vspd/main.go
2020-05-17 07:49:53 +01:00

114 lines
2.8 KiB
Go

package main
import (
"context"
"errors"
"fmt"
"net"
"net/http"
"os"
"time"
"github.com/jholdstock/dcrvsp/database"
"github.com/jrick/wsrpc/v2"
)
var (
cfg *config
db *database.VspDatabase
nodeConnection *wsrpc.Client
)
func main() {
// Create a context that is cancelled when a shutdown request is received
// through an interrupt signal.
ctx := withShutdownCancel(context.Background())
go shutdownListener()
// Run until error is returned, or shutdown is requested.
if err := run(ctx); err != nil && !errors.Is(err, context.Canceled) {
os.Exit(1)
}
}
// run is the main startup and teardown logic performed by the main package. It
// is responsible for parsing the config, creating a dcrwallet RPC client,
// opening the database, starting the webserver, and stopping all started
// services when the context is cancelled.
func run(ctx context.Context) error {
var err error
// Load config file and parse CLI args.
cfg, err = loadConfig()
if err != nil {
// Don't use logger here because it may not be initialised.
fmt.Fprintf(os.Stderr, "Config error: %v", err)
return err
}
// Open database.
db, err = database.New(cfg.dbPath)
if err != nil {
log.Errorf("Database error: %v", err)
return err
}
// Close database.
defer func() {
log.Debug("Closing database...")
err := db.Close()
if err != nil {
log.Errorf("Error closing database: %v", err)
} else {
log.Debug("Database closed")
}
}()
// Create TCP listener for webserver.
var listenConfig net.ListenConfig
listener, err := listenConfig.Listen(ctx, "tcp", cfg.Listen)
if err != nil {
log.Errorf("Failed to create tcp listener: %v", err)
return err
}
log.Infof("Listening on %s", cfg.Listen)
// Create webserver.
// TODO: Make releaseMode properly configurable.
releaseMode := true
srv := http.Server{
Handler: newRouter(releaseMode),
ReadTimeout: 5 * time.Second, // slow requests should not hold connections opened
WriteTimeout: 60 * time.Second, // hung responses must die
}
// Start webserver.
go func() {
err = srv.Serve(listener)
// If the server dies for any reason other than ErrServerClosed (from
// graceful server.Shutdown), log the error and request dcrvsp be
// shutdown.
if err != nil && err != http.ErrServerClosed {
log.Errorf("Unexpected webserver error: %v", err)
requestShutdown()
}
}()
// Stop webserver.
defer func() {
log.Debug("Stopping webserver...")
// Give the webserver 5 seconds to finish what it is doing.
timeoutCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
if err := srv.Shutdown(timeoutCtx); err != nil {
log.Errorf("Failed to stop webserver cleanly: %v", err)
}
log.Debug("Webserver stopped")
}()
// Wait until shutdown is signaled before returning and running deferred
// shutdown tasks.
<-ctx.Done()
return ctx.Err()
}