fix(lnd): send SIGINT to lnd to terminate

app/lib/lnd/neutrino.js

@@ -15,7 +15,7 @@ const CHAIN_SYNC_COMPLETE = 'chain-sync-finished'
 
 // Events
 const ERROR = 'error'
-const CLOSE = 'close'
+const EXIT = 'exit'
 const WALLET_UNLOCKER_GRPC_ACTIVE = 'wallet-unlocker-grpc-active'
 const LIGHTNING_GRPC_ACTIVE = 'lightning-grpc-active'
 const GOT_CURRENT_BLOCK_HEIGHT = 'got-current-block-height'
@@ -90,11 +90,25 @@ class Neutrino extends EventEmitter {
       // neutrinoArgs.push('--neutrino.connect=testnet2-btcd.zaphq.io')
     }
 
+    mainLog.info(
+      'Spawning Neutrino process: %s %s',
+      this.lndConfig.binaryPath,
+      neutrinoArgs.join(' ')
+    )
+
     this.process = spawn(this.lndConfig.binaryPath, neutrinoArgs)
-      .on('error', error => this.emit(ERROR, error))
+      .on('error', error => {
-      .on('close', code => {
+        mainLog.debug('Neutrino process received "error" event with error: %s', error)
-        this.emit(CLOSE, code, this.lastError)
+        this.emit(ERROR, error, this.lastError)
+      })
+      .on('exit', (code, signal) => {
+        mainLog.debug(
+          'Neutrino process received "exit" event with code %s and signal %s',
+          code,
+          signal
+        )
         this.process = null
+        this.emit(EXIT, code, signal, this.lastError)
       })
 
     // Listen for when neutrino prints data to stderr.
@@ -230,11 +244,10 @@ class Neutrino extends EventEmitter {
   /**
    * Stop the Lnd process.
    */
-  kill() {
+  kill(signalName: string = 'SIGINT') {
     if (this.process) {
       mainLog.info('Killing Neutrino process...')
-      this.process.kill()
+      this.process.kill(signalName)
-      this.process = null
     }
   }
 

app/lib/zap/controller.js

@@ -288,11 +288,8 @@ class ZapController {
     }
   }
 
-  /**
   /**
    * Starts the LND node and attach event listeners.
-   * @param  {string} alias Alias to assign to the lnd node.
-   * @param  {boolean} autopilot True if autopilot should be enabled.
    * @return {Neutrino} Neutrino instance.
    */
   startNeutrino() {
@@ -307,12 +304,12 @@ class ZapController {
       })
     })
 
-    this.neutrino.on('close', (code, lastError) => {
+    this.neutrino.on('exit', (code, signal, lastError) => {
-      mainLog.info(`Lnd process has shut down (code ${code})`)
+      mainLog.info(`Lnd process has shut down (code: ${code}, signal: ${signal})`)
       if (this.is('running') || this.is('connected')) {
         dialog.showMessageBox({
           type: 'error',
-          message: `Lnd has unexpectedly quit: ${lastError}`
+          message: `Lnd has unexpectedly quit:\n\nError code: ${code}\nExit signal: ${signal}\nLast error: ${lastError}`
         })
         this.terminate()
       }
@@ -358,61 +355,45 @@ class ZapController {
    */
   async shutdownNeutrino() {
     // We only want to shut down LND if we are running it locally.
-    if (this.lndConfig.type !== 'local') {
+    if (this.lndConfig.type !== 'local' || !this.neutrino || !this.neutrino.process) {
       return Promise.resolve()
     }
 
-    // Attempt a graceful shutdown if we can.
-    if (this.lightning && this.lightning.can('terminate')) {
     mainLog.info('Shutting down Neutrino...')
 
-      return new Promise(resolve => {
+    return new Promise(async resolve => {
       // HACK: Sometimes there are errors during the shutdown process that prevent the daeming from shutting down at
       // all. If we haven't received notification of the process closing within 10 seconds, kill it.
       // See https://github.com/lightningnetwork/lnd/pull/1781
       // See https://github.com/lightningnetwork/lnd/pull/1783
       const shutdownTimeout = setTimeout(() => {
-          this.neutrino.removeListener('close', closeHandler)
+        this.neutrino.removeListener('exit', exitHandler)
         if (this.neutrino) {
           mainLog.warn('Graceful shutdown failed to complete within 10 seconds.')
-            this.neutrino.kill()
+          this.neutrino.kill('SIGTERM')
           resolve()
         }
       }, 1000 * 10)
 
-        // HACK: The Lightning.stopDaemon` call returns before lnd has actually fully completed the shutdown process
+      const exitHandler = () => {
-        // so we add a listener on the close event so that we can wrap things up once the process has been fully closed
-        // out.
-        const closeHandler = function() {
-          mainLog.info('Neutrino shutdown complete.')
         clearTimeout(shutdownTimeout)
         resolve()
       }
-        this.neutrino.once('close', closeHandler)
+      this.neutrino.once('exit', exitHandler)
 
-        this.lightning
+      // The Lightning service is only active once the wallet has been unlocked and a gRPC connection has been made.
-          .terminate()
+      // If it is active, disconnect from it before we terminate neutrino.
-          .then(() => mainLog.info('Neutrino Daemon shutdown complete'))
+      if (this.lightning && this.lightning.can('terminate')) {
-          .catch(err => {
+        await this.lightning.disconnect()
-            mainLog.error('Unable to gracefully shutdown LND: %o', err)
-            // Kill the process ourselves here to ensure that we don't leave hanging processes.
-            if (this.neutrino) {
-              this.neutrino.kill()
-              resolve()
-            }
-          })
-      })
       }
-
+      // Kill the Neutrino process (sends SIGINT to Neutrino process)
-    // The Lightning service is only active after the wallet has been unlocked and a gRPC connection has been
-    // established. In this case, kill the Neutrino process to ensure that we don't leave hanging process.
-    // FIXME: This currencly doesn't do a graceful shutdown as LND does not properly handle SIGTERM.
-    // See https://github.com/lightningnetwork/lnd/issues/1028
-    else if (this.neutrino) {
       this.neutrino.kill()
-    }
+    }).then(() => mainLog.info('Neutrino shutdown complete'))
   }
 
+  /**
+   * Start or connect to lnd process after onboarding has been completed by the app.
+   */
   finishOnboarding(options: onboardingOptions) {
     mainLog.info('Finishing onboarding')
     // Save the lnd config options that we got from the renderer.

test/unit/lnd/neutrino.spec.js

@@ -200,19 +200,4 @@ describe('Neutrino', function() {
       })
     })
   })
-
-  describe('.kill', () => {
-    describe('called when neutrino is already running', () => {
-      beforeEach(() => {
-        this.neutrino = new Neutrino(new LndConfig())
-        this.neutrino.process = {
-          kill: jest.fn()
-        }
-        this.neutrino.kill()
-      })
-      it('should kill the neutrino process', () => {
-        expect(this.neutrino.process).toBeNull()
-      })
-    })
-  })
 })