@ludovicm67/scheduler

Node scheduler

A simple Node.js based tasks and services scheduler.

Concepts

Process

A process is something that runs continuously. It is started when the scheduler starts and kept running. If it crashes, it is restarted by default.

Task

A task is something that runs once and then stops. It should be started manually when needed using a HTTP request or through a schedule.

Schedule

A schedule is a way to run tasks automatically at specific times or intervals, without manual intervention. Schedules are defined using cron syntax.

Quick Start

npx @ludovicm67/scheduler -c ./path/to/scheduler-config.yaml

Where -c is the path to your configuration file. If not provided, it defaults to ./scheduler-config.yaml or to the value of the SCHEDULER_CONFIG_PATH environment variable if it is defined.

The configuration file is a YAML file that defines the processes, tasks, and schedules to be managed by the scheduler.

An example of configuration file is available here: scheduler-config.yaml.

You can control the log level using the LOG_LEVEL environment variable. It defaults to info, but you can set it to debug, warn, error, etc. depending on your needs, or silent to disable them.

Configuration File Structure

The configuration file is a YAML object with three main sections: processes, tasks, and schedules. Each section is an object whose keys are unique names, and values are configuration objects.

Top-Level Keys

Key	Description	Type	Required
processes	Processes to run continuously	object	No
tasks	One-off tasks to run	object	No
schedules	Scheduled tasks (using cron syntax)	object	No

1. processes and tasks Structure

Both processes and tasks have similar structure. Each key is a unique name, and the value is an object with these properties:

Property	Description	Type	Required	Default
cmd	The command to execute	string	Yes
args	Arguments to pass to the command	array	No	[]
restart	Restart if exits (processes: default true, tasks: default false)	boolean	No	see left
unique	Only one instance can run at a time	boolean	No	true
logs	Log file paths (see below)	object	Yes

logs object (required):

Property	Description	Type	Required
stdout	Path to standard output log file	string	Yes
stderr	Path to standard error log file	string	Yes

2. schedules Structure

Each key is a unique name, and the value is an object:

Property	Description	Type	Required
cron	Cron expression for scheduling	string	Yes
task	Name of the task to run	string	Yes

Example

processes:
  my-process:
    cmd: "node"
    args: ["server.js"]
    restart: true
    unique: true
    logs:
      stdout: "/var/log/my-process.out"
      stderr: "/var/log/my-process.err"

tasks:
  my-task:
    cmd: "npm"
    args: ["run", "build"]
    restart: false
    unique: true
    logs:
      stdout: "/var/log/my-task.out"
      stderr: "/var/log/my-task.err"

schedules:
  nightly-build:
    cron: "0 2 * * *"
    task: "my-task"

Notes:

• All keys under processes, tasks, and schedules must be unique.
• No additional properties are allowed outside the defined structure.

License

Node scheduler is licensed under the Apache-2.0 license.