Alert when disk usage is high

Supported platforms

LinuxmacOS

Prerequisites

• df and awk
• A Slack incoming webhook URL exposed through an environment-backed Dagu secret

description: Notify Slack when a filesystem reaches its utilization threshold.
schedule: "*/15 * * * *"

params:
  - name: path
    default: /
  - name: threshold_percent
    type: integer
    default: 85
    minimum: 1
    maximum: 100

secrets:
  - name: SLACK_WEBHOOK_URL
    provider: env
    key: SLACK_WEBHOOK_URL

handler_on:
  failure:
    action: http.request
    with:
      method: POST
      url: ${env.SLACK_WEBHOOK_URL}
      headers:
        Content-Type: application/json
      body: '{"text":"Disk usage for ${params.path} reached the ${params.threshold_percent}% alert threshold on the Dagu host."}'

steps:
  - id: check_usage
    run: |
      #!/bin/sh
      set -eu
      usage="$(df -P "${params.path}" | awk 'NR == 2 { gsub(/%/, "", $5); print $5 }')"
      printf 'Disk usage for %s: %s%%\n' "${params.path}" "$usage"
      test "$usage" -lt "${params.threshold_percent}"