mr-kot-fs-validators

Reusable filesystem validator factories for Mr. Kot checks. This package provides a set of validator factories that you compose inside your own checks using check_all().

Usage

from mr_kot import check, check_all
from mr_kot_fs_validators import (
    Exists, IsFile, HasMode, OwnerIs, GroupIs
)

@check
def hosts_file_state():
    return check_all(
        "/etc/hosts",
        Exists(),
        IsFile(),
        HasMode("0644"),
        OwnerIs("root"),
        GroupIs("root"),
    )

Each validator is a small factory returning a callable: validator(target_path) -> (status, evidence). Statuses follow Mr. Kot conventions: PASS, FAIL, ERROR (and occasionally WARN).

Evidence style

• PASS: path=/etc/hosts exists
• FAIL: path=/data mode expected=0755 actual=0775
• FAIL(recursive): path=/data child=/data/logs/old owner expected=mysql actual=root
• ERROR: path=/var/log error=PermissionError: [Errno 13] Permission denied

Validators

• Existence and type: Exists, IsFile, IsDir, IsSymlink, IsSocket, IsBlockDevice, IsCharDevice.
• Permissions/ownership: HasMode, OwnerIs, GroupIs, IsExecutable, IsReadable, IsWritable.
• Content/size: Empty, SizeBetween.
• State/links: SymlinkPointsTo, RecentThan, HasSubdirs, HasFiles.
• Mounts/devices/capacity: FSTypeIs, MountExists, FreeSpaceAtLeast, DeviceAvailable.
• I/O smoke: CanReadFile, CanWriteFile.

Notes

• recursive=True in HasMode, OwnerIs, GroupIs traverses directories with os.walk and fails on the first mismatch.
• follow_symlinks controls stat-like checks; default False unless stated otherwise.
• RecentThan() accepts a file path or an epoch timestamp (float or int).
• FSTypeIs/MountExists parse /proc/self/mountinfo on Linux.
• I/O smoke tests avoid leaving artifacts; CanWriteFile() always removes the temporary file it creates.

Permissions shortcuts

IsExecutable(by_user=True, by_group=False, by_others=False), IsReadable(...), and IsWritable(...) accept flags to select which bits to require. If all flags are False, they fall back to checking any of the three categories.