community.general.filesize – Create a file with a given size, or resize it if it exists

Note

This plugin is part of the community.general collection (version 3.8.1).

You might already have this collection installed if you are using the ansible package. It is not included in ansible-core. To check whether it is installed, run ansible-galaxy collection list.

To install it, use: ansible-galaxy collection install community.general.

To use it in a playbook, specify: community.general.filesize.

New in version 3.0.0: of community.general

Synopsis
Requirements
Parameters
Notes
See Also
Examples
Return Values

Synopsis

This module is a simple wrapper around dd to create, extend or truncate a file, given its size. It can be used to manage swap files (that require contiguous blocks) or alternatively, huge sparse files.

Requirements

The below requirements are needed on the host that executes this module.

dd (Data Duplicator) in PATH

Parameters

Parameter	Choices/Defaults	Comments
attributes string added in 2.3 of ansible.builtin		The attributes the resulting file or directory should have. To get supported flags look at the man page for chattr on the target system. This string should contain the attributes in the same order as the one displayed by lsattr. The `=` operator is assumed as default, otherwise `+` or `-` operators need to be included in the string. aliases: attr
blocksize raw		Size of blocks, in bytes if not followed by a multiplicative suffix. The numeric value (before the unit) `MUST` be an integer (or a `float` if it equals an integer). If not set, the size of blocks is guessed from the OS and commonly results in `512` or `4096` bytes, that is used internally by the module or when size has no unit.
force boolean	Choices: no ← yes	Whether or not to overwrite the file if it exists, in other words, to truncate it from 0. When `true`, the module is not idempotent, that means it always reports changed=true. force=true and sparse=true are mutually exclusive.
group string		Name of the group that should own the file/directory, as would be fed to chown.
mode raw		The permissions the resulting file or directory should have. For those used to /usr/bin/chmod remember that modes are actually octal numbers. You must either add a leading zero so that Ansible's YAML parser knows it is an octal number (like `0644` or `01777`) or quote it (like `'644'` or `'1777'`) so Ansible receives a string and can do its own conversion from string into number. Giving Ansible a number without following one of these rules will end up with a decimal number which will have unexpected results. As of Ansible 1.8, the mode may be specified as a symbolic mode (for example, `u+rwx` or `u=rw,g=r,o=r`). If `mode` is not specified and the destination file does not exist, the default `umask` on the system will be used when setting the mode for the newly created file. If `mode` is not specified and the destination file does exist, the mode of the existing file will be used. Specifying `mode` is the best way to ensure files are created with the correct permissions. See CVE-2020-1736 for further details.
owner string		Name of the user that should own the file/directory, as would be fed to chown.
path path / required		Path of the regular file to create or resize.
selevel string		The level part of the SELinux file context. This is the MLS/MCS attribute, sometimes known as the `range`. When set to `_default`, it will use the `level` portion of the policy if available.
serole string		The role part of the SELinux file context. When set to `_default`, it will use the `role` portion of the policy if available.
setype string		The type part of the SELinux file context. When set to `_default`, it will use the `type` portion of the policy if available.
seuser string		The user part of the SELinux file context. By default it uses the `system` policy, where applicable. When set to `_default`, it will use the `user` portion of the policy if available.
size raw / required		Requested size of the file. The value is a number (either `int` or `float`) optionally followed by a multiplicative suffix, that can be one of `B` (bytes), `KB` or `kB` (= 1000B), `MB` or `mB` (= 1000kB), `GB` or `gB` (= 1000MB), and so on for `T`, `P`, `E`, `Z` and `Y`; or alternatively one of `K`, `k` or `KiB` (= 1024B); `M`, `m` or `MiB` (= 1024KiB); `G`, `g` or `GiB` (= 1024MiB); and so on. If the multiplicative suffix is not provided, the value is treated as an integer number of blocks of blocksize bytes each (float values are rounded to the closest integer). When the size value is equal to the current file size, does nothing. When the size value is bigger than the current file size, bytes from source (if sparse is not `false`) are appended to the file without truncating it, in other words, without modifying the existing bytes of the file. When the size value is smaller than the current file size, it is truncated to the requested value without modifying bytes before this value. That means that a file of any arbitrary size can be grown to any other arbitrary size, and then resized down to its initial size without modifying its initial content.
source path	Default: "/dev/zero"	Device or file that provides input data to provision the file. This parameter is ignored when sparse=true.
sparse boolean	Choices: no ← yes	Whether or not the file to create should be a sparse file. This option is effective only on newly created files, or when growing a file, only for the bytes to append. This option is not supported on OpenBSD, Solaris and AIX. force=true and sparse=true are mutually exclusive.
unsafe_writes boolean added in 2.2 of ansible.builtin	Choices: no ← yes	This option is silently ignored. This module always modifies file size in-place.

Notes

Note

This module supports check_mode and diff.

Examples

- name: Create a file of 1G filled with null bytes
  community.general.filesize:
    path: /var/bigfile
    size: 1G

- name: Extend the file to 2G (2*1024^3)
  community.general.filesize:
    path: /var/bigfile
    size: 2G

- name: Reduce the file to 2GB (2*1000^3)
  community.general.filesize:
    path: /var/bigfile
    size: 2GB

- name: Fill a file with random bytes for backing a LUKS device
  community.general.filesize:
    path: ~/diskimage.luks
    size: 512.0 MiB
    source: /dev/urandom

- name: Take a backup of MBR boot code into a file, overwriting it if it exists
  community.general.filesize:
    path: /media/sdb1/mbr.bin
    size: 440B
    source: /dev/sda
    force: true

- name: Create/resize a sparse file of/to 8TB
  community.general.filesize:
    path: /var/local/sparsefile
    size: 8TB
    sparse: true

- name: Create a file with specific size and attributes, to be used as swap space
  community.general.filesize:
    path: /var/swapfile
    size: 2G
    blocksize: 512B
    mode: u=rw,go=
    owner: root
    group: root

Return Values

Common return values are documented here, the following are the fields unique to this module:

Key		Returned	Description
cmd string		when changed or failed	Command executed to create or resize the file. Sample: /usr/bin/dd if=/dev/zero of=/var/swapfile bs=1048576 seek=3072 count=1024
filesize dictionary		always	Dictionary of sizes related to the file.
	blocks integer	success	Number of blocks in the file. Sample: 500
	blocksize integer	success	Size of the blocks in bytes. Sample: 1024
	bytes integer	success	Size of the file, in bytes, as the product of `blocks` and `blocksize`. Sample: 512000
	iec string	success	Size of the file, in human-readable format, following IEC standard. Sample: 500.0 KiB
	si string	success	Size of the file, in human-readable format, following SI standard. Sample: 512.0 kB
path string		always	Realpath of the file if it is a symlink, otherwise the same than module's param. Sample: /var/swap0
size_diff integer		always	Difference (positive or negative) between old size and new size, in bytes. Sample: -1234567890

Authors

quidame (@quidame)

© 2012–2018 Michael DeHaan
© 2018–2021 Red Hat, Inc.
Licensed under the GNU General Public License version 3.
https://docs.ansible.com/ansible/latest/collections/community/general/filesize_module.html