From ba17b32dd5a806cac5408a708ee4edb21b465b00 Mon Sep 17 00:00:00 2001
From: Louis Thibault <l.thibault@sentimens.com>
Date: Fri, 15 Jul 2022 17:55:02 +0200
Subject: [PATCH] Clean up client dial API. Add vat.NewClientHost.

---
 examples/dial-client/main.go | 14 +++-----------
 examples/pubsub/main.go      | 16 +++++-----------
 pkg/client/dialer.go         | 23 ++---------------------
 pkg/vat/util.go              | 25 +++++++++++++++++++++++++
 4 files changed, 35 insertions(+), 43 deletions(-)
 create mode 100644 pkg/vat/util.go

diff --git a/examples/dial-client/main.go b/examples/dial-client/main.go
index 46613f1e..b7a74dbd 100644
--- a/examples/dial-client/main.go
+++ b/examples/dial-client/main.go
@@ -6,24 +6,16 @@ import (
 	"io"
 	"log"
 
-	"github.com/libp2p/go-libp2p"
-	libp2pquic "github.com/libp2p/go-libp2p-quic-transport"
 	bootutil "github.com/wetware/casm/pkg/boot/util"
 	"github.com/wetware/ww/pkg/client"
 	"github.com/wetware/ww/pkg/vat"
 )
 
-func main() {
-	ctx := context.Background()
+var ctx = context.Background()
 
+func main() {
 	// Instantiate the libp2p host that the Wetware client will use.
-	host, err := libp2p.New(
-		// Don't listen for incoming network connections.  This is
-		// common practice for Wetware clients.
-		libp2p.NoListenAddrs,
-		// Wetware uses the QUIC transport, so let's enable it.
-		libp2p.Transport(libp2pquic.NewTransport),
-	)
+	host, err := vat.NewClientHost()
 	if err != nil {
 		log.Fatal(err)
 	}
diff --git a/examples/pubsub/main.go b/examples/pubsub/main.go
index 6c4f9ffe..386c3c76 100644
--- a/examples/pubsub/main.go
+++ b/examples/pubsub/main.go
@@ -7,24 +7,16 @@ import (
 	"log"
 	"time"
 
-	"github.com/libp2p/go-libp2p"
-	libp2pquic "github.com/libp2p/go-libp2p-quic-transport"
 	bootutil "github.com/wetware/casm/pkg/boot/util"
 	"github.com/wetware/ww/pkg/client"
 	"github.com/wetware/ww/pkg/vat"
 )
 
-func main() {
-	ctx := context.Background()
+var ctx = context.Background()
 
+func main() {
 	// Instantiate the libp2p host that the Wetware client will use.
-	host, err := libp2p.New(
-		// Don't listen for incoming network connections.  This is
-		// common practice for Wetware clients.
-		libp2p.NoListenAddrs,
-		// Wetware uses the QUIC transport, so let's enable it.
-		libp2p.Transport(libp2pquic.NewTransport),
-	)
+	host, err := vat.NewClientHost()
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -91,6 +83,8 @@ func main() {
 	}
 	defer sub.Cancel()
 
+	// Print messages received on the subscription.  This will
+	// include messages we have sent ourselves.
 	for {
 		b, err := sub.Next(ctx)
 		if err != nil {
diff --git a/pkg/client/dialer.go b/pkg/client/dialer.go
index 99d497d8..cb0e0281 100644
--- a/pkg/client/dialer.go
+++ b/pkg/client/dialer.go
@@ -9,38 +9,19 @@ import (
 	"github.com/libp2p/go-libp2p-core/peer"
 	"github.com/lthibault/log"
 
-	"github.com/wetware/casm/pkg/boot"
 	"github.com/wetware/ww/pkg/vat"
 	"github.com/wetware/ww/pkg/vat/cap/cluster"
 	"github.com/wetware/ww/pkg/vat/cap/pubsub"
 )
 
-type Addr string
-
-func (addr Addr) FindPeers(ctx context.Context, ns string, opt ...discovery.Option) (<-chan peer.AddrInfo, error) {
-	info, err := peer.AddrInfoFromString(string(addr))
-	if err != nil {
-		return nil, err
-	}
-
-	return boot.StaticAddrs{*info}.FindPeers(ctx, ns, opt...)
-}
-
+// Dialer is a factory type for Node.  It uses Boot to join the
+// cluster identified by Vat.NS, and returns a Node.
 type Dialer struct {
 	Log  log.Logger
 	Vat  vat.Network
 	Boot discovery.Discoverer
 }
 
-// Dial is a convenience function that joins a cluster using the
-// supplied address string.
-//
-// See Dialer.Dial for an important notice about the lifetime of
-// ctx.
-func Dial(ctx context.Context, vat vat.Network, a Addr) (*Node, error) {
-	return Dialer{Vat: vat, Boot: a}.Dial(ctx)
-}
-
 // Dial creates a client and connects it to a cluster.
 func (d Dialer) Dial(ctx context.Context) (*Node, error) {
 	if d.Log == nil {
diff --git a/pkg/vat/util.go b/pkg/vat/util.go
new file mode 100644
index 00000000..9d32887d
--- /dev/null
+++ b/pkg/vat/util.go
@@ -0,0 +1,25 @@
+// Package vatutil provides utilities for creating and configuring network vats.
+package vat
+
+import (
+	"github.com/libp2p/go-libp2p"
+	"github.com/libp2p/go-libp2p-core/host"
+	libp2pquic "github.com/libp2p/go-libp2p-quic-transport"
+)
+
+// NewClientHost returns a libp2p.Host suitable for use in a Wetware
+// client vat.  By default, the returned host uses the QUIC transport,
+// and does not accept incoming network connections.
+//
+// Callers can override these defaults by passing libp2p.Options.
+func NewClientHost(opt ...libp2p.Option) (host.Host, error) {
+	return libp2p.New(withClientDefault(opt)...)
+}
+
+func withClientDefault(opt []libp2p.Option) []libp2p.Option {
+	return append([]libp2p.Option{
+		libp2p.NoTransports,
+		libp2p.NoListenAddrs,
+		libp2p.Transport(libp2pquic.NewTransport),
+	}, opt...)
+}