Windows Remote Management
=========================
Unlike Linux/Unix hosts, which use SSH by default, Windows hosts are
configured with WinRM. This topic covers how to configure and use WinRM with Ansible.

.. contents:: Topics

What is WinRM?
``````````````
WinRM is a management protocol used by Windows to remotely communicate with
another server. It is a SOAP-based protocol that communicates over HTTP/HTTPS, and is
included in all recent Windows operating systems. Since Windows
Server 2012, WinRM has been enabled by default, but in most cases extra
configuration is required to use WinRM with Ansible.

Ansible uses the `pywinrm <https://github.com/diyan/pywinrm>`_ package to
communicate with Windows servers over WinRM. It is not installed by default
with the Ansible package, but can be installed by running the following::

   pip install "pywinrm>=0.2.2"

.. Note:: on distributions with multiple python versions, use pip2 or pip2.x,
    where x matches the python minor version Ansible is running under.

Authentication Options
``````````````````````
When connecting to a Windows host, there are several different options that can be used
when authentication with an account. The authentication type may be set on inventory 
hosts or groups with the ``ansible_winrm_transport`` variable.

The following matrix is a high level overview of the options:

+-------------+----------------+---------------------------+-----------------------+-----------------+
| Option      | Local Accounts | Active Directory Accounts | Credential Delegation | HTTP Encryption |
+=============+================+===========================+=======================+=================+
| Basic       | Yes            | No                        | No                    | No              |
+-------------+----------------+---------------------------+-----------------------+-----------------+
| Certificate | Yes            | No                        | No                    | No              |
+-------------+----------------+---------------------------+-----------------------+-----------------+
| Kerberos    | No             | Yes                       | Yes                   | Yes             |
+-------------+----------------+---------------------------+-----------------------+-----------------+
| NTLM        | Yes            | Yes                       | No                    | Yes             |
+-------------+----------------+---------------------------+-----------------------+-----------------+
| CredSSP     | Yes            | Yes                       | Yes                   | Yes             |
+-------------+----------------+---------------------------+-----------------------+-----------------+

Basic
-----
Basic authentication is one of the simplest authentication options to use, but is
also the most insecure. This is because the username and password are simply
base64 encoded, and if a secure channel is not in use (eg, HTTPS) then it can be
decoded by anyone. Basic authentication can only be used for local accounts (not domain accounts).

The following example shows host vars configured for basic authentication::

    ansible_user: LocalUsername
    ansible_password: Password
    ansible_connection: winrm
    ansible_winrm_transport: basic

Basic authentication is not enabled by default on a Windows host but can be
enabled by running the following in PowerShell:

.. code-block:: powershell

    Set-Item -Path WSMan:\localhost\Service\Auth\Basic -Value $true

Certificate
-----------
Certificate authentication uses certificates as keys similar to SSH key
pairs, but the file format and key generation process is different.

The following example shows host vars configured for certificate authentication::

    ansible_connection: winrm
    ansible_winrm_cert_pem: /path/to/certificate/public/key.pem
    ansible_winrm_cert_key_pem: /path/to/certificate/private/key.pem
    ansible_winrm_transport: certificate

Certificate authentication is not enabled by default on a Windows host but can
be enabled by running the following in PowerShell:

.. code-block:: powershell

    Set-Item -Path WSMan:\localhost\Service\Auth\Certificate -Value $true

.. Note:: Encrypted private keys cannot be used as the urllib3 library that
    is used by Ansible for WinRM does not support this functionality.

Generate a Certificate
++++++++++++++++++++++
A certificate must be generated before it can be mapped to a local user.
This can be done using one of the following methods:

* OpenSSL
* PowerShell, using the ``New-SelfSignedCertificate`` cmdlet
* Active Directory Certificate Services

Active Directory Certificate Services is beyond of scope in this documentation but may be
the best option to use when running in a domain environment. For more information, 
see the `Active Directory Certificate Services documentation <https://technet.microsoft.com/en-us/library/cc732625(v=ws.11).aspx>`_.

.. Note:: Using the PowerShell cmdlet ``New-SelfSignedCertificate`` to generate
    a certificate for authentication only works when being generated from a
    Windows 10 or Windows Server 2012 R2 host or later. OpenSSL is still required to
    extract the private key from the PFX certificate to a PEM file for Ansible
    to use.

To generate a certificate with ``OpenSSL``:

.. code-block:: shell

    # set the name of the local user that will have the key mapped to
    USERNAME="username"

    cat > openssl.conf << EOL
    distinguished_name = req_distinguished_name
    [req_distinguished_name]
    [v3_req_client]
    extendedKeyUsage = clientAuth
    subjectAltName = otherName:1.3.6.1.4.1.311.20.2.3;UTF8:$USERNAME@localhost
    EOL

    export OPENSSL_CONF=openssl.conf
    openssl req -x509 -nodes -days 3650 -newkey rsa:2048 -out cert.pem -outform PEM -keyout cert_key.pem -subj "/CN=$USERNAME" -extensions v3_req_client
    rm openssl.conf


To generate a certificate with ``New-SelfSignedCertificate``:

.. code-block:: powershell

    # set the name of the local user that will have the key mapped
    $username = "username"
    $output_path = "C:\temp"

    # instead of generating a file, the cert will be added to the personal
    # LocalComputer folder in the certificate store
    $cert = New-SelfSignedCertificate -Type Custom `
        -Subject "CN=$username" `
        -TextExtension @("2.5.29.37={text}1.3.6.1.5.5.7.3.2","2.5.29.17={text}upn=$username@localhost") `
        -KeyUsage DigitalSignature,KeyEncipherment `
        -KeyAlgorithm RSA `
        -KeyLength 2048
    
    # export the public key
    $pem_output = @()
    $pem_output += "-----BEGIN CERTIFICATE-----"
    $pem_output += [System.Convert]::ToBase64String($cert.RawData) -replace ".{64}", "$&`n"
    $pem_output += "-----END CERTIFICATE-----"
    [System.IO.File]::WriteAllLines("$output_path\cert.pem", $pem_output)

    # export the private key in a PFX file
    [System.IO.File]::WriteAllBytes("$output_path\cert.pfx", $cert.Export("Pfx"))


.. Note:: To convert the PFX file to a private key that pywinrm can use, run
    the following command with OpenSSL
    ``openssl pkcs12 -in cert.pfx -nocerts -nodes -out cert_key.pem -passin pass: -passout pass:``

Import a Certificate to the Certificate Store
+++++++++++++++++++++++++++++++++++++++++++++
Once a certificate has been generated, the issuing certificate needs to be
imported into the ``Trusted Root Certificate Authorities`` of the
``LocalMachine`` store, and the client certificate public key must be present
in the ``Trusted People`` folder of the ``LocalMachine`` store. For this example,
both the issuing certificate and public key are the same.

Following example shows how to import the issuing certificate:

.. code-block:: powershell

    $cert = New-Object -TypeName System.Security.Cryptography.X509Certificates.X509Certificate2
    $cert.Import("cert.pem")

    $store_name = [System.Security.Cryptography.X509Certificates.StoreName]::Root
    $store_location = [System.Security.Cryptography.X509Certificates.StoreLocation]::LocalMachine
    $store = New-Object -TypeName System.Security.Cryptography.X509Certificates.X509Store -ArgumentList $store_name, $store_location
    $store.Open("MaxAllowed")
    $store.Add($cert)
    $store.Close()


.. Note:: If using ADCS to generate the certificate, then the issuing
    certificate will already be imported and this step can be skipped.

The code to import the client certificate public key is:

.. code-block:: powershell

    $cert = New-Object -TypeName System.Security.Cryptography.X509Certificates.X509Certificate2
    $cert.Import("cert.pem")

    $store_name = [System.Security.Cryptography.X509Certificates.StoreName]::TrustedPeople
    $store_location = [System.Security.Cryptography.X509Certificates.StoreLocation]::LocalMachine
    $store = New-Object -TypeName System.Security.Cryptography.X509Certificates.X509Store -ArgumentList $store_name, $store_location
    $store.Open("MaxAllowed")
    $store.Add($cert)
    $store.Close()


Mapping a Certificate to an Account
+++++++++++++++++++++++++++++++++++
Once the certificate has been imported, it needs to be mapped to the local user account.

This can be done with the following PowerShell command:

.. code-block:: powershell

    $username = "username"
    $password = ConvertTo-SecureString -String "password" -AsPlainText -Force
    $credential = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList $username, $password

    # this is the issuer thumbprint which in the case of a self generated cert
    # is the public key thumbprint, additional logic may be required for other
    # scenarios
    $thumbprint = (Get-ChildItem -Path cert:\LocalMachine\root | Where-Object { $_.Subject -eq "CN=$username" }).Thumbprint

    New-Item -Path WSMan:\localhost\ClientCertificate `
        -Subject "$username@localhost" `
        -URI * `
        -Issuer $thumbprint `
        -Credential $credential `
        -Force


Once this is complete, the hostvar ``ansible_winrm_cert_pem`` should be set to
the path of the public key and the ``ansible_winrm_cert_key_pem`` variable should be set to
the path of the private key.

NTLM
----
NTLM is an older authentication mechanism used by Microsoft that can support
both local and domain accounts. NTLM is enabled by default on the WinRM
service, so no setup is required before using it.

NTLM is the easiest authentication protocol to use and is more secure than
``Basic`` authentication. If running in a domain environment, ``Kerberos`` should be used
instead of NTLM. 

Kerberos has several advantages over using NTLM:

* NTLM is an older protocol and does not support newer encryption
  protocols.
* NTLM is slower to authenticate because it requires more round trips to the host in
  the authentication stage.
* Unlike Kerberos, NTLM does not allow credential delegation.

This example shows host variables configured to use NTLM authentication::

    ansible_user: LocalUsername
    ansible_password: Password
    ansible_connection: winrm
    ansible_winrm_transport: ntlm

Kerberos
--------
Kerberos is the recommended authentication option to use when running in a
domain environment. Kerberos supports features like credential delegation and
message encryption over HTTP and is one of the more secure options that
is available through WinRM.

Kerberos requires some additional setup work on the Ansible host before it can be
used properly.

The following example shows host vars configured for Kerberos authentication::

    ansible_user: username@MY.DOMAIN.COM
    ansible_password: Password
    ansible_connection: winrm
    ansible_winrm_transport: kerberos

As of Ansible version 2.3, the Kerberos ticket will be created based on
``ansible_user`` and ``ansible_password``. If running on an older version of 
Ansible or when ``ansible_winrm_kinit_mode`` is ``manual``, a Kerberos
ticket must already be obtained. See below for more details.

There are some extra host variables that can be set::

    ansible_winrm_kinit_mode: managed/manual (manual means Ansible will not obtain a ticket)
    ansible_winrm_kinit_cmd: the kinit binary to use to obtain a Kerberos ticket (default to kinit)
    ansible_winrm_keytab: the path to the keytab file
    ansible_winrm_kerberos_delegation: allows the credentials to traverse multiple hops
    ansible_winrm_kerberos_hostname_override: the hostname to be used for the kerberos exchange

Installing the Kerberos Library
+++++++++++++++++++++++++++++++
Some system dependencies that must be installed prior to using Kerberos. The script below lists the dependencies based on the distro:

.. code-block:: shell

    # Via Yum (RHEL/Centos/Fedora)
    yum -y install python-devel krb5-devel krb5-libs krb5-workstation

    # Via Apt (Ubuntu)
    sudo apt-get install python-dev libkrb5-dev krb5-user

    # Via Portage (Gentoo)
    emerge -av app-crypt/mit-krb5
    emerge -av dev-python/setuptools

    # Via Pkg (FreeBSD)
    sudo pkg install security/krb5

    # Via OpenCSW (Solaris)
    pkgadd -d http://get.opencsw.org/now
    /opt/csw/bin/pkgutil -U
    /opt/csw/bin/pkgutil -y -i libkrb5_3

    # Via Pacman (Arch Linux)
    pacman -S krb5


Once the dependencies have been installed, the ``python-kerberos`` wrapper can
be install using ``pip``:

.. code-block:: shell

    pip install pywinrm[kerberos]


Configuring Host Kerberos
+++++++++++++++++++++++++
Once the dependencies have been installed, Kerberos needs to be configured so
that it can communicate with a domain. This configuration is done through the
``/etc/krb5.conf`` file, which is installed with the packages in the script above.

To configure Kerberos, in the section that starts with:

::

    [realms]

Add the full domain name and the fully qualified domain names of the primary
and secondary Active Directory domain controllers. It should look something
like this:

::

    [realms]
        MY.DOMAIN.COM = {
            kdc = domain-controller1.my.domain.com
            kdc = domain-controller2.my.domain.com
        }

In the section that starts with:

::

    [domain_realm]

Add a line like the following for each domain that Ansible needs access for:

::

    [domain_realm]
        .my.domain.com = MY.DOMAIN.COM

You can configure other settings in this file such as the default domain. See
`krb5.conf <https://web.mit.edu/kerberos/krb5-1.12/doc/admin/conf_files/krb5_conf.html>`_
for more details.

Automatic Kerberos Ticket Management
++++++++++++++++++++++++++++++++++++
Ansible version 2.3 and later defaults to automatically managing Kerberos tickets
when both ``ansible_user`` and ``ansible_password`` are specified for a host. In
this process, a new ticket is created in a temporary credential cache for each
host. This is done before each task executes to minimize the chance of ticket
expiration. The temporary credential caches are deleted after each task
completes and will not interfere with the default credential cache.

To disable automatic ticket management, set ``ansible_winrm_kinit_mode=manual``
via the inventory.

Automatic ticket management requires a standard ``kinit`` binary on the control
host system path. To specify a different location or binary name, set the
``ansible_winrm_kinit_cmd`` hostvar to the fully qualified path to a MIT krbv5
``kinit``-compatible binary.

Manual Kerberos Ticket Management
+++++++++++++++++++++++++++++++++
To manually manage Kerberos tickets, the ``kinit`` binary is used. To
obtain a new ticket the following command is used:

.. code-block:: shell

    kinit username@MY.DOMAIN.COM

.. Note:: The domain must match the configured Kerberos realm exactly, and must be in upper case.

To see what tickets (if any) have been acquired, use the following command:

.. code-block:: shell

    klist

To destroy all the tickets that have been acquired, use the following command:

.. code-block:: shell

    kdestroy

Troubleshooting Kerberos
++++++++++++++++++++++++
Kerberos is reliant on a properly-configured environment to
work. To troubleshoot Kerberos issues, ensure that:

* The hostname set for the Windows host is the FQDN and not an IP address.

* The forward and reverse DNS lookups are working properly in the domain. To
  test this, ping the windows host by name and then use the ip address returned
  with ``nslookup``. The same name should be returned when using ``nslookup``
  on the IP address.

* The Ansible host's clock is synchronized with the domain controller. Kerberos
  is time sensitive, and a little clock drift can cause the ticket generation
  process to fail.

* Ensure that the fully qualified domain name for the domain is configured in
  the ``krb5.conf`` file. To check this, run::

    kinit -C username@MY.DOMAIN.COM
    klist

  If the domain name returned by ``klist`` is different from the one requested,
  an alias is being used. The ``krb5.conf`` file needs to be updated so that
  the fully qualified domain name is used and not an alias.

CredSSP
-------
CredSSP authentication is a newer authentication protocol that allows
credential delegation. This is achieved by encrypting the username and password
after authentication has succeeded and sending that to the server using the
CredSSP protocol.

Because the username and password are sent to the server to be used for double
hop authentication, ensure that the hosts that the Windows host communicates with are
not compromised and are trusted.

CredSSP can be used for both local and domain accounts and also supports
message encryption over HTTP.

To use CredSSP authentication, the host vars are configured like so::

    ansible_user: Username
    ansible_password: Password
    ansible_connection: winrm
    ansible_winrm_transport: credssp

There are some extra host variables that can be set as shown below::

    ansible_winrm_credssp_disable_tlsv1_2: when true, will not use TLS 1.2 in the CredSSP auth process

CredSSP authentication is not enabled by default on a Windows host, but can
be enabled by running the following in PowerShell:

.. code-block:: powershell

    Enable-WSManCredSSP -Role Server -Force

Installing CredSSP Library
++++++++++++++++++++++++++

The ``requests-credssp`` wrapper can be installed using ``pip``:

.. code-block:: bash

    pip install pywinrm[credssp]

CredSSP and TLS 1.2
+++++++++++++++++++
By default the ``requests-credssp`` library is configured to authenticate over
the TLS 1.2 protocol. TLS 1.2 is installed and enabled by default for Windows Server 2012
and Windows 8 and more recent releases. 

There are two ways that older hosts can be used with CredSSP:

* Install and enable a hotfix to enable TLS 1.2 support (recommended
  for Server 2008 R2 and Windows 7).

* Set ``ansible_winrm_credssp_disable_tlsv1_2=True`` in the inventory to run
  over TLS 1.0. This is the only option when connecting to Windows Server 2008, which 
  has no way of supporting TLS 1.2

To enable TLS 1.2 support on Server 2008 R2 and Windows 7, the optional update
`KRB3080079 <https://support.microsoft.com/en-us/help/3080079/update-to-add-rds-support-for-tls-1.1-and-tls-1.2-in-windows-7-or-windows-server-2008-r2>`_
needs to be installed. 

Once the update has been applied and the Windows host rebooted, run the following
PowerShell commands to enable TLS 1.2:

.. code-block:: powershell

    $reg_path = "HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProvider\SCHANNEL\Protocols\TLS 1.2"
    New-Item -Path $reg_path
    New-Item -Path "$reg_path\Server"
    New-Item -Path "$reg_path\Client"

    New-ItemProperty -Path "$reg_path\Server" -Name "Enabled" -Value 1 -PropertyType DWord
    New-ItemProperty -Path "$reg_path\Server" -Name "DisabledByDefault" -Value 0 -PropertyType DWord
    New-ItemProperty -Path "$reg_path\Client" -Name "Enabled" -Value 1 -PropertyType DWord
    New-ItemProperty -Path "$reg_path\Client" -Name "DisabledByDefault" -Value 0 -PropertyType DWord

Set CredSSP Certificate
+++++++++++++++++++++++
CredSSP works by encrypting the credentials through the TLS protocol and uses a self-signed certificate by default. The ``CertificateThumbprint`` option under the WinRM service configuration can be used to specify the thumbprint of
another certificate.

.. Note:: This certificate configuration is independent of the WinRM listener
    certificate. With CredSSP, message transport still occurs over the WinRM listener, 
    but the TLS-encrypted messages inside the channel use the service-level certificate.

To explicitly set the certificate to use for CredSSP:

.. code-block:: powershell

    # note the value $certificate_thumbprint will be different in each
    # situation, this needs to be set based on the cert that is used.
    $certificate_thumbprint = "7C8DCBD5427AFEE6560F4AF524E325915F51172C"

    # set the thumbprint value
    Set-Item -Path WSMan:\localhost\Service\CertificateThumbprint -Value $certificate_thumbprint

Non-Administrator Accounts
``````````````````````````
WinRM is configured by default to only allow connections from accounts in the local
``Administrators`` group. This can be changed by running:

.. code-block:: powershell

    winrm configSDDL default

This will display an ACL editor, where new users or groups may be added. To run commands
over WinRM, users and groups must have at least the ``Read`` and ``Execute`` permissions 
enabled.

While non-administrative accounts can be used with WinRM, most typical server administration
tasks require some level of administrative access, so the utility is usually limited.

WinRM Encryption
````````````````
By default WinRM will fail to work when running over an unencrypted channel.
The WinRM protocol considers the channel to be encrypted if using TLS over HTTP
(HTTPS) or using message level encryption. Using WinRM with TLS is the
recommended option as it works with all authentication options, but requires
a certificate to be created and used on the WinRM listener.

The ``ConfigureRemotingForAnsible.ps1`` creates a self-signed certificate and
creates the listener with that certificate. If in a domain environment, ADCS
can also create a certificate for the host that is issued by the domain itself.

If using HTTPS is not an option, then HTTP can be used when the authentication
option is ``NTLM``, ``Kerberos`` or ``CredSSP``. These protocols will encrypt
the WinRM payload with their own encryption method before sending it to the
server. The message-level encryption is not used when running over HTTPS because the
encryption uses the more secure TLS protocol instead. If both transport and
message encryption is required, set ``ansible_winrm_message_encryption=always``
in the host vars.

A last resort is to disable the encryption requirement on the Windows host. This
should only be used for development and debugging purposes, as anything sent
from Ansible can viewed by anyone on the network. To disable the encryption
requirement, run the following from PowerShell on the target host:

.. code-block:: powershell

    Set-Item -Path WSMan:\localhost\Service\AllowUnencrypted -Value $true

.. Note:: Do not disable the encryption check unless it is
    absolutely required. Doing so could allow sensitive information like
    credentials and files to be intercepted by others on the network.

Inventory Options
`````````````````
Ansible's Windows support relies on a few standard variables to indicate the
username, password, and connection type of the remote hosts. These variables
are most easily set up in the inventory, but can be set on the ``host_vars``/
``group_vars`` level.

When setting up the inventory, the following variables are required::

    # it is suggested that these be encrypted with ansible-vault:
    # ansible-vault edit group_vars/windows.yml
    
    ansible_connection: winrm

    # may also be passed on the command-line via --user
    ansible_user: Administrator
    
    # may also be supplied at runtime with --ask-pass
    ansible_password: SecretPasswordGoesHere


Using the variables above, Ansible will connect to the Windows host with Basic
authentication through HTTPS. If ``ansible_user`` has a UPN value like
``username@MY.DOMAIN.COM`` then the authentication option will automatically attempt
to use Kerberos unless ``ansible_winrm_transport`` has been set to something other than
``kerberos``.

The following custom inventory variables are also supported
for additional configuration of WinRM connections:

* ``ansible_port``: The port WinRM will run over, HTTPS is ``5986`` which is
  the default while HTTP is ``5985``

* ``ansible_winrm_scheme``: Specify the connection scheme (``http`` or
  ``https``) to use for the WinRM connection. Ansible uses ``https`` by default
  unless ``ansible_port`` is ``5985``

* ``ansible_winrm_path``: Specify an alternate path to the WinRM endpoint,
  Ansible uses ``/wsman`` by default

* ``ansible_winrm_realm``: Specify the realm to use for Kerberos
  authentication. If ``ansible_user`` contains ``@``, Ansible will use the part
  of the username after ``@`` by default

* ``ansible_winrm_transport``: Specify one or more authentication transport
  options as a comma-separated list. By default, Ansible will use ``kerberos,
  basic`` if the ``kerberos`` module is installed and a realm is defined,
  otherwise it will be ``plaintext``

* ``ansible_winrm_server_cert_validation``: Specify the server certificate
  validation mode (``ignore`` or ``validate``). Ansible defaults to
  ``validate`` on Python 2.7.9 and higher, which will result in certificate
  validation errors against the Windows self-signed certificates. Unless
  verifiable certificates have been configured on the WinRM listeners, this
  should be set to ``ignore``

* ``ansible_winrm_operation_timeout_sec``: Increase the default timeout for
  WinRM operations, Ansible uses ``20`` by default

* ``ansible_winrm_read_timeout_sec``: Increase the WinRM read timeout, Ansible
  uses ``30`` by default. Useful if there are intermittent network issues and
  read timeout errors keep occurring

* ``ansible_winrm_message_encryption``: Specify the message encryption
  operation (``auto``, ``always``, ``never``) to use, Ansible uses ``auto`` by
  default. ``auto`` means message encryption is only used when
  ``ansible_winrm_scheme`` is ``http`` and ``ansible_winrm_transport`` supports
  message encryption. ``always`` means message encryption will always be used
  and ``never`` means message encryption will never be used

* ``ansible_winrm_*``: Any additional keyword arguments supported by
  ``winrm.Protocol`` may be provided in place of ``*``

In addtion, there are also specific variables that need to be set
for each authentication option. See the section on authentication above for more information.

.. Note:: Ansible 2.0 has deprecated the "ssh" from ``ansible_ssh_user``,
    ``ansible_ssh_pass``, ``ansible_ssh_host``, and ``ansible_ssh_port`` to
    become ``ansible_user``, ``ansible_password``, ``ansible_host``, and
    ``ansible_port``. If using a version of Ansible prior to 2.0, the older
    style (``ansible_ssh_*``) should be used instead. The shorter variables
    are ignored, without warning, in older versions of Ansible.

.. Note:: ``ansible_winrm_message_encryption`` is different from transport
    encryption done over TLS. The WinRM payload is still encrypted with TLS
    when run over HTTPS, even if ``ansible_winrm_message_encryption=never``.

Limitations
```````````
Due to the design of the WinRM protocol , there are a few limitations
when using WinRM that can cause issues when creating playbooks for Ansible.
These include:

* Credentials are not delegated for most authentication types, which causes
  authentication errors when accessing network resources or installing certain
  programs.

* Many calls to the Windows Update API are blocked when running over WinRM.

* Some programs fail to install with WinRM due to no credential delegation or
  because they access forbidden Windows API like WUA over WinRM.

* Commands under WinRM are done under a non-interactive session, which can prevent
  certain commands or executables from running.

* You cannot run a process that interacts with ``DPAPI``, which is used by some 
  installers (like Microsoft SQL Server).
  
Some of these limitations can be mitigated by doing one of the following:

* Set ``ansible_winrm_transport`` to ``credssp`` or ``kerberos`` (with
  ``ansible_winrm_kerberos_delegation=true``) to bypass the double hop issue
  and access network resources

* Use ``become`` to bypass all WinRM restrictions and run a command as it would
  locally. Unlike using an authentication transport like ``credssp``, this will
  also remove the non-interactive restriction and API restrictions like WUA and
  DPAPI

* Use a scheduled task to run a command which can be created with the
  ``win_scheduled_task`` module. Like ``become``, this bypasses all WinRM
  restrictions but can only run a command and not modules.


.. seealso::

   :doc:`index`
       The documentation index
   :doc:`playbooks`
       An introduction to playbooks
   :doc:`playbooks_best_practices`
       Best practices advice
   `List of Windows Modules <http://docs.ansible.com/list_of_windows_modules.html>`_
       Windows specific module list, all implemented in PowerShell
   `User Mailing List <http://groups.google.com/group/ansible-project>`_
       Have a question?  Stop by the google group!
   `irc.freenode.net <http://irc.freenode.net>`_
       #ansible IRC chat channel
