cmd.go

// Copyright 2016-2018 Stratumn SAS. 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 storehttp

import (
	"context"
	"flag"
	"os"
	"os/signal"
	"runtime"
	"syscall"
	"time"

	"github.com/stratumn/go-core/jsonhttp"
	"github.com/stratumn/go-core/jsonws"
	"github.com/stratumn/go-core/monitoring"
	"github.com/stratumn/go-core/store"
)

var (
	storeEventsChanSize int
	addr                string
	wsReadBufSize       int
	wsWriteBufSize      int
	wsWriteChanSize     int
	wsWriteTimeout      time.Duration
	wsPongTimeout       time.Duration
	wsPingInterval      time.Duration
	wsMaxMsgSize        int64
	certFile            string
	keyFile             string
	readTimeout         time.Duration
	writeTimeout        time.Duration
	maxHeaderBytes      int
	shutdownTimeout     time.Duration
	enableCORS          bool
)

// Run launches a storehttp server.
func Run(
	a store.Adapter,
	config *Config,
	monitoringConfig *monitoring.Config,
	httpConfig *jsonhttp.Config,
	basicConfig *jsonws.BasicConfig,
	bufConnConfig *jsonws.BufferedConnConfig,
	shutdownTimeout time.Duration,
) {
	monitoring.LogEntry().Info("Copyright (c) 2017 Stratumn SAS")
	monitoring.LogEntry().Info("Apache License 2.0")
	monitoring.LogEntry().Infof("Runtime %s %s %s", runtime.Version(), runtime.GOOS, runtime.GOARCH)

	h := New(a, config, httpConfig, basicConfig, bufConnConfig)
	if err := h.exposeMetrics(monitoringConfig); err != nil {
		monitoring.LogEntry().Fatal(err)
	}

	go func() {
		sigc := make(chan os.Signal, 1)
		signal.Notify(sigc, syscall.SIGINT, syscall.SIGTERM)
		sig := <-sigc
		monitoring.LogEntry().WithField("signal", sig).Info("Got exit signal")
		monitoring.LogEntry().Info("Cleaning up")
		ctx, cancel := context.WithTimeout(context.Background(), shutdownTimeout)
		defer cancel()
		if err := h.Shutdown(ctx); err != nil {
			monitoring.LogEntry().WithField("error", err).Fatal("Failed to shutdown server")
		}
		monitoring.LogEntry().Info("Stopped")
		os.Exit(0)
	}()

	monitoring.LogEntry().WithField("http", httpConfig.Address).Info("Listening")
	if err := h.ListenAndServe(); err != nil {
		monitoring.LogEntry().WithField("error", err).Fatal("Server stopped")
	}
}

// RegisterFlags register the flags used by RunWithFlags.
func RegisterFlags() {
	flag.IntVar(&storeEventsChanSize, "store_events_chan_size", DefaultStoreEventsChanSize, "Size of the store events channel")
	flag.StringVar(&addr, "http", DefaultAddress, "HTTP address")
	flag.IntVar(&wsReadBufSize, "ws_read_buf_size", jsonws.DefaultWebSocketReadBufferSize, "Web socket read buffer size")
	flag.IntVar(&wsWriteBufSize, "ws_write_buf_size", jsonws.DefaultWebSocketWriteBufferSize, "Web socket write buffer size")
	flag.IntVar(&wsWriteChanSize, "ws_write_chan_size", jsonws.DefaultWebSocketWriteChanSize, "Size of a web socket connection write channel")
	flag.DurationVar(&wsWriteTimeout, "ws_write_timeout", jsonws.DefaultWebSocketWriteTimeout, "Timeout for a web socket write")
	flag.DurationVar(&wsPongTimeout, "ws_pong_timeout", jsonws.DefaultWebSocketPongTimeout, "Timeout for a web socket expected pong")
	flag.DurationVar(&wsPingInterval, "ws_ping_interval", jsonws.DefaultWebSocketPingInterval, "Interval between web socket pings")
	flag.Int64Var(&wsMaxMsgSize, "max_msg_size", jsonws.DefaultWebSocketMaxMsgSize, "Maximum size of a received web socket message")
	flag.StringVar(&certFile, "tls_cert", "", "TLS certificate file")
	flag.StringVar(&keyFile, "tls_key", "", "TLS private key file")
	flag.DurationVar(&readTimeout, "read_timeout", jsonhttp.DefaultReadTimeout, "Read timeout")
	flag.DurationVar(&writeTimeout, "write_timeout", jsonhttp.DefaultWriteTimeout, "Write timeout")
	flag.IntVar(&maxHeaderBytes, "max_header_bytes", jsonhttp.DefaultMaxHeaderBytes, "Maximum header bytes")
	flag.DurationVar(&shutdownTimeout, "shutdown_timeout", 10*time.Second, "Shutdown timeout")
	flag.BoolVar(&enableCORS, "enable_cors", false, "Allow cross-origin requests")
}

// RunWithFlags should be called after RegisterFlags and flag.Parse to launch
// a storehttp server configured using flag values.
func RunWithFlags(a store.Adapter) {
	config := &Config{
		StoreEventsChanSize: storeEventsChanSize,
	}
	monitoringConfig := monitoring.ConfigurationFromFlags()
	httpConfig := &jsonhttp.Config{
		Address:        addr,
		ReadTimeout:    readTimeout,
		WriteTimeout:   writeTimeout,
		MaxHeaderBytes: maxHeaderBytes,
		CertFile:       certFile,
		KeyFile:        keyFile,
		EnableCORS:     enableCORS,
	}
	basicConfig := &jsonws.BasicConfig{
		ReadBufferSize:  wsReadBufSize,
		WriteBufferSize: wsWriteBufSize,
		EnableCORS:      enableCORS,
	}
	bufConnConfig := &jsonws.BufferedConnConfig{
		Size:         wsWriteChanSize,
		WriteTimeout: wsWriteTimeout,
		PongTimeout:  wsPongTimeout,
		PingInterval: wsPingInterval,
		MaxMsgSize:   wsMaxMsgSize,
	}

	Run(
		a,
		config,
		monitoringConfig,
		httpConfig,
		basicConfig,
		bufConnConfig,
		shutdownTimeout,
	)
}