interceptor: move client interceptor to its own package

Author: orbitalturtle

lsat/client_interceptor.go renamed to interceptor/client_interceptor.go

@@ -1,4 +1,4 @@
-package lsat
+package interceptor
 
 import (
 	"context"
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/btcsuite/btcd/btcutil"
+	"github.com/lightninglabs/aperture/lsat"
 	"github.com/lightninglabs/lndclient"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lnwire"
@@ -77,18 +78,18 @@ var (
 // connection to lnd to automatically pay for an authentication token.
 type ClientInterceptor struct {
 	lnd           *lndclient.LndServices
-	store         Store
+	store         lsat.Store
 	callTimeout   time.Duration
 	maxCost       btcutil.Amount
 	maxFee        btcutil.Amount
 	lock          sync.Mutex
 	allowInsecure bool
 }
 
-// NewInterceptor creates a new gRPC client interceptor that uses the provided
+// NewClientInterceptor creates a new gRPC client interceptor that uses the provided
 // lnd connection to automatically acquire and pay for LSAT tokens, unless the
 // indicated store already contains a usable token.
-func NewInterceptor(lnd *lndclient.LndServices, store Store,
+func NewClientInterceptor(lnd *lndclient.LndServices, store lsat.Store,
 	rpcCallTimeout time.Duration, maxCost,
 	maxFee btcutil.Amount, allowInsecure bool) *ClientInterceptor {
 
@@ -108,7 +109,7 @@ type interceptContext struct {
 	mainCtx  context.Context
 	opts     []grpc.CallOption
 	metadata *metadata.MD
-	token    *Token
+	token    *lsat.Token
 }
 
 // UnaryInterceptor is an interceptor method that can be used directly by gRPC
@@ -223,7 +224,7 @@ func (i *ClientInterceptor) newInterceptContext(ctx context.Context,
 	iCtx.token, err = i.store.CurrentToken()
 	switch {
 	// If there is no token yet, nothing to do at this point.
-	case err == ErrNoToken:
+	case err == lsat.ErrNoToken:
 
 	// Some other error happened that we have to surface.
 	case err != nil:
@@ -235,7 +236,7 @@ func (i *ClientInterceptor) newInterceptContext(ctx context.Context,
 	// payment just yet, since we don't even know if a token is required for
 	// this call. We also never send a pending payment to the server since
 	// we know it's not valid.
-	case !iCtx.token.isPending():
+	case !iCtx.token.IsPending():
 		if err = i.addLsatCredentials(iCtx); err != nil {
 			log.Errorf("Adding macaroon to request failed: %v", err)
 			return nil, fmt.Errorf("adding macaroon failed: %v",
@@ -257,7 +258,7 @@ func (i *ClientInterceptor) newInterceptContext(ctx context.Context,
 func (i *ClientInterceptor) handlePayment(iCtx *interceptContext) error {
 	switch {
 	// Resume/track a pending payment if it was interrupted for some reason.
-	case iCtx.token != nil && iCtx.token.isPending():
+	case iCtx.token != nil && iCtx.token.IsPending():
 		log.Infof("Payment of LSAT token is required, resuming/" +
 			"tracking previous payment from pending LSAT token")
 		err := i.trackPayment(iCtx.mainCtx, iCtx.token)
@@ -321,7 +322,7 @@ func (i *ClientInterceptor) addLsatCredentials(iCtx *interceptContext) error {
 		return err
 	}
 	iCtx.opts = append(iCtx.opts, grpc.PerRPCCredentials(
-		NewMacaroonCredential(macaroon, i.allowInsecure),
+		lsat.NewMacaroonCredential(macaroon, i.allowInsecure),
 	))
 	return nil
 }
@@ -330,7 +331,7 @@ func (i *ClientInterceptor) addLsatCredentials(iCtx *interceptContext) error {
 // to pay the invoice encoded in them, returning a paid LSAT token if
 // successful.
 func (i *ClientInterceptor) payLsatToken(ctx context.Context, md *metadata.MD) (
-	*Token, error) {
+	*lsat.Token, error) {
 
 	// First parse the authentication header that was stored in the
 	// metadata.
@@ -367,7 +368,7 @@ func (i *ClientInterceptor) payLsatToken(ctx context.Context, md *metadata.MD) (
 
 	// Create and store the pending token so we can resume the payment in
 	// case the payment is interrupted somehow.
-	token, err := tokenFromChallenge(macBytes, invoice.PaymentHash)
+	token, err := lsat.TokenFromChallenge(macBytes, invoice.PaymentHash)
 	if err != nil {
 		return nil, fmt.Errorf("unable to create token: %v", err)
 	}
@@ -407,7 +408,9 @@ func (i *ClientInterceptor) payLsatToken(ctx context.Context, md *metadata.MD) (
 
 // trackPayment tries to resume a pending payment by tracking its state and
 // waiting for a conclusive result.
-func (i *ClientInterceptor) trackPayment(ctx context.Context, token *Token) error {
+func (i *ClientInterceptor) trackPayment(ctx context.Context,
+	token *lsat.Token) error {
+
 	// Lookup state of the payment.
 	paymentStateCtx, cancel := context.WithCancel(ctx)
 	defer cancel()
@@ -486,7 +489,7 @@ func IsPaymentRequired(err error) bool {
 
 // extractPaymentDetails extracts the preimage and amounts paid for a payment
 // from the payment status and stores them in the token.
-func extractPaymentDetails(token *Token, status lndclient.PaymentStatus) {
+func extractPaymentDetails(token *lsat.Token, status lndclient.PaymentStatus) {
 	token.Preimage = status.Preimage
 	token.AmountPaid = status.Value
 	token.RoutingFeePaid = status.Fee

lsat/client_interceptor_test.go renamed to interceptor/client_interceptor_test.go

@@ -1,4 +1,4 @@
-package lsat
+package interceptor
 
 import (
 	"context"
@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/lightninglabs/aperture/internal/test"
+	"github.com/lightninglabs/aperture/lsat"
 	"github.com/lightninglabs/lndclient"
 	"github.com/lightningnetwork/lnd/lnrpc"
 	"github.com/lightningnetwork/lnd/lntypes"
@@ -36,21 +37,21 @@ type interceptTestCase struct {
 }
 
 type mockStore struct {
-	token *Token
+	token *lsat.Token
 }
 
-func (s *mockStore) CurrentToken() (*Token, error) {
+func (s *mockStore) CurrentToken() (*lsat.Token, error) {
 	if s.token == nil {
-		return nil, ErrNoToken
+		return nil, lsat.ErrNoToken
 	}
 	return s.token, nil
 }
 
-func (s *mockStore) AllTokens() (map[string]*Token, error) {
-	return map[string]*Token{"foo": s.token}, nil
+func (s *mockStore) AllTokens() (map[string]*lsat.Token, error) {
+	return map[string]*lsat.Token{"foo": s.token}, nil
 }
 
-func (s *mockStore) StoreToken(token *Token) error {
+func (s *mockStore) StoreToken(token *lsat.Token) error {
 	s.token = token
 	return nil
 }
@@ -64,11 +65,11 @@ var (
 	lnd         = test.NewMockLnd()
 	store       = &mockStore{}
 	testTimeout = 5 * time.Second
-	interceptor = NewInterceptor(
+	interceptor = NewClientInterceptor(
 		&lnd.LndServices, store, testTimeout,
 		DefaultMaxCostSats, DefaultMaxRoutingFeeSats, false,
 	)
-	testMac         = makeMac()
+	testMac         = lsat.MakeMac()
 	testMacBytes    = serializeMac(testMac)
 	testMacHex      = hex.EncodeToString(testMacBytes)
 	paidPreimage    = lntypes.Preimage{1, 2, 3, 4, 5}
@@ -135,7 +136,7 @@ var (
 		expectMacaroonCall2: false,
 	}, {
 		name:            "auth required, has pending token",
-		initialPreimage: &zeroPreimage,
+		initialPreimage: &lsat.ZeroPreimage,
 		interceptor:     interceptor,
 		resetCb: func() {
 			resetBackend(
@@ -166,7 +167,7 @@ var (
 		expectMacaroonCall2: true,
 	}, {
 		name:            "auth required, has pending but expired token",
-		initialPreimage: &zeroPreimage,
+		initialPreimage: &lsat.ZeroPreimage,
 		interceptor:     interceptor,
 		resetCb: func() {
 			resetBackend(
@@ -207,7 +208,7 @@ var (
 	}, {
 		name:            "auth required, no token yet, cost limit",
 		initialPreimage: nil,
-		interceptor: NewInterceptor(
+		interceptor: NewClientInterceptor(
 			&lnd.LndServices, store, testTimeout, 100,
 			DefaultMaxRoutingFeeSats, false,
 		),
@@ -393,7 +394,7 @@ func testInterceptor(t *testing.T, tc interceptTestCase,
 		require.NoError(t, err)
 		require.Equal(t, paidPreimage, storeToken.Preimage)
 	} else {
-		require.Equal(t, ErrNoToken, err)
+		require.Equal(t, lsat.ErrNoToken, err)
 	}
 	if tc.expectMacaroonCall2 {
 		require.Len(t, callMD, 1)
@@ -405,27 +406,16 @@ func testInterceptor(t *testing.T, tc interceptTestCase,
 	require.Equal(t, tc.expectBackendCalls, numBackendCalls)
 }
 
-func makeToken(preimage *lntypes.Preimage) *Token {
+func makeToken(preimage *lntypes.Preimage) *lsat.Token {
 	if preimage == nil {
 		return nil
 	}
-	return &Token{
+	return &lsat.Token{
 		Preimage: *preimage,
-		baseMac:  testMac,
+		BaseMac:  testMac,
 	}
 }
 
-func makeMac() *macaroon.Macaroon {
-	dummyMac, err := macaroon.New(
-		[]byte("aabbccddeeff00112233445566778899"), []byte("AA=="),
-		"LSAT", macaroon.LatestVersion,
-	)
-	if err != nil {
-		panic(fmt.Errorf("unable to create macaroon: %v", err))
-	}
-	return dummyMac
-}
-
 func serializeMac(mac *macaroon.Macaroon) []byte {
 	macBytes, err := mac.MarshalBinary()
 	if err != nil {

interceptor/log.go

@@ -0,0 +1,26 @@
+package interceptor
+
+import (
+	"github.com/btcsuite/btclog"
+	"github.com/lightningnetwork/lnd/build"
+)
+
+// Subsystem defines the sub system name of this package.
+const Subsystem = "INPR"
+
+// log is a logger that is initialized with no output filters.  This
+// means the package will not perform any logging by default until the caller
+// requests it.
+var log btclog.Logger
+
+// The default amount of logging is none.
+func init() {
+	UseLogger(build.NewSubLogger(Subsystem, nil))
+}
+
+// UseLogger uses a specified Logger to output package logging info.
+// This should be used in preference to SetLogWriter if the caller is also
+// using btclog.
+func UseLogger(logger btclog.Logger) {
+	log = logger
+}

log.go

@@ -4,6 +4,7 @@ import (
 	"github.com/btcsuite/btclog"
 	"github.com/lightninglabs/aperture/auth"
 	"github.com/lightninglabs/aperture/challenger"
+	"github.com/lightninglabs/aperture/interceptor"
 	"github.com/lightninglabs/aperture/lsat"
 	"github.com/lightninglabs/aperture/proxy"
 	"github.com/lightninglabs/lndclient"
@@ -31,6 +32,9 @@ func SetupLoggers(root *build.RotatingLogWriter, intercept signal.Interceptor) {
 	lnd.AddSubLogger(
 		root, challenger.Subsystem, intercept, challenger.UseLogger,
 	)
+	lnd.AddSubLogger(
+		root, interceptor.Subsystem, intercept, interceptor.UseLogger,
+	)
 	lnd.AddSubLogger(root, lsat.Subsystem, intercept, lsat.UseLogger)
 	lnd.AddSubLogger(root, proxy.Subsystem, intercept, proxy.UseLogger)
 	lnd.AddSubLogger(root, "LNDC", intercept, lndclient.UseLogger)

lsat/store.go

@@ -24,7 +24,12 @@ var (
 	// errNoReplace is the error that is returned if a new token is
 	// being written to a store that already contains a paid token.
 	errNoReplace = errors.New("won't replace existing paid token with " +
-		"new token. " + manualRetryHint)
+		"new token. " + ManualRetryHint)
+
+	// ManualRetryHint is the error text we return to tell the user how a
+	// token payment can be retried if the payment fails.
+	ManualRetryHint = "consider removing pending token file if error " +
+		"persists. use 'listauth' command to find out token file name"
 )
 
 // Store is an interface that allows users to store and retrieve an LSAT token.
@@ -152,7 +157,7 @@ func (f *FileStore) StoreToken(newToken *Token) error {
 	case err == ErrNoToken:
 		// What's the target file name we are going to write?
 		newFileName := f.fileName
-		if newToken.isPending() {
+		if newToken.IsPending() {
 			newFileName = f.fileNamePending
 		}
 		return os.WriteFile(newFileName, bytes, 0600)
@@ -162,7 +167,7 @@ func (f *FileStore) StoreToken(newToken *Token) error {
 		return err
 
 	// Replace a pending token with a paid one.
-	case currentToken.isPending() && !newToken.isPending():
+	case currentToken.IsPending() && !newToken.IsPending():
 		// Make sure we replace the the same token, just with a
 		// different state.
 		if currentToken.PaymentHash != newToken.PaymentHash {

lsat/store_test.go

@@ -22,11 +22,11 @@ func TestFileStore(t *testing.T) {
 		paidPreimage = lntypes.Preimage{1, 2, 3, 4, 5}
 		paidToken    = &Token{
 			Preimage: paidPreimage,
-			baseMac:  makeMac(),
+			BaseMac:  MakeMac(),
 		}
 		pendingToken = &Token{
-			Preimage: zeroPreimage,
-			baseMac:  makeMac(),
+			Preimage: ZeroPreimage,
+			BaseMac:  MakeMac(),
 		}
 	)
 
@@ -61,7 +61,7 @@ func TestFileStore(t *testing.T) {
 	if err != nil {
 		t.Fatalf("could not read pending token: %v", err)
 	}
-	if !token.baseMac.Equal(pendingToken.baseMac) {
+	if !token.BaseMac.Equal(pendingToken.BaseMac) {
 		t.Fatalf("expected macaroon to match")
 	}
 	tokens, err = store.AllTokens()
@@ -73,7 +73,7 @@ func TestFileStore(t *testing.T) {
 			len(tokens), 1)
 	}
 	for key := range tokens {
-		if !tokens[key].baseMac.Equal(pendingToken.baseMac) {
+		if !tokens[key].BaseMac.Equal(pendingToken.BaseMac) {
 			t.Fatalf("expected macaroon to match")
 		}
 	}
@@ -96,7 +96,7 @@ func TestFileStore(t *testing.T) {
 	if err != nil {
 		t.Fatalf("could not read pending token: %v", err)
 	}
-	if !token.baseMac.Equal(paidToken.baseMac) {
+	if !token.BaseMac.Equal(paidToken.BaseMac) {
 		t.Fatalf("expected macaroon to match")
 	}
 	tokens, err = store.AllTokens()
@@ -108,7 +108,7 @@ func TestFileStore(t *testing.T) {
 			len(tokens), 1)
 	}
 	for key := range tokens {
-		if !tokens[key].baseMac.Equal(paidToken.baseMac) {
+		if !tokens[key].BaseMac.Equal(paidToken.BaseMac) {
 			t.Fatalf("expected macaroon to match")
 		}
 	}

lsat/test_utils.go

@@ -0,0 +1,18 @@
+package lsat
+
+import (
+	"fmt"
+
+	"gopkg.in/macaroon.v2"
+)
+
+func MakeMac() *macaroon.Macaroon {
+	dummyMac, err := macaroon.New(
+		[]byte("aabbccddeeff00112233445566778899"), []byte("AA=="),
+		"LSAT", macaroon.LatestVersion,
+	)
+	if err != nil {
+		panic(fmt.Errorf("unable to create macaroon: %v", err))
+	}
+	return dummyMac
+}