The following items are new for Chef Infra Client 12.9 and/or are changes from previous versions. The short version:

- **New apt_repository resource**
- **64-bit chef-client for Microsoft Windows** Starting with
    chef-client 12.9, 64-bit
- **New property for the mdadm resource** Use the `mdadm_defaults`
    property to set the default values for `chunk` and `metadata` to
    `nil`, which allows mdadm to apply its own default values.
- **File redirection in Windows for 32-bit applications** Files on
    Microsoft Windows that are managed by the **file** and **directory**
    resources are subject to file redirection, depending if Chef Infra Client
    is 64-bit or 32-bit.
- **Registry key redirection in Windows for 32-bit applications**
    Registry keys on Microsoft Windows that are managed by the
    **registry_key** resource are subject to key redirection, depending
    if Chef Infra Client is 64-bit or 32-bit.
- **New values for log_location** Use `:win_evt` to write log output
    to the (Windows Event Logger and `:syslog` to write log output to
    the syslog daemon facility with the originator set as `chef-client`.
- **New timeout setting for knife ssh** Set the `--ssh-timeout`
    setting to an integer (in seconds) as part of a `knife ssh` command.
    The `ssh_timeout` setting may also be configured (as seconds) in the
    knife.rb file.
- **New "seconds to wait before first chef-client run" setting** The
    `-daemonized` option for Chef Infra Client now allows the seconds to wait
    before starting Chef Infra Client run to be specified. For example, if
    `--daemonize 10` is specified, Chef Infra Client will wait ten seconds.

## apt_repository resource

The apt_repository resource, previously available in the apt cookbook,
is now included in chef-client. With this change you will no longer need
to depend on the apt cookbook to use the apt_repository resource.

## 64-bit chef-client

Chef Infra Client now runs on 64-bit Microsoft Windows operating systems.

- Support for file redirection
- Support for key redirection

### File Redirection

64-bit versions of Microsoft Windows have a 32-bit compatibility layer
that redirects attempts by 32-bit application to access the `System32`
directory to a different location. Starting with chef-client version
12.9, the 32-bit version of Chef Infra Client is subject to the file
redirection policy.

For example, consider the following script:

```ruby
process_type = ENV['PROCESSOR_ARCHITECTURE'] == 'AMD64' ? '64-bit' : '32-bit'
system32_dir = ::File.join(ENV['SYSTEMROOT'], 'system32')
test_dir = ::File.join(system32_dir, 'cheftest')
test_file = ::File.join(test_dir, 'chef_architecture.txt')

directory test_dir do
  # some directory
end

file test_file do
  content "Chef made me, I come from a #{process_type} process."
end
```

When running a 32-bit version of chef-client, the script will write the
`chef_architecture` file to the `C:\Windows\SysWow64` directory.
However, when running a native 64-bit version of the chef-client, the
script will write a file to the `C:\Windows\System32` directory, as
expected.

For more information, see: [File System
Redirector](https://msdn.microsoft.com/en-us/library/windows/desktop/aa384187(v=vs.85).aspx).

### Key Redirection

64-bit versions of Microsoft Windows have a 32-bit compatibility layer
in the registry that reflects and redirects certain keys (and their
values) into specific locations (or logical views) of the registry hive.

Chef Infra Client can access any reflected or redirected registry key. The
machine architecture of the system on which Chef Infra Client is running is
used as the default (non-redirected) location. Access to the `SysWow64`
location is redirected must be specified. Typically, this is only
necessary to ensure compatibility with 32-bit applications that are
running on a 64-bit operating system.

32-bit versions of Chef Infra Client (12.8 and earlier) and 64-bit versions of
Chef Infra Client (12.9 and later) generally behave the same in this
situation, with one exception: it is only possible to read and write
from a redirected registry location using chef-client version 12.9 (and
later).

For more information, see: [Registry
Reflection](https://msdn.microsoft.com/en-us/library/windows/desktop/aa384235(v=vs.85).aspx).