inspec/docs/resources/file.md.erb
Jerry Aldrich f1bd34def3 docs: Fix small issues with the file resource (#3515)
Signed-off-by: Jerry Aldrich <jerryaldrichiii@gmail.com>
2018-10-17 23:44:45 -04:00

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---
title: About the file Resource
platform: os
---
# file
Use the `file` InSpec audit resource to test all system file types, including files, directories, symbolic links, named pipes, sockets, character devices, block devices, and doors.
<br>
## Availability
### Installation
This resource is distributed along with InSpec itself. You can use it automatically.
### Version
This resource first became available in v1.0.0 of InSpec.
## Syntax
A `file` resource block declares the location of the file type to be tested, the expected file type (if required), and one (or more) resource properties.
describe file('path') do
it { should PROPERTY 'value' }
end
where
* `('path')` is the name of the file and/or the path to the file.
* `PROPERTY` is a valid resource property for this resource'
* `'value'` is the value to be tested.
<br>
## Properties
### General Properties
content, size, basename, path, owner, group, type
### Unix/Linux Properties
symlink, mode, link\_path, shallow\_link\_path, mtime, size, selinux\_label, md5sum, sha256sum, path, source, source\_path, uid, gid
### Windows Properties
file\_version, product\_version
<br>
## Resource Property Examples
### content
The `content` property tests if contents in the file match the value specified in a regular expression. The values of the `content` property are arbitrary and depend on the file type being tested and also the type of information that is expected to be in that file:
its('content') { should match REGEX }
The following complete example tests the `pg_hba.conf` file in PostgreSQL for MD5 requirements. The tests look at all `host` and `local` settings in that file, and then compare the MD5 checksums against the values in the test:
describe file('/etc/postgresql/9.1/main/pg_hba.conf') do
its('content') { should match(%r{local\s.*?all\s.*?all\s.*?md5}) }
its('content') { should match(%r{host\s.*?all\s.*?all\s.*?127.0.0.1\/32\s.*?md5}) }
its('content') { should match(%r{host\s.*?all\s.*?all\s.*?::1\/128\s.*?md5}) }
end
### file_version
The `file_version` property tests if a Windows file's version matches the specified value. The difference between a file's "file version" and "product version" is that the file version is the version number of the file itself, whereas the product version is the version number associated with the application from which that file originates:
its('file_version') { should eq '1.2.3' }
### group
The `group` property tests if the group to which a file belongs matches the specified value.
its('group') { should eq 'admins' }
The following examples show how to use this InSpec audit resource.
### link_path
The `link_path` property tests if the file exists at the specified path. If the file is a symlink,
InSpec will resolve the symlink recursively and return the ultimate linked file.
its('link_path') { should eq '/some/path/to/file' }
### shallow\_link\_path
The `shallow_link_path`` property returns the path that the file refers to, only resolving
it once (that is, it performs a readlink operation). If the file is not a symlink, nil is returned.
its('shallow_link_path') { should eq '/some/path/to/file' }
### md5sum
The `md5sum` property tests if the MD5 checksum for a file matches the specified value.
its('md5sum') { should eq '3329x3hf9130gjs9jlasf2305mx91s4j' }
### mode
The `mode` property tests if the mode assigned to the file matches the specified value.
its('mode') { should cmp '0644' }
InSpec [octal](https://en.wikipedia.org/wiki/Leading_zero#0_as_a_prefix) values begin the numeric mode specification with zero.
For example, write:
{ should cmp '0644' }
not
{ should cmp '644' }
Without the zero prefix for the octal value, InSpec will interpret it as the _decimal_ value 644, which is octal 1024 or `-----w-r-T`, and any test for a file that is `-rw-r--r--` will fail.
### mtime
The `mtime` property tests if the file modification time for the file matches the specified value. The mtime, where supported, is returned as the number of seconds since the epoch.
describe file('/') do
its('mtime') { should <= Time.now.to_i }
its('mtime') { should >= Time.now.to_i - 1000 }
end
### owner
The `owner` property tests if the owner of the file matches the specified value.
its('owner') { should eq 'root' }
### product_version
The `product_version` property tests if a Windows file's product version matches the specified value. The difference between a file's "file version" and "product version" is that the file version is the version number of the file itself, whereas the product version is the version number associated with the application from which that file originates.
its('product_version') { should eq '2.3.4' }
### selinux_label
The `selinux_label` property tests if the SELinux label for a file matches the specified value.
its('selinux_label') { should eq 'system_u:system_r:httpd_t:s0' }
### sha256sum
The `sha256sum` property tests if the SHA-256 checksum for a file matches the specified value.
its('sha256sum') { should eq 'b837ch38lh19bb8eaopl8jvxwd2e4g58jn9lkho1w3ed9jbkeicalplaad9k0pjn' }
### size
The `size` property tests if a file's size matches, is greater than, or is less than the specified value. For example, equal:
its('size') { should eq 32375 }
Greater than:
its('size') { should > 64 }
Less than:
its('size') { should < 10240 }
### type
The `type` property tests for the file type. The available types are:
* `file`: the object is a file
* `directory`: the object is a directory
* `link`: the object is a symbolic link
* `pipe`: the object is a named pipe
* `socket`: the object is a socket
* `character_device`: the object is a character device
* `block_device`: the object is a block device
* `door`: the object is a door device
The `type` method usually returns the type as a Ruby "symbol". We recommend using the `cmp` matcher to match
either by symbol or string.
For example:
its('type') { should eq :file }
its('type') { should cmp 'file' }
or:
its('type') { should eq :socket }
its('type') { should cmp 'socket' }
### Test the contents of a file for MD5 requirements
describe file('/etc/postgresql/9.1/main/pg_hba.conf') do
its('content') { should match /local\s.*?all\s.*?all\s.*?md5/ }
its('content') { should match %r{/host\s.*?all\s.*?all\s.*?127.0.0.1\/32\s.*?md5/} }
its('content') { should match %r{/host\s.*?all\s.*?all\s.*?::1\/128\s.*?md5/} }
end
### Test if a file exists
describe file('/tmp') do
it { should exist }
end
### Test that a file does not exist
describe file('/tmpest') do
it { should_not exist }
end
### Test if a path is a directory
describe file('/tmp') do
its('type') { should eq :directory }
it { should be_directory }
end
### Test if a path is a file and not a directory
describe file('/proc/version') do
its('type') { should cmp 'file' }
it { should be_file }
it { should_not be_directory }
end
### Test if a file is a symbolic link
describe file('/dev/stdout') do
its('type') { should cmp 'symlink' }
it { should be_symlink }
it { should_not be_file }
it { should_not be_directory }
end
### Test if a file is a character device
describe file('/dev/zero') do
its('type') { should cmp 'character' }
it { should be_character_device }
it { should_not be_file }
it { should_not be_directory }
end
### Test if a file is a block device
describe file('/dev/zero') do
its('type') { should cmp 'block' }
it { should be_character_device }
it { should_not be_file }
it { should_not be_directory }
end
### Test the mode for a file
describe file('/dev') do
its('mode') { should cmp '00755' }
end
### Test the owner of a file
describe file('/root') do
its('owner') { should eq 'root' }
end
### Test if a file is owned by the root user
describe file('/dev') do
it { should be_owned_by 'root' }
end
### Test the mtime for a file
describe file('/') do
its('mtime') { should <= Time.now.to_i }
its('mtime') { should >= Time.now.to_i - 1000 }
end
### Test that a file's size is between 64 and 10240
describe file('/') do
its('size') { should be > 64 }
its('size') { should be < 10240 }
end
### Test that a file's size is zero
describe file('/proc/cpuinfo') do
its('size') { should be 0 }
end
### Test an MD5 checksum
require 'digest'
cpuinfo = file('/proc/cpuinfo').content
md5sum = Digest::MD5.hexdigest(cpuinfo)
describe file('/proc/cpuinfo') do
its('md5sum') { should eq md5sum }
end
### Test an SHA-256 checksum
require 'digest'
cpuinfo = file('/proc/cpuinfo').content
sha256sum = Digest::SHA256.hexdigest(cpuinfo)
describe file('/proc/cpuinfo') do
its('sha256sum') { should eq sha256sum }
end
### Verify NTP
The following example shows how to use the `file` audit resource to verify if the `ntp.conf` and `leap-seconds` files are present, and then the `command` resource to verify if NTP is installed and running:
describe file('/etc/ntp.conf') do
it { should be_file }
end
describe file('/etc/ntp.leapseconds') do
it { should be_file }
end
describe command('pgrep ntp') do
its('exit_status') { should eq 0 }
end
### Test parameters of symlinked file
If you need to test the parameters of the target file for a symlink, you can use the `link_path` (recursive resolution) or `shallow_link_path` (direct link) method for the `file` resource.
For example, for the following symlink:
lrwxrwxrwx. 1 root root 11 03-10 17:56 /dev/virtio-ports/com.redhat.rhevm.vdsm -> ../vport2p1
... you can write controls for both the link and the target.
describe file('/dev/virtio-ports/com.redhat.rhevm.vdsm') do
it { should be_symlink }
end
virito_port_vdsm = file('/dev/virtio-ports/com.redhat.rhevm.vdsm').link_path
describe file(virito_port_vdsm) do
it { should exist }
it { should be_character_device }
it { should be_owned_by 'ovirtagent' }
it { should be_grouped_into 'ovirtagent' }
end
<br>
## Matchers
For a full list of available matchers, please visit our [matchers page](https://www.inspec.io/docs/reference/matchers/).
### be\_allowed
The `be_allowed` matcher tests if the file contains a certain permission set, such as `execute` or `write` in Unix and [`full-control` or `modify` in Windows](https://www.codeproject.com/Reference/871338/AccessControl-FileSystemRights-Permissions-Table).
it { should be_allowed('read') }
Just like with `be_executable` and other permissions, one can check for the permission with respect to the specific user or group.
it { should be_allowed('full-control', by_user: 'MyComputerName\Administrator') }
OR
it { should be_allowed('write', by: 'root') }
### be\_block\_device
The `be_block_device` matcher tests if the file exists as a block device, such as `/dev/disk0` or `/dev/disk0s9`:
it { should be_block_device }
### be\_character\_device
The `be_character_device` matcher tests if the file exists as a character device (that corresponds to a block device), such as `/dev/rdisk0` or `/dev/rdisk0s9`:
it { should be_character_device }
### be_directory
The `be_directory` matcher tests if the file exists as a directory, such as `/etc/passwd`, `/etc/shadow`, or `/var/log/httpd`:
it { should be_directory }
### be_executable
The `be_executable` matcher tests if the file exists as an executable:
it { should be_executable }
The `be_executable` matcher may also test if the file is executable by a specific owner, group, or user. For example, a group:
it { should be_executable.by('group') }
an owner:
it { should be_executable.by('owner') }
any user other than the owner or members of the file's group:
it { should be_executable.by('others') }
a user:
it { should be_executable.by_user('user') }
### be_file
The `be_file` matcher tests if the file exists as a file. This can be useful with configuration files like `/etc/passwd` where there typically is not an associated file extension---`passwd.txt`:
it { should be_file }
### be\_grouped\_into
The `be_grouped_into` matcher tests if the file exists as part of the named group:
it { should be_grouped_into 'group' }
### be_immutable
The `be_immutable` matcher tests if the file is immutable, i.e. "cannot be changed":
it { should be_immutable }
### be\_linked\_to
The `be_linked_to` matcher tests if the file is linked to the named target:
it { should be_linked_to '/etc/target-file' }
### be\_owned\_by
The `be_owned_by` matcher tests if the file is owned by the named user, such as `root`:
it { should be_owned_by 'root' }
### be_pipe
The `be_pipe` matcher tests if the file exists as first-in, first-out special file (`.fifo`) that is typically used to define a named pipe, such as `/var/log/nginx/access.log.fifo`:
it { should be_pipe }
### be_readable
The `be_readable` matcher tests if the file is readable:
it { should be_readable }
The `be_readable` matcher may also test if the file is readable by a specific owner, group, or user. For example, a group:
it { should be_readable.by('group') }
an owner:
it { should be_readable.by('owner') }
any user other than the owner or members of the file's group:
it { should be_readable.by('others') }
a user:
it { should be_readable.by_user('user') }
### be_setgid
The `be_setgid` matcher tests if the 'setgid' permission is set on the file or directory. On executable files, this causes the process to be started owned by the group that owns the file, rather than the primary group of the invocating user. This can result in escalation of privilege. On Linux, when setgid is set on directories, setgid causes newly created files and directories to be owned by the group that owns the setgid parent directory; additionally, newly created subdirectories will have the setgid bit set. To use this matcher:
it { should be_setgid }
### be_socket
The `be_socket` matcher tests if the file exists as socket (`.sock`), such as `/var/run/php-fpm.sock`:
it { should be_socket }
### be_sticky
The `be_sticky` matcher tests if the 'sticky bit' permission is set on the directory. On directories, this restricts file deletion to the owner of the file, even if the permission of the parent directory would normally permit deletion by others. This is commonly used on /tmp filesystems. To use this matcher:
it { should be_sticky }
### be_setuid
The `be_setuid` matcher tests if the 'setuid' permission is set on the file. On executable files, this causes the process to be started owned by the user that owns the file, rather than invocating user. This can result in escalation of privilege. To use this matcher:
it { should be_setuid }
### be_symlink
The `be_symlink` matcher tests if the file exists as a symbolic, or soft link that contains an absolute or relative path reference to another file:
it { should be_symlink }
### be_version
The `be_version` matcher tests the version of the file:
it { should be_version '1.2.3' }
### be_writable
The `be_writable` matcher tests if the file is writable:
it { should be_writable }
The `be_writable` matcher may also test if the file is writable by a specific owner, group, or user. For example, a group:
it { should be_writable.by('group') }
an owner:
it { should be_writable.by('owner') }
any user other than the owner or members of the file's group:
it { should be_writable.by('others') }
a user:
it { should be_writable.by_user('user') }
### exist
The `exist` matcher tests if the named file exists:
it { should exist }
### have_mode
The `have_mode` matcher tests if a file has a mode assigned to it:
it { should have_mode }