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Ansible:检测Linux文件系统是否以只读方式装载

mount-point ansible-2.x readonly ubuntu-16.04 ansible

Isac Casapu · 技术社区 · 8 年前

我试图检测Linux(Ubuntu 16.04)上是否以只读或读写方式装载了特定的文件系统。使用 统计数据 模块无法工作,因为它总是返回posix权限,而不管写入目录的实际能力如何。我可以用下面的代码来完成这项任务,这些代码试图创建一个点文件。我希望有一个更干净、更优雅的替代方案,它还可以检测目录是否不是装入点(这将是一个错误)。

- name: Determine whether we have write access to the shared dir
    command: touch /mnt/shared-data/.WriteTest
    register: shared_dir_write_test
    failed_when: "shared_dir_write_test.rc != 0 and 'read-only' not in (shared_dir_write_test.stderr | lower)"
    changed_when: shared_dir_write_test.rc == 0

Ansible建议我使用文件具有的模块 状态=触摸 但是,下面的代码失败了,因为似乎没有办法检查文件。

  - name: Determine whether we have write access to the shared dir
    file: path=/mnt/shared-data/.WriteTest state=touch
    register: shared_dir_write_test
    failed_when: "shared_dir_write_test.failed and 'read-only' not in (shared_dir_write_test.msg | lower)"

条件检查“shared\u dir\u write\u test”。失败且为“只读” not in(shared\u dir\u write\u test.stderr | lower)失败。错误是: 计算条件时出错(shared\u dir\u write\u test.failed and “只读”不在(shared\u dir\u write\u test.stderr | lower)):“dict” 对象“”没有属性“”失败“”

2 回复 | 直到 8 年前

ilias-sp 8 年前

您可以收集可靠的事实,每个装载都有装载选项:

ansible localhost -m setup -a "filter=ansible_mounts"

示例输出:

[root@ansible ansible]# ansible localhost -m setup -a "filter=ansible_mounts"
localhost | SUCCESS => {
    "ansible_facts": {
        "ansible_mounts": [
            {
                "block_available": 3007928, 
                "block_size": 4096, 
                "block_total": 3929600, 
                "block_used": 921672, 
                "device": "/dev/mapper/fedora-root", 
                "fstype": "xfs", 
                "inode_available": 7787042, 
                "inode_total": 7864320, 
                "inode_used": 77278, 
                "mount": "/", 
                "options": "rw,relatime,attr2,inode64,noquota", 
                "size_available": 12320473088, 
                "size_total": 16095641600, 
                "uuid": "5faf23bb-281b-41d9-bd20-f8da6463eba0"
            }, 
            {
                "block_available": 185772, 
                "block_size": 4096, 
                "block_total": 249830, 
                "block_used": 64058, 
                "device": "/dev/sda1", 
                "fstype": "ext4", 
                "inode_available": 65179, 
                "inode_total": 65536, 
                "inode_used": 357, 
                "mount": "/boot", 
                "options": "rw,relatime,data=ordered", 
                "size_available": 760922112, 
                "size_total": 1023303680, 
                "uuid": "866845e7-6c62-41c9-bbd2-87b463326601"
            }
        ]
    }, 
    "changed": false
}
[root@ansible ansible]# ansible localhost -m setup -a "filter=ansible_mounts"

Isac Casapu 8 年前

这些信息可以从可靠的事实中获得。完成此操作的Ansible代码:

- name: Determine shared-dir mount point
command: "/usr/bin/env stat -c '%m' {{ shared_dir_real_path }}"
register: shared_dir_mount_point
changed_when: False

- name: Determine the mount point's filesystem type and mount options
set_fact:
    "shared_dir_mount_{{ item }}": "{{ ansible_mounts | selectattr('mount', 'equalto', shared_dir_mount_point.stdout) | map(attribute = item) | join(',') }}"
with_items:
    - fstype
    - options

- name: Determine the access to the shared-data directory
set_fact:
    shared_dir_access_flags: "{{ ['ro', 'rw']  | intersect( shared_dir_mount_options.split(',') )}}"

- name: Verify Access mode sanity
assert:
    that: shared_dir_access_flags | length == 1

然后,要确定支座是否为R/W或R/O I,请使用:

when: "'rw' in shared_dir_access_flags"

或

when: "'ro' in shared_dir_access_flags"

我之前使用的另一种更简洁但可能不太干净的方法是从/proc/self/mountinfo获取信息。比我所希望的更具体一点的平台,但它只依赖于文档化的intreface。

- name: Get Shared dir mount options
shell: "grep -F `stat -c '%m' {{ shared_dir_path }}` /proc/self/mountinfo | cut -d' ' -f 6"
register: shared_dir_mount_options
changed_when: False

然后,用于确定挂载是R/W还是R/O I的表达式将变得更加繁琐:

when: "'rw' in shared_dir_mount_options.stdout.split(',')"

或

when: "'ro' in shared_dir_mount_options.stdout.split(',')"