watch.json

{
  "trigger": {
    "schedule": {
      "interval": "1m"
    }
  },
  "input": {
    "search": {
      "request": {
        "indices": [
          "logs"
        ],
        "body": {
          "query": {
            "bool": {
              "must": [
                {
                  "query_string": {
                    "query": "error OR loglevel:ERROR"
                  }
                },
                {
                  "range": {
                    "@timestamp": {
                      "gte": "now-1m"
                    }
                  }
                }
              ]
            }
          },
          "_source": [
            "message"
          ],
          "sort": [
            {
              "@timestamp": {
                "order": "desc"
              }
            }
          ]
        }
      }
    }
  },
  "condition": {
    "compare": {
      "ctx.payload.hits.total": {
        "gt": 0
      }
    }
  },
  "throttle_period": "15m",
  "actions": {
    "log": {
      "logging": {
        "level": "info",
        "text": "{{ctx.payload.hits.total}} Errors have occured in the logs:{{#ctx.payload.hits.hits}}{{_id}}:{{/ctx.payload.hits.hits}}"
      }
    }
  }
}