@optask/nestjs

A wrapper package that allows usage of @optask/tasker within a nestjs application.

Quickstart

Install tasker and nestjs plugin:

yarn add @optask/tasker @optask/nestjs

First create a task you want to run:

import { Injectable } from '@nestjs/common';
import { Task, BaseTask } from '@optask/nextjs';

@Injectable()
@Task({
  name: 'task',
})
class MyTask extends BaseTask {
  run() {
    // do something
  }
}

note you must extend BaseTask and use the @Task decorator for the task to be registered successfully.

Then create a module that provides this task:

import { Module } from '@nestjs/common';

import { MyTask } from './MyTask';

@Module({
    providers: [MyTask],
    exports: [MyTask],
});
export class TaskModule {}

Finally, import this module and register the scheduler module:

import { Module } from '@nestjs/common';
import { TaskSchedulerModule } from '@optask/nestjs';
import { InMemoryStore } from '@optask/tasker';

import { TaskModule } from './TaskModule';
import { RunTasker } from './RunTasker';

@Module({
  imports: [
    TaskSchedulerModule.register({
      imports: [TaskModule],
      store: new InMemoryStore(), // Use a real store here if you need it!
    }),
  ],
  providers: [RunTasker],
})
export class AppModule {}

Then the scheduler service can be used to run the tasks:

import { Injectable } from '@nestjs/common';
import { TaskSchedulerService } from '@optask/nestjs';

@Injectable()
export class TaskRunner {
    constructor(private readonly scheduler: TaskSchedulerService){}

    async run() {
        // Do any editing you need to
        this.scheduler.addCondition('myCondition', 'test');

        // Run the tasks
        await this.scheduler.run();
    }
}

Creating Tasks

Tasks are providers registered in the scheduler with the @Task decorator. They should extend BaseTask from this library, which provides the base implementation of a task in tasker.

You can optionally provide the task's run condition, modifiers, and dependencies as well with the provided metadata to the @Task decorator. See the @optask/tasker documentation for information on task conditions, modifiers, and dependencies.

For example, to define a task that would run once on each version on a pre deploy step, and depends on a task called migrate, you could pass this configuration:

import { Injectable } from '@nestjs/common';
import { Task, BaseTask } from '@optask/nestjs';
import { EqualsCondition, RunOnceModifier } from '@optask/tasker';

@Injectable()
@Task({
  name: 'validate',
  dependencies: ['migrate'],
  condition: new EqualsCondition('step', 'pre-deploy'),
  modifiers: [new RunOnceModifier(['version'])],
})
export class ValidateTask extends BaseTask {
  async run() {
    // do some validation here
  }
}

Setting the task scheduler conditions

In the above example, we need the conditions of version and step to be defined. To do so, you can provide the conditions directly in the register method of the TaskSchedulerModule

Here is an example of providing the configuration directly:

import { Module } from '@nestjs/common';
import { TaskSchedulerModule } from '@optask/nestjs';
import { FileSystemStore } from '@optask/tasker';

@Module({
  imports: [
    TaskSchedulerModule.register({
      imports: [ModuleWithTasks],
      store: new FileSystemStore(),
      conditions: {
        step: process.env.STEP,
        version: process.env.VERSION,
      },
    }),
  ],
})
export class AppModule {}

You can also use another provider that implements the ConfigurationProvider interface (or both!)

import { Module } from '@nestjs/common';
import { TaskSchedulerModule } from '@optask/nestjs';
import { FileSystemStore } from '@optask/tasker';

@Module({
  imports: [
    TaskSchedulerModule.register({
      imports: [ModuleWithTasksAndConditionProvider],
      store: new FileSystemStore(),
      conditions: {
        step: `pre-deploy`,
      },
      conditionsProvider: MyConditionsProvider, // Make sure this is provided from the imported modules
    }),
  ],
})
export class PreDeployModule {}

Example of a conditions provider:

import { Injectable } from '@nestjs/common';
import { ConditionsProvider } from '@optask/nestjs';

@Injectable()
export class MyConditionsProvider implements ConditionsProvider {
    async getConditions() {
        const version = await getVersion(); // can be async or pull from another injected provider

        return {
            version,
        };
    }
}

In the above example, the conditions will get merged together from the raw values and the result of getConditions call, where the getConditions values will override those from the raw values.