win_exec: refactor PS exec runner (#45334)

* win_exec: refactor PS exec runner

* more changes for PSCore compatibility

* made some changes based on the recent review

* split up module exec scripts for smaller payload

* removed C# module support to focus on just error msg improvement

* cleaned up c# test classifier code

lib/ansible/executor/powershell/module_wrapper.ps1

@@ -0,0 +1,165 @@
+# (c) 2018 Ansible Project
+# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
+
+<#
+.SYNOPSIS
+Invokes an Ansible module in a new Runspace. This cmdlet will output the
+module's output and write any errors to the error stream of the current
+host.
+
+.PARAMETER Scripts
+[Object[]] String or ScriptBlocks to execute.
+
+.PARAMETER Variables
+[System.Collections.ArrayList] The variables to set in the new Pipeline.
+Each value is a hashtable that contains the parameters to use with
+Set-Variable;
+    Name: the name of the variable to set
+    Value: the value of the variable to set
+    Scope: the scope of the variable
+
+.PARAMETER Environment
+[System.Collections.IDictionary] A Dictionary of environment key/values to
+set in the new Pipeline.
+
+.PARAMETER Modules
+[System.Collections.IDictionary] A Dictionary of PowerShell modules to
+import into the new Pipeline. The key is the name of the module and the
+value is a base64 string of the module util code.
+
+.PARAMETER ModuleName
+[String] The name of the module that is being executed.
+#>
+param(
+    [Object[]]$Scripts,
+    [System.Collections.ArrayList][AllowEmptyCollection()]$Variables,
+    [System.Collections.IDictionary]$Environment,
+    [System.Collections.IDictionary]$Modules,
+    [String]$ModuleName
+)
+
+Write-AnsibleLog "INFO - creating new PowerShell pipeline for $ModuleName" "module_wrapper"
+$ps = [PowerShell]::Create()
+
+# do not set ErrorActionPreference for script
+if ($ModuleName -ne "script") {
+    $ps.Runspace.SessionStateProxy.SetVariable("ErrorActionPreference", "Stop")
+}
+
+# force input encoding to preamble-free UTF8 so PS sub-processes (eg,
+# Start-Job) don't blow up. This is only required for WinRM, a PSRP
+# runspace doesn't have a host console and this will bomb out
+if ($host.Name -eq "ConsoleHost") {
+    Write-AnsibleLog "INFO - setting console input encoding to UTF8 for $ModuleName" "module_wrapper"
+    $ps.AddScript('[Console]::InputEncoding = New-Object Text.UTF8Encoding $false').AddStatement() > $null
+}
+
+# set the variables
+foreach ($variable in $Variables) {
+    Write-AnsibleLog "INFO - setting variable '$($variable.Name)' for $ModuleName" "module_wrapper"
+    $ps.AddCommand("Set-Variable").AddParameters($variable).AddStatement() > $null
+}
+
+# set the environment vars
+if ($Environment) {
+    foreach ($env_kv in $Environment.GetEnumerator()) {
+        Write-AnsibleLog "INFO - setting environment '$($env_kv.Key)' for $ModuleName" "module_wrapper"
+        $env_key = $env_kv.Key.Replace("'", "''")
+        $env_value = $env_kv.Value.ToString().Replace("'", "''")
+        $escaped_env_set = "[System.Environment]::SetEnvironmentVariable('$env_key', '$env_value')"
+        $ps.AddScript($escaped_env_set).AddStatement() > $null
+    }
+}
+
+# import the PS modules
+if ($Modules) {
+    foreach ($module in $Modules.GetEnumerator()) {
+        Write-AnsibleLog "INFO - create module util '$($module.Key)' for $ModuleName" "module_wrapper"
+        $module_name = $module.Key
+        $module_code = [System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($module.Value))
+        $ps.AddCommand("New-Module").AddParameters(@{Name=$module_name; ScriptBlock=[ScriptBlock]::Create($module_code)}) > $null
+        $ps.AddCommand("Import-Module").AddParameter("WarningAction", "SilentlyContinue") > $null
+        $ps.AddCommand("Out-Null").AddStatement() > $null
+    }
+}
+
+# redefine Write-Host to dump to output instead of failing
+# lots of scripts still use it
+$ps.AddScript('Function Write-Host($msg) { Write-Output -InputObject $msg }').AddStatement() > $null
+
+# add the scripts and run
+foreach ($script in $Scripts) {
+    $ps.AddScript($script).AddStatement() > $null
+}
+
+Write-AnsibleLog "INFO - start module exec with Invoke() - $ModuleName" "module_wrapper"
+try {
+    $module_output = $ps.Invoke()
+} catch {
+    # uncaught exception while executing module, present a prettier error for
+    # Ansible to parse
+    Write-AnsibleError -Message "Unhandled exception while executing module" `
+        -ErrorRecord $_.Exception.InnerException.ErrorRecord
+    $host.SetShouldExit(1)
+    return
+}
+
+# other types of errors may not throw an exception in Invoke but rather just
+# set the pipeline state to failed
+if ($ps.InvocationStateInfo.State -eq "Failed" -and $ModuleName -ne "script") {
+    Write-AnsibleError -Message "Unhandled exception while executing module" `
+        -ErrorRecord $ps.InvocationStateInfo.Reason.ErrorRecord
+    $host.SetShouldExit(1)
+    return
+}
+
+Write-AnsibleLog "INFO - module exec ended $ModuleName" "module_wrapper"
+$ansible_output = $ps.Runspace.SessionStateProxy.GetVariable("_ansible_output")
+
+# _ansible_output is a special var used by new modules to store the
+# output JSON. If set, we consider the ExitJson and FailJson methods
+# called and assume it contains the JSON we want and the pipeline
+# output won't contain anything of note
+# TODO: should we validate it or use a random variable name?
+# TODO: should we use this behaviour for all new modules and not just
+# ones running under psrp
+if ($null -ne $ansible_output) {
+    Write-AnsibleLog "INFO - using the _ansible_output variable for module output - $ModuleName" "module_wrapper"
+    Write-Output -InputObject $ansible_output.ToString()
+} elseif ($module_output.Count -gt 0) {
+    # do not output if empty collection
+    Write-AnsibleLog "INFO - using the output stream for module output - $ModuleName" "module_wrapper"
+    Write-Output -InputObject ($module_output -join "`r`n")
+}
+
+# we attempt to get the return code from the LASTEXITCODE variable
+# this is set explicitly in newer style variables when calling
+# ExitJson and FailJson. If set we set the current hosts' exit code
+# to that same value
+$rc = $ps.Runspace.SessionStateProxy.GetVariable("LASTEXITCODE")
+if ($null -ne $rc) {
+    Write-AnsibleLog "INFO - got an rc of $rc from $ModuleName exec" "module_wrapper"
+    $host.SetShouldExit($rc)
+}
+
+# PS3 doesn't properly set HadErrors in many cases, inspect the error stream as a fallback
+# with the trap handler that's now in place, this should only write to the output if
+# $ErrorActionPreference != "Stop", that's ok because this is sent to the stderr output
+# for a user to manually debug if something went horribly wrong
+if ($ps.HadErrors -or ($PSVersionTable.PSVersion.Major -lt 4 -and $ps.Streams.Error.Count -gt 0)) {
+    Write-AnsibleLog "WARN - module had errors, outputting error info $ModuleName" "module_wrapper"
+    # if the rc wasn't explicitly set, we return an exit code of 1
+    if ($null -eq $rc) {
+        $host.SetShouldExit(1)
+    }
+
+    # output each error to the error stream of the current pipeline
+    foreach ($err in $ps.Streams.Error) {
+        $error_msg = Format-AnsibleException -ErrorRecord $err
+
+        # need to use the current hosts's UI class as we may not have
+        # a console to write the stderr to, e.g. psrp
+        Write-AnsibleLog "WARN - error msg for for $($ModuleName):`r`n$error_msg" "module_wrapper"
+        $host.UI.WriteErrorLine($error_msg)
+    }
+}