Add Azure VM support for add_cloud_metadata processor

CHANGELOG.asciidoc

@@ -63,6 +63,7 @@ https://github.com/elastic/beats/compare/v6.0.0-beta2...master[Check the HEAD di
 - Changed beat helper script to use `exec` when running the beat. {pull}5051[5051]
 - Fix reloader error message to only print on actual error {pull}5066[5066]
 - Add support for enabling TLS renegotiation. {issue}4386[4386]
+- Add Azure VM support for add_cloud_metadata processor {pull}5355[5355]
 
 *Auditbeat*
 

libbeat/docs/processors-using.asciidoc

@@ -260,6 +260,7 @@ The following cloud providers are supported:
 - Google Compute Engine (GCE)
 - https://www.qcloud.com/?lang=en[Tencent Cloud] (QCloud)
 - Alibaba Cloud (ECS)
+- Azure Virtual Machine
 
 The simple configuration below enables the processor.
 
@@ -365,6 +366,24 @@ ECS instance.
 }
 -------------------------------------------------------------------------------
 
+_Azure Virtual Machine_
+
+[source,json]
+-------------------------------------------------------------------------------
+{
+  "meta": {
+    "cloud": {
+      "provider": "az",
+      "instance_id": "04ab04c3-63de-4709-a9f9-9ab8c0411d5e",
+      "instance_name": "test-az-vm",
+      "machine_type": "Standard_D3_v2",
+      "region": "eastus2"
+    }
+  }
+}
+-------------------------------------------------------------------------------
+
+
 [[add-locale]]
 === Add the local time zone
 

libbeat/processors/add_cloud_metadata/add_cloud_metadata.go

@@ -260,13 +260,18 @@ func setupFetchers(c *common.Config) ([]*metadataFetcher, error) {
 	if err != nil {
 		return fetchers, err
 	}
+	azFetcher, err := newAzureVmMetadataFetcher(c)
+	if err != nil {
+		return fetchers, err
+	}
 
 	fetchers = []*metadataFetcher{
 		doFetcher,
 		ec2Fetcher,
 		gceFetcher,
 		qcloudFetcher,
 		ecsFetcher,
+		azFetcher,
 	}
 	return fetchers, nil
 }

libbeat/processors/add_cloud_metadata/provider_azure_vm.go

@@ -0,0 +1,25 @@
+package add_cloud_metadata
+
+import (
+	"github.com/elastic/beats/libbeat/common"
+	s "github.com/elastic/beats/libbeat/common/schema"
+	c "github.com/elastic/beats/libbeat/common/schema/mapstriface"
+)
+
+// Azure VM Metadata Service
+func newAzureVmMetadataFetcher(config *common.Config) (*metadataFetcher, error) {
+	azMetadataURI := "/metadata/instance/compute?api-version=2017-04-02"
+	azHeaders := map[string]string{"Metadata": "true"}
+	azSchema := func(m map[string]interface{}) common.MapStr {
+		out, _ := s.Schema{
+			"instance_id":   c.Str("vmId"),
+			"instance_name": c.Str("name"),
+			"machine_type":  c.Str("vmSize"),
+			"region":        c.Str("location"),
+		}.Apply(m)
+		return out
+	}
+
+	fetcher, err := newMetadataFetcher(config, "az", azHeaders, metadataHost, azSchema, azMetadataURI)
+	return fetcher, err
+}

libbeat/processors/add_cloud_metadata/provider_azure_vm_test.go

@@ -0,0 +1,77 @@
+package add_cloud_metadata
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/elastic/beats/libbeat/beat"
+	"github.com/elastic/beats/libbeat/common"
+	"github.com/elastic/beats/libbeat/logp"
+)
+
+const azInstanceIdentityDocument = `{
+	"location": "eastus2",
+	"name": "test-az-vm",
+	"offer": "UbuntuServer",
+	"osType": "Linux",
+	"platformFaultDomain": "0",
+	"platformUpdateDomain": "0",
+	"publisher": "Canonical",
+	"sku": "14.04.4-LTS",
+	"version": "14.04.201605091",
+	"vmId": "04ab04c3-63de-4709-a9f9-9ab8c0411d5e",
+	"vmSize": "Standard_D3_v2"
+}`
+
+func initAzureTestServer() *httptest.Server {
+	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.RequestURI == "/metadata/instance/compute?api-version=2017-04-02" && r.Header.Get("Metadata") == "true" {
+			w.Write([]byte(azInstanceIdentityDocument))
+			return
+		}
+
+		http.Error(w, "not found", http.StatusNotFound)
+	}))
+}
+
+func TestRetrieveAzureMetadata(t *testing.T) {
+	if testing.Verbose() {
+		logp.LogInit(logp.LOG_DEBUG, "", false, true, []string{"*"})
+	}
+
+	server := initAzureTestServer()
+	defer server.Close()
+
+	config, err := common.NewConfigFrom(map[string]interface{}{
+		"host": server.Listener.Addr().String(),
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	p, err := newCloudMetadata(config)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	actual, err := p.Run(&beat.Event{Fields: common.MapStr{}})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expected := common.MapStr{
+		"meta": common.MapStr{
+			"cloud": common.MapStr{
+				"provider":      "az",
+				"instance_id":   "04ab04c3-63de-4709-a9f9-9ab8c0411d5e",
+				"instance_name": "test-az-vm",
+				"machine_type":  "Standard_D3_v2",
+				"region":        "eastus2",
+			},
+		},
+	}
+	assert.Equal(t, expected, actual.Fields)
+}