为什么ansible库存解析器我的json这么慢答案

【问题标题】：why ansible inventory parser my json so slow为什么ansible库存解析器我的json这么慢
【发布时间】：2019-02-26 13:42:13
【问题描述】：

我从公共云生成一个 json，但是使用这个 inventory.json 太慢了。请告诉我为什么我的 json 是这样的：

{
  "angelbeats": {
    "hosts": ["10.193.0.24", "10.193.0.23"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "grammy": {
    "hosts": ["10.193.2.5", "10.193.0.9", "10.193.10.4", "10.193.8.5"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "cdn": {
    "hosts": ["10.193.0.12", "10.193.0.11", "10.193.2.7", "10.193.2.8"],
    "vars": {
      "ansible_ssh_user": "root"
    }
  },
  "mdianying": {
    "hosts": ["10.193.0.31"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "zkmq": {
    "hosts": ["10.193.0.26", "10.193.0.27", "10.193.0.25"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "bmovie": {
    "hosts": [],
    "children": ["angelbeats", "growingpains", "forrestgump", "zkmq", "job", "tm", "inception"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "xxljob": {
    "hosts": ["10.193.0.6"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "redis": {
    "hosts": ["10.193.0.40", "10.193.2.13"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "tm": {
    "hosts": ["10.193.0.13", "10.193.0.14", "10.193.0.16", "10.193.0.17", "10.193.0.15"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "dns": {
    "hosts": ["10.193.0.100", "10.193.2.100", "10.193.10.10", "10.193.8.19"],
    "vars": {
      "ansible_ssh_user": "root"
    }
  },
  "yctask": {
    "hosts": ["10.193.8.15"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "cmovie": {
    "hosts": [],
    "children": ["angelbeats", "growingpains", "forrestgump", "zkmq", "job", "tm", "inception"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "forrestgump": {
    "hosts": ["10.193.0.104", "10.193.2.101", "10.193.8.20", "10.193.10.11"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "pwapi": {
    "hosts": ["10.193.0.28", "10.193.2.11", "10.193.8.10", "10.193.10.9"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "pwweb": {
    "hosts": ["10.193.0.20", "10.193.0.19", "10.193.2.9", "10.193.2.10", "10.193.8.9", "10.193.8.8", "10.193.10.6", "10.193.10.7"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "pwtask": {
    "hosts": ["10.193.0.29"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "apishow": {
    "hosts": ["10.193.0.32", "10.193.8.11"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "inception": {
    "hosts": ["10.193.0.10", "10.193.2.6", "10.193.8.7", "10.193.10.5"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "moviebi": {
    "hosts": ["10.193.0.42", "10.193.8.18"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "yanchu": {
    "hosts": ["10.193.0.35", "10.193.8.14"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "growingpains": {
    "hosts": ["10.193.0.21", "10.193.0.22"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "goods": {
    "hosts": ["10.193.0.33", "10.193.8.12"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "urm": {
    "hosts": ["10.193.0.39", "10.193.2.12"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "job": {
    "hosts": ["10.193.0.105"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  },
  "order": {
    "hosts": ["10.193.0.34", "10.193.8.13"],
    "vars": {
      "ansible_ssh_user": "wangluoli"
    }
  }
}

【问题讨论】：

您能否更具体地说明inventory.json 是如何变慢的？

标签： performance ansible inventory

【解决方案1】：

您需要在 JSON 中创建一个 _meta 部分：

https://docs.ansible.com/ansible/latest/dev_guide/developing_inventory.html#tuning-the-external-inventory-script

上面详述的库存脚本系统适用于所有人 Ansible 的版本，但为每个主机调用 --host 可能相当效率低下，尤其是涉及到远程 API 调用时子系统。

为避免这种低效率，如果清单脚本返回顶部级别元素称为“_meta”，可以返回所有主机一个脚本执行中的变量。当此元元素包含 “hostvars”的值，清单脚本将不会被调用 --host 每个主机。这会显着提高大量主机的性能。

【讨论】：