File size: 5,299 Bytes
aec3094 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 | import { Logger } from '@n8n/backend-common';
import { TaskRunnersConfig } from '@n8n/config';
import { OnShutdown } from '@n8n/decorators';
import { Service } from '@n8n/di';
import * as a from 'node:assert/strict';
import { spawn } from 'node:child_process';
import * as process from 'node:process';
import { forwardToLogger } from './forward-to-logger';
import { NodeProcessOomDetector } from './node-process-oom-detector';
import { TaskBrokerAuthService } from './task-broker/auth/task-broker-auth.service';
import { TaskRunnerLifecycleEvents } from './task-runner-lifecycle-events';
import { TypedEmitter } from '../typed-emitter';
type ChildProcess = ReturnType<typeof spawn>;
export type ExitReason = 'unknown' | 'oom';
export type TaskRunnerProcessEventMap = {
exit: {
reason: ExitReason;
};
};
/**
* Manages the JS task runner process as a child process
*/
@Service()
export class TaskRunnerProcess extends TypedEmitter<TaskRunnerProcessEventMap> {
get isRunning() {
return this.process !== null;
}
/** The process ID of the task runner process */
get pid() {
return this.process?.pid;
}
/** Promise that resolves when the process has exited */
get runPromise() {
return this._runPromise;
}
private process: ChildProcess | null = null;
private _runPromise: Promise<void> | null = null;
private oomDetector: NodeProcessOomDetector | null = null;
private isShuttingDown = false;
private logger: Logger;
/** Environment variables inherited by the child process from the current environment. */
private readonly passthroughEnvVars = [
'PATH',
'HOME', // So home directory can be resolved correctly
'GENERIC_TIMEZONE',
'NODE_FUNCTION_ALLOW_BUILTIN',
'NODE_FUNCTION_ALLOW_EXTERNAL',
'N8N_SENTRY_DSN',
'N8N_RUNNERS_ALLOW_PROTOTYPE_MUTATION',
// Metadata about the environment
'N8N_VERSION',
'ENVIRONMENT',
'DEPLOYMENT_NAME',
'NODE_PATH',
] as const;
constructor(
logger: Logger,
private readonly runnerConfig: TaskRunnersConfig,
private readonly authService: TaskBrokerAuthService,
private readonly runnerLifecycleEvents: TaskRunnerLifecycleEvents,
) {
super();
a.ok(
this.runnerConfig.mode !== 'external',
'Task Runner Process cannot be used in external mode',
);
this.logger = logger.scoped('task-runner');
this.runnerLifecycleEvents.on('runner:failed-heartbeat-check', () => {
this.logger.warn('Task runner failed heartbeat check, restarting...');
void this.forceRestart();
});
this.runnerLifecycleEvents.on('runner:timed-out-during-task', () => {
this.logger.warn('Task runner timed out during task, restarting...');
void this.forceRestart();
});
}
async start() {
a.ok(!this.process, 'Task Runner Process already running');
const grantToken = await this.authService.createGrantToken();
const taskBrokerUri = `http://127.0.0.1:${this.runnerConfig.port}`;
this.process = this.startNode(grantToken, taskBrokerUri);
forwardToLogger(this.logger, this.process, '[Task Runner]: ');
this.monitorProcess(this.process);
}
startNode(grantToken: string, taskBrokerUri: string) {
const startScript = require.resolve('@n8n/task-runner/start');
return spawn(
'node',
['--disallow-code-generation-from-strings', '--disable-proto=delete', startScript],
{
env: this.getProcessEnvVars(grantToken, taskBrokerUri),
},
);
}
@OnShutdown()
async stop() {
if (!this.process) return;
this.isShuttingDown = true;
// TODO: Timeout & force kill
this.killNode();
await this._runPromise;
this.isShuttingDown = false;
}
/** Force-restart a runner suspected of being unresponsive. */
async forceRestart() {
if (!this.process) return;
this.process.kill('SIGKILL');
await this._runPromise;
}
killNode() {
if (!this.process) return;
this.process.kill();
}
private monitorProcess(taskRunnerProcess: ChildProcess) {
this._runPromise = new Promise((resolve) => {
this.oomDetector = new NodeProcessOomDetector(taskRunnerProcess);
taskRunnerProcess.on('exit', (code) => {
this.onProcessExit(code, resolve);
});
});
}
private onProcessExit(_code: number | null, resolveFn: () => void) {
this.process = null;
this.emit('exit', { reason: this.oomDetector?.didProcessOom ? 'oom' : 'unknown' });
resolveFn();
if (!this.isShuttingDown) {
setImmediate(async () => await this.start());
}
}
private getProcessEnvVars(grantToken: string, taskBrokerUri: string) {
const envVars: Record<string, string> = {
N8N_RUNNERS_GRANT_TOKEN: grantToken,
N8N_RUNNERS_TASK_BROKER_URI: taskBrokerUri,
N8N_RUNNERS_MAX_PAYLOAD: this.runnerConfig.maxPayload.toString(),
N8N_RUNNERS_MAX_CONCURRENCY: this.runnerConfig.maxConcurrency.toString(),
N8N_RUNNERS_TASK_TIMEOUT: this.runnerConfig.taskTimeout.toString(),
N8N_RUNNERS_HEARTBEAT_INTERVAL: this.runnerConfig.heartbeatInterval.toString(),
...this.getPassthroughEnvVars(),
};
if (this.runnerConfig.maxOldSpaceSize) {
envVars.NODE_OPTIONS = `--max-old-space-size=${this.runnerConfig.maxOldSpaceSize}`;
}
return envVars;
}
private getPassthroughEnvVars() {
return this.passthroughEnvVars.reduce<Record<string, string>>((env, key) => {
if (process.env[key]) {
env[key] = process.env[key];
}
return env;
}, {});
}
}
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