internal/queue/queue.go - pkgsite-metrics - Git at Google

 // Copyright 2022 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

 // Package queue provides queue implementations that can be used for
 // asynchronous scheduling of fetch actions.
 package queue

 import (
 	"context"
 	"crypto/sha256"
 	"encoding/hex"
 	"errors"
 	"fmt"
 	"io"
 	"strings"
 	"time"

 	cloudtasks "cloud.google.com/go/cloudtasks/apiv2"
 	taskspb "cloud.google.com/go/cloudtasks/apiv2/cloudtaskspb"
 	"golang.org/x/pkgsite-metrics/internal/config"
 	"golang.org/x/pkgsite-metrics/internal/derrors"
 	"golang.org/x/pkgsite-metrics/internal/log"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 	"google.golang.org/protobuf/types/known/durationpb"
 )

 // A Task can produce information needed for Cloud Tasks.
 type Task interface {
 	Name() string   // Human-readable string for the task. Need not be unique.
 	Path() string   // URL path
 	Params() string // URL query params
 }

 // A Queue provides an interface for asynchronous scheduling of fetch actions.
 type Queue interface {
 	// EnqueueScan enqueues a scan request.
 	// It reports whether a new task was actually added.
 	EnqueueScan(context.Context, Task, *Options) (bool, error)
 }

 // New creates a new Queue with name queueName based on the configuration
 // in cfg. When running locally, Queue uses numWorkers concurrent workers.
 func New(ctx context.Context, cfg *config.Config, processFunc inMemoryProcessFunc) (Queue, error) {
 	if !config.OnCloudRun() {
 		return NewInMemory(ctx, cfg.LocalQueueWorkers, processFunc), nil
 	}
 	client, err := cloudtasks.NewClient(ctx)
 	if err != nil {
 		return nil, err
 	}
 	g, err := newGCP(cfg, client, cfg.QueueName)
 	if err != nil {
 		return nil, err
 	}
 	log.Infof(ctx, "enqueuing at %s with queueURL=%q", g.queueName, g.queueURL)
 	return g, nil
 }

 // GCP provides a Queue implementation backed by the Google Cloud Tasks API.
 type GCP struct {
 	client    *cloudtasks.Client
 	queueName string // full GCP name of the queue
 	queueURL  string // non-AppEngine URL to post tasks to
 	// token holds information that lets the task queue construct an authorized request to the worker.
 	// Since the worker sits behind the IAP, the queue needs an identity token that includes the
 	// identity of a service account that has access, and the client ID for the IAP.
 	// We use the service account of the current process.
 	token *taskspb.HttpRequest_OidcToken
 }

 // newGCP returns a new Queue that can be used to enqueue tasks using the
 // cloud tasks API.  The given queueID should be the name of the queue in the
 // cloud tasks console.
 func newGCP(cfg *config.Config, client *cloudtasks.Client, queueID string) (_ *GCP, err error) {
 	defer derrors.Wrap(&err, "newGCP(cfg, client, %q)", queueID)
 	if queueID == "" {
 		return nil, errors.New("empty queueID")
 	}
 	if cfg.ProjectID == "" {
 		return nil, errors.New("empty ProjectID")
 	}
 	if cfg.LocationID == "" {
 		return nil, errors.New("empty LocationID")
 	}
 	if cfg.QueueURL == "" {
 		return nil, errors.New("empty QueueURL")
 	}
 	if cfg.ServiceAccount == "" {
 		return nil, errors.New("empty ServiceAccount")
 	}
 	return &GCP{
 		client:    client,
 		queueName: fmt.Sprintf("projects/%s/locations/%s/queues/%s", cfg.ProjectID, cfg.LocationID, queueID),
 		queueURL:  cfg.QueueURL,
 		token: &taskspb.HttpRequest_OidcToken{
 			OidcToken: &taskspb.OidcToken{
 				ServiceAccountEmail: cfg.ServiceAccount,
 			},
 		},
 	}, nil
 }

 // EnqueueScan enqueues a scan task on GCP.
 // It returns an error if there was an error hashing the task name, or
 // an error pushing the task to GCP.
 // If the task was a duplicate, it returns (false, nil).
 func (q *GCP) EnqueueScan(ctx context.Context, task Task, opts *Options) (enqueued bool, err error) {
 	defer derrors.WrapStack(&err, "queue.EnqueueScan(%s, %s, %v)", task.Path(), task.Params(), opts)
 	if opts == nil {
 		opts = &Options{}
 	}
 	// Cloud Tasks enforces an RPC timeout of at most 30s. I couldn't find this
 	// in the documentation, but using a larger value, or no timeout, results in
 	// an InvalidArgument error with the text "The deadline cannot be more than
 	// 30s in the future."
 	ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
 	defer cancel()

 	req, err := q.newTaskRequest(task, opts)
 	if err != nil {
 		return false, fmt.Errorf("newTaskRequest: %v", err)
 	}

 	enqueued = true
 	if _, err := q.client.CreateTask(ctx, req); err != nil {
 		if status.Code(err) == codes.AlreadyExists {
 			log.Debugf(ctx, "ignoring duplicate task ID %s", req.Task.Name)
 			enqueued = false
 		} else {
 			return false, fmt.Errorf("q.client.CreateTask(ctx, req): %v", err)
 		}
 	}
 	return enqueued, nil
 }

 // Options is used to provide option arguments for a task queue.
 type Options struct {
 	// Namespace prefixes the URL path.
 	Namespace string
 	// DisableProxyFetch reports whether proxyfetch should be set to off when
 	// making a fetch request.
 	DisableProxyFetch bool

 	// TaskNameSuffix is appended to the task name to force reprocessing of
 	// tasks that would normally be de-duplicated.
 	TaskNameSuffix string
 }

 // maxCloudTasksTimeout is the maximum timeout for HTTP tasks.
 // See https://cloud.google.com/tasks/docs/creating-http-target-tasks.
 const maxCloudTasksTimeout = 30 * time.Minute

 const disableProxyFetchParam = "proxyfetch=off"

 func (q *GCP) newTaskRequest(task Task, opts *Options) (*taskspb.CreateTaskRequest, error) {
 	if opts.Namespace == "" {
 		return nil, errors.New("Options.Namespace cannot be empty")
 	}
 	relativeURI := fmt.Sprintf("/%s/scan/%s", opts.Namespace, task.Path())
 	params := task.Params()
 	if opts.DisableProxyFetch {
 		if params == "" {
 			params = disableProxyFetchParam
 		} else {
 			params += "&" + disableProxyFetchParam
 		}
 	}
 	if params != "" {
 		relativeURI += "?" + params
 	}

 	taskID := newTaskID(opts.Namespace, task)
 	taskpb := &taskspb.Task{
 		Name:             fmt.Sprintf("%s/tasks/%s", q.queueName, taskID),
 		DispatchDeadline: durationpb.New(maxCloudTasksTimeout),
 		MessageType: &taskspb.Task_HttpRequest{
 			HttpRequest: &taskspb.HttpRequest{
 				HttpMethod:          taskspb.HttpMethod_POST,
 				Url:                 q.queueURL + relativeURI,
 				AuthorizationHeader: q.token,
 			},
 		},
 	}
 	req := &taskspb.CreateTaskRequest{
 		Parent: q.queueName,
 		Task:   taskpb,
 	}
 	// If suffix is non-empty, append it to the task name.
 	// This lets us force reprocessing of tasks that would normally be de-duplicated.
 	if opts.TaskNameSuffix != "" {
 		req.Task.Name += "-" + opts.TaskNameSuffix
 	}
 	return req, nil
 }

 // newTaskID creates a task ID for the given task.
 // Tasks with the same ID that are created within a few hours of each other. will be de-duplicated.
 // See https://cloud.google.com/tasks/docs/reference/rpc/google.cloud.tasks.v2#createtaskrequest
 // under "Task De-duplication".
 func newTaskID(namespace string, task Task) string {
 	name := task.Name()
 	// Hash the path and params of the task.
 	hasher := sha256.New()
 	io.WriteString(hasher, task.Path())
 	io.WriteString(hasher, task.Params())
 	hash := hex.EncodeToString(hasher.Sum(nil))
 	return escapeTaskID(fmt.Sprintf("%s-%s-%s", name, namespace, hash[:8]))
 }

 // escapeTaskID escapes s so it contains only valid characters for a Cloud Tasks name.
 // It tries to produce a readable result.
 // Task IDs can contain only letters ([A-Za-z]), numbers ([0-9]), hyphens (-), or underscores (_).
 func escapeTaskID(s string) string {
 	var b strings.Builder
 	for _, r := range s {
 		switch {
 		case r >= 'A' && r <= 'Z' || r >= 'a' && r <= 'z' || r >= '0' && r <= '9' || r == '-':
 			b.WriteRune(r)
 		case r == '_':
 			b.WriteString("__")
 		case r == '/':
 			b.WriteString("_-")
 		case r == '@':
 			b.WriteString("_")
 		case r == '.':
 			b.WriteString("_")
 		default:
 			fmt.Fprintf(&b, "_%04x", r)
 		}
 	}
 	return b.String()
 }

 // InMemory is a Queue implementation that schedules in-process fetch
 // operations. Unlike the GCP task queue, it will not automatically retry tasks
 // on failure.
 //
 // This should only be used for local development.
 type InMemory struct {
 	queue chan Task
 	done  chan struct{}
 }

 type inMemoryProcessFunc func(context.Context, Task) (int, error)

 // NewInMemory creates a new InMemory that asynchronously fetches
 // from proxyClient and stores in db. It uses workerCount parallelism to
 // execute these fetches.
 func NewInMemory(ctx context.Context, workerCount int, processFunc inMemoryProcessFunc) *InMemory {
 	q := &InMemory{
 		queue: make(chan Task, 1000),
 		done:  make(chan struct{}),
 	}
 	sem := make(chan struct{}, workerCount)
 	go func() {
 		for v := range q.queue {
 			select {
 			case <-ctx.Done():
 				return
 			case sem <- struct{}{}:
 			}

 			// If a worker is available, make a request to the fetch service inside a
 			// goroutine and wait for it to finish.
 			go func(t Task) {
 				defer func() { <-sem }()

 				log.Infof(ctx, "Fetch requested: %v (workerCount = %d)", t, cap(sem))

 				fetchCtx, cancel := context.WithTimeout(ctx, 5*time.Minute)
 				defer cancel()

 				if _, err := processFunc(fetchCtx, t); err != nil {
 					log.Errorf(fetchCtx, err, "processFunc(%v)", t)
 				}
 			}(v)
 		}
 		for i := 0; i < cap(sem); i++ {
 			select {
 			case <-ctx.Done():
 				panic(fmt.Sprintf("InMemory queue context done: %v", ctx.Err()))
 			case sem <- struct{}{}:
 			}
 		}
 		close(q.done)
 	}()
 	return q
 }

 // EnqueueScan pushes a scan task into the local queue to be processed
 // asynchronously.
 func (q *InMemory) EnqueueScan(ctx context.Context, task Task, _ *Options) (bool, error) {
 	q.queue <- task
 	return true, nil
 }

 // WaitForTesting waits for all queued requests to finish. It should only be
 // used by test code.
 func (q *InMemory) WaitForTesting(ctx context.Context) {
 	close(q.queue)
 	<-q.done
 }
	// Copyright 2022 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	// Package queue provides queue implementations that can be used for
	// asynchronous scheduling of fetch actions.
	package queue

	import (
	"context"
	"crypto/sha256"
	"encoding/hex"
	"errors"
	"fmt"
	"io"
	"strings"
	"time"

	cloudtasks "cloud.google.com/go/cloudtasks/apiv2"
	taskspb "cloud.google.com/go/cloudtasks/apiv2/cloudtaskspb"
	"golang.org/x/pkgsite-metrics/internal/config"
	"golang.org/x/pkgsite-metrics/internal/derrors"
	"golang.org/x/pkgsite-metrics/internal/log"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
	"google.golang.org/protobuf/types/known/durationpb"
	)

	// A Task can produce information needed for Cloud Tasks.
	type Task interface {
	Name() string // Human-readable string for the task. Need not be unique.
	Path() string // URL path
	Params() string // URL query params
	}

	// A Queue provides an interface for asynchronous scheduling of fetch actions.
	type Queue interface {
	// EnqueueScan enqueues a scan request.
	// It reports whether a new task was actually added.
	EnqueueScan(context.Context, Task, *Options) (bool, error)
	}

	// New creates a new Queue with name queueName based on the configuration
	// in cfg. When running locally, Queue uses numWorkers concurrent workers.
	func New(ctx context.Context, cfg *config.Config, processFunc inMemoryProcessFunc) (Queue, error) {
	if !config.OnCloudRun() {
	return NewInMemory(ctx, cfg.LocalQueueWorkers, processFunc), nil
	}
	client, err := cloudtasks.NewClient(ctx)
	if err != nil {
	return nil, err
	}
	g, err := newGCP(cfg, client, cfg.QueueName)
	if err != nil {
	return nil, err
	}
	log.Infof(ctx, "enqueuing at %s with queueURL=%q", g.queueName, g.queueURL)
	return g, nil
	}

	// GCP provides a Queue implementation backed by the Google Cloud Tasks API.
	type GCP struct {
	client *cloudtasks.Client
	queueName string // full GCP name of the queue
	queueURL string // non-AppEngine URL to post tasks to
	// token holds information that lets the task queue construct an authorized request to the worker.
	// Since the worker sits behind the IAP, the queue needs an identity token that includes the
	// identity of a service account that has access, and the client ID for the IAP.
	// We use the service account of the current process.
	token *taskspb.HttpRequest_OidcToken
	}

	// newGCP returns a new Queue that can be used to enqueue tasks using the
	// cloud tasks API. The given queueID should be the name of the queue in the
	// cloud tasks console.
	func newGCP(cfg config.Config, client cloudtasks.Client, queueID string) (_ *GCP, err error) {
	defer derrors.Wrap(&err, "newGCP(cfg, client, %q)", queueID)
	if queueID == "" {
	return nil, errors.New("empty queueID")
	}
	if cfg.ProjectID == "" {
	return nil, errors.New("empty ProjectID")
	}
	if cfg.LocationID == "" {
	return nil, errors.New("empty LocationID")
	}
	if cfg.QueueURL == "" {
	return nil, errors.New("empty QueueURL")
	}
	if cfg.ServiceAccount == "" {
	return nil, errors.New("empty ServiceAccount")
	}
	return &GCP{
	client: client,
	queueName: fmt.Sprintf("projects/%s/locations/%s/queues/%s", cfg.ProjectID, cfg.LocationID, queueID),
	queueURL: cfg.QueueURL,
	token: &taskspb.HttpRequest_OidcToken{
	OidcToken: &taskspb.OidcToken{
	ServiceAccountEmail: cfg.ServiceAccount,
	},
	},
	}, nil
	}

	// EnqueueScan enqueues a scan task on GCP.
	// It returns an error if there was an error hashing the task name, or
	// an error pushing the task to GCP.
	// If the task was a duplicate, it returns (false, nil).
	func (q GCP) EnqueueScan(ctx context.Context, task Task, opts Options) (enqueued bool, err error) {
	defer derrors.WrapStack(&err, "queue.EnqueueScan(%s, %s, %v)", task.Path(), task.Params(), opts)
	if opts == nil {
	opts = &Options{}
	}
	// Cloud Tasks enforces an RPC timeout of at most 30s. I couldn't find this
	// in the documentation, but using a larger value, or no timeout, results in
	// an InvalidArgument error with the text "The deadline cannot be more than
	// 30s in the future."
	ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
	defer cancel()

	req, err := q.newTaskRequest(task, opts)
	if err != nil {
	return false, fmt.Errorf("newTaskRequest: %v", err)
	}

	enqueued = true
	if _, err := q.client.CreateTask(ctx, req); err != nil {
	if status.Code(err) == codes.AlreadyExists {
	log.Debugf(ctx, "ignoring duplicate task ID %s", req.Task.Name)
	enqueued = false
	} else {
	return false, fmt.Errorf("q.client.CreateTask(ctx, req): %v", err)
	}
	}
	return enqueued, nil
	}

	// Options is used to provide option arguments for a task queue.
	type Options struct {
	// Namespace prefixes the URL path.
	Namespace string
	// DisableProxyFetch reports whether proxyfetch should be set to off when
	// making a fetch request.
	DisableProxyFetch bool

	// TaskNameSuffix is appended to the task name to force reprocessing of
	// tasks that would normally be de-duplicated.
	TaskNameSuffix string
	}

	// maxCloudTasksTimeout is the maximum timeout for HTTP tasks.
	// See https://cloud.google.com/tasks/docs/creating-http-target-tasks.
	const maxCloudTasksTimeout = 30 * time.Minute

	const disableProxyFetchParam = "proxyfetch=off"

	func (q GCP) newTaskRequest(task Task, opts Options) (*taskspb.CreateTaskRequest, error) {
	if opts.Namespace == "" {
	return nil, errors.New("Options.Namespace cannot be empty")
	}
	relativeURI := fmt.Sprintf("/%s/scan/%s", opts.Namespace, task.Path())
	params := task.Params()
	if opts.DisableProxyFetch {
	if params == "" {
	params = disableProxyFetchParam
	} else {
	params += "&" + disableProxyFetchParam
	}
	}
	if params != "" {
	relativeURI += "?" + params
	}

	taskID := newTaskID(opts.Namespace, task)
	taskpb := &taskspb.Task{
	Name: fmt.Sprintf("%s/tasks/%s", q.queueName, taskID),
	DispatchDeadline: durationpb.New(maxCloudTasksTimeout),
	MessageType: &taskspb.Task_HttpRequest{
	HttpRequest: &taskspb.HttpRequest{
	HttpMethod: taskspb.HttpMethod_POST,
	Url: q.queueURL + relativeURI,
	AuthorizationHeader: q.token,
	},
	},
	}
	req := &taskspb.CreateTaskRequest{
	Parent: q.queueName,
	Task: taskpb,
	}
	// If suffix is non-empty, append it to the task name.
	// This lets us force reprocessing of tasks that would normally be de-duplicated.
	if opts.TaskNameSuffix != "" {
	req.Task.Name += "-" + opts.TaskNameSuffix
	}
	return req, nil
	}

	// newTaskID creates a task ID for the given task.
	// Tasks with the same ID that are created within a few hours of each other. will be de-duplicated.
	// See https://cloud.google.com/tasks/docs/reference/rpc/google.cloud.tasks.v2#createtaskrequest
	// under "Task De-duplication".
	func newTaskID(namespace string, task Task) string {
	name := task.Name()
	// Hash the path and params of the task.
	hasher := sha256.New()
	io.WriteString(hasher, task.Path())
	io.WriteString(hasher, task.Params())
	hash := hex.EncodeToString(hasher.Sum(nil))
	return escapeTaskID(fmt.Sprintf("%s-%s-%s", name, namespace, hash[:8]))
	}

	// escapeTaskID escapes s so it contains only valid characters for a Cloud Tasks name.
	// It tries to produce a readable result.
	// Task IDs can contain only letters ([A-Za-z]), numbers ([0-9]), hyphens (-), or underscores (_).
	func escapeTaskID(s string) string {
	var b strings.Builder
	for _, r := range s {
	switch {
	case r >= 'A' && r <= 'Z' \|\| r >= 'a' && r <= 'z' \|\| r >= '0' && r <= '9' \|\| r == '-':
	b.WriteRune(r)
	case r == '_':
	b.WriteString("__")
	case r == '/':
	b.WriteString("_-")
	case r == '@':
	b.WriteString("_")
	case r == '.':
	b.WriteString("_")
	default:
	fmt.Fprintf(&b, "_%04x", r)
	}
	}
	return b.String()
	}

	// InMemory is a Queue implementation that schedules in-process fetch
	// operations. Unlike the GCP task queue, it will not automatically retry tasks
	// on failure.
	//
	// This should only be used for local development.
	type InMemory struct {
	queue chan Task
	done chan struct{}
	}

	type inMemoryProcessFunc func(context.Context, Task) (int, error)

	// NewInMemory creates a new InMemory that asynchronously fetches
	// from proxyClient and stores in db. It uses workerCount parallelism to
	// execute these fetches.
	func NewInMemory(ctx context.Context, workerCount int, processFunc inMemoryProcessFunc) *InMemory {
	q := &InMemory{
	queue: make(chan Task, 1000),
	done: make(chan struct{}),
	}
	sem := make(chan struct{}, workerCount)
	go func() {
	for v := range q.queue {
	select {
	case <-ctx.Done():
	return
	case sem <- struct{}{}:
	}

	// If a worker is available, make a request to the fetch service inside a
	// goroutine and wait for it to finish.
	go func(t Task) {
	defer func() { <-sem }()

	log.Infof(ctx, "Fetch requested: %v (workerCount = %d)", t, cap(sem))

	fetchCtx, cancel := context.WithTimeout(ctx, 5*time.Minute)
	defer cancel()

	if _, err := processFunc(fetchCtx, t); err != nil {
	log.Errorf(fetchCtx, err, "processFunc(%v)", t)
	}
	}(v)
	}
	for i := 0; i < cap(sem); i++ {
	select {
	case <-ctx.Done():
	panic(fmt.Sprintf("InMemory queue context done: %v", ctx.Err()))
	case sem <- struct{}{}:
	}
	}
	close(q.done)
	}()
	return q
	}

	// EnqueueScan pushes a scan task into the local queue to be processed
	// asynchronously.
	func (q InMemory) EnqueueScan(ctx context.Context, task Task, _ Options) (bool, error) {
	q.queue <- task
	return true, nil
	}

	// WaitForTesting waits for all queued requests to finish. It should only be
	// used by test code.
	func (q *InMemory) WaitForTesting(ctx context.Context) {
	close(q.queue)
	<-q.done
	}