add metrics integration tests

This PR adds happy path integration testing for metrics. TODO included
for testing changes in service discovery response as VMs are started and
stopped and evicted from the demux snapshotter cache.

Signed-off-by: Gavin Inglis <[email protected]>

Author: ginglis13

snapshotter/metrics_integ_test.go

@@ -0,0 +1,176 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file 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 main
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"testing"
+
+	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/namespaces"
+	"github.com/firecracker-microvm/firecracker-containerd/firecracker-control/client"
+	"github.com/firecracker-microvm/firecracker-containerd/internal/integtest"
+	"github.com/firecracker-microvm/firecracker-containerd/proto"
+	"github.com/firecracker-microvm/firecracker-containerd/snapshotter/internal/integtest/stargz/fs/source"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/sync/errgroup"
+)
+
+const (
+	serviceDiscoveryEndpoint = "http://localhost:8080"
+
+	stargzFsOperation     = "stargz_fs_operation_duration_milliseconds_bucket"
+	stargzFsOperationHelp = "# HELP stargz_fs_operation_duration_milliseconds Latency"
+	stargzFsOperationType = "# TYPE stargz_fs_operation_duration_milliseconds histogram"
+)
+
+func TestSnapshotterMetrics_Isolated(t *testing.T) {
+	integtest.Prepare(t)
+
+	vmID := 0
+
+	ctx := namespaces.WithNamespace(context.Background(), strconv.Itoa(vmID))
+
+	fcClient, err := integtest.NewFCControlClient(integtest.ContainerdSockPath)
+	defer fcClient.StopVM(ctx, &proto.StopVMRequest{VMID: strconv.Itoa(vmID)})
+	require.NoError(t, err, "Failed to create fccontrol client")
+
+	require.NoError(t, pullImageWithRemoteSnapshotterInVM(ctx, strconv.Itoa(vmID), fcClient))
+	verifyMetricsResponse(t, 1)
+}
+
+func TestSnapshotterMetricsMultipleVMs_Isolated(t *testing.T) {
+	integtest.Prepare(t)
+
+	numberOfVms := integtest.NumberOfVms
+	fcClient, err := integtest.NewFCControlClient(integtest.ContainerdSockPath)
+	require.NoError(t, err, "Failed to create fccontrol client")
+
+	group, ctx := errgroup.WithContext(context.Background())
+
+	for vmID := 0; vmID < numberOfVms; vmID++ {
+		id := vmID
+		ctxNamespace := namespaces.WithNamespace(ctx, strconv.Itoa(id))
+		defer fcClient.StopVM(ctxNamespace, &proto.StopVMRequest{VMID: strconv.Itoa(id)})
+
+		group.Go(
+			func() error {
+				return pullImageWithRemoteSnapshotterInVM(ctxNamespace, strconv.Itoa(id), fcClient)
+			},
+		)
+
+	}
+
+	err = group.Wait()
+	require.NoError(t, err)
+	verifyMetricsResponse(t, numberOfVms)
+}
+
+// TODO (ginglis13): ensure service discovery response changes as VMs are started and stopped.
+// pending https://github.com/firecracker-microvm/firecracker-containerd/issues/651
+// func TestSnapshotterMetricsMultipleVMsStopStart_Isolated(t *testing.T) {}
+
+func pullImageWithRemoteSnapshotterInVM(ctx context.Context, vmID string, fcClient *client.Client) error {
+	client, err := containerd.New(integtest.ContainerdSockPath, containerd.WithDefaultRuntime(integtest.FirecrackerRuntime))
+	if err != nil {
+		return fmt.Errorf("Unable to create client to containerd service at %s, is containerd running?: %v", integtest.ContainerdSockPath, err)
+	}
+	if _, err = fcClient.CreateVM(ctx, &proto.CreateVMRequest{
+		VMID: vmID,
+		RootDrive: &proto.FirecrackerRootDrive{
+			HostPath: "/var/lib/firecracker-containerd/runtime/rootfs-stargz.img",
+		},
+		NetworkInterfaces: []*proto.FirecrackerNetworkInterface{
+			{
+				AllowMMDS: true,
+				CNIConfig: &proto.CNIConfiguration{
+					NetworkName:   "fcnet",
+					InterfaceName: "veth0",
+				},
+			},
+		},
+		MachineCfg: &proto.FirecrackerMachineConfiguration{
+			VcpuCount:  1,
+			MemSizeMib: 512,
+		},
+		ContainerCount: 1,
+	}); err != nil {
+		return fmt.Errorf("Failed to create microVM[%s]: %v", vmID, err)
+	}
+
+	if _, err = fcClient.SetVMMetadata(ctx, &proto.SetVMMetadataRequest{
+		VMID:     vmID,
+		Metadata: fmt.Sprintf(dockerMetadataTemplate, "ghcr.io", noAuth, noAuth),
+	}); err != nil {
+		return fmt.Errorf("Failed to set metadata on microVM[%s]: %v", vmID, err)
+	}
+
+	image, err := client.Pull(ctx, al2stargz,
+		containerd.WithPullUnpack,
+		containerd.WithPullSnapshotter(snapshotterName),
+		containerd.WithImageHandlerWrapper(source.AppendDefaultLabelsHandlerWrapper(al2stargz, 10*1024*1024)),
+	)
+	if err != nil {
+		return fmt.Errorf("Failed to pull image on microVM[%s]: %v", vmID, err)
+	}
+	if err = client.ImageService().Delete(ctx, image.Name()); err != nil {
+		return fmt.Errorf("Failed to delete image on microVM[%s]: %v", vmID, err)
+	}
+
+	return nil
+}
+
+type metricsTarget struct {
+	Targets []string          `json:"targets"`
+	Labels  map[string]string `json:"labels"`
+}
+
+func verifyMetricsResponse(t *testing.T, numberOfVms int) {
+	sdResponse, err := http.Get(serviceDiscoveryEndpoint)
+	require.NoError(t, err, "Get service discovery failed")
+	defer sdResponse.Body.Close()
+
+	sdBytes, err := io.ReadAll(sdResponse.Body)
+	require.NoError(t, err, "Failed to read service discovery response body")
+
+	var metricsTargets []metricsTarget
+	err = json.Unmarshal(sdBytes, &metricsTargets)
+	require.NoError(t, err, "Failed to unmarshall service discovery response")
+
+	require.Len(t, metricsTargets, numberOfVms)
+
+	// Test pulling individual metrics proxies
+	// uniqueTargets acts as a set to ensure each metrics target is a unique host:port
+	uniqueTargets := make(map[string]struct{})
+	for _, mt := range metricsTargets {
+		uniqueTargets[mt.Targets[0]] = struct{}{}
+		metricsResponse, err := http.Get("http://" + mt.Targets[0] + "/metrics")
+		require.NoError(t, err, "Failed to get metrics proxy")
+		require.Equal(t, metricsResponse.StatusCode, http.StatusOK)
+		defer metricsResponse.Body.Close()
+
+		mBytes, err := io.ReadAll(metricsResponse.Body)
+		require.NoError(t, err, "Failed to read metrics response body")
+		require.NotEmpty(t, mBytes, "Empty metrics response body")
+		require.True(t, bytes.Contains(mBytes, []byte(stargzFsOperation)), "metrics response missing fs operations bucket")
+		require.True(t, bytes.Contains(mBytes, []byte(stargzFsOperationHelp)), "metrics response missing fs operations HELP")
+		require.True(t, bytes.Contains(mBytes, []byte(stargzFsOperationType)), "metrics response missing fs operations TYPE")
+	}
+	require.Len(t, uniqueTargets, numberOfVms)
+}

tools/docker/entrypoint.sh

@@ -45,7 +45,11 @@ cat > /etc/demux-snapshotter/config.toml <<EOF
 [snapshotter.proxy.address.resolver]
   type = "http"
   address = "http://127.0.0.1:10001"
-
+[snapshotter.metrics]
+  enable = true
+  port_range = "9000-9999"
+  host = "0.0.0.0"
+  service_discovery_port = 8080
 [debug]
   logLevel = "debug"
 EOF