win_service - Cannot find an overload for "ToString" and the argument count: "0".

[cruscio]

SUMMARY

win_service failures trying to stop and remove a service.

The below error happened on 41 of the first 1500 servers I ran the playbook against.
I reran it on just those servers and it kept happening.
The issue is infrequent, but consistent.

ISSUE TYPE

• Bug Report

COMPONENT NAME

ansible.windows.win_service
module file /usr/local/lib/python3.6/site-packages/ansible_collections/ansible/windows/plugins/modules/win_service.ps1

ANSIBLE VERSION

ansible 2.10.3
  config file = None
  configured module search path = ['/root/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/local/lib/python3.6/site-packages/ansible
  executable location = /usr/local/bin/ansible
  python version = 3.6.8 (default, Apr 16 2020, 01:36:27) [GCC 8.3.1 20191121 (Red Hat 8.3.1-5)]

CONFIGURATION

DEFAULT_CALLBACK_WHITELIST(/opt/ansible/ansible.cfg) = ['log_plays']
DEFAULT_FORKS(/opt/ansible/ansible.cfg) = 500
DEFAULT_LOG_PATH(env: ANSIBLE_LOG_PATH) = /var/log/ansible/20201105_175340/ansible.log

OS / ENVIRONMENT

Target:

"ansible_distribution": "Microsoft Windows Server 2012 R2 Datacenter",
"ansible_distribution_version": "6.3.9600.0",

$PSVersionTable
Name                           Value
----                           -----
PSRemotingProtocolVersion      2.3
BuildVersion                   10.0.10586.117
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
PSVersion                      5.0.10586.117
CLRVersion                     4.0.30319.36627
WSManStackVersion              3.0
SerializationVersion           1.1.0.1

STEPS TO REPRODUCE

Run a playbook with a single task to remove the SaltStack minion service

---
- name: Remove Salt Minion Service
  hosts: all
  gather_facts: false
    - name: Saltstack Uninstall | Remove the salt-minion service
      win_service:
        name: salt-minion
        state: absent

EXPECTED RESULTS

On this server, the named service existed and was running.
The win_service task should have stop the service, removed it, and reported a change

ACTUAL RESULTS

Task failed

TASK [Saltstack Uninstall | Remove the salt-minion service] ***********************************************************************************************************************************************************************************************************************
task path: /my/playbook.yml:146
redirecting (type: modules) ansible.builtin.win_service to ansible.windows.win_service
Using module file /usr/local/lib/python3.6/site-packages/ansible_collections/ansible/windows/plugins/modules/win_service.ps1
Pipelining is enabled.
<some.windows.server.com> ESTABLISH WINRM CONNECTION FOR USER: ******** on PORT 5985 TO some.windows.server.com
EXEC (via pipeline wrapper)
The full traceback is:
Cannot find an overload for "ToString" and the argument count: "0".
At line:240 char:28
+ ... vice_type = ConvertTo-ServiceTypeDiff -ServiceType $Service.ServiceTy ...
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [ConvertTo-ServiceTypeDiff], MethodException
    + FullyQualifiedErrorId : MethodCountCouldNotFindBest,ConvertTo-ServiceTypeDiff

ScriptStackTrace:
at ConvertTo-ServiceTypeDiff, <No file>: line 198
at Get-ServiceDiff, <No file>: line 240
at <ScriptBlock>, <No file>: line 885

System.Management.Automation.MethodException: Cannot find an overload for "ToString" and the argument count: "0".
   at System.Management.Automation.ExceptionHandlingOps.CheckActionPreference(FunctionContext funcContext, Exception exception)
   at System.Management.Automation.Interpreter.ActionCallInstruction`2.Run(InterpretedFrame frame)
   at System.Management.Automation.Interpreter.EnterTryCatchFinallyInstruction.Run(InterpretedFrame frame)
   at System.Management.Automation.Interpreter.EnterTryCatchFinallyInstruction.Run(InterpretedFrame frame)
   at System.Management.Automation.Interpreter.Interpreter.Run(InterpretedFrame frame)
   at System.Management.Automation.Interpreter.LightLambda.RunVoid1[T0](T0 arg0)
   at System.Management.Automation.PSScriptCmdlet.RunClause(Action`1 clause, Object dollarUnderbar, Object inputToProcess)
   at System.Management.Automation.CommandProcessorBase.Complete()
fatal: [some.windows.server.com]: FAILED! => {
    "changed": false,
    "msg": "Unhandled exception while executing module: Cannot find an overload for \"ToString\" and the argument count: \"0\"."
}

[cruscio]

Spent some time looking at this and I'm not sure, but I think the ToString() doesn't belong there. The whole point of the switch seems to be to convert the enum value back to a string. I'm not comfortable yet saying this will work for all supported versions, but it seems to be working for me. If I can find time to test it a bit more, and can meet the contributor guidelines, I'll submit a pull request

Current code:

Function ConvertTo-ServiceTypeDiff {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory=$true)]
        [Ansible.Windows.SCManager.ServiceType]
        $ServiceType
    )

    # Converts the enum ServiceType to the valud for a diff.
    $ServiceType = [uint32]$ServiceType -band -bnot [uint32][Ansible.Windows.SCManager.ServiceType]::InteractiveProcess
    $ServiceType = $ServiceType -band -bnot [uint32][Ansible.Windows.SCManager.ServiceType]::UserServiceInstance
    switch (([Ansible.Windows.SCManager.ServiceType]$ServiceType).ToString()) {
        KernelDriver { 'kernel_driver' }
        FileSystemDriver { 'file_system_driver' }
        Adapter { 'adapter' }
        RecognizerDriver { 'recognizer_driver' }
        Win32OwnProcess { 'win32_own_process' }
        Win32ShareProcess { 'win32_share_process' }
        UserOwnprocess { 'user_own_process' }
        UserShareProcess { 'user_share_process' }
        PkgService { 'pkg_service' }
    }
}

Modified (potential fix):

Function ConvertTo-ServiceTypeDiff {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory=$true)]
        [Ansible.Windows.SCManager.ServiceType]
        $ServiceType
    )

    # Converts the enum ServiceType to the valud for a diff.
    $ServiceType = [uint32]$ServiceType -band -bnot [uint32][Ansible.Windows.SCManager.ServiceType]::InteractiveProcess
    $ServiceType = $ServiceType -band -bnot [uint32][Ansible.Windows.SCManager.ServiceType]::UserServiceInstance
    switch ([Ansible.Windows.SCManager.ServiceType]$ServiceType) {
        [Ansible.Windows.SCManager.ServiceType]::KernelDriver { 'kernel_driver' }
        [Ansible.Windows.SCManager.ServiceType]::FileSystemDriver { 'file_system_driver' }
        [Ansible.Windows.SCManager.ServiceType]::Adapter { 'adapter' }
        [Ansible.Windows.SCManager.ServiceType]::RecognizerDriver { 'recognizer_driver' }
        [Ansible.Windows.SCManager.ServiceType]::Win32OwnProcess { 'win32_own_process' }
        [Ansible.Windows.SCManager.ServiceType]::Win32ShareProcess { 'win32_share_process' }
        [Ansible.Windows.SCManager.ServiceType]::UserOwnprocess { 'user_own_process' }
        [Ansible.Windows.SCManager.ServiceType]::UserShareProcess { 'user_share_process' }
        [Ansible.Windows.SCManager.ServiceType]::PkgService { 'pkg_service' }
    }
}

[briantist]

@cruscio I'm not the most familiar with this code but the fix looks sound. Why not put in a PR? Even if you can't run the tests locally, they will be run via the PR so that should help. I'd recommend trying to add a test to catch this before committing the fix, to see if you can get a test executing that properly catches the condition, then hopefully you'll see that test pass after adding the fix to the PR

[jborean93]

I can't remember why I had it converting to a string, maybe it was just the line length. But your changes seem sound so happy to accept a PR with them and get them merged in.

[jborean93]

I was only able to replicate this issue when running against WMF 5.0 and seems like a bonafide bug with PowerShell itself at that version. A quick reproducer of this bug is the following

[IO.FileAttributes]$a = 'Archive'
([IO.FileAttributes]$a).ToString()

There seems to be a problem trying to group a cast to an enum type then call .ToString() on that groups output. I have no idea why but it's no longer a problem on 5.1+ (or even on 4.0 and earlier). I went a slightly different way to the switch as you've proposed just to keep the code mostly the same but when testing against a 5.0 instance it works just fine.