Knife Windows

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Knife Windows Overview

The knife windows subcommand is used to interact with Windows systems managed by Chef Infra. Nodes are configured using WinRM, which allows external applications to call native objects like batch scripts, Windows PowerShell scripts, or scripting library variables. The knife windows subcommand supports NTLM and Kerberos methods of authentication.

Note

Review the list of common options available to this (and all) knife subcommands and plugins.

Requirements

This subcommand requires WinRM to be installed, and then configured correctly, including ensuring the correct ports are open. For more information, see: https://docs.microsoft.com/en-us/windows/desktop/WinRM/installation-and-configuration-for-windows-remote-management and/or https://support.microsoft.com/en-us/help/968930/windows-management-framework-core-package-windows-powershell-2-0-and-w. Use the quick configuration option in WinRM to allow outside connections and the entire network path from knife (and the workstation). Run the following on the Windows target:

C:\> winrm quickconfig -q

The following WinRM configuration settings should be updated:

Setting Description
MaxMemoryPerShellMB Chef Infra Client and Ohai typically require more memory than the default setting allows. Increase this value to 300MB. Only required on Windows Server 2008 R2 Standard and older. The default in Windows Server 2012 was increased to 1024MB.
MaxTimeoutms Often commands can take longer than the default setting. Increase this value to 1800000 (30 minutes).

To update these settings, run the following commands on the Windows target:

C:\> winrm set winrm/config/winrs '@{MaxMemoryPerShellMB="300"}'

and then:

C:\> winrm set winrm/config '@{MaxTimeoutms="1800000"}'

Ensure that the Windows Firewall is configured to allow WinRM connections between the workstation and the Chef Infra Server. For example:

C:\> netsh advfirewall firewall set rule name="Windows Remote Management (HTTP-In)" profile=public protocol=tcp localport=5985 remoteip=localsubnet new remoteip=any

Negotiate, NTLM

When knife is executed from a Microsoft Windows system, it is no longer necessary to make additional configuration of the WinRM listener on the target node to enable successful authentication from the workstation. It is sufficient to have a WinRM listener on the remote node configured to use the default configuration for winrm quickconfig. This is because knife windows supports the Microsoft Windows negotiate protocol, including NTLM authentication, which matches the authentication requirements for the default configuration of the WinRM listener.

Note

To use Negotiate or NTLM to authenticate as the user specified by the --winrm-user option, include the user’s Microsoft Windows domain, using the format domain\user, where the backslash (\) separates the domain from the user.

For example:

$ knife winrm web1.cloudapp.net 'dir' -x 'proddomain\webuser' -P 'password'

and:

$ knife winrm db1.cloudapp.net 'dir' -x '.\localadmin' -P 'password'

Domain Authentication

The knife windows plugin supports Microsoft Windows domain authentication. This requires:

To create the listener over HTTPS, run the following command on the Windows target:

C:\> winrm create winrm/config/Listener?Address=IP:<ip_address>+Transport=HTTPS @{Hostname="<fqdn>";CertificateThumbprint="<hexidecimal_thumbprint_value>"}

where the CertificateThumbprint is the thumbprint hex value copied from the certificate details. (The hex value may require that spaces be removed before passing them to the node using the knife windows plugin.) WinRM 2.0 uses port 5985 for HTTP and port 5986 for HTTPS traffic, by default.

To validate communication with the Windows system using domain authentication run:

$ knife winrm 'node1.domain.com' 'dir' -m -x domain\\administrator -P 'super_secret_password' –p 5986

cert generate

Use the cert generate argument to generate certificates for use with WinRM SSL listeners. This argument also generates a related public key file (in .pem format) to validate communication between listeners that are configured to use the generated certificate.

Syntax

This argument has the following syntax:

$ knife windows cert generate FILE_PATH (options)

Options

This argument has the following options:

-cp PASSWORD, --cert-passphrase PASSWORD
The password for the SSL certificate.
-cv MONTHS, --cert-validity MONTHS
The number of months for which a certificate is valid. Default value: 24.
-h HOSTNAME, --hostname HOSTNAME
The hostname for the listener. For example, --hostname something.mydomain.com or *.mydomain.com. Default value: *.
-k LENGTH, --key-length LENGTH
The length of the key. Default value: 2048.
-o PATH, --output-file PATH
The location in which the winrmcert.b64, winrmcert.pem, and winrmcert.pfx files are generated. For example: --output-file /home/.winrm/server_cert will create server_cert.b64, server_cert.pem, and server_cert.pfx in the server_cert directory. Default location: current_directory/winrmcert.

cert install

Use the cert install argument to install a certificate (such as one generated by the cert generate argument) into the Microsoft Windows certificate store so that it may be used as the SSL certificate by a WinRM listener.

Syntax

This argument has the following syntax:

$ knife windows cert install CERT [CERT] (options)

Options

This argument has the following options:

-cp PASSWORD, --cert-passphrase PASSWORD
The password for the SSL certificate.

listener create

Use the listener create argument to create a WinRM listener on the Microsoft Windows platform.

Note

This command may only be used on the Microsoft Windows platform.

Syntax

This argument has the following syntax:

$ knife windows listener create (options)

Options

This argument has the following options:

-c CERT_PATH, --cert-install CERT_PATH
Add the specified certificate to the store before creating the listener.
-cp PASSWORD, --cert-passphrase PASSWORD
The password for the SSL certificate.
-h HOST_NAME, --hostname HOST_NAME
The hostname for the listener. For example, --hostname something.mydomain.com or *.mydomain.com. Default value: *.
-p PORT, --port PORT
The WinRM port. Default value: 5986.
-t THUMBPRINT, --cert-thumbprint THUMBPRINT
The thumbprint of the SSL certificate. Required when the --cert-install option is not part of a command.

winrm

Use the winrm argument to create a connection to one or more remote machines. As each connection is created, a password must be provided. This argument uses the same syntax as the search subcommand.

WinRM requires that a target node be accessible via the ports configured to support access via HTTP or HTTPS.

Syntax

This argument has the following syntax:

$ knife winrm SEARCH_QUERY SSH_COMMAND (options)

Options

This argument has the following options:

-a ATTR, --attribute ATTR
The attribute used when opening a connection. The default attribute is the FQDN of the host. Other possible values include a public IP address, a private IP address, or a hostname.
-C NUM, --concurrency NUM
Changed in knife-windows 1.9.0. The number of allowed concurrent connections. Defaults to 1.
-f CA_TRUST_FILE, --ca-trust-file CA_TRUST_FILE
Optional. The certificate authority (CA) trust file used for SSL transport.
-p PORT, --winrm-port PORT
The WinRM port. The TCP port on the remote system to which knife windows commands that are made using WinRM are sent. Default: 5986 when --winrm-transport is set to ssl, otherwise 5985.
-P PASSWORD, --winrm-password PASSWORD
The WinRM password.
-R KERBEROS_REALM, --kerberos-realm KERBEROS_REALM
Optional. The administrative domain to which a user belongs.
--returns CODES
A comma-delimited list of return codes that indicate the success or failure of the command that was run remotely.
-S KERBEROS_SERVICE, --kerberos-service KERBEROS_SERVICE
Optional. The service principal used during Kerberos-based authentication.
SEARCH_QUERY
The search query used to return a list of servers to be accessed using SSH and the specified SSH_COMMAND. This option uses the same syntax as the search subcommand.
SSH_COMMAND
The command to be run against the results of a search query.
--session-timeout MINUTES
The amount of time (in minutes) for the maximum length of a WinRM session.
--ssl-peer-fingerprint FINGERPRINT
SSL Cert Fingerprint to bypass normal cert chain checks
-t TRANSPORT, --winrm-transport TRANSPORT
The WinRM transport type. Possible values: ssl or plaintext.
-T, --keytab-file KEYTAB_FILE
The keytab file that contains the encryption key required by Kerberos-based authentication.
--winrm-authentication-protocol PROTOCOL
The authentication protocol to be used during WinRM communication. Possible values: basic, kerberos or negotiate. Default value: negotiate.
--winrm-codepage Codepage
The codepage to use for the WinRM Command Shell
--winrm-shell SHELL
The WinRM shell type. Valid choices are cmd, powershell or elevated. Default value: cmd. The elevated shell is similar to the powershell option, but runs the powershell command from a scheduled task.
--winrm-ssl-verify-mode MODE
The peer verification mode that is used during WinRM communication. Possible values: verify_none or verify_peer. Default value: verify_peer.
-x USERNAME, --winrm-user USERNAME
The WinRM user name.

Examples

Find Uptime for Web Servers

To find the uptime of all web servers, enter:

$ knife winrm "role:web" "net stats srv" -x Administrator -P password

Force a Chef Infra Client run

To force a Chef Infra Client run:

knife winrm 'ec2-50-xx-xx-124.amazonaws.com' 'chef-client -c c:/chef/client.rb' -m -x admin -P 'password'
ec2-50-xx-xx-124.amazonaws.com [date] INFO: Starting Chef Run (Version 0.9.12)
ec2-50-xx-xx-124.amazonaws.com [date] WARN: Node ip-0A502FFB has an empty run list.
ec2-50-xx-xx-124.amazonaws.com [date] INFO: Chef Run complete in 4.383966 seconds
ec2-50-xx-xx-124.amazonaws.com [date] INFO: cleaning the checksum cache
ec2-50-xx-xx-124.amazonaws.com [date] INFO: Running report handlers
ec2-50-xx-xx-124.amazonaws.com [date] INFO: Report handlers complete

Where in the examples above, [date] represents the date and time the long entry was created. For example: [Fri, 04 Mar 2011 22:00:53 +0000].

Generate an SSL certificate, and then create a listener

Use the listener create, cert generate, and cert install arguments to create a new listener and assign it a newly-generated SSL certificate. First, make sure that WinRM is enabled on the machine. Do so by running the following command on the Windows node:

C:\> winrm quickconfig

Create the SSL certificate

$ knife windows cert generate --domain myorg.org --output-file $env:userprofile/winrmcerts/winrm-ssl

This command may be run on any machine and will output three file types: .b64, .pem, and .pfx.

Next, create the SSL listener:

$ knife windows listener create --hostname *.myorg.org --cert-install $env:userprofile/winrmcerts/winrm-ssl.pfx

This will use the same .pfx file that was output by the cert generate argument. If the command is run on a different machine from that which generated the certificates, the required certificate files must first be transferred securely to the system on which the listener will be created. (Use the cert install argument to install a certificate on a machine.)

The SSL listener is created and should be listening on TCP port 5986, which is the default WinRM SSL port.