Add test cases and documentation

receiver/azuremonitorreceiver/README.md

@@ -22,7 +22,7 @@ The following settings are required:
 
 The following settings are optional:
 
-- `auth` (default = service_principal): Specifies the used authentication method. Supported values are `service_principal`, `workload_identity`.
+- `auth` (default = service_principal): Specifies the used authentication method. Supported values are `service_principal`, `workload_identity`, `managed_identity`, `default_credentials`.
 - `resource_groups` (default = none): Filter metrics for specific resource groups, not setting a value will scrape metrics for all resources in the subscription.
 - `services` (default = none): Filter metrics for specific services, not setting a value will scrape metrics for all services integrated with Azure Monitor.
 - `cache_resources` (default = 86400): List of resources will be cached for the provided amount of time in seconds.
@@ -43,9 +43,13 @@ Authenticating using workload identities requires following additional settings:
 - `client_id`
 - `federate_token_file`
 
+Authenticating using managed identities has the following optional settings:
+
+- `client_id`
+
 ### Example Configurations
 
-Using Service Principal for authentication:
+Using [Service Principal](https://learn.microsoft.com/en-us/azure/developer/go/azure-sdk-authentication?tabs=bash#service-principal-with-a-secret) for authentication:
 
 ```yaml
 receivers:
@@ -65,7 +69,7 @@ receivers:
     initial_delay: 1s
 ```
 
-Using Azure Workload Identity for authentication:
+Using [Azure Workload Identity](https://learn.microsoft.com/en-us/azure/developer/go/azure-sdk-authentication?tabs=bash#option-2-use-workload-identity) for authentication:
 
 ```yaml
 receivers:
@@ -77,6 +81,26 @@ receivers:
     federated_token_file: "${env:AZURE_FEDERATED_TOKEN_FILE}"
 ```
 
+Using [Managed Identity](https://learn.microsoft.com/en-us/azure/developer/go/azure-sdk-authentication?tabs=bash#option-3-use-a-managed-identity) for authentication:
+
+```yaml
+receivers:
+  azuremonitor:
+    subscription_id: "${subscription_id}"
+    auth: "managed_identity"
+    client_id: "${env:AZURE_CLIENT_ID}"
+```
+
+Using [Environment Variables](https://learn.microsoft.com/en-us/azure/developer/go/azure-sdk-authentication?tabs=bash#option-1-define-environment-variables) for authentication:
+
+```yaml
+receivers:
+  azuremonitor:
+    subscription_id: "${subscription_id}"
+    auth: "default_credentials"
+```
+
+
 ## 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/scraper_test.go

@@ -41,6 +41,14 @@ func azIDWorkloadFuncMock(*azidentity.WorkloadIdentityCredentialOptions) (*azide
 	return &azidentity.WorkloadIdentityCredential{}, nil
 }
 
+func azManagedIdentityFuncMock(*azidentity.ManagedIdentityCredentialOptions) (*azidentity.ManagedIdentityCredential, error) {
+	return &azidentity.ManagedIdentityCredential{}, nil
+}
+
+func azDefaultCredentialsFuncMock(*azidentity.DefaultAzureCredentialOptions) (*azidentity.DefaultAzureCredential, error) {
+	return &azidentity.DefaultAzureCredential{}, nil
+}
+
 func armClientFuncMock(string, azcore.TokenCredential, *arm.ClientOptions) (*armresources.Client, error) {
 	return &armresources.Client{}, nil
 }
@@ -137,6 +145,62 @@ func TestAzureScraperStart(t *testing.T) {
 				require.IsType(t, &azidentity.WorkloadIdentityCredential{}, s.cred)
 			},
 		},
+		{
+			name: "managed_identity",
+			testFunc: func(t *testing.T) {
+				customCfg := &Config{
+					ControllerConfig:              cfg.ControllerConfig,
+					MetricsBuilderConfig:          metadata.DefaultMetricsBuilderConfig(),
+					CacheResources:                24 * 60 * 60,
+					CacheResourcesDefinitions:     24 * 60 * 60,
+					MaximumNumberOfMetricsInACall: 20,
+					Services:                      monitorServices,
+					Authentication:                managedIdentity,
+				}
+				s := &azureScraper{
+					cfg:                             customCfg,
+					azIDCredentialsFunc:             azIDCredentialsFuncMock,
+					azManagedIdentityFunc:           azManagedIdentityFuncMock,
+					armClientFunc:                   armClientFuncMock,
+					armMonitorDefinitionsClientFunc: armMonitorDefinitionsClientFuncMock,
+					armMonitorMetricsClientFunc:     armMonitorMetricsClientFuncMock,
+				}
+
+				if err := s.start(context.Background(), componenttest.NewNopHost()); err != nil {
+					t.Errorf("azureScraper.start() error = %v", err)
+				}
+				require.NotNil(t, s.cred)
+				require.IsType(t, &azidentity.ManagedIdentityCredential{}, s.cred)
+			},
+		},
+		{
+			name: "default_credentials",
+			testFunc: func(t *testing.T) {
+				customCfg := &Config{
+					ControllerConfig:              cfg.ControllerConfig,
+					MetricsBuilderConfig:          metadata.DefaultMetricsBuilderConfig(),
+					CacheResources:                24 * 60 * 60,
+					CacheResourcesDefinitions:     24 * 60 * 60,
+					MaximumNumberOfMetricsInACall: 20,
+					Services:                      monitorServices,
+					Authentication:                defaultCredentials,
+				}
+				s := &azureScraper{
+					cfg:                             customCfg,
+					azIDCredentialsFunc:             azIDCredentialsFuncMock,
+					azDefaultCredentialsFunc:        azDefaultCredentialsFuncMock,
+					armClientFunc:                   armClientFuncMock,
+					armMonitorDefinitionsClientFunc: armMonitorDefinitionsClientFuncMock,
+					armMonitorMetricsClientFunc:     armMonitorMetricsClientFuncMock,
+				}
+
+				if err := s.start(context.Background(), componenttest.NewNopHost()); err != nil {
+					t.Errorf("azureScraper.start() error = %v", err)
+				}
+				require.NotNil(t, s.cred)
+				require.IsType(t, &azidentity.DefaultAzureCredential{}, s.cred)
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, tt.testFunc)