feat(receiver/azuremonitorreceiver)! : Collect metrics labels from Azure Resource tags (#41117)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

Updated `append_tags_as_attributes` configuration type from boolean to
array. It controls which Azure resource tags are added as resource
attributes to the metrics. The values can be a list of specific tag
names or `["*"]` to include all tags.

<!-- Issue number (e.g. #1234) or full URL to issue, if applicable. -->
#### Link to tracking issue
Fixes #40988 

<!--Describe what testing was performed and which tests were added.-->
#### Testing

Comprehensive unit tests have been added/updated to validate the changes
introduced in this PR. All newly added code is covered with 100% unit
test coverage to ensure correctness.

Please note that I do not currently have access to an Azure account, so
I have not been able to perform end-to-end testing against live Azure
resources. All changes have been validated through unit tests.
If verification with an actual Azure environment is required, please let
me know, and I will coordinate accordingly.

<!--Describe the documentation added.-->
#### Documentation

The `azuremonitorreceiver` README has been updated to reflect the
configuration changes introduced in this PR

<!--Please delete paragraphs that you did not use before submitting.-->

Author: Angith

.chloggen/azuremonitorreceiver_metrics-labels-from-tags.yaml

@@ -0,0 +1,12 @@
+change_type: breaking
+
+component: azuremonitorreceiver
+
+note: |
+  Updated `append_tags_as_attributes` configuration type from boolean to array. It controls which Azure resource tags are added as resource attributes to the metrics. The values can be a list of specific tag names or `["*"]` to include all tags.
+
+issues: [40988]
+
+subtext:
+
+change_logs: [user]

receiver/azuremonitorreceiver/README.md

@@ -37,6 +37,7 @@ The following settings are optional:
 - `cloud` (default = `AzureCloud`): defines which Azure cloud to use. Valid values: `AzureCloud`, `AzureUSGovernment`, `AzureChinaCloud`.
 - `dimensions.enabled` (default = `true`): allows to opt out from automatically split by all the dimensions of the resource type.
 - `dimensions.overrides` (default = `{}`): if dimensions are enabled, it allows you to specify a set of dimensions for a particular metric. This is a two levels map with first key being the resource type and second key being the metric name. Programmatic value should be used for metric name https://learn.microsoft.com/en-us/azure/azure-monitor/reference/metrics-index
+- `append_tags_as_attributes` (default = `[]`): Controls which Azure resource tags are added as resource attributes to the metrics. Can be a list of specific tag names or `["*"]` to include all tags.
 - `use_batch_api` (default = `false`): Use the batch API to fetch metrics. This is useful when the number of subscriptions is high and the API calls are rate limited.
 - `maximum_resources_per_batch` (default = 50): If batch is enabled, the maximum number of unique resource IDs to fetch per API call, current limit is 50 (as of 06/16/2025) https://learn.microsoft.com/en-us/azure/azure-monitor/metrics/migrate-to-batch-api?tabs=individual-response
 
@@ -182,6 +183,18 @@ receivers:
           "NetworkRuleHit": [Reason, Status]
 ```
 
+Selectively including resource tags as attributes:
+
+```yaml
+receivers:
+  azuremonitor:
+    # Include all tags
+    append_tags_as_attributes: ["*"]
+    
+    # Or include only specific tags
+    append_tags_as_attributes: ["service", "environment"]
+```
+
 ## Metrics
 
 Details about the metrics scraped by this receiver can be found in [Supported metrics with Azure Monitor](https://learn.microsoft.com/en-us/azure/azure-monitor/essentials/metrics-supported). This receiver adds the prefix "azure_" to all scraped metrics.

receiver/azuremonitorreceiver/config.go

@@ -252,7 +252,7 @@ type Config struct {
 	CacheResourcesDefinitions         float64                       `mapstructure:"cache_resources_definitions"`
 	MaximumNumberOfMetricsInACall     int                           `mapstructure:"maximum_number_of_metrics_in_a_call"`
 	MaximumNumberOfRecordsPerResource int32                         `mapstructure:"maximum_number_of_records_per_resource"`
-	AppendTagsAsAttributes            bool                          `mapstructure:"append_tags_as_attributes"`
+	AppendTagsAsAttributes            []string                      `mapstructure:"append_tags_as_attributes"`
 	UseBatchAPI                       bool                          `mapstructure:"use_batch_api"`
 	Dimensions                        DimensionsConfig              `mapstructure:"dimensions"`
 	MaximumResourcesPerBatch          int                           `mapstructure:"maximum_resources_per_batch"`

receiver/azuremonitorreceiver/config_test.go

@@ -46,6 +46,26 @@ func TestLoadConfig(t *testing.T) {
 				return cfg
 			}(),
 		},
+		{
+			id: component.NewIDWithName(metadata.Type, "append_tags_all"),
+			expected: func() component.Config {
+				cfg := createDefaultConfig().(*Config)
+				cfg.SubscriptionIDs = []string{"test"}
+				cfg.Credentials = defaultCredentials
+				cfg.AppendTagsAsAttributes = []string{"*"}
+				return cfg
+			}(),
+		},
+		{
+			id: component.NewIDWithName(metadata.Type, "append_tags_specific"),
+			expected: func() component.Config {
+				cfg := createDefaultConfig().(*Config)
+				cfg.SubscriptionIDs = []string{"test"}
+				cfg.Credentials = defaultCredentials
+				cfg.AppendTagsAsAttributes = []string{"service", "environment"}
+				return cfg
+			}(),
+		},
 		{
 			id:          component.NewIDWithName(metadata.Type, "missing_subscription"),
 			expectedErr: errMissingSubscriptionIDs.Error(),

receiver/azuremonitorreceiver/scraper.go

@@ -279,6 +279,8 @@ func (s *azureScraper) getResources(ctx context.Context, subscriptionID string)
 		Filter: &filter,
 	}
 
+	tagsFilterMap := getTagsFilterMap(s.cfg.AppendTagsAsAttributes)
+
 	pager := clientResources.NewListPager(opts)
 
 	for pager.More() {
@@ -300,7 +302,7 @@ func (s *azureScraper) getResources(ctx context.Context, subscriptionID string)
 				}
 				s.resources[subscriptionID][*resource.ID] = &azureResource{
 					attributes:   attributes,
-					tags:         resource.Tags,
+					tags:         filterResourceTags(tagsFilterMap, resource.Tags),
 					resourceType: resource.Type,
 				}
 			}
@@ -449,11 +451,9 @@ func (s *azureScraper) getResourceMetricsValues(ctx context.Context, subscriptio
 						name := metadataPrefix + *value.Name.Value
 						attributes[name] = value.Value
 					}
-					if s.cfg.AppendTagsAsAttributes {
-						for tagName, value := range res.tags {
-							name := tagPrefix + tagName
-							attributes[name] = value
-						}
+					for tagName, value := range res.tags {
+						name := tagPrefix + tagName
+						attributes[name] = value
 					}
 					for _, metricValue := range timeseriesElement.Data {
 						s.processTimeseriesData(resourceID, metric, metricValue, attributes)
@@ -564,3 +564,30 @@ func mapFindInsensitive[T any](m map[string]T, key string) (T, bool) {
 	var got T
 	return got, false
 }
+
+// getTagsFilterMap returns a map used to filter tags.
+// Each user-configured tag key is normalized to lowercase and added to the map for case-insensitive lookup.
+func getTagsFilterMap(appendTagsAsAttributes []string) (tagsFilterMap map[string]struct{}) {
+	tagsFilterMap = make(map[string]struct{}, len(appendTagsAsAttributes))
+	for _, v := range appendTagsAsAttributes {
+		tagsFilterMap[strings.ToLower(v)] = struct{}{}
+	}
+	return tagsFilterMap
+}
+
+// filterResourceTags filter out resource tags according to configured tag list (append_tags_as_attributes)
+func filterResourceTags(tagFilterList map[string]struct{}, resourceTags map[string]*string) map[string]*string {
+	if _, includeAll := tagFilterList["*"]; includeAll {
+		return resourceTags
+	}
+
+	// wildcard not found. include only configured tags
+	includedTags := make(map[string]*string, len(resourceTags))
+	for tagName, value := range resourceTags {
+		if _, ok := tagFilterList[strings.ToLower(tagName)]; ok {
+			includedTags[tagName] = value
+		}
+	}
+
+	return includedTags
+}

receiver/azuremonitorreceiver/scraper_batch.go

@@ -233,6 +233,8 @@ func (s *azureBatchScraper) getResourcesAndTypes(ctx context.Context, subscripti
 		Filter: &filter,
 	}
 
+	tagsFilterMap := getTagsFilterMap(s.cfg.AppendTagsAsAttributes)
+
 	resourceTypes := map[string]*azureType{}
 	pager := clientResources.NewListPager(opts)
 
@@ -256,7 +258,7 @@ func (s *azureBatchScraper) getResourcesAndTypes(ctx context.Context, subscripti
 				}
 				s.resources[subscriptionID][*resource.ID] = &azureResource{
 					attributes:   attributes,
-					tags:         resource.Tags,
+					tags:         filterResourceTags(tagsFilterMap, resource.Tags),
 					resourceType: resource.Type,
 				}
 				if resourceTypes[*resource.Type] == nil {
@@ -449,11 +451,9 @@ func (s *azureBatchScraper) getBatchMetricsValues(ctx context.Context, subscript
 									name := metadataPrefix + *value.Name.Value
 									attributes[name] = value.Value
 								}
-								if s.cfg.AppendTagsAsAttributes {
-									for tagName, value := range res.tags {
-										name := tagPrefix + tagName
-										attributes[name] = value
-									}
+								for tagName, value := range res.tags {
+									name := tagPrefix + tagName
+									attributes[name] = value
 								}
 								attributes["timegrain"] = &compositeKey.timeGrain
 								for i := len(timeseriesElement.Data) - 1; i >= 0; i-- { // reverse for loop because newest timestamp is at the end of the slice

receiver/azuremonitorreceiver/scraper_batch_test.go

@@ -219,10 +219,21 @@ func TestAzureScraperBatchScrape(t *testing.T) {
 	}
 	cfg := createDefaultTestConfig()
 	cfg.MaximumNumberOfMetricsInACall = 2
+	cfg.AppendTagsAsAttributes = []string{}
 	cfg.SubscriptionIDs = []string{"subscriptionId1", "subscriptionId3"}
 
+	cfgTagsSelective := createDefaultTestConfig()
+	cfgTagsSelective.AppendTagsAsAttributes = []string{"tagName1"}
+	cfgTagsSelective.MaximumNumberOfMetricsInACall = 2
+	cfgTagsSelective.SubscriptionIDs = []string{"subscriptionId1", "subscriptionId3"}
+
+	cfgTagsCaseInsensitive := createDefaultTestConfig()
+	cfgTagsCaseInsensitive.AppendTagsAsAttributes = []string{"TAGNAME1"}
+	cfgTagsCaseInsensitive.MaximumNumberOfMetricsInACall = 2
+	cfgTagsCaseInsensitive.SubscriptionIDs = []string{"subscriptionId1", "subscriptionId3"}
+
 	cfgTagsEnabled := createDefaultTestConfig()
-	cfgTagsEnabled.AppendTagsAsAttributes = true
+	cfgTagsEnabled.AppendTagsAsAttributes = []string{"*"}
 	cfgTagsEnabled.MaximumNumberOfMetricsInACall = 2
 
 	tests := []struct {
@@ -249,6 +260,24 @@ func TestAzureScraperBatchScrape(t *testing.T) {
 				ctx: context.Background(),
 			},
 		},
+		{
+			name: "metrics_selective_tags",
+			fields: fields{
+				cfg: cfgTagsSelective,
+			},
+			args: args{
+				ctx: context.Background(),
+			},
+		},
+		{
+			name: "metrics_selective_tags",
+			fields: fields{
+				cfg: cfgTagsCaseInsensitive,
+			},
+			args: args{
+				ctx: context.Background(),
+			},
+		},
 	}
 
 	for _, tt := range tests {
@@ -258,7 +287,7 @@ func TestAzureScraperBatchScrape(t *testing.T) {
 			optionsResolver := newMockClientOptionsResolver(
 				getSubscriptionByIDMockData(),
 				getSubscriptionsMockData(),
-				getResourcesMockData(tt.fields.cfg.AppendTagsAsAttributes),
+				getResourcesMockData(),
 				getMetricsDefinitionsMockData(),
 				nil,
 				getMetricsQueryResponseMockData(),

receiver/azuremonitorreceiver/scraper_test.go

@@ -94,17 +94,29 @@ func TestAzureScraperScrape(t *testing.T) {
 	}
 	cfg := createDefaultTestConfig()
 	cfg.MaximumNumberOfMetricsInACall = 2
+	cfg.AppendTagsAsAttributes = []string{}
 	cfg.SubscriptionIDs = []string{"subscriptionId1", "subscriptionId3"}
 
 	cfgTagsEnabled := createDefaultTestConfig()
-	cfgTagsEnabled.AppendTagsAsAttributes = true
+	cfgTagsEnabled.AppendTagsAsAttributes = []string{"*"}
 	cfgTagsEnabled.MaximumNumberOfMetricsInACall = 2
 	cfgTagsEnabled.SubscriptionIDs = []string{"subscriptionId1", "subscriptionId3"}
 
+	cfgTagsSelective := createDefaultTestConfig()
+	cfgTagsSelective.AppendTagsAsAttributes = []string{"tagName1"}
+	cfgTagsSelective.MaximumNumberOfMetricsInACall = 2
+	cfgTagsSelective.SubscriptionIDs = []string{"subscriptionId1", "subscriptionId3"}
+
 	cfgSubNameAttr := createDefaultTestConfig()
+	cfgSubNameAttr.AppendTagsAsAttributes = []string{}
 	cfgSubNameAttr.SubscriptionIDs = []string{"subscriptionId1", "subscriptionId3"}
 	cfgSubNameAttr.MetricsBuilderConfig.ResourceAttributes.AzuremonitorSubscription.Enabled = true
 
+	cfgTagsCaseInsensitive := createDefaultTestConfig()
+	cfgTagsCaseInsensitive.AppendTagsAsAttributes = []string{"TAGNAME1"}
+	cfgTagsCaseInsensitive.MaximumNumberOfMetricsInACall = 2
+	cfgTagsCaseInsensitive.SubscriptionIDs = []string{"subscriptionId1", "subscriptionId3"}
+
 	tests := []struct {
 		name    string
 		fields  fields
@@ -129,6 +141,15 @@ func TestAzureScraperScrape(t *testing.T) {
 				ctx: context.Background(),
 			},
 		},
+		{
+			name: "metrics_selective_tags",
+			fields: fields{
+				cfg: cfgTagsSelective,
+			},
+			args: args{
+				ctx: context.Background(),
+			},
+		},
 		{
 			name: "metrics_subname_golden",
 			fields: fields{
@@ -138,6 +159,15 @@ func TestAzureScraperScrape(t *testing.T) {
 				ctx: context.Background(),
 			},
 		},
+		{
+			name: "metrics_selective_tags",
+			fields: fields{
+				cfg: cfgTagsCaseInsensitive,
+			},
+			args: args{
+				ctx: context.Background(),
+			},
+		},
 	}
 
 	for _, tt := range tests {
@@ -147,7 +177,7 @@ func TestAzureScraperScrape(t *testing.T) {
 			optionsResolver := newMockClientOptionsResolver(
 				getSubscriptionByIDMockData(),
 				getSubscriptionsMockData(),
-				getResourcesMockData(tt.fields.cfg.AppendTagsAsAttributes),
+				getResourcesMockData(),
 				getMetricsDefinitionsMockData(),
 				getMetricsValuesMockData(),
 				nil,
@@ -460,7 +490,7 @@ func getNominalTestScraper() *azureScraper {
 	optionsResolver := newMockClientOptionsResolver(
 		getSubscriptionByIDMockData(),
 		getSubscriptionsMockData(),
-		getResourcesMockData(false),
+		getResourcesMockData(),
 		getMetricsDefinitionsMockData(),
 		getMetricsValuesMockData(),
 		nil,
@@ -570,7 +600,7 @@ func getTimeMock() timeNowIface {
 	return &timeMock{time: time.Now()}
 }
 
-func getResourcesMockData(tags bool) map[string][]armresources.ClientListResponse {
+func getResourcesMockData() map[string][]armresources.ClientListResponse {
 	id1, id2, id3, id4,
 		location1, name1, type1 := "/subscriptions/subscriptionId1/resourceGroups/group1/resourceId1",
 		"/subscriptions/subscriptionId1/resourceGroups/group1/resourceId2",
@@ -584,10 +614,14 @@ func getResourcesMockData(tags bool) map[string][]armresources.ClientListRespons
 		Name:     &name1,
 		Type:     &type1,
 	}
-	if tags {
-		tagName1, tagValue1 := "tagName1", "tagValue1"
-		resourceID1.Tags = map[string]*string{tagName1: &tagValue1}
+
+	tagName1, tagValue1 := "tagName1", "tagValue1"
+	tagName2, tagValue2 := "tagName2", "tagValue2"
+	resourceID1.Tags = map[string]*string{
+		tagName1: &tagValue1,
+		tagName2: &tagValue2,
 	}
+
 	return map[string][]armresources.ClientListResponse{
 		"subscriptionId1": {
 			{

receiver/azuremonitorreceiver/testdata/config.yaml

@@ -48,3 +48,15 @@ azuremonitor/max_resources_per_batch_negative_value:
   credentials: does-not-matter
   use_batch_api: true
   maximum_resources_per_batch: -1
+
+azuremonitor/append_tags_all:
+  subscription_ids:
+    - test
+  credentials: default_credentials
+  append_tags_as_attributes: ["*"]
+
+azuremonitor/append_tags_specific:
+  subscription_ids:
+    - test
+  credentials: default_credentials
+  append_tags_as_attributes: ["service", "environment"]