Ansible/Yaml文件中的不一致列表缩进

Question

我有一个Ansible YAML文件格式如下所示。注意- name和- when部件。

- name: populate package facts
  package_facts:
- name: install auditd
  apt:
    name: auditd
    state: present
  register: apt_status
  until: apt_status is success
  retries: 12
  delay: 10
- name: touch stig.rules
  file:
    path: /etc/audit/rules.d/stig.rules
    state: touch
    mode: '0640'
    modification_time: preserve
    access_time: preserve
# R-238197 UBTU-20-010002
- name: stigrule_238197__etc_gdm3_greeter_dconf_defaults_enable
  ini_file:
    path: /etc/gdm3/greeter.dconf-defaults
    section: org/gnome/login-screen
    option: banner-message-enable
    value: "{{ ubuntu2004STIG_stigrule_238197__etc_gdm3_greeter_dconf_defaults_enable_Value }}"
    no_extra_spaces: yes
  notify: dconf_update
  when:
    - ubuntu2004STIG_stigrule_238197_Manage
    - "'gdm3' in packages"

我处理它并删除一些元素，然后使用下面的方法将其转储到文件中：

def dump(path: str, export: list) -> None:
    yaml: YAML = YAML()
    yaml.default_flow_style = False
    yaml.preserve_quotes = True
    yaml.width = 4096 # Prevent line breaks
    yaml.indent(mapping=2, sequence=2, offset=0) # Default values

    with open(path, "w", encoding=ENCODING) as fp:
        yaml.dump(export, fp)

对于默认缩进，结果如下所示：

- name: populate package facts
  package_facts:
- name: install auditd
  apt:
    name: auditd
    state: present
  register: apt_status
  until: apt_status is success
  retries: 12
  delay: 10
- name: touch stig.rules
  file:
    path: /etc/audit/rules.d/stig.rules
    state: touch
    mode: '0640'
    modification_time: preserve
    access_time: preserve
# R-238197 UBTU-20-010002
- name: stigrule_238197__etc_gdm3_greeter_dconf_defaults_enable
  ini_file:
    path: /etc/gdm3/greeter.dconf-defaults
    section: org/gnome/login-screen
    option: banner-message-enable
    value: "{{ ubuntu2004STIG_stigrule_238197__etc_gdm3_greeter_dconf_defaults_enable_Value }}"
    no_extra_spaces: yes
  notify: dconf_update
  when:
  - ubuntu2004STIG_stigrule_238197_Manage
  - "'gdm3' in packages"

如您所见，Ansible文件已经是一个元素列表，从偏移量0开始。然后，- when之后的列表项也将使用该0偏移量值。如何将原始缩进-offset 0保存为- name，而对所有其他缩进保留2？

Answer 1

使用ruamel.yaml，所有映射只能有一个缩进，所有序列只能有一个缩进。

如果要保留不一致性，则需要缩进4和偏移量2，并删除开始每一行的额外两个空格(有效地增加根级序列)：

import sys
import ruamel.yaml
YAML = ruamel.yaml.YAML
from pathlib import Path

def dump(path: str, export: list) -> None:
    def strip_first_two(s):
        res = []
        for x in s.splitlines(True):
            xl = x.lstrip()
            # do not dedent full comment lines
            if xl and xl[0] == '#' or not x.startswith('  '):
                res.append(x)
            else:
                res.append(x[2:])
        return ''.join(res)

    yaml: YAML = YAML()
    yaml.default_flow_style = False # default
    yaml.width = 4096 # Prevent line breaks
    yaml.indent(mapping=2, sequence=4, offset=2)
    yaml.dump(export, Path(path), transform=strip_first_two)

yaml = ruamel.yaml.YAML()
yaml.preserve_quotes = True

data = yaml.load(Path('input.yaml'))
dump('output.yaml', data)
print(Path('output.yaml').read_text())

这意味着：

- name: populate package facts
  package_facts:
- name: install auditd
  apt:
    name: auditd
    state: present
  register: apt_status
  until: apt_status is success
  retries: 12
  delay: 10
- name: touch stig.rules
  file:
    path: /etc/audit/rules.d/stig.rules
    state: touch
    mode: '0640'
    modification_time: preserve
    access_time: preserve
# R-238197 UBTU-20-010002
- name: stigrule_238197__etc_gdm3_greeter_dconf_defaults_enable
  ini_file:
    path: /etc/gdm3/greeter.dconf-defaults
    section: org/gnome/login-screen
    option: banner-message-enable
    value: "{{ ubuntu2004STIG_stigrule_238197__etc_gdm3_greeter_dconf_defaults_enable_Value }}"
    no_extra_spaces: yes
  notify: dconf_update
  when:
    - ubuntu2004STIG_stigrule_238197_Manage
    - "'gdm3' in packages"

如果您有任何行尾注释，这些都会向左移动两个位置。如果您没有嵌入注释标记的多行标量，那么可以在strip_first_two中通过在每一行中用' #'替换' #'来轻松地处理这些问题。如果两者都有，这并不是那么简单，而且您必须在转储和调整每个EOL注释的每个开始列之前遍历数据结构。

设置yaml.default_flow_style = False不是必要的，因为这是往返转储的默认设置(另一方面，显式要比隐式好)。但是您不应该在您的yaml.preserve_quotes函数中对YAML实例设置dump，因为它只在加载YAML文档时才能工作，因此实际上可能会误导某人。

我还倾向于使用pathlib.Path实例，让ruamel.yaml在编码和打开方面做正确的事情('w‘vs 'wb')。