itest: introduce harness miner

This commit adds a new component, harness miner, to the itest. This
newly added component is responsible for checking the mempool and blocks
for the itest.

lntest/harness_miner.go

@@ -0,0 +1,161 @@
+package lntest
+
+import (
+	"context"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/btcsuite/btcd/chaincfg"
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/integration/rpctest"
+	"github.com/btcsuite/btcd/rpcclient"
+)
+
+const (
+	// minerLogFilename is the default log filename for the miner node.
+	minerLogFilename = "output_btcd_miner.log"
+
+	// minerLogDir is the default log dir for the miner node.
+	minerLogDir = ".minerlogs"
+)
+
+var harnessNetParams = &chaincfg.RegressionNetParams
+
+type HarnessMiner struct {
+	*rpctest.Harness
+
+	// runCtx is a context with cancel method. It's used to signal when the
+	// node needs to quit, and used as the parent context when spawning
+	runCtx context.Context
+	cancel context.CancelFunc
+
+	// logPath is the directory path of the miner's logs.
+	logPath string
+
+	// logFilename is the saved log filename of the miner node.
+	logFilename string
+}
+
+// NewMiner creates a new miner using btcd backend with the default log file
+// dir and name.
+func NewMinerTemp() (*HarnessMiner, error) { // TODO(yy): rename
+	return newMiner(minerLogDir, minerLogFilename)
+}
+
+// NewTempMiner creates a new miner using btcd backend with the specified log
+// file dir and name.
+func NewTempMiner(tempDir, tempLogFilename string) (*HarnessMiner, error) {
+	return newMiner(tempDir, tempLogFilename)
+}
+
+// newMiner creates a new miner using btcd's rpctest.
+func newMiner(minerDirName, logFilename string) (*HarnessMiner, error) {
+	handler := &rpcclient.NotificationHandlers{}
+	btcdBinary := GetBtcdBinary()
+	baseLogPath := fmt.Sprintf("%s/%s", GetLogDir(), minerDirName)
+
+	args := []string{
+		"--rejectnonstd",
+		"--txindex",
+		"--nowinservice",
+		"--nobanning",
+		"--debuglevel=debug",
+		"--logdir=" + baseLogPath,
+		"--trickleinterval=100ms",
+		// Don't disconnect if a reply takes too long.
+		"--nostalldetect",
+	}
+
+	miner, err := rpctest.New(harnessNetParams, handler, args, btcdBinary)
+	if err != nil {
+		return nil, fmt.Errorf("unable to create mining node: %v", err)
+	}
+
+	ctxt, cancel := context.WithCancel(context.Background())
+	m := &HarnessMiner{
+		Harness:     miner,
+		runCtx:      ctxt,
+		cancel:      cancel,
+		logPath:     baseLogPath,
+		logFilename: logFilename,
+	}
+	return m, nil
+}
+
+// Stop shuts down the miner and saves its logs.
+func (h *HarnessMiner) Stop() error {
+	h.cancel()
+
+	if err := h.TearDown(); err != nil {
+		return fmt.Errorf("tear down miner got error: %s", err)
+	}
+
+	return h.saveLogs()
+}
+
+// saveLogs copies the node logs and save it to the file specified by
+// h.logFilename.
+func (h *HarnessMiner) saveLogs() error {
+	// After shutting down the miner, we'll make a copy of the log files
+	// before deleting the temporary log dir.
+	path := fmt.Sprintf("%s/%s", h.logPath, harnessNetParams.Name)
+	files, err := ioutil.ReadDir(path)
+	if err != nil {
+		return fmt.Errorf("unable to read log directory: %v", err)
+	}
+
+	for _, file := range files {
+		newFilename := strings.Replace(
+			file.Name(), "btcd.log", h.logFilename, 1,
+		)
+		copyPath := fmt.Sprintf("%s/../%s", h.logPath, newFilename)
+
+		logFile := fmt.Sprintf("%s/%s", path, file.Name())
+		err := CopyFile(filepath.Clean(copyPath), logFile)
+		if err != nil {
+			return fmt.Errorf("unable to copy file: %v", err)
+		}
+	}
+
+	if err = os.RemoveAll(h.logPath); err != nil {
+		return fmt.Errorf("cannot remove dir %s: %v", h.logPath, err)
+	}
+
+	return nil
+}
+
+// waitForTxInMempool blocks until the target txid is seen in the mempool. If
+// the transaction isn't seen within the network before the passed timeout,
+// then an error is returned.
+func (h *HarnessMiner) waitForTxInMempool(txid chainhash.Hash) error {
+	ticker := time.NewTicker(50 * time.Millisecond)
+	defer ticker.Stop()
+
+	var mempool []*chainhash.Hash
+	for {
+		select {
+		case <-h.runCtx.Done():
+			return fmt.Errorf("NetworkHarness has been torn down")
+		case <-time.After(DefaultTimeout):
+			return fmt.Errorf("wanted %v, found %v txs "+
+				"in mempool: %v", txid, len(mempool), mempool)
+
+		case <-ticker.C:
+			var err error
+			mempool, err = h.Client.GetRawMempool()
+			if err != nil {
+				return err
+			}
+
+			for _, mempoolTx := range mempool {
+				if *mempoolTx == txid {
+					return nil
+				}
+			}
+		}
+	}
+}