overrides map[string]GroupResource `json:"overrides,omitempty" yaml:"overrides,omitempty"`
+	// Namespaced ignores the source namespace of the requester and requires one in the query
+	Namespaced *bool `json:"namespaced,omitempty" yaml:"namespaced,omitempty"`
 }
 
 // GroupResource represents a Kubernetes group-resource.

pkg/naming/metric_namer.go

@@ -131,8 +131,6 @@ func (n *metricNamer) QueryForSeries(series string, resource schema.GroupResourc
 }
 
 func (n *metricNamer) QueryForExternalSeries(series string, namespace string, metricSelector labels.Selector) (prom.Selector, error) {
-	//test := prom.Selector()
-	//return test, nil
 	return n.metricsQuery.BuildExternal(series, namespace, "", []string{}, metricSelector)
 }
 
@@ -155,7 +153,13 @@ func NamersFromConfig(cfg []config.DiscoveryRule, mapper apimeta.RESTMapper) ([]
 			return nil, err
 		}
 
-		metricsQuery, err := NewMetricsQuery(rule.MetricsQuery, resConv)
+		// queries are namespaced by default unless the rule specifically disables it
+		namespaced := true
+		if rule.Resources.Namespaced != nil {
+			namespaced = *rule.Resources.Namespaced
+		}
+
+		metricsQuery, err := NewExternalMetricsQuery(rule.MetricsQuery, resConv, namespaced)
 		if err != nil {
 			return nil, fmt.Errorf("unable to construct metrics query associated with series query %q: %v", rule.SeriesQuery, err)
 		}

pkg/naming/metrics_query.go

@@ -59,6 +59,27 @@ func NewMetricsQuery(queryTemplate string, resourceConverter ResourceConverter)
 	return &metricsQuery{
 		resConverter: resourceConverter,
 		template:     templ,
+		namespaced:   true,
+	}, nil
+}
+
+// NewExternalMetricsQuery constructs a new MetricsQuery by compiling the given Go template.
+// The delimiters on the template are `<<` and `>>`, and it may use the following fields:
+// - Series: the series in question
+// - LabelMatchers: a pre-stringified form of the label matchers for the resources in the query
+// - LabelMatchersByName: the raw map-form of the above matchers
+// - GroupBy: the group-by clause to use for the resources in the query (stringified)
+// - GroupBySlice: the raw slice form of the above group-by clause
+func NewExternalMetricsQuery(queryTemplate string, resourceConverter ResourceConverter, namespaced bool) (MetricsQuery, error) {
+	templ, err := template.New("metrics-query").Delims("<<", ">>").Parse(queryTemplate)
+	if err != nil {
+		return nil, fmt.Errorf("unable to parse metrics query template %q: %v", queryTemplate, err)
+	}
+
+	return &metricsQuery{
+		resConverter: resourceConverter,
+		template:     templ,
+		namespaced:   namespaced,
 	}, nil
 }
 
@@ -68,6 +89,7 @@ func NewMetricsQuery(queryTemplate string, resourceConverter ResourceConverter)
 type metricsQuery struct {
 	resConverter ResourceConverter
 	template     *template.Template
+	namespaced   bool
 }
 
 // queryTemplateArgs contains the arguments for the template used in metricsQuery.
@@ -150,7 +172,7 @@ func (q *metricsQuery) BuildExternal(seriesName string, namespace string, groupB
 	// Build up the query parts from the selector.
 	queryParts = append(queryParts, q.createQueryPartsFromSelector(metricSelector)...)
 
-	if namespace != "" {
+	if q.namespaced && namespace != "" {
 		namespaceLbl, err := q.resConverter.LabelForResource(NsGroupResource)
 		if err != nil {
 			return "", err

pkg/naming/metrics_query_test.go

@@ -272,7 +272,15 @@ func TestBuildSelector(t *testing.T) {
 
 func TestBuildExternalSelector(t *testing.T) {
 	mustNewQuery := func(queryTemplate string) MetricsQuery {
-		mq, err := NewMetricsQuery(queryTemplate, &resourceConverterMock{true})
+		mq, err := NewExternalMetricsQuery(queryTemplate, &resourceConverterMock{true}, true)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return mq
+	}
+
+	mustNewNonNamespacedQuery := func(queryTemplate string) MetricsQuery {
+		mq, err := NewExternalMetricsQuery(queryTemplate, &resourceConverterMock{true}, false)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -348,6 +356,19 @@ func TestBuildExternalSelector(t *testing.T) {
 				hasSelector("default [foo bar]"),
 			),
 		},
+		{
+			name: "multiple GroupBySlice values with namespace disabled",
+
+			mq:             mustNewNonNamespacedQuery(`<<index .LabelValuesByName "namespaces">> <<.GroupBySlice>>`),
+			namespace:      "default",
+			groupBySlice:   []string{"foo", "bar"},
+			metricSelector: labels.NewSelector(),
+
+			check: checks(
+				hasError(nil),
+				hasSelector(" [foo bar]"),
+			),
+		},
 		{
 			name: "single LabelMatchers value",