multi: add open channel utility

templates/golang/bitcoin.go

@@ -0,0 +1,22 @@
+package main
+
+import (
+	"fmt"
+	"os/exec"
+	"strconv"
+)
+
+// Mine n blocks using bitcoin cli.
+func Mine(n int) error {
+        // Santiy check for fat fingering to stop us setting our laptops on 
+        // fire, can be removed.
+        if n > 1000{
+                return fmt.Errorf("trying to mine: %v blocks failed "+
+                "santiy check", n)
+        }
+
+	cmd := exec.Command("bitcoin-cli", "-generate", strconv.Itoa(n))
+
+	_, err := cmd.Output()
+	return err
+}

templates/golang/graph.go

@@ -0,0 +1,160 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/btcsuite/btcd/btcutil"
+	"github.com/btcsuite/btcd/wire"
+	"github.com/lightninglabs/lndclient"
+	"github.com/lightningnetwork/lnd/routing/route"
+)
+
+// GraphHarness is responsible for all graph related operations (P2P, channels,
+// gossip etc).
+type GraphHarness struct {
+	LndNodes Nodes
+}
+
+type OpenChannelReq struct {
+	Source int
+	Dest   route.Vertex
+	// Host is an optional host address for the node, we'll lookup in our
+	// graph if this value is empty.
+	Host        string
+	CapacitySat btcutil.Amount
+	PushAmt     btcutil.Amount
+	Private     bool
+}
+
+// OpenChannel is a blocking call that opens a channel from the source node
+// provided to the target:
+// - looks up a node in the graph
+// - connects to it if we are not currently connected
+// - opens a channel with the parameters provided
+// - opens a channel and mines block to confirm it
+// - waits for the channel to be active
+func (c *GraphHarness) OpenChannel(ctx context.Context,
+	req OpenChannelReq) (*wire.OutPoint, error) {
+
+	connected, err := c.PeerConnected(ctx, req.Source, req.Dest)
+	if err != nil {
+		return nil, err
+	}
+
+	if !connected {
+		host := req.Host
+		if host == "" {
+			node, err := c.LookupNode(
+				ctx, req.Source, req.Dest, false,
+			)
+			if err != nil {
+				return nil, err
+			}
+
+			if len(node.Addresses) == 0 {
+				return nil, fmt.Errorf("no public address "+
+					"for: %v", req.Dest)
+			}
+
+			host = node.Addresses[0]
+		}
+
+		err = c.ConnectPeer(ctx, req.Source, req.Dest, host)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	sourceNode := c.LndNodes.GetNode(req.Source)
+	streamChan, errChan, err := sourceNode.Client.OpenChannelStream(
+		ctx, req.Dest, req.CapacitySat, req.PushAmt, req.Private,
+	)
+	if err != nil {
+		return nil, err
+	}
+	for {
+		select {
+		case update := <-streamChan:
+                        // Wait for the channel to be pending before we mine.
+			if update.ChanPending != nil {
+				if err := Mine(6); err != nil {
+					return nil, fmt.Errorf("could not "+
+						"mine: %v", err)
+				}
+			}
+
+			if update.ChanOpen != nil {
+				return outpointFromRPC(
+					update.ChanOpen.ChannelPoint,
+				), nil
+			}
+
+		case e := <-errChan:
+			return nil, e
+
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		}
+
+	}
+}
+
+func (c *GraphHarness) LookupNode(ctx context.Context, source int,
+	dest route.Vertex, includeChannels bool) (*lndclient.NodeInfo, error) {
+
+	sourceNode := c.LndNodes.GetNode(source)
+	destNode, err := sourceNode.Client.GetNodeInfo(
+		ctx, dest, includeChannels,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return destNode, nil
+}
+
+func (c *GraphHarness) ConnectPeer(ctx context.Context, source int,
+	dest route.Vertex, addr string) error {
+
+	sourceNode := c.LndNodes.GetNode(source)
+	if err := sourceNode.Client.Connect(ctx, dest, addr, true); err != nil {
+		return err
+	}
+
+	for i := 0; i < 5; i++ {
+		connected, err := c.PeerConnected(ctx, source, dest)
+		if err != nil || connected {
+			return err
+		}
+
+		select {
+		case <-time.After(time.Second):
+
+		case <-ctx.Done():
+			return ctx.Err()
+		}
+	}
+
+	return fmt.Errorf("timeout waiting for peer: %v to connect", dest)
+}
+
+func (c *GraphHarness) PeerConnected(ctx context.Context, source int,
+	target route.Vertex) (bool, error) {
+
+	sourceNode := c.LndNodes.GetNode(source)
+
+	peers, err := sourceNode.Client.ListPeers(ctx)
+	if err != nil {
+		return false, nil
+	}
+
+	for _, peer := range peers {
+		if peer.Pubkey == target {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}

templates/golang/utils.go

@@ -3,6 +3,9 @@ package main
 import (
 	"crypto/rand"
 
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/wire"
+	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lntypes"
 )
 
@@ -16,10 +19,34 @@ func genPreimage() lntypes.Preimage {
 		panic(err)
 	}
 
-        preimage, err:= lntypes.MakePreimage(randomBytes)
-        if err!=nil{
-                panic(err)
-        }
+	preimage, err := lntypes.MakePreimage(randomBytes)
+	if err != nil {
+		panic(err)
+	}
 
-        return preimage
+	return preimage
+}
+
+func outpointFromRPC(rpc *lnrpc.ChannelPoint) *wire.OutPoint {
+	var (
+		hash *chainhash.Hash
+		err  error
+	)
+
+	switch h := rpc.FundingTxid.(type) {
+	case *lnrpc.ChannelPoint_FundingTxidBytes:
+		hash, err = chainhash.NewHash(h.FundingTxidBytes)
+
+	case *lnrpc.ChannelPoint_FundingTxidStr:
+		hash, err = chainhash.NewHashFromStr(h.FundingTxidStr)
+
+	default:
+		panic("Unknown channel point type")
+	}
+
+	if err != nil {
+		panic(err)
+	}
+
+	return wire.NewOutPoint(hash, rpc.OutputIndex)
 }