Add support for Azure App Service cloud metadata

apmtest/env.go

@@ -20,6 +20,8 @@ package apmtest // import "go.elastic.co/apm/apmtest"
 import "os"
 
 func init() {
-	// Disable cloud metadata sniffing by default in tests.
-	os.Setenv("ELASTIC_APM_CLOUD_PROVIDER", "none")
+	if os.Getenv("ELASTIC_APM_CLOUD_PROVIDER") == "" {
+		// Disable cloud metadata sniffing by default in tests.
+		os.Setenv("ELASTIC_APM_CLOUD_PROVIDER", "none")
+	}
 }

features/azure_app_service_metadata.feature

@@ -0,0 +1,71 @@
+Feature: Extracting Metadata for Azure App Service
+
+  Background:
+    Given an instrumented application is configured to collect cloud provider metadata for azure
+
+  Scenario Outline: Azure App Service with all environment variables present in expected format
+    Given the following environment variables are present
+      | name                   | value                |
+      | WEBSITE_OWNER_NAME     | <WEBSITE_OWNER_NAME> |
+      | WEBSITE_RESOURCE_GROUP | resource_group       |
+      | WEBSITE_SITE_NAME      | site_name            |
+      | WEBSITE_INSTANCE_ID    | instance_id          |
+    When cloud metadata is collected
+    Then cloud metadata is not null
+    And cloud metadata 'account.id' is 'f5940f10-2e30-3e4d-a259-63451ba6dae4'
+    And cloud metadata 'provider' is 'azure'
+    And cloud metadata 'instance.id' is 'instance_id'
+    And cloud metadata 'instance.name' is 'site_name'
+    And cloud metadata 'project.name' is 'resource_group'
+    And cloud metadata 'region' is 'AustraliaEast'
+    Examples:
+      | WEBSITE_OWNER_NAME                                                                          |
+      | f5940f10-2e30-3e4d-a259-63451ba6dae4+elastic-apm-AustraliaEastwebspace                      |
+      | f5940f10-2e30-3e4d-a259-63451ba6dae4+appsvc_linux_australiaeast-AustraliaEastwebspace-Linux |
+
+  # WEBSITE_OWNER_NAME is expected to include a + character
+  Scenario: WEBSITE_OWNER_NAME environment variable not expected format
+    Given the following environment variables are present
+    | name                   | value                                                                  |
+    | WEBSITE_OWNER_NAME     | f5940f10-2e30-3e4d-a259-63451ba6dae4-elastic-apm-AustraliaEastwebspace |
+    | WEBSITE_RESOURCE_GROUP | resource_group                                                         |
+    | WEBSITE_SITE_NAME      | site_name                                                              |
+    | WEBSITE_INSTANCE_ID    | instance_id                                                            |
+    When cloud metadata is collected
+    Then cloud metadata is null
+
+  Scenario: Missing WEBSITE_OWNER_NAME environment variable
+    Given the following environment variables are present
+    | name                   | value                                                                  |
+    | WEBSITE_RESOURCE_GROUP | resource_group                                                         |
+    | WEBSITE_SITE_NAME      | site_name                                                              |
+    | WEBSITE_INSTANCE_ID    | instance_id                                                            |
+    When cloud metadata is collected
+    Then cloud metadata is null
+
+  Scenario: Missing WEBSITE_RESOURCE_GROUP environment variable
+    Given the following environment variables are present
+    | name                   | value                                                                  |
+    | WEBSITE_OWNER_NAME     | f5940f10-2e30-3e4d-a259-63451ba6dae4+elastic-apm-AustraliaEastwebspace |
+    | WEBSITE_SITE_NAME      | site_name                                                              |
+    | WEBSITE_INSTANCE_ID    | instance_id                                                            |
+    When cloud metadata is collected
+    Then cloud metadata is null
+
+  Scenario: Missing WEBSITE_SITE_NAME environment variable
+    Given the following environment variables are present
+    | name                   | value                                                                  |
+    | WEBSITE_OWNER_NAME     | f5940f10-2e30-3e4d-a259-63451ba6dae4+elastic-apm-AustraliaEastwebspace |
+    | WEBSITE_RESOURCE_GROUP | resource_group                                                         |
+    | WEBSITE_INSTANCE_ID    | instance_id                                                            |
+    When cloud metadata is collected
+    Then cloud metadata is null
+
+  Scenario: Missing WEBSITE_INSTANCE_ID environment variable
+    Given the following environment variables are present
+    | name                   | value                                                                  |
+    | WEBSITE_OWNER_NAME     | f5940f10-2e30-3e4d-a259-63451ba6dae4+elastic-apm-AustraliaEastwebspace |
+    | WEBSITE_RESOURCE_GROUP | resource_group                                                         |
+    | WEBSITE_SITE_NAME      | site_name                                                              |
+    When cloud metadata is collected
+    Then cloud metadata is null

internal/apmcloudutil/azure.go

@@ -22,6 +22,8 @@ import (
 	"encoding/json"
 	"errors"
 	"net/http"
+	"os"
+	"strings"
 
 	"go.elastic.co/apm/model"
 )
@@ -32,6 +34,12 @@ const (
 
 // See: https://docs.microsoft.com/en-us/azure/virtual-machines/windows/instance-metadata-service
 func getAzureCloudMetadata(ctx context.Context, client *http.Client, out *model.Cloud) error {
+	// First check for Azure App Service environment variables, which can
+	// be done without performing any network requests.
+	if getAzureAppServiceCloudMetadata(ctx, out) {
+		return nil
+	}
+
 	req, err := http.NewRequest("GET", azureMetadataURL, nil)
 	if err != nil {
 		return err
@@ -76,3 +84,46 @@ func getAzureCloudMetadata(ctx context.Context, client *http.Client, out *model.
 	}
 	return nil
 }
+
+func getAzureAppServiceCloudMetadata(ctx context.Context, out *model.Cloud) bool {
+	// WEBSITE_OWNER_NAME has the form:
+	//    {subscription id}+{app service plan resource group}-{region}webspace{.*}
+	websiteOwnerName := os.Getenv("WEBSITE_OWNER_NAME")
+	if websiteOwnerName == "" {
+		return false
+	}
+	websiteInstanceID := os.Getenv("WEBSITE_INSTANCE_ID")
+	if websiteInstanceID == "" {
+		return false
+	}
+	websiteSiteName := os.Getenv("WEBSITE_SITE_NAME")
+	if websiteSiteName == "" {
+		return false
+	}
+	websiteResourceGroup := os.Getenv("WEBSITE_RESOURCE_GROUP")
+	if websiteResourceGroup == "" {
+		return false
+	}
+
+	plus := strings.IndexRune(websiteOwnerName, '+')
+	if plus == -1 {
+		return false
+	}
+	out.Account = &model.CloudAccount{ID: websiteOwnerName[:plus]}
+	websiteOwnerName = websiteOwnerName[plus+1:]
+
+	webspace := strings.LastIndex(websiteOwnerName, "webspace")
+	if webspace == -1 {
+		return false
+	}
+	websiteOwnerName = websiteOwnerName[:webspace]
+
+	hyphen := strings.LastIndex(websiteOwnerName, "-")
+	if hyphen == -1 {
+		return false
+	}
+	out.Region = websiteOwnerName[hyphen+1:]
+	out.Instance = &model.CloudInstance{ID: websiteInstanceID, Name: websiteSiteName}
+	out.Project = &model.CloudProject{Name: websiteResourceGroup}
+	return true
+}

internal/apmcloudutil/azure_test.go

@@ -21,6 +21,7 @@ import (
 	"context"
 	"net/http"
 	"net/http/httptest"
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -57,6 +58,42 @@ func TestAzureCloudMetadata(t *testing.T) {
 	}
 }
 
+func TestAzureAppServiceCloudMetadata(t *testing.T) {
+	client := &http.Client{Transport: newTargetedRoundTripper("", "testing.invalid")}
+
+	os.Setenv("WEBSITE_OWNER_NAME", "f5940f10-2e30-3e4d-a259-63451ba6dae4+elastic-apm-AustraliaEastwebspace")
+	os.Setenv("WEBSITE_RESOURCE_GROUP", "resource_group")
+	os.Setenv("WEBSITE_SITE_NAME", "site_name")
+	os.Setenv("WEBSITE_INSTANCE_ID", "instance_id")
+	defer func() {
+		os.Unsetenv("WEBSITE_OWNER_NAME")
+		os.Unsetenv("WEBSITE_RESOURCE_GROUP")
+		os.Unsetenv("WEBSITE_SITE_NAME")
+		os.Unsetenv("WEBSITE_INSTANCE_ID")
+	}()
+
+	for _, provider := range []Provider{Auto, Azure} {
+		var out model.Cloud
+		var logger testLogger
+		assert.True(t, provider.getCloudMetadata(context.Background(), client, &logger, &out))
+		assert.Zero(t, logger)
+		assert.Equal(t, model.Cloud{
+			Provider: "azure",
+			Region:   "AustraliaEast",
+			Instance: &model.CloudInstance{
+				ID:   "instance_id",
+				Name: "site_name",
+			},
+			Project: &model.CloudProject{
+				Name: "resource_group",
+			},
+			Account: &model.CloudAccount{
+				ID: "f5940f10-2e30-3e4d-a259-63451ba6dae4",
+			},
+		}, out)
+	}
+}
+
 func newAzureMetadataServer() (*httptest.Server, *http.Client) {
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if r.URL.Path != "/metadata/instance/compute" {

internal/apmgodog/doc.go

@@ -0,0 +1,19 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you 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 apmgodog implements the Gherkin feature spec tests.
+package apmgodog

internal/apmgodog/feature_test.go

@@ -17,7 +17,7 @@
 
 // +build go1.9
 
-package apmgodog
+package apmgodog_test
 
 import "testing"
 

internal/apmgodog/formatter.go → internal/apmgodog/formatter_test.go

@@ -17,7 +17,7 @@
 
 // +build go1.9
 
-package apmgodog
+package apmgodog_test
 
 import (
 	"fmt"

internal/apmgodog/go.mod

@@ -7,6 +7,7 @@ require (
 	go.elastic.co/apm v1.11.0
 	go.elastic.co/apm/module/apmgrpc v1.11.0
 	go.elastic.co/apm/module/apmhttp v1.11.0
+	go.elastic.co/fastjson v1.1.0
 	google.golang.org/grpc v1.17.0
 )