Fixed websocket related tasks in InvokeAzContainerInstanceCommand_ExecuteExpanded.cs

[andreygoran]

Description

This PR fixes the problem with Invoke-AzContainerInstanceCommand not returning any result when it's run under certain conditions, and closes #22453

The problem occurres when powershell is launched with redirection of input stream (and apparently this is how it's being run in Azure ARM Powershell Deployment Scripts and in Azure Powershell Functions).

Test.ps1 code used to reproduce the problem:

$HostName = Invoke-AzContainerInstanceCommand -ContainerGroupName mypowershellapp -ContainerName mypowershellapp -ResourceGroupName MyResourceGroup -PassThru -Command 'hostname'
("Host: " + $HostName) | Out-Host

Results before the fix:

$ pwsh Test.ps1
SandboxHost-638266427706169802
Host: SandboxHost-638266427706169802
$ echo | pwsh Test.ps1
Host: 

Results after the fix:

$ pwsh Test.ps1
SandboxHost-638266427706169802
Host: SandboxHost-638266427706169802
$ echo | pwsh Test.ps1
SandboxHost-638266427706169802
Host: SandboxHost-638266427706169802

Related Issues

Fixed: #22453
Probably related: #19247
Probably related: #15754 (comment)

Root Cause Analysis

The root cause of the bug was using a return Task.Factory.StartNew(async () => {...}) construction to handle working with websockets doing actual communication with container instance. This code pattern is dangerous and should not be used, see for details https://blog.stephencleary.com/2013/08/startnew-is-dangerous.html

Another problem was using Console.KeyAvailable which throws an exception when input redirection is used. This was fixed by adding Console.IsInputRedirected validation.

Checklist

• Check this box to confirm: I have read the Submitting Changes section of CONTRIBUTING.md and reviewed the following information:

• SHOULD select appropriate branch. Cmdlets from Autorest.PowerShell should go to generation branch.
• SHOULD make the title of PR clear and informative, and in the present imperative tense.
• SHOULD update ChangeLog.md file(s) appropriately
  • For any service, the ChangeLog.md file can be found at src/{{SERVICE}}/{{SERVICE}}/ChangeLog.md
  • A snippet outlining the change(s) made in the PR should be written under the ## Upcoming Release header in the past tense. Add changelog in description section if PR goes into generation branch.
  • Should not change ChangeLog.md if no new release is required, such as fixing test case only.
• SHOULD have approved design review for the changes in this repository (Microsoft internal only) with following situations
  • Create new module from scratch
  • Create new resource types which are not easy to conform to Azure PowerShell Design Guidelines
  • Create new resource type which name doesn't use module name as prefix
  • Have design question before implementation
• SHOULD regenerate markdown help files if there is cmdlet API change. Instruction
• SHOULD have proper test coverage for changes in pull request.
• SHOULD NOT introduce breaking changes in Az minor release except preview version.
• SHOULD NOT adjust version of module manually in pull request

[azure-client-tools-bot-prd]

️✔️Az.Accounts

️✔️Build

️✔️PowerShell Core - Windows

⚠️Az.ContainerInstance

️✔️Build

️✔️PowerShell Core - Windows

️✔️Breaking Change Check

️✔️PowerShell Core - Windows

⚠️Signature Check

⚠️PowerShell Core - Windows

Type	Cmdlet	Description	Remediation
⚠️	Get-AzContainerGroup	Get-AzContainerGroup Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	Get-AzContainerGroup	Get-AzContainerGroup changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	Get-AzContainerInstanceCachedImage	Get-AzContainerInstanceCachedImage Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	Get-AzContainerInstanceCachedImage	Get-AzContainerInstanceCachedImage changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	Get-AzContainerInstanceCapability	Get-AzContainerInstanceCapability Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	Get-AzContainerInstanceCapability	Get-AzContainerInstanceCapability changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	Get-AzContainerInstanceContainerGroupOutboundNetworkDependencyEndpoint	Get-AzContainerInstanceContainerGroupOutboundNetworkDependencyEndpoint Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	Get-AzContainerInstanceContainerGroupOutboundNetworkDependencyEndpoint	Get-AzContainerInstanceContainerGroupOutboundNetworkDependencyEndpoint changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	Get-AzContainerInstanceLog	Get-AzContainerInstanceLog Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	Get-AzContainerInstanceLog	Get-AzContainerInstanceLog changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	Get-AzContainerInstanceUsage	Get-AzContainerInstanceUsage Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	Get-AzContainerInstanceUsage	Get-AzContainerInstanceUsage changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	New-AzContainerGroupImageRegistryCredentialObject	New-AzContainerGroupImageRegistryCredentialObject Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	New-AzContainerGroupImageRegistryCredentialObject	New-AzContainerGroupImageRegistryCredentialObject changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	New-AzContainerGroupPortObject	New-AzContainerGroupPortObject Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	New-AzContainerGroupPortObject	New-AzContainerGroupPortObject changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	New-AzContainerGroupVolumeObject	New-AzContainerGroupVolumeObject Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	New-AzContainerGroupVolumeObject	New-AzContainerGroupVolumeObject changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	New-AzContainerInstanceEnvironmentVariableObject	New-AzContainerInstanceEnvironmentVariableObject Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	New-AzContainerInstanceEnvironmentVariableObject	New-AzContainerInstanceEnvironmentVariableObject changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	New-AzContainerInstanceHttpHeaderObject	New-AzContainerInstanceHttpHeaderObject Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	New-AzContainerInstanceHttpHeaderObject	New-AzContainerInstanceHttpHeaderObject changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	New-AzContainerInstanceInitDefinitionObject	New-AzContainerInstanceInitDefinitionObject Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	New-AzContainerInstanceInitDefinitionObject	New-AzContainerInstanceInitDefinitionObject changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	New-AzContainerInstanceObject	New-AzContainerInstanceObject Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	New-AzContainerInstanceObject	New-AzContainerInstanceObject changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	New-AzContainerInstancePortObject	New-AzContainerInstancePortObject Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	New-AzContainerInstancePortObject	New-AzContainerInstancePortObject changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.
⚠️	New-AzContainerInstanceVolumeMountObject	New-AzContainerInstanceVolumeMountObject Changes the ConfirmImpact but does not set the SupportsShouldProcess property to true in the cmdlet attribute.	Determine if the cmdlet should implement ShouldProcess and if so determine if it should implement Force / ShouldContinue
⚠️	New-AzContainerInstanceVolumeMountObject	New-AzContainerInstanceVolumeMountObject changes the confirm impact. Please ensure that the change in ConfirmImpact is justified	Verify that ConfirmImpact is changed appropriately by the cmdlet. It is very rare for a cmdlet to change the ConfirmImpact.

️✔️Help File Existence Check

️✔️PowerShell Core - Windows

⚠️File Change Check

⚠️PowerShell Core - Windows

Type	Cmdlet	Description	Remediation
⚠️		It is required to update ChangeLog.md if you want to release a new version for Az.ContainerInstance.	Add a changelog record under Upcoming Release section with past tense.

️✔️UX Metadata Check

️✔️PowerShell Core - Windows

️✔️Test

️✔️PowerShell Core - Linux

️✔️PowerShell Core - MacOS

️✔️PowerShell Core - Windows

[ghost]

Thank you for your contribution andreygoran! We will review the pull request and get back to you soon.

[BethanyZhou]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[BethanyZhou]

https://code-maze.com/csharp-task-run-vs-task-factory-startnew/
Task.Factory.StartNew() vs Task.Run()

1. TaskCreationOptions.AttachedToParent vs TaskCreationOptions.DenyChildAttach? TaskCreationOptions.AttachedToParent as WriteObject() in PullResponse() depends on parent task.
2. Current vs Default TaskScheduler? Default TaskScheduler. No sure is current TaskScheduler same with default scheduler in ARM deployment environment?
3. Task<Task<void>> vs Task<void>? No difference in this case due to no return.
4. Object State? No difference in this case as no shared variable is scoped outside of the task block except socket.

[BethanyZhou]

Maybe should use Task.Factory.StartNew/Task.Run(action, this._cancellationTokenSource.Token, TaskCreationOptions.None, TaskScheduler.Default);? @andreygoran what's your thought?

[andreygoran]

@BethanyZhou,

3. Task<Task<void>> vs Task<void> I think it's actually crucial in this case. We use Task.WaitAll later in code https://github.com/Azure/azure-powershell/blob/d6e1dc5e5759ae025a6509886ac5d7580113f5a6/src/ContainerInstance/custom/InvokeAzContainerInstanceCommand_ExecuteExpanded.cs#L45C13-L45C25 and Task<Task<void>> means that the waiting is over when the inner Task is returned, but this does not mean that the inner Task is actually completed by that time. However Task.Run does understand the semantics of Task<Task<void>> and actually waits until the inner task is completed.
   Another solution would be to use .Unwrap() instead of switching Task.Factory.StartNew to Task.Run:

            return Task.Factory.StartNew(async () =>
            {
...
            }, this._cancellationTokenSource.Token).Unwrap();

Maybe should use Task.Factory.StartNew/Task.Run(action, this._cancellationTokenSource.Token, TaskCreationOptions.None, TaskScheduler.Default);?

I randomly checked a few usages of Task.Run in the project, and I do not see any additional parameters used anywhere. So probably it's fine the way it is.

[BethanyZhou]

Thanks for your opinions.

I prefer

return Task.Factory.StartNew(async () =>
            {
...
            }, this._cancellationTokenSource.Token).Unwrap();

Because we need TaskCreationOptions.AttachedToParent but Task.Run() uses TaskCreationOptions.DenyChildAttach

[andreygoran]

@BethanyZhou I added new commit that restores Task.Factory.StartNew and adds Unwrap()

[vidai-msft]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[BethanyZhou]

LGTM

[BethanyZhou]

/azp run azure-powershell - powershell-core

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).