Capture index sizes daily

gistfile1.txt

POST _watcher/watch/_execute
{
  "watch": {
    "trigger": {
      "schedule": {
        "interval": "1d"
      }
    },
    "input": {
      "http": {
        "request": {
          "host": "e1964ea9b74a4168a7e26c3be7bb330f.europe-west1.gcp.cloud.es.io",
          "port": 9243,
          "scheme": "https",
        "path": "/_cat/indices/*,-.*",
        "params": {
          "format": "json",
          "h": "index,store.size",
          "bytes": "b"
        },
          "headers": {},
          "auth": {
            "basic": {
              "username": "elastic",
              "password": "xxx"
            }
          }
        }
      }
    },
  "condition": {
    "always": {}
  }, 
  "actions" : {
    "index_payload": {
    "transform": {
      "script": """
       def documents = ctx.payload.data.stream()
        .map(hit -> [
          "_index": "index_sizes", 
          "index": hit.index, 
          "store.size": hit['store.size']
        ])
        .collect(Collectors.toList());
      return [ "_doc" : documents]; 
      """
    },
    "index": {
        "execution_time_field": "@timestamp"
        }
    }
  }
}
}

GET index_sizes/_search will yield something like:

{
  "took": 0,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 8,
      "relation": "eq"
    },
    "max_score": 1,
    "hits": [
      {
        "_index": "index_sizes",
        "_id": "y1jD-IwBRZWNq0rMQ4W9",
        "_score": 1,
        "_source": {
          "@timestamp": "2024-01-11T13:43:15.438Z",
          "index": "test-data",
          "store.size": "907197"
        }
      },
      {
        "_index": "index_sizes",
        "_id": "zFjD-IwBRZWNq0rMQ4W9",
        "_score": 1,
        "_source": {
          "@timestamp": "2024-01-11T13:43:15.438Z",
          "index": "my-index",
          "store.size": "284852"
        }
      },
      {
        "_index": "index_sizes",
        "_id": "zVjD-IwBRZWNq0rMQ4W9",
        "_score": 1,
        "_source": {
          "@timestamp": "2024-01-11T13:43:15.438Z",
          "index": "firmware_info",
          "store.size": "17610"
        }
      },
      {
        "_index": "index_sizes",
        "_id": "zljD-IwBRZWNq0rMQ4W9",
        "_score": 1,
        "_source": {
          "@timestamp": "2024-01-11T13:43:15.438Z",
          "index": "end_firmware_mismatch",
          "store.size": "14622"
        }
      },
      {
        "_index": "index_sizes",
        "_id": "z1jD-IwBRZWNq0rMQ4W9",
        "_score": 1,
        "_source": {
          "@timestamp": "2024-01-11T13:43:15.438Z",
          "index": "vbtime",
          "store.size": "11148"
        }
      },
      {
        "_index": "index_sizes",
        "_id": "0FjD-IwBRZWNq0rMQ4W9",
        "_score": 1,
        "_source": {
          "@timestamp": "2024-01-11T13:43:15.438Z",
          "index": "firmware_records",
          "store.size": "31034"
        }
      },
      {
        "_index": "index_sizes",
        "_id": "0VjD-IwBRZWNq0rMQ4W9",
        "_score": 1,
        "_source": {
          "@timestamp": "2024-01-11T13:43:15.438Z",
          "index": "kibana_sample_data_ecommerce",
          "store.size": "8783478"
        }
      },
      {
        "_index": "index_sizes",
        "_id": "0ljD-IwBRZWNq0rMQ4W9",
        "_score": 1,
        "_source": {
          "@timestamp": "2024-01-11T13:43:15.438Z",
          "index": "start_firmware_mismatch",
          "store.size": "15344"
        }
      }
    ]
  }
}