Move default associator to its own package. (prometheus-community#908)

Author: cristiangreco

pkg/job/associator.go renamed to pkg/job/associator/associator.go

@@ -1,4 +1,4 @@
-package job
+package associator
 
 import (
 	"strings"
@@ -15,11 +15,11 @@ import (
 type valueToResource map[string]*model.TaggedResource
 
 // metricsToResourceAssociator contains for each dimension, the matched values and resources.
-type metricsToResourceAssociator map[string]valueToResource
+type Associator map[string]valueToResource
 
-// newMetricsToResourceAssociator creates a new metricsToResourceAssociator given a set of dimensions regexs that can extract
+// NewAssociator creates a new metricsToResourceAssociator given a set of dimensions regexs that can extract
 // dimensions from a resource ARN, and a set of resources from which to extract.
-func newMetricsToResourceAssociator(dimensionRegexps []*regexp.Regexp, resources []*model.TaggedResource) metricsToResourceAssociator {
+func NewAssociator(dimensionRegexps []*regexp.Regexp, resources []*model.TaggedResource) Associator {
 	dimensionsFilter := make(map[string]valueToResource)
 	for _, dimensionRegexp := range dimensionRegexps {
 		names := dimensionRegexp.SubexpNames()
@@ -48,7 +48,7 @@ func newMetricsToResourceAssociator(dimensionRegexps []*regexp.Regexp, resources
 // AssociateMetricToResource finds, for a given cloudwatch.Metrics, the resource that matches the better.
 // If no match is found, nil is returned. Also, there are some conditions where the metric shouldn't be
 // considered, and that is dictated by the skip return value.
-func (asoc metricsToResourceAssociator) AssociateMetricToResource(cwMetric *cloudwatch.Metric) (*model.TaggedResource, bool) {
+func (asoc Associator) AssociateMetricToResource(cwMetric *cloudwatch.Metric) (*model.TaggedResource, bool) {
 	var r *model.TaggedResource
 	skip := false
 	alreadyFound := false

pkg/job/associator_test.go renamed to pkg/job/associator/associator_test.go

@@ -1,4 +1,4 @@
-package job
+package associator
 
 import (
 	"fmt"
@@ -290,7 +290,7 @@ func TestAssociator(t *testing.T) {
 				t.Skip("failure is expected. Remove skip after https://github.com/nerdswords/yet-another-cloudwatch-exporter/issues/821 is fixed.")
 				return
 			}
-			associator := newMetricsToResourceAssociator(tc.args.dimensionRegexps, tc.args.resources)
+			associator := NewAssociator(tc.args.dimensionRegexps, tc.args.resources)
 			res, skip := associator.AssociateMetricToResource(tc.args.metric)
 			require.Equal(t, tc.expectedSkip, skip)
 			require.Equal(t, tc.expectedResource, res)

pkg/job/discovery.go

@@ -9,17 +9,21 @@ import (
 	"sync"
 
 	"github.com/aws/aws-sdk-go/service/cloudwatch"
-	"github.com/grafana/regexp"
 
 	"github.com/nerdswords/yet-another-cloudwatch-exporter/pkg/apicloudwatch"
 	"github.com/nerdswords/yet-another-cloudwatch-exporter/pkg/apitagging"
 	"github.com/nerdswords/yet-another-cloudwatch-exporter/pkg/config"
+	"github.com/nerdswords/yet-another-cloudwatch-exporter/pkg/job/associator"
 	"github.com/nerdswords/yet-another-cloudwatch-exporter/pkg/job/maxdimassociator"
 	"github.com/nerdswords/yet-another-cloudwatch-exporter/pkg/logging"
 	"github.com/nerdswords/yet-another-cloudwatch-exporter/pkg/model"
 	"github.com/nerdswords/yet-another-cloudwatch-exporter/pkg/session"
 )
 
+type resourceAssociator interface {
+	AssociateMetricToResource(cwMetric *cloudwatch.Metric) (*model.TaggedResource, bool)
+}
+
 func runDiscoveryJob(
 	ctx context.Context,
 	logger logging.Logger,
@@ -199,8 +203,19 @@ func getMetricDataForQueries(
 		for _, metric := range discoveryJob.Metrics {
 			go func(metric *config.Metric) {
 				defer wg.Done()
+
+				var assoc resourceAssociator
+				if config.FlagsFromCtx(ctx).IsFeatureEnabled(config.MaxDimensionsAssociator) {
+					assoc = maxdimassociator.NewAssociator(svc.DimensionRegexps, resources)
+				} else {
+					assoc = associator.NewAssociator(svc.DimensionRegexps, resources)
+				}
+				if logger.IsDebugEnabled() {
+					logger.Debug("associator", assoc)
+				}
+
 				_, err := clientCloudwatch.ListMetrics(ctx, svc.Namespace, metric, func(page *cloudwatch.ListMetricsOutput) {
-					data := getFilteredMetricDatas(ctx, logger, region, accountID, discoveryJob.Type, discoveryJob.CustomTags, tagsOnMetrics, svc.DimensionRegexps, resources, page.Metrics, discoveryJob.DimensionNameRequirements, metric)
+					data := getFilteredMetricDatas(ctx, logger, region, accountID, discoveryJob.Type, discoveryJob.CustomTags, tagsOnMetrics, page.Metrics, discoveryJob.DimensionNameRequirements, metric, assoc)
 
 					mux.Lock()
 					getMetricDatas = append(getMetricDatas, data...)
@@ -217,13 +232,23 @@ func getMetricDataForQueries(
 			go func(metric *config.Metric) {
 				defer wg.Done()
 
+				var assoc resourceAssociator
+				if config.FlagsFromCtx(ctx).IsFeatureEnabled(config.MaxDimensionsAssociator) {
+					assoc = maxdimassociator.NewAssociator(svc.DimensionRegexps, resources)
+				} else {
+					assoc = associator.NewAssociator(svc.DimensionRegexps, resources)
+				}
+				if logger.IsDebugEnabled() {
+					logger.Debug("associator", assoc)
+				}
+
 				metricsList, err := clientCloudwatch.ListMetrics(ctx, svc.Namespace, metric, nil)
 				if err != nil {
 					logger.Error(err, "Failed to get full metric list", "metric_name", metric.Name, "namespace", svc.Namespace)
 					return
 				}
 
-				data := getFilteredMetricDatas(ctx, logger, region, accountID, discoveryJob.Type, discoveryJob.CustomTags, tagsOnMetrics, svc.DimensionRegexps, resources, metricsList.Metrics, discoveryJob.DimensionNameRequirements, metric)
+				data := getFilteredMetricDatas(ctx, logger, region, accountID, discoveryJob.Type, discoveryJob.CustomTags, tagsOnMetrics, metricsList.Metrics, discoveryJob.DimensionNameRequirements, metric, assoc)
 
 				mux.Lock()
 				getMetricDatas = append(getMetricDatas, data...)
@@ -244,27 +269,11 @@ func getFilteredMetricDatas(
 	namespace string,
 	customTags []model.Tag,
 	tagsOnMetrics model.ExportedTagsOnMetrics,
-	dimensionRegexps []*regexp.Regexp,
-	resources []*model.TaggedResource,
 	metricsList []*cloudwatch.Metric,
 	dimensionNameList []string,
 	m *config.Metric,
+	assoc resourceAssociator,
 ) []*model.CloudwatchData {
-	type resourceAssociator interface {
-		AssociateMetricToResource(cwMetric *cloudwatch.Metric) (*model.TaggedResource, bool)
-	}
-
-	var assoc resourceAssociator
-	if config.FlagsFromCtx(ctx).IsFeatureEnabled(config.MaxDimensionsAssociator) {
-		assoc = maxdimassociator.NewAssociator(dimensionRegexps, resources)
-	} else {
-		assoc = newMetricsToResourceAssociator(dimensionRegexps, resources)
-	}
-
-	if logger.IsDebugEnabled() {
-		logger.Debug("FilterMetricData DimensionsFilter", "dimensionsFilter", assoc)
-	}
-
 	getMetricsData := make([]*model.CloudwatchData, 0, len(metricsList))
 	for _, cwMetric := range metricsList {
 		if len(dimensionNameList) > 0 && !metricDimensionsMatchNames(cwMetric, dimensionNameList) {