refactor: Move process exit handlers from the trackerless-network to the node package

docs/docs/usage/sdk/how-to-use.md

@@ -29,6 +29,15 @@ If using Node.js you can import the library with:
 const { StreamrClient } = require('@streamr/sdk');
 ```
 
+### Cleaning up
+
+After the StreamrClient is no longer needed or the process is shutting down it is very important to destroy the StreamrClient:
+
+```js
+const client = new StreamrClient()
+await client.destroy()
+```
+
 ### Environments and frameworks
 
 #### Node.js

packages/node/bin/streamr-node.ts

@@ -1,11 +1,13 @@
 #!/usr/bin/env node
 import { program } from 'commander'
 import pkg from '../package.json'
-
+import { Logger } from '@streamr/utils'
 import { createBroker } from '../src/broker'
 import { readConfigAndMigrateIfNeeded } from '../src/config/migration'
 import { overrideConfigToEnvVarsIfGiven } from '../src/config/config'
 
+const logger = new Logger(module)
+
 program
     .version(pkg.version)
     .name('streamr-node')
@@ -17,6 +19,28 @@ program
             const config = readConfigAndMigrateIfNeeded(configFile)
             overrideConfigToEnvVarsIfGiven(config)
             const broker = await createBroker(config)
+
+            // Set up graceful shutdown handlers
+            const shutdown = async (exitCode: number) => {
+                await broker.stop()
+                process.exit(exitCode)
+            }
+
+            const exitEvents = ['SIGINT', 'SIGTERM', 'SIGUSR1', 'SIGUSR2']
+            exitEvents.forEach((event) => {
+                process.on(event, () => shutdown(0))
+            })
+
+            process.on('uncaughtException', (err) => {
+                logger.fatal('Encountered uncaughtException', { err })
+                shutdown(1)
+            })
+
+            process.on('unhandledRejection', (err) => {
+                logger.fatal('Encountered unhandledRejection', { err })
+                shutdown(1)
+            })
+
             if (!program.opts().test) {
                 await broker.start()
             } else {

packages/node/src/broker.ts

@@ -78,13 +78,3 @@ export const createBroker = async (configWithoutDefaults: Config): Promise<Broke
         }
     }
 }
-
-process.on('uncaughtException', (err) => {
-    logger.fatal('Encountered uncaughtException', { err })
-    process.exit(1)
-})
-
-process.on('unhandledRejection', (err) => {
-    logger.fatal('Encountered unhandledRejection', { err })
-    process.exit(1)
-})

packages/sdk/README.md

@@ -118,6 +118,13 @@ streamr.resend(streamId, { last: 10 }, (msgs) => {
 });
 ```
 
+### Clean up
+After the `StreamrClient` is no longer used or the process is shutting down it is very important to call `destroy()` on the `StreamrClient`. This ensures that the network node of the client will be shutdown gracefully. 
+
+```js
+await streamr.destroy()
+```
+
 ___
 
 **This Readme only scratches the surface of what's possible - be sure to [checkout our documentation](https://docs.streamr.network) for the full usage instructions.**

packages/trackerless-network/src/NetworkStack.ts

@@ -8,7 +8,6 @@ import {
     toNodeId
 } from '@streamr/dht'
 import { Logger, MetricsContext, StreamID, StreamPartID, toStreamPartID, until } from '@streamr/utils'
-import pull from 'lodash/pull'
 import { version as applicationVersion } from '../package.json'
 import { ContentDeliveryManager, ContentDeliveryManagerOptions, StreamPartDeliveryOptions } from './ContentDeliveryManager'
 import { ControlLayerNode } from './control-layer/ControlLayerNode'
@@ -25,31 +24,6 @@ export interface NetworkOptions {
 
 const logger = new Logger(module)
 
-const instances: NetworkStack[] = []
-const stopInstances = async () => {
-    // make a clone so that it is ok for each instance.stop() to remove itself from the list (at line 139)
-    // while the map function is iterating the list
-    const clonedInstances = [...instances]
-    await Promise.all(clonedInstances.map((instance) => instance.stop()))
-}
-const EXIT_EVENTS = [`exit`, `SIGINT`, `SIGUSR1`, `SIGUSR2`, `uncaughtException`, `unhandledRejection`, `SIGTERM`]
-EXIT_EVENTS.forEach((event) => {
-    process.on(event, async (eventArg) => {
-        const isError = (event === 'uncaughtException') || (event === 'unhandledRejection')
-        if (isError) {
-            logger.error(`exit event: ${event}`, eventArg)
-        }
-        await stopInstances()
-        process.exit(isError ? 1 : 0)
-    })
-})
-declare let window: any
-if (typeof window === 'object') {
-    window.addEventListener('unload', async () => {
-        await stopInstances()
-    })
-}
-
 export class NetworkStack {
 
     private controlLayerNode?: ControlLayerNode
@@ -72,7 +46,6 @@ export class NetworkStack {
             ...options.networkNode,
             metricsContext: this.metricsContext
         })
-        instances.push(this)
     }
 
     async joinStreamPart(
@@ -190,7 +163,6 @@ export class NetworkStack {
     async stop(): Promise<void> {
         if (!this.stopped) {
             this.stopped = true
-            pull(instances, this)
             await this.contentDeliveryManager!.destroy()
             await this.controlLayerNode!.stop()
             this.contentDeliveryManager = undefined