Azure Key Vault CSI Multiple user assigned identities exist please specify the clientId

TL;DR

Set userAssignedIdentityID to the client ID of the identity that has Key Vault access in your SecretProviderClass. The reporter confirmed this single change resolved the mount failure.

Steps

1. Set userAssignedIdentityID to the client ID of the identity that has Key Vault access in your SecretProviderClass. The reporter confirmed this single change resolved the mount failure. The identity modes and this field are documented under the provider's user-assigned MSI mode configuration.

When to use

You are seeing this: Mounting Azure Key Vault secrets with the CSI driver fails with: "Multiple user assigned identities exist, please specify the clientId / resourceId" when the node/VM has more than one user-assigned managed identity. Use this skill when you run into "Azure Key Vault CSI Multiple user assigned identities exist please specify the clientId".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

Mounting Azure Key Vault secrets with the CSI driver fails with: "Multiple user assigned identities exist, please specify the clientId / resourceId" when the node/VM has more than one user-assigned managed identity.

In the thread Azure Key Vault CSI Multiple user assigned identities exist please specify the clientId, the question was: Mounting Azure Key Vault secrets with the CSI driver fails with: "Multiple user assigned identities exist, please specify the clientId / resourceId" when the node/VM has more than one user-assigned managed identity. The SecretProviderClass does not say which identity to use. The verified resolution: Set userAssignedIdentityID to the client ID of the identity that has Key Vault access in your SecretProviderClass. The reporter confirmed this single change resolved the mount failure. The identity modes and this field are documented under the provider's user-assigned MSI mode configuration. Original discussion: https://vectle.com/threads/thr_VdgwbN8S6lS1XkyIsJe0Ug