cmd/worker/main.go

// Copyright 2019 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.

// The worker command runs a service with the primary job of fetching modules
// from a proxy and writing them to the database.
package main

import (
	"context"
	"flag"
	"net/http"
	"os"
	"time"

	"cloud.google.com/go/profiler"
	"github.com/go-redis/redis/v8"
	"github.com/google/safehtml/template"
	_ "github.com/jackc/pgx/v5/stdlib" // for pgx driver
	"go.opencensus.io/plugin/ochttp"
	octrace "go.opencensus.io/trace"
	"golang.org/x/pkgsite/cmd/internal/cmdconfig"
	"golang.org/x/pkgsite/internal/config"
	"golang.org/x/pkgsite/internal/config/serverconfig"
	"golang.org/x/pkgsite/internal/dcensus"
	"golang.org/x/pkgsite/internal/index"
	"golang.org/x/pkgsite/internal/log"
	"golang.org/x/pkgsite/internal/middleware"
	mtimeout "golang.org/x/pkgsite/internal/middleware/timeout"
	"golang.org/x/pkgsite/internal/proxy"
	"golang.org/x/pkgsite/internal/queue"
	"golang.org/x/pkgsite/internal/queue/gcpqueue"
	"golang.org/x/pkgsite/internal/queue/inmemqueue"
	"golang.org/x/pkgsite/internal/queue/pgqueue"
	"golang.org/x/pkgsite/internal/source"
	"golang.org/x/pkgsite/internal/trace"
	"golang.org/x/pkgsite/internal/worker"
)

var (
	timeout   = serverconfig.GetEnvInt(context.Background(), "GO_DISCOVERY_WORKER_TIMEOUT_MINUTES", 10)
	queueName = serverconfig.GetEnv("GO_DISCOVERY_WORKER_TASK_QUEUE", "")
	workers   = flag.Int("workers", 10, "number of concurrent requests to the fetch service, when running locally")
	// flag used in call to safehtml/template.TrustedSourceFromFlag
	_                  = flag.String("static", "static", "path to folder containing static files served")
	bypassLicenseCheck = flag.Bool("bypass_license_check", false, "insert all data into the DB, even for non-redistributable paths")
	queueType          = flag.String("queue", "inmemory", `queue implementation when not on GCP: "inmemory" or "postgres"`)

	// Ordinarily, index polling is initiated by a separate scheduler that calls
	// /poll. But for convenience, you can instead have the worker periodically
	// do the same.
	pollIndexPeriod  = flag.Duration("poll_index_period", 0, "when set >0, schedules an index poll at this period")
	pollIndexLimit   = flag.Int("poll_index_limit", 10, "the amount of modules to fetch from the index when periodically polling")
	pollIndexHorizon = flag.Duration("poll_index_horizon", time.Hour, "the amount of time ago to request modules each iteration when periodically polling")

	// Ordinarily, module version process enqueueing is initiated by a separate
	// scheduler that calls /enqueue. But for convenience, you can instead have
	// the worker periodically do the same.
	enqueuePeriod = flag.Duration("enqueue_period", 0, "when set >0, schedules the worker to periodically enqueue work from the module_version_states table for processing, at this period")
	enqueueLimit  = flag.Int("enqueue_limit", 10, "the amount of modules to enqueue when periodically enqueueing")
)

func main() {
	flag.Parse()

	ctx := context.Background()

	cfg, err := serverconfig.Init(ctx)
	if err != nil {
		log.Fatal(ctx, err)
	}
	cfg.Dump(os.Stdout)

	if cfg.UseProfiler {
		if err := profiler.Start(profiler.Config{}); err != nil {
			log.Fatalf(ctx, "profiler.Start: %v", err)
		}
	}

	db, err := cmdconfig.OpenDB(ctx, cfg, *bypassLicenseCheck)
	if err != nil {
		log.Fatalf(ctx, "%v", err)
	}
	defer db.Close()

	if err := worker.PopulateExcluded(ctx, cfg, db); err != nil {
		log.Fatal(ctx, err)
	}

	indexClient, err := index.New(cfg.IndexURL)
	if err != nil {
		log.Fatal(ctx, err)
	}
	proxyClient, err := proxy.New(cfg.ProxyURL, new(ochttp.Transport))
	if err != nil {
		log.Fatal(ctx, err)
	}
	sourceClient := source.NewClient(&http.Client{
		Transport: &ochttp.Transport{},
		Timeout:   config.SourceTimeout,
	})
	expg := cmdconfig.ExperimentGetter(ctx, cfg)

	var fetchQueue queue.Queue
	if serverconfig.OnGCP() {
		q, err := gcpqueue.New(ctx, cfg, queueName, *workers)
		if err != nil {
			log.Fatalf(ctx, "error creating GCP queue: %v", err)
		}
		fetchQueue = q
	} else {
		f := &worker.Fetcher{
			ProxyClient:  proxyClient,
			SourceClient: sourceClient,
			DB:           db,
		}
		processFunc := func(ctx context.Context, modulePath, version string) (int, error) {
			code, _, err := f.FetchAndUpdateState(ctx, modulePath, version, cfg.AppVersionLabel())
			return code, err
		}
		switch *queueType {
		case "postgres":
			q, err := pgqueue.New(ctx, db.Underlying())
			if err != nil {
				log.Fatalf(ctx, "error creating postgres queue: %v", err)
			}
			go q.Poll(ctx, *workers, processFunc)
			fetchQueue = q
		default:
			experiments, err := expg(ctx)
			if err != nil {
				log.Fatalf(ctx, "error getting experiment: %v", err)
			}
			var names []string
			for _, e := range experiments {
				if e.Rollout > 0 {
					names = append(names, e.Name)
				}
			}
			fetchQueue = inmemqueue.New(ctx, *workers, names, processFunc)
		}
	}

	reporter := cmdconfig.Reporter(ctx, cfg)
	trace.SetTraceFunction(func(ctx context.Context, name string) (context.Context, trace.Span) {
		return octrace.StartSpan(ctx, name)
	})
	redisCacheClient := getCacheRedis(ctx, cfg)
	experimenter := cmdconfig.Experimenter(ctx, cfg, expg, reporter)
	server, err := worker.NewServer(cfg, worker.ServerConfig{
		DB:               db,
		IndexClient:      indexClient,
		ProxyClient:      proxyClient,
		SourceClient:     sourceClient,
		RedisCacheClient: redisCacheClient,
		Queue:            fetchQueue,
		Reporter:         reporter,
		StaticPath:       template.TrustedSourceFromFlag(flag.Lookup("static").Value),
		GetExperiments:   experimenter.Experiments,
	})
	if err != nil {
		log.Fatal(ctx, err)
	}

	if *pollIndexPeriod != 0 {
		go func() {
			log.Infof(ctx, "starting periodic index polling. period=%v, limit=%v, horizon=%v", *pollIndexPeriod, *pollIndexLimit, *pollIndexHorizon)
			ticker := time.NewTicker(*pollIndexPeriod)
			for {
				select {
				case <-ctx.Done():
					log.Warningf(ctx, "cancelling periodic index polling: %v", ctx.Err())
					return
				case <-ticker.C:
					since := time.Now().Add(-1 * *pollIndexHorizon)
					if err := server.PollIndex(ctx, since, *pollIndexLimit); err != nil {
						log.Warningf(ctx, "error during periodic index polling: %v", err)
					}
				}
			}
		}()
	}

	if *enqueuePeriod != 0 {
		go func() {
			log.Infof(ctx, "starting periodic enqueueing. period=%v, limit=%v", *enqueuePeriod, *enqueueLimit)
			ticker := time.NewTicker(*enqueuePeriod)
			for {
				select {
				case <-ctx.Done():
					log.Warningf(ctx, "cancelling periodic enqueueing: %v", ctx.Err())
					return
				case <-ticker.C:
					if err := server.Enqueue(ctx, nil, *enqueueLimit, ""); err != nil {
						log.Warningf(ctx, "error during periodic enqueueing: %v", err)
					}
				}
			}
		}()
	}

	router := dcensus.NewRouter(nil)
	server.Install(router.Handle)

	views := append(dcensus.ServerViews,
		worker.EnqueueResponseCount,
		worker.ProcessingLag,
		worker.UnprocessedModules,
		worker.UnprocessedNewModules,
		worker.DBProcesses,
		worker.DBWaitingProcesses,
		worker.SheddedFetchCount,
		worker.FetchLatencyDistribution,
		worker.FetchResponseCount,
		worker.FetchPackageCount)
	if err := dcensus.Init(cfg, views...); err != nil {
		log.Fatal(ctx, err)
	}

	iap := middleware.Identity()
	if aud := os.Getenv("GO_DISCOVERY_IAP_AUDIENCE"); aud != "" {
		iap = middleware.ValidateIAPHeader(aud)
	}

	mw := middleware.Chain(
		middleware.RequestInfo(), // must be first
		middleware.RequestLog(cmdconfig.Logger(ctx, cfg, "worker-log")),
		mtimeout.Timeout(time.Duration(timeout)*time.Minute),
		iap,
		middleware.Experiment(experimenter),
	)
	http.Handle("/", mw(router))

	dh, err := server.DebugHandler()
	if err != nil {
		log.Fatal(ctx, err)
	}
	http.Handle("/debug/", mw(http.StripPrefix("/debug", dh)))

	addr := cfg.HostAddr("localhost:8000")
	log.Infof(ctx, "Timeout is %d minutes", timeout)
	log.Infof(ctx, "Listening on addr %s", addr)
	log.Fatal(ctx, http.ListenAndServe(addr, nil))
}

func getCacheRedis(ctx context.Context, cfg *config.Config) *redis.Client {
	return getRedis(ctx, cfg.RedisCacheHost, cfg.RedisCachePort, 0, 6*time.Second)
}

func getRedis(ctx context.Context, host, port string, writeTimeout, readTimeout time.Duration) *redis.Client {
	if host == "" {
		return nil
	}
	var dialTimeout time.Duration
	if dl, ok := ctx.Deadline(); ok {
		dialTimeout = time.Until(dl)
	}
	return redis.NewClient(&redis.Options{
		Addr:         host + ":" + port,
		DialTimeout:  dialTimeout,
		WriteTimeout: writeTimeout,
		ReadTimeout:  readTimeout,
	})
}