lndclient: Add watchtower client interface

Add the wtclient_client.go file which contains the lnd watchtower client
interface.

Signed-off-by: Jonathan <[email protected]>

Author: Jontified

wtclient_client.go

@@ -0,0 +1,238 @@
+package lndclient
+
+import (
+	"context"
+	"time"
+
+	"github.com/lightningnetwork/lnd/lnrpc/wtclientrpc"
+	"google.golang.org/grpc"
+)
+
+// WatchtowerClientClient implements the watchtower client interface
+// https://lightning.engineering/api-docs/category/watchtowerclient-service/
+// NOTE: For the macaroon code to work correctly, this needs to be named
+// WatchtowerClientClient since we use reflection to set macaroon permissions.
+type WatchtowerClientClient interface {
+	ServiceClient[wtclientrpc.WatchtowerClientClient]
+
+	// AddTower adds a new watchtower reachable at the given address and
+	// considers it for new sessions. If the watchtower already exists, then
+	// any new addresses included will be considered when dialing it for
+	// session negotiations and backups.
+	AddTower(ctx context.Context, pubkey []byte, address string) error
+
+	// DeactivateTower sets the given tower's status to inactive so that it
+	// is not considered for session negotiation. Its sessions will also not
+	// be used while the tower is inactive.
+	DeactivateTower(ctx context.Context, pubkey []byte) (string, error)
+
+	// GetTowerInfo gets information about a watchtower that corresponds to
+	// the given pubkey. The `includeSessions` flag controls whether session
+	// information is included. The `excludeExhaustedSessions` controls
+	// whether exhausted sessions are included in the response.
+	GetTowerInfo(ctx context.Context, pubkey []byte, includeSessions,
+		excludeExhaustedSessions bool) (*wtclientrpc.Tower, error)
+
+	// ListTowers gets information about all registered watchtowers. The
+	// `includeSessions` and `excludeExhaustedSessions` flags serve the same
+	// function as in the `GetTowerInfo` method.
+	ListTowers(ctx context.Context, includeSessions,
+		excludeExhaustedSessions bool) ([]*wtclientrpc.Tower, error)
+
+	// Policy returns the active watchtower client policy configuration.
+	Policy(ctx context.Context, policyType wtclientrpc.PolicyType) (
+		*wtclientrpc.PolicyResponse, error)
+
+	// RemoveTower removes a watchtower from being considered for future
+	// session negotiations and from being used for any subsequent backups
+	// until it's added again. If an address is provided, then this RPC only
+	// serves as a way of removing the address from the watchtower instead.
+	RemoveTower(ctx context.Context, pubkey []byte, address string) error
+
+	// Stats returns the in-memory statistics of the client since startup.
+	Stats(ctx context.Context) (*wtclientrpc.StatsResponse, error)
+
+	// TerminateSession terminates the given session and marks it to not be
+	// used for backups anymore. Returns a human-readable status string.
+	TerminateSession(ctx context.Context, sessionId []byte) (string, error)
+}
+
+type wtClient struct {
+	client      wtclientrpc.WatchtowerClientClient
+	wtClientMac serializedMacaroon
+	timeout     time.Duration
+}
+
+// A compile time check to ensure that wtClientClient implements the
+// WtclientClient interface.
+var _ WatchtowerClientClient = (*wtClient)(nil)
+
+// newClientClient creates a new watchtower client interface.
+func newWtClient(conn grpc.ClientConnInterface, wtClientMac serializedMacaroon,
+	timeout time.Duration) *wtClient {
+
+	return &wtClient{
+		client:      wtclientrpc.NewWatchtowerClientClient(conn),
+		wtClientMac: wtClientMac,
+		timeout:     timeout,
+	}
+}
+
+// RawClientWithMacAuth returns a context with the proper macaroon
+// authentication, the default RPC timeout, and the raw client.
+func (m *wtClient) RawClientWithMacAuth(
+	parentCtx context.Context) (context.Context, time.Duration,
+	wtclientrpc.WatchtowerClientClient) {
+
+	return m.wtClientMac.WithMacaroonAuth(parentCtx), m.timeout, m.client
+}
+
+// AddTower adds a new watchtower reachable at the given address and
+// considers it for new sessions. If the watchtower already exists, then
+// any new addresses included will be considered when dialing it for
+// session negotiations and backups.
+func (m *wtClient) AddTower(ctx context.Context, pubkey []byte,
+	address string) error {
+
+	rpcCtx, cancel := context.WithTimeout(ctx, m.timeout)
+	defer cancel()
+
+	rpcReq := &wtclientrpc.AddTowerRequest{
+		Pubkey:  pubkey,
+		Address: address,
+	}
+
+	rpcCtx = m.wtClientMac.WithMacaroonAuth(rpcCtx)
+	_, err := m.client.AddTower(rpcCtx, rpcReq)
+
+	return err
+}
+
+// DeactivateTower sets the given tower's status to inactive so that it
+// is not considered for session negotiation. Its sessions will also not
+// be used while the tower is inactive.
+func (m *wtClient) DeactivateTower(ctx context.Context, pubkey []byte) (
+	string, error) {
+
+	rpcCtx, cancel := context.WithTimeout(ctx, m.timeout)
+	defer cancel()
+
+	rpcCtx = m.wtClientMac.WithMacaroonAuth(rpcCtx)
+	resp, err := m.client.DeactivateTower(rpcCtx,
+		&wtclientrpc.DeactivateTowerRequest{
+			Pubkey: pubkey,
+		},
+	)
+	if err != nil {
+		return "", err
+	}
+
+	return resp.Status, nil
+}
+
+// GetTowerInfo gets information about a watchtower that corresponds to
+// the given pubkey. The `includeSessions` flag controls whether session
+// information is included. The `excludeExhaustedSessions` controls
+// whether exhausted sessions are included in the response.
+func (m *wtClient) GetTowerInfo(ctx context.Context, pubkey []byte,
+	includeSessions, excludeExhaustedSessions bool) (*wtclientrpc.Tower,
+	error) {
+
+	rpcCtx, cancel := context.WithTimeout(ctx, m.timeout)
+	defer cancel()
+
+	rpcCtx = m.wtClientMac.WithMacaroonAuth(rpcCtx)
+	return m.client.GetTowerInfo(rpcCtx,
+		&wtclientrpc.GetTowerInfoRequest{
+			Pubkey:                   pubkey,
+			IncludeSessions:          includeSessions,
+			ExcludeExhaustedSessions: excludeExhaustedSessions,
+		},
+	)
+}
+
+// ListTowers gets information about all registered watchtowers. The
+// `includeSessions` and `excludeExhaustedSessions` flags serve the same
+// function as in the `GetTowerInfo` method.
+func (m *wtClient) ListTowers(ctx context.Context, includeSessions,
+	excludeExhaustedSessions bool) ([]*wtclientrpc.Tower, error) {
+
+	rpcCtx, cancel := context.WithTimeout(ctx, m.timeout)
+	defer cancel()
+
+	rpcCtx = m.wtClientMac.WithMacaroonAuth(rpcCtx)
+	resp, err := m.client.ListTowers(rpcCtx, &wtclientrpc.ListTowersRequest{
+		IncludeSessions:          includeSessions,
+		ExcludeExhaustedSessions: excludeExhaustedSessions,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return resp.Towers, nil
+}
+
+// Policy returns the active watchtower client policy configuration.
+func (m *wtClient) Policy(ctx context.Context,
+	policyType wtclientrpc.PolicyType) (*wtclientrpc.PolicyResponse,
+	error) {
+
+	rpcCtx, cancel := context.WithTimeout(ctx, m.timeout)
+	defer cancel()
+
+	rpcCtx = m.wtClientMac.WithMacaroonAuth(rpcCtx)
+	return m.client.Policy(rpcCtx, &wtclientrpc.PolicyRequest{
+		PolicyType: policyType,
+	})
+}
+
+// RemoveTower removes a watchtower from being considered for future
+// session negotiations and from being used for any subsequent backups
+// until it's added again. If an address is provided, then this RPC only
+// serves as a way of removing the address from the watchtower instead.
+func (m *wtClient) RemoveTower(ctx context.Context, pubkey []byte,
+	address string) error {
+
+	rpcCtx, cancel := context.WithTimeout(ctx, m.timeout)
+	defer cancel()
+
+	rpcCtx = m.wtClientMac.WithMacaroonAuth(rpcCtx)
+	_, err := m.client.RemoveTower(rpcCtx, &wtclientrpc.RemoveTowerRequest{
+		Pubkey:  pubkey,
+		Address: address,
+	})
+
+	return err
+}
+
+// Stats returns the in-memory statistics of the client since startup.
+func (m *wtClient) Stats(ctx context.Context) (*wtclientrpc.StatsResponse,
+	error) {
+
+	rpcCtx, cancel := context.WithTimeout(ctx, m.timeout)
+	defer cancel()
+
+	rpcCtx = m.wtClientMac.WithMacaroonAuth(rpcCtx)
+	return m.client.Stats(rpcCtx, &wtclientrpc.StatsRequest{})
+}
+
+// TerminateSession terminates the given session and marks it to not be used
+// for backups anymore. Returns a human-readable status string.
+func (m *wtClient) TerminateSession(ctx context.Context,
+	sessionId []byte) (string, error) {
+
+	rpcCtx, cancel := context.WithTimeout(ctx, m.timeout)
+	defer cancel()
+
+	rpcCtx = m.wtClientMac.WithMacaroonAuth(rpcCtx)
+	resp, err := m.client.TerminateSession(rpcCtx,
+		&wtclientrpc.TerminateSessionRequest{
+			SessionId: sessionId,
+		},
+	)
+	if err != nil {
+		return "", err
+	}
+
+	return resp.Status, nil
+}