Is there any way doing a "one-shot" vm creation without doing any polling?

[stipx]

Hi,

basically we want to achieve a task queue which only creates the machine and does not do the polling directly.

So our workflow is:

• Create a VM -> store the ID
• Request the VM state with the ID after 5 minutes with a task which is put into a task queue
• If not yet finished just enqueue a new task which might run after 5 minutes if there is nothing else in the queue

Also: Is it possible to just create the VM and directly attach a extension without waiting for it to be finally created.

My concern is: We have a microservice which does the azure provisioning and it is container based. So it might be redeployed several times. When the polling is done in one JVM it might get interrupted when the azure handling microservice gets killed. I mean there is a grace period until the JVM exits, but I dont want it to be 20 minutes or more.

Maybe someone has an idea how to achieve something like this with the java sdk.
The REST api (which is used here anyway) supports sending just one PUT http call to create a VM, but as far as I can see there is no way to do such "one-shot" action with the sdk.

Thanks
stipx

[martinsawicki]

it's something we've been thinking about - a generalized approach for this nature of operations is needed an d is under investigation. Parking on @anuchandy .

[anuchandy]

This should be addressed in new track2 lite SDK with new Poller, where customers can initiate the LRO, take(1) and unsubscribe, which does not make any more network calls.

Assigning this to new owner @yaohaizh to update the issue when the work is done.

[yaohaizh]

Thanks, @anuchandy.

[yungezz]

part of this is beginCreate work @weidongxu-microsoft is working on

[weidongxu-microsoft]

https://github.com/Azure/azure-sdk-for-java/blob/main/sdk/resourcemanager/docs/DESIGN_PREVIEW.md

[ghost]

Hi @stipx. Thank you for opening this issue and giving us the opportunity to assist. We believe that this has been addressed. If you feel that further discussion is needed, please add a comment with the text “/unresolve” to remove the “issue-addressed” label and continue the conversation.

[ghost]

Hi @stipx, since you haven’t asked that we “/unresolve” the issue, we’ll close this out. If you believe further discussion is needed, please add a comment “/unresolve” to reopen the issue.

[fkorotkov]

I'm trying to use the beginCreate method but getting "postRunDependent is not supported" exception with not much of useful information. If I use just create() or createAsync() everything seems work just fine. Here is the related stacktrace:

 java.lang.IllegalStateException: postRunDependent is not supported
	at com.azure.resourcemanager.resources.fluentcore.dag.TaskGroup.lambda$invokeDependencyAsync$2(TaskGroup.java:300)
	at reactor.core.publisher.FluxDefer.subscribe(FluxDefer.java:46)
	at reactor.core.publisher.Flux.subscribe(Flux.java:8468)
	at reactor.core.publisher.Flux.blockLast(Flux.java:2643)
	at com.azure.resourcemanager.compute.implementation.VirtualMachineImpl.lambda$beginCreate$12(VirtualMachineImpl.java:1895)
	at com.azure.resourcemanager.resources.fluentcore.model.implementation.AcceptedImpl.newAccepted(AcceptedImpl.java:414)
	at com.azure.resourcemanager.compute.implementation.VirtualMachineImpl.beginCreate(VirtualMachineImpl.java:1872)

[weidongxu-microsoft]

@fkorotkov

Sorry for the obscure message (we will improve it in next version). It usually means that certain operation in your VM configure code is required to be done after VM creation (to my memory, maybe VM extension?), hence the "post run dependent".
These operation is handled by create call, as it poll until VM created, then do that operation.

But if via beginCreate call, since it does not poll (or depends on user to poll), it will not know when VM creation is completed, hence it is not able to do this follow up operation.

You can e.g. use beginCreate to create the VM (without extension), then when you sure VM is provided, call update to it to add e.g. VM extension.

If you think your use case does not (or should not) involve such "operation after VM created", would you show us your code?

PS: we might have later response as we are going to have week long holiday here.

[fkorotkov]

@weidongxu-microsoft thank you for the response! I was kind of lost in debugging the issue and just posted here.

Indeed I have a Custom Script Execution attached to the VM that I'm trying to create. In my case I was looking to an option to do a "one-shot" VM creation with a custom script that will bootstrap the VM.

For context, I'm working on adding support for Azure VMs to Cirrus CI cirruslabs/cirrus-ci-docs#953. We already support Azure Container Instances which has handy withStartingCommandLine method. And most other cloud providers allow to specify "startup scripts" at the moment of VM creation. Seems as you suggested I'll need to do two "one-shot" calls:

1. Create VM with beginCreate.
2. Wait for the VM creation.
3. Update the extension to run a script. Or run a command.

[weidongxu-microsoft]

@fkorotkov

I am not sure about the exact requirement of "one-shot". If you just call createAsync().toFuture(), does it count as "one-shot" (most of the case, user does not care about the polling requests)?
If you call beginCreate and forget about it, how to you know whether the VM creation is successful or not?

For VM extension, from what I know it had to be done after VM creation.

• On page from your comment (https://docs.microsoft.com/en-us/azure/virtual-machines/extensions/custom-script-windows), ARM template says below which mean it depends on an existing VM resource:

    "dependsOn": [
        "[concat('Microsoft.Compute/virtualMachines/', variables('vmName'),copyindex())]",
        "[variables('musicstoresqlName')]"
    ],

• REST API on PUT VM does not have configure on VM extension https://docs.microsoft.com/en-us/rest/api/compute/virtual-machines/create-or-update
• And VM extension is on another REST API https://docs.microsoft.com/en-us/rest/api/compute/virtual-machine-extensions/create-or-update