Vendor dependencies for GCS

vendor/cloud.google.com/go/profiler/profiler.go

@@ -0,0 +1,416 @@
+// Copyright 2017 Google Inc. 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.
+// 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 profiler is a client for the Google Cloud Profiler service.
+//
+// This package is still experimental and subject to change.
+//
+// Calling Start will start a goroutine to collect profiles and
+// upload to Cloud Profiler server, at the rhythm specified by
+// the server.
+//
+// The caller should provide the target string in the config so Cloud
+// Profiler knows how to group the profile data. Otherwise the target
+// string is set to "unknown".
+//
+// Optionally DebugLogging can be set in the config to enable detailed
+// logging from profiler.
+//
+// Start should only be called once. The first call will start
+// the profiling goroutine. Any additional calls will be ignored.
+package profiler
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"log"
+	"runtime/pprof"
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	gcemd "cloud.google.com/go/compute/metadata"
+	"cloud.google.com/go/internal/version"
+	"github.com/golang/protobuf/proto"
+	"github.com/golang/protobuf/ptypes"
+	gax "github.com/googleapis/gax-go"
+	"golang.org/x/net/context"
+	"golang.org/x/oauth2/google"
+	"google.golang.org/api/option"
+	gtransport "google.golang.org/api/transport/grpc"
+	pb "google.golang.org/genproto/googleapis/devtools/cloudprofiler/v2"
+	edpb "google.golang.org/genproto/googleapis/rpc/errdetails"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	grpcmd "google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/status"
+)
+
+var (
+	config    = &Config{}
+	startOnce sync.Once
+	// getProjectID, getInstanceName, getZone, startCPUProfile, stopCPUProfile,
+	// writeHeapProfile and sleep are overrideable for testing.
+	getProjectID     = gcemd.ProjectID
+	getInstanceName  = gcemd.InstanceName
+	getZone          = gcemd.Zone
+	startCPUProfile  = pprof.StartCPUProfile
+	stopCPUProfile   = pprof.StopCPUProfile
+	writeHeapProfile = pprof.WriteHeapProfile
+	sleep            = gax.Sleep
+)
+
+const (
+	apiAddress            = "cloudprofiler.googleapis.com:443"
+	xGoogAPIMetadata      = "x-goog-api-client"
+	deploymentKeyMetadata = "x-profiler-deployment-key-bin"
+	zoneNameLabel         = "zone"
+	instanceLabel         = "instance"
+	scope                 = "https://www.googleapis.com/auth/monitoring.write"
+
+	initialBackoff = time.Second
+	// Ensure the agent will recover within 1 hour.
+	maxBackoff        = time.Hour
+	backoffMultiplier = 1.3 // Backoff envelope increases by this factor on each retry.
+	retryInfoMetadata = "google.rpc.retryinfo-bin"
+)
+
+// Config is the profiler configuration.
+type Config struct {
+	// Target groups related deployments together, defaults to "unknown".
+	Target string
+
+	// DebugLogging enables detailed debug logging from profiler.
+	DebugLogging bool
+
+	// ProjectID is the Cloud Console project ID to use instead of
+	// the one read from the VM metadata server.
+	//
+	// Set this if you are running the agent in your local environment
+	// or anywhere else outside of Google Cloud Platform.
+	ProjectID string
+
+	// InstanceName is the name of the VM instance to use instead of
+	// the one read from the VM metadata server.
+	//
+	// Set this if you are running the agent in your local environment
+	// or anywhere else outside of Google Cloud Platform.
+	InstanceName string
+
+	// ZoneName is the name of the zone to use instead of
+	// the one read from the VM metadata server.
+	//
+	// Set this if you are running the agent in your local environment
+	// or anywhere else outside of Google Cloud Platform.
+	ZoneName string
+
+	// APIAddr is the HTTP endpoint to use to connect to the profiler
+	// agent API. Defaults to the production environment, overridable
+	// for testing.
+	APIAddr string
+}
+
+// startError represents the error occured during the
+// initializating and starting of the agent.
+var startError error
+
+// Start starts a goroutine to collect and upload profiles.
+// See package level documentation for details.
+func Start(cfg *Config, options ...option.ClientOption) error {
+	startOnce.Do(func() {
+		startError = start(cfg, options...)
+	})
+	return startError
+}
+
+func start(cfg *Config, options ...option.ClientOption) error {
+	initializeConfig(cfg)
+
+	ctx := context.Background()
+
+	ts, err := google.DefaultTokenSource(ctx, scope)
+	if err != nil {
+		debugLog("failed to get application default credentials: %v", err)
+		return err
+	}
+
+	opts := []option.ClientOption{
+		option.WithEndpoint(config.APIAddr),
+		option.WithTokenSource(ts),
+		option.WithScopes(scope),
+	}
+	opts = append(opts, options...)
+
+	conn, err := gtransport.Dial(ctx, opts...)
+	if err != nil {
+		debugLog("failed to dial GRPC: %v", err)
+		return err
+	}
+
+	d, err := initializeDeployment()
+	if err != nil {
+		debugLog("failed to initialize deployment: %v", err)
+		return err
+	}
+
+	a, ctx := initializeResources(ctx, conn, d)
+	go pollProfilerService(ctx, a)
+	return nil
+}
+
+func debugLog(format string, e ...interface{}) {
+	if config.DebugLogging {
+		log.Printf(format, e...)
+	}
+}
+
+// agent polls Cloud Profiler server for instructions on behalf of
+// a task, and collects and uploads profiles as requested.
+type agent struct {
+	client             *client
+	deployment         *pb.Deployment
+	creationErrorCount int64
+}
+
+// abortedBackoffDuration retrieves the retry duration from gRPC trailing
+// metadata, which is set by Cloud Profiler server.
+func abortedBackoffDuration(md grpcmd.MD) (time.Duration, error) {
+	elem := md[retryInfoMetadata]
+	if len(elem) <= 0 {
+		return 0, errors.New("no retry info")
+	}
+
+	var retryInfo edpb.RetryInfo
+	if err := proto.Unmarshal([]byte(elem[0]), &retryInfo); err != nil {
+		return 0, err
+	} else if time, err := ptypes.Duration(retryInfo.RetryDelay); err != nil {
+		return 0, err
+	} else {
+		if time < 0 {
+			return 0, errors.New("negative retry duration")
+		}
+		return time, nil
+	}
+}
+
+type retryer struct {
+	backoff gax.Backoff
+	md      grpcmd.MD
+}
+
+func (r *retryer) Retry(err error) (time.Duration, bool) {
+	st, _ := status.FromError(err)
+	if st != nil && st.Code() == codes.Aborted {
+		dur, err := abortedBackoffDuration(r.md)
+		if err == nil {
+			return dur, true
+		}
+		debugLog("failed to get backoff duration: %v", err)
+	}
+	return r.backoff.Pause(), true
+}
+
+// createProfile talks to Cloud Profiler server to create profile. In
+// case of error, the goroutine will sleep and retry. Sleep duration may
+// be specified by the server. Otherwise it will be an exponentially
+// increasing value, bounded by maxBackoff.
+func (a *agent) createProfile(ctx context.Context) *pb.Profile {
+	req := pb.CreateProfileRequest{
+		Deployment:  a.deployment,
+		ProfileType: []pb.ProfileType{pb.ProfileType_CPU, pb.ProfileType_HEAP},
+	}
+
+	var p *pb.Profile
+	md := grpcmd.New(map[string]string{})
+
+	gax.Invoke(ctx, func(ctx context.Context, settings gax.CallSettings) error {
+		var err error
+		p, err = a.client.client.CreateProfile(ctx, &req, grpc.Trailer(&md))
+		return err
+	}, gax.WithRetry(func() gax.Retryer {
+		return &retryer{
+			backoff: gax.Backoff{
+				Initial:    initialBackoff,
+				Max:        maxBackoff,
+				Multiplier: backoffMultiplier,
+			},
+			md: md,
+		}
+	}))
+
+	debugLog("successfully created profile %v", p.GetProfileType())
+	return p
+}
+
+func (a *agent) profileAndUpload(ctx context.Context, p *pb.Profile) {
+	var prof bytes.Buffer
+	pt := p.GetProfileType()
+
+	switch pt {
+	case pb.ProfileType_CPU:
+		duration, err := ptypes.Duration(p.Duration)
+		if err != nil {
+			debugLog("failed to get profile duration: %v", err)
+			return
+		}
+		if err := startCPUProfile(&prof); err != nil {
+			debugLog("failed to start CPU profile: %v", err)
+			return
+		}
+		sleep(ctx, duration)
+		stopCPUProfile()
+	case pb.ProfileType_HEAP:
+		if err := writeHeapProfile(&prof); err != nil {
+			debugLog("failed to write heap profile: %v", err)
+			return
+		}
+	default:
+		debugLog("unexpected profile type: %v", pt)
+		return
+	}
+
+	// Starting Go 1.9 the profiles are symbolized by runtime/pprof.
+	// TODO(jianqiaoli): Remove the symbolization code when we decide to
+	// stop supporting Go 1.8.
+	if !shouldAssumeSymbolized {
+		if err := parseAndSymbolize(&prof); err != nil {
+			debugLog("failed to symbolize profile: %v", err)
+		}
+	}
+
+	p.ProfileBytes = prof.Bytes()
+	req := pb.UpdateProfileRequest{Profile: p}
+
+	// Upload profile, discard profile in case of error.
+	debugLog("start uploading profile")
+	if _, err := a.client.client.UpdateProfile(ctx, &req); err != nil {
+		debugLog("failed to upload profile: %v", err)
+	}
+}
+
+// client is a client for interacting with Cloud Profiler API.
+type client struct {
+	// gRPC API client.
+	client pb.ProfilerServiceClient
+
+	// Metadata for google API to be sent with each request.
+	xGoogHeader []string
+
+	// Metadata for Cloud Profiler API to be sent with each request.
+	profilerHeader []string
+}
+
+// setProfilerHeader sets the unique key string for a deployment target in
+// the `x-profiler-deployment-key-bin` header passed on each request.
+// Intended for use by Cloud Profiler agents.
+func (c *client) setProfilerHeader(d *pb.Deployment) {
+	labels := make([]string, 0, len(d.Labels))
+	for k, v := range d.Labels {
+		labels = append(labels, fmt.Sprintf("%s|%s", k, v))
+	}
+	sort.Strings(labels)
+	key := d.ProjectId + "##" + d.Target + "##" + strings.Join(labels, "#")
+	c.profilerHeader = []string{key}
+}
+
+// setXGoogHeader sets the name and version of the application in
+// the `x-goog-api-client` header passed on each request. Intended for
+// use by Google-written clients.
+func (c *client) setXGoogHeader(keyval ...string) {
+	kv := append([]string{"gl-go", version.Go(), "gccl", version.Repo}, keyval...)
+	kv = append(kv, "gax", gax.Version, "grpc", grpc.Version)
+	c.xGoogHeader = []string{gax.XGoogHeader(kv...)}
+}
+
+func (c *client) insertMetadata(ctx context.Context) context.Context {
+	md, _ := grpcmd.FromOutgoingContext(ctx)
+	md = md.Copy()
+	md[xGoogAPIMetadata] = c.xGoogHeader
+	md[deploymentKeyMetadata] = c.profilerHeader
+	return grpcmd.NewOutgoingContext(ctx, md)
+}
+
+func initializeDeployment() (*pb.Deployment, error) {
+	var err error
+
+	projectID := config.ProjectID
+	if projectID == "" {
+		projectID, err = getProjectID()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	instance := config.InstanceName
+	if instance == "" {
+		instance, err = getInstanceName()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	zone := config.ZoneName
+	if zone == "" {
+		zone, err = getZone()
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return &pb.Deployment{
+		ProjectId: projectID,
+		Target:    config.Target,
+		Labels: map[string]string{
+			instanceLabel: instance,
+			zoneNameLabel: zone,
+		},
+	}, nil
+}
+
+func initializeResources(ctx context.Context, conn *grpc.ClientConn, d *pb.Deployment) (*agent, context.Context) {
+	c := &client{
+		client: pb.NewProfilerServiceClient(conn),
+	}
+	c.setXGoogHeader()
+	c.setProfilerHeader(d)
+
+	ctx = c.insertMetadata(ctx)
+	return &agent{
+		client:     c,
+		deployment: d,
+	}, ctx
+}
+
+func initializeConfig(cfg *Config) {
+	*config = *cfg
+
+	if config.Target == "" {
+		config.Target = "unknown"
+	}
+	if config.APIAddr == "" {
+		config.APIAddr = apiAddress
+	}
+}
+
+// pollProfilerService starts an endless loop to poll Cloud Profiler
+// server for instructions, and collects and uploads profiles as
+// requested.
+func pollProfilerService(ctx context.Context, a *agent) {
+	for {
+		p := a.createProfile(ctx)
+		a.profileAndUpload(ctx, p)
+	}
+}