{ "rules_update_index" : {
    "LABEL" : "update index",
    "PLUGIN" : "reaction rule",
    "OWNER" : "rules",
    "REQUIRES" : [ "commerce", "search_api", "entity" ],
    "ON" : { "commerce_product_update" : [  ] },
    "IF" : [
      { "entity_exists" : {
          "type" : "node",
          "property" : "field_product",
          "value" : [ "commerce-product:field-product-node:0:nid" ]
        }
      }
    ],
    "DO" : [
      { "search_api_index" : { "entity" : [ "commerce-product:field-product-node:0" ] } }
    ]
  }
}