Deployment of resource type MachineLearning fails using Lighthouse

Ivelin Andreev 25 Reputation points
2025-05-16T12:06:53.06+00:00

We are deploying a large number of Azure resources to customer subscription using AZ Lighthouse. The ARM templates work well when executed with a member/guest user directly in the subscription, but do not when we use resource delegation with Lighthouse:

  • The error is AccessDenied
  • The whole deployment stalls and after hours the whole deployment fails with a timeout.

As of request interaction with support team, Ref# 2504240050002808, we shall raise the topic to Lighthouse PG for further actions. The ticket was managed by the Machine Learning service support team. During our online meeting with them they checked an internal documentation and made the statement that Lighthouse does not support ML Service.

Could you please verify and provide a workaround or estimated time for support.

Cheers

Azure Lighthouse
Azure Lighthouse
An Azure service that provides secure managed services and access control for partners and customers.
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  1. Anonymous
    2025-05-27T13:44:23.4+00:00

    Hi Ivelin Andreev,

    The challenge you’re encountering stems from a fundamental architectural constraint in how Azure Machine Learning (AML) handles identity when used in cross-tenant scenarios via Azure Lighthouse. Specifically, AML requires access tokens that include a valid oid (Object ID) claim, which delegated service principal tokens commonly used via Lighthouse often lack. As a result, internal control plane operations fail authorization, leading to long-running deployments that eventually time out.

    At this time, Azure Machine Learning does not fully support creation or management through delegated identities enabled via Azure Lighthouse. This limitation has been confirmed internally through Microsoft support engagements and aligns with how the AML backend validates identity during resource provisioning.

    Recommended Workarounds:

    To proceed while staying within supported boundaries, here are a few alternatives you can adopt:

    Use a service principal or managed identity native to the customer tenant (i.e., where the ML workspace is being deployed) to ensure tokens contain the correct oid claims.

    Run deployment tasks using Azure DevOps agents or Azure Automation hosted in the customer tenant, where full Entra ID context is available.

    Split deployment into stages deploy delegate-supported resources through Lighthouse, and deploy AML workspaces using an identity that exists within the customer’s tenant.

    To ensure this gap is visible to the Product Group (PG) and prioritized accordingly, I’ll take the following steps:

    • Since it is not publicly available to report this. I will Internally surface this scenario through Microsoft’s private feedback channels related to Azure ML and Lighthouse product teams.

    In parallel, I strongly encourage submitting this as a public request via link under the Azure Machine Learning category. This allows the broader community and PG to gauge interest and urgency.

    If you do create a feedback item, feel free to share the link. I’ll make sure it gets amplified on our side as well.


    I hope this has been helpful!

    If anything remains unclear, or you’d like further clarification, feel free to drop a comment below.

    Please click Accept if this response answers your question. It helps the community discover solutions more quickly.

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  1. Alex Burlachenko 13,330 Reputation points Volunteer Moderator
    2025-05-30T09:09:40.9566667+00:00

    Ivelin Andreev hi ))) u’re stuck in that awkward spot where u have to rely on customers to run the ARM template because u can’t get member access everywhere, and it’s clunky as heck )) yeah, that’s a rough UX look for sure.

    bad news first u’re right, this isn’t just a "flip a switch and it’ll work tomorrow" thing. the way azure ml workspace hooks into identity and resource management makes it a real headache for lighthouse delegation. microsoft’s docs don’t sugarcoat it either cross-tenant ml workspace deployment isn’t officially supported (check the "limitations" section).

    lets workarounds together? let’s brainstorm so, service principal + custom role in customer tenant – if u can get the customer to set up a service principal with just the permissions u need (ml workspace contributor + network/keys/etc.), u could automate deployments without full member access. still a bit of back-and-forth, but less than asking them to run ARM manually. guide here. azure devops pipelines in their tenant – if they let u drop a pipeline in their subscription, u could trigger deployments remotely. not ideal, but better than "hey customer, click this button for us" ) bicep/terraform + approval flows if u’re using infra-as-code, u could package the template and have customers approve/reject via azure blueprints or a devops pipeline. still manual, but at least it’s a one-click thing for them.

    would u like a feature request? ABSOLUTELY. u’re spot-on – this needs to be a loud voice in microsoft’s ear. upvote existing requests (or make a new one) on azure feedback. the more noise, the better. reference ur support case when u post – it shows real-world pain, not just "wouldn’t it be nice". tag it with both machine learning and lighthouse so the right teams see it.

    it’s a bummer, but u’re not alone this trips up a lot of folks trying to do multi-tenant ml ops. for now, the service principal hack is the least-worst option unless microsoft surprises us with a lighthouse update )) keep pushing for that feature request though! the more of us yell, the faster they’ll prioritize it. and yes I know microsoft u’re listening, so… pretty please?

    )))))) have a good fridy!

    Best regards,

    Alex

    and "yes" if you would follow me at Q&A - personaly thx.
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    PPS That is my Answer and not a Comment
    

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