Spinning up Windows Minions

It is possible to use Salt Cloud to spin up Windows instances, and then install Salt on them. This functionality is available on all cloud providers that are supported by Salt Cloud. However, it may not necessarily be available on all Windows images.

Requirements

Salt Cloud makes use of impacket and winexe to set up the Windows Salt Minion installer.

impacket is usually available as either the impacket or the python-impacket package, depending on the distribution. More information on impacket can be found at the project home:

winexe is less commonly available in distribution-specific repositories. However, it is currently being built for various distributions in 3rd party channels:

Optionally WinRM can be used instead of winexe if the python module pywinrm is available and WinRM is supported on the target Windows version. Information on pywinrm can be found at the project home:

Additionally, a copy of the Salt Minion Windows installer must be present on the system on which Salt Cloud is running. This installer may be downloaded from saltstack.com:

Firewall Settings

Because Salt Cloud makes use of smbclient and winexe, port 445 must be open on the target image. This port is not generally open by default on a standard Windows distribution, and care must be taken to use an image in which this port is open, or the Windows firewall is disabled.

If supported by the cloud provider, a PowerShell script may be used to open up this port automatically, using the cloud provider's userdata. The following script would open up port 445, and apply the changes:

<powershell>
New-NetFirewallRule -Name "SMB445" -DisplayName "SMB445" -Protocol TCP -LocalPort 445
Set-Item (dir wsman:\localhost\Listener\*\Port -Recurse).pspath 445 -Force
Restart-Service winrm
</powershell>

For EC2, this script may be saved as a file, and specified in the provider or profile configuration as userdata_file. For instance:

userdata_file: /etc/salt/windows-firewall.ps1

If you are using WinRM on EC2 the HTTPS port for the WinRM service must also be enabled in your userdata. By default EC2 Windows images only have insecure HTTP enabled. To enable HTTPS and basic authentication required by pywinrm consider the following userdata example:

<powershell>
New-NetFirewallRule -Name "SMB445" -DisplayName "SMB445" -Protocol TCP -LocalPort 445
New-NetFirewallRule -Name "WINRM5986" -DisplayName "WINRM5986" -Protocol TCP -LocalPort 5986

winrm quickconfig -q
winrm set winrm/config/winrs '@{MaxMemoryPerShellMB="300"}'
winrm set winrm/config '@{MaxTimeoutms="1800000"}'
winrm set winrm/config/service/auth '@{Basic="true"}'

$SourceStoreScope = 'LocalMachine'
$SourceStorename = 'Remote Desktop'

$SourceStore = New-Object  -TypeName System.Security.Cryptography.X509Certificates.X509Store  -ArgumentList $SourceStorename, $SourceStoreScope
$SourceStore.Open([System.Security.Cryptography.X509Certificates.OpenFlags]::ReadOnly)

$cert = $SourceStore.Certificates | Where-Object  -FilterScript {
    $_.subject -like '*'
}

$DestStoreScope = 'LocalMachine'
$DestStoreName = 'My'

$DestStore = New-Object  -TypeName System.Security.Cryptography.X509Certificates.X509Store  -ArgumentList $DestStoreName, $DestStoreScope
$DestStore.Open([System.Security.Cryptography.X509Certificates.OpenFlags]::ReadWrite)
$DestStore.Add($cert)

$SourceStore.Close()
$DestStore.Close()

winrm create winrm/config/listener?Address=*+Transport=HTTPS  `@`{Hostname=`"($certId)`"`;CertificateThumbprint=`"($cert.Thumbprint)`"`}

Restart-Service winrm
</powershell>

No certificate store is available by default on EC2 images and creating one does not seem possible without an MMC (cannot be automated). To use the default EC2 Windows images the above copies the RDP store.

Configuration

Configuration is set as usual, with some extra configuration settings. The location of the Windows installer on the machine that Salt Cloud is running on must be specified. This may be done in any of the regular configuration files (main, providers, profiles, maps). For example:

Setting the installer in /etc/salt/cloud.providers:

my-softlayer:
  driver: softlayer
  user: MYUSER1138
  apikey: 'e3b68aa711e6deadc62d5b76355674beef7cc3116062ddbacafe5f7e465bfdc9'
  minion:
    master: saltmaster.example.com
  win_installer: /root/Salt-Minion-2014.7.0-AMD64-Setup.exe
  win_username: Administrator
  win_password: letmein
  smb_port: 445

The default Windows user is Administrator, and the default Windows password is blank.

If WinRM is to be used use_winrm needs to be set to True. winrm_port can be used to specify a custom port (must be HTTPS listener).

Auto-Generated Passwords on EC2

On EC2, when the win_password is set to auto, Salt Cloud will query EC2 for an auto-generated password. This password is expected to take at least 4 minutes to generate, adding additional time to the deploy process.

When the EC2 API is queried for the auto-generated password, it will be returned in a message encrypted with the specified keyname. This requires that the appropriate private_key file is also specified. Such a profile configuration might look like:

windows-server-2012:
  provider: my-ec2-config
  image: ami-c49c0dac
  size: m1.small
  securitygroup: windows
  keyname: mykey
  private_key: /root/mykey.pem
  userdata_file: /etc/salt/windows-firewall.ps1
  win_installer: /root/Salt-Minion-2014.7.0-AMD64-Setup.exe
  win_username: Administrator
  win_password: auto