Agreement Receiver service (#546)

* setup config and server structure for receiving bandwidth agreements

* add error channel

pkg/agreementreceiver/config.go

@@ -0,0 +1,37 @@
+// Copyright (C) 2018 Storj Labs, Inc.
+// See LICENSE for copying information.
+
+package agreementreceiver
+
+import (
+	"context"
+
+	"go.uber.org/zap"
+
+	monkit "gopkg.in/spacemonkeygo/monkit.v2"
+	"storj.io/storj/pkg/pb"
+	"storj.io/storj/pkg/provider"
+)
+
+var (
+	mon = monkit.Package()
+)
+
+// Config is a configuration struct that is everything you need to start an
+// agreement receiver responsibility
+type Config struct {
+	DatabaseURL string `help:"the database connection string to use" default:"$CONFDIR/agreements.db"`
+}
+
+// Run implements the provider.Responsibility interface
+func (c Config) Run(ctx context.Context, server *provider.Provider) (err error) {
+	defer mon.Task()(&ctx)(&err)
+	ns, err := NewServer(c.DatabaseURL, server.Identity(), zap.L())
+	if err != nil {
+		return err
+	}
+
+	pb.RegisterBandwidthServer(server.GRPC(), ns)
+
+	return server.Run(ctx)
+}

pkg/agreementreceiver/server.go

@@ -0,0 +1,66 @@
+// Copyright (C) 2018 Storj Labs, Inc.
+// See LICENSE for copying information.
+
+package agreementreceiver
+
+import (
+	"fmt"
+
+	"storj.io/storj/pkg/pb"
+	"storj.io/storj/pkg/provider"
+
+	"go.uber.org/zap"
+)
+
+// Server is an implementation of the pb.BandwidthServer interface
+type Server struct {
+	// DB       *dbx.DB
+	identity *provider.FullIdentity
+	logger   *zap.Logger
+}
+
+// NewServer initializes a Server struct
+func NewServer(source string, fi *provider.FullIdentity, logger *zap.Logger) (*Server, error) {
+	//TODO: open dbx postgres database and pass to Server
+	return &Server{
+		identity: fi,
+		logger:   logger,
+	}, nil
+}
+
+// BandwidthAgreements receives and stores bandwidth agreements from storage nodes
+func (s *Server) BandwidthAgreements(stream pb.Bandwidth_BandwidthAgreementsServer) (err error) {
+	ctx := stream.Context()
+	defer mon.Task()(&ctx)(&err)
+
+	ch := make(chan *pb.RenterBandwidthAllocation, 1)
+	errch := make(chan error, 1)
+	go func() {
+		for {
+			msg, err := stream.Recv()
+			if err != nil {
+				errch <- err
+				return
+			}
+			ch <- msg
+		}
+	}()
+
+	for {
+		select {
+		case err := <-errch:
+			return err
+		case <-ctx.Done():
+			return nil
+		case agreement := <-ch:
+			go func() {
+				fmt.Println(agreement)
+				//TODO: write to DB
+				//err = s.DB.WriteAgreement(agreement)
+				// if err != nil {
+				// 	return err
+				// }
+			}()
+		}
+	}
+}