如何通过app.json配置Heroku Scheduler脚本与执行频率实现一键部署？

Short answer: No, you can't directly define Scheduler tasks (script name + frequency) through the addons field in app.json—the addons config only enables the Scheduler add-on for your app, it doesn't handle task-specific settings. But there's a reliable workaround to auto-configure tasks when using the "Deploy to Heroku" button.

The Workaround: Use Postdeploy Scripts #

You can leverage Heroku's postdeploy script (defined in app.json) to automatically create Scheduler tasks right after deployment completes. Here's how to set this up:

1. Update Your app.json #

Add the Scheduler add-on and define a postdeploy script that creates your task. You have two options for this script: using the Heroku CLI, or calling the Heroku API directly (more reliable, no CLI dependency).

Option A: Using Heroku CLI

{
  "name": "Your App",
  "description": "Auto-configured with Heroku Scheduler",
  "addons": [
    {
      "plan": "scheduler:standard"
    }
  ],
  "scripts": {
    "postdeploy": "heroku scheduler:add --command 'node path/to/your-script.js' --frequency 'daily' --time '09:00' --app $HEROKU_APP_NAME"
  },
  "env": {
    "HEROKU_APP_NAME": {
      "description": "Auto-set by Heroku during deployment",
      "required": true
    }
  }
}

• The $HEROKU_APP_NAME variable is automatically populated by Heroku during the deployment process.
• Adjust --command to match your script (e.g., python script.py for Python apps), --frequency (options: hourly, daily, every X minutes), and --time (for daily tasks, specify a UTC time like 09:00).

Option B: Using Heroku API (No CLI Dependency)

If you want to avoid relying on the Heroku CLI being available in the build environment, use a curl call to the Heroku API:

{
  "name": "Your App",
  "description": "Auto-configured with Heroku Scheduler",
  "addons": [
    {
      "plan": "scheduler:standard"
    }
  ],
  "scripts": {
    "postdeploy": "curl -n -X POST https://api.heroku.com/apps/$HEROKU_APP_NAME/scheduler/jobs \
      -H \"Content-Type: application/json\" \
      -H \"Accept: application/vnd.heroku+json; version=3\" \
      -d '{
        \"command\": \"node path/to/your-script.js\",
        \"schedule\": \"daily\",
        \"time_zone\": \"UTC\"
      }'"
  },
  "env": {
    "HEROKU_APP_NAME": {
      "description": "Auto-set by Heroku during deployment",
      "required": true
    }
  }
}

• For more granular scheduling, replace "schedule": "daily" with a cron expression (e.g., "0 9 * * *" for daily at 9 UTC).
• The -n flag tells curl to use Heroku's built-in credentials in the deployment environment, so you don't need to add API keys manually.

2. Key Notes #

• Multiple Tasks: To add multiple Scheduler tasks, just chain commands in the postdeploy script (separate with &&).
• Script Paths: Double-check your script's relative path—make sure it matches where the file lives in your deployed app.
• Testing: Before sharing the "Deploy to Heroku" button, test the postdeploy script manually by running it in a local Heroku environment to confirm tasks are created correctly.

Why app.json Can't Do This Directly #

Heroku's addons configuration in app.json only handles enabling the add-on itself, not configuring its specific resources (like Scheduler tasks). Task definitions are tied to your app's runtime, not the add-on's initial provisioning.

内容的提问来源于stack exchange，提问作者tuck1s