cluster-api-provider-azure
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kubernetes-sigs
Add principal type to role assignment create parameters
What type of PR is this?
/kind feature
What this PR does / why we need it:
Context: when using identity: SystemAssigned in an AzureMachineTemplate with role definition ID myrole.
Accordingly to the CAPZ documentation: https://capz.sigs.k8s.io/topics/vm-identity#system-assigned-managed-identity the service principal used to run CAPZ controller manager requires User Access Administrator on the Subscription of Workload cluster.
Based on customer feedback, we agree that this is a very wide permissions set assigned to the service principal at hand. The only restriction that can be achieved right now is to limit this access to Role Based Access Control Administrator with a condition on a role to be assigned, for example:
(
(
!(ActionMatches{'Microsoft.Authorization/roleAssignments/write'})
)
OR
(
@Request[Microsoft.Authorization/roleAssignments:RoleDefinitionId] ForAnyOfAnyValues:GuidEquals <myrole guid>
)
)
AND
(
(
!(ActionMatches{'Microsoft.Authorization/roleAssignments/delete'})
)
OR
(
@Resource[Microsoft.Authorization/roleAssignments:RoleDefinitionId] ForAnyOfAnyValues:GuidEquals <myrole guid>
)
)
This however creates a security flaw, where, if the CAPZ service principal is leaked, the myrole role can be assigned to any resource type, including users.
Desired behaviour: I would like to restrict the role assignment using a constraint like this one:
(
(
!(ActionMatches{'Microsoft.Authorization/roleAssignments/write'})
)
OR
(
@Request[Microsoft.Authorization/roleAssignments:RoleDefinitionId] ForAnyOfAnyValues:GuidEquals <myrole guid> AND
@Request[Microsoft.Authorization/roleAssignments:PrincipalType] ForAnyOfAnyValues:StringEqualsIgnoreCase {'ServicePrincipal'}
)
)
AND
(
(
!(ActionMatches{'Microsoft.Authorization/roleAssignments/delete'})
)
OR
(
@Resource[Microsoft.Authorization/roleAssignments:RoleDefinitionId] ForAnyOfAnyValues:GuidEquals <myrole guid>
AND
@Resource[Microsoft.Authorization/roleAssignments:PrincipalType] ForAnyOfAnyValues:StringEqualsIgnoreCase {'ServicePrincipal'}
)
)
This would prevent assigning the myrole role to a User or Group while still allowing assignment to Service Principals.
Problem: doing so without the changes introduced in this PR leads to a permission error:
E0305 14:05:39.993346 14 controller.go:329] "Reconciler error" err=<
failed to reconcile AzureMachine: failed to reconcile AzureMachine service roleassignments: cannot assign role to VirtualMachine system assigned identity: failed to create or update resource systemassignedidentity-4639/244a1de6-b46f-4fe4-b9cf-58f9b57643fe (service: roleassignments): PUT https://management.azure.com/subscriptions/6b1f6e4a-6d0e-4aa4-9a5a-fbaca65a23b3/resourceGroups/systemassignedidentity-4639/providers/Microsoft.Authorization/roleAssignments/244a1de6-b46f-4fe4-b9cf-58f9b57643fe
--------------------------------------------------------------------------------
RESPONSE 403: 403 Forbidden
ERROR CODE: AuthorizationFailed
--------------------------------------------------------------------------------
{
"error": {
"code": "AuthorizationFailed",
"message": "The client 'cab64998-4bbb-447d-a0f5-0f6590b46db7' with object id 'cab64998-4bbb-447d-a0f5-0f6590b46db7' does not have authorization to perform action 'Microsoft.Authorization/roleAssignments/write' over scope '/subscriptions/6b1f6e4a-6d0e-4aa4-9a5a-fbaca65a23b3/resourceGroups/systemassignedidentity-4639/providers/Microsoft.Authorization/roleAssignments/244a1de6-b46f-4fe4-b9cf-58f9b57643fe' or the scope is invalid. If access was recently granted, please refresh your credentials."
}
}
--------------------------------------------------------------------------------
This is because in the RoleAssignmentCreate API call, the principalType field is not assigned.
This PR addresses that problem by setting the PrincipalType to ServicePrincipal in the role assignment creation API call.
Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
None that I'm aware of.
Special notes for your reviewer:
- [x] cherry-pick candidate
TODOs:
- [x] squashed commits
- [ ] includes documentation
- [ ] adds unit tests
Release note:
Set `PrincipalType` in RoleAssignment creation API call when using `SystemAssigned` identity.
Hi @whites11. Thanks for your PR.
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LGTM label has been added.
LGTM label has been added.
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This pull-request has been approved by: mboersma
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@mboersma: once the present PR merges, I will cherry-pick it on top of release-1.14 in a new PR and assign it to you.
In response to this:
/cherrypick release-1.14
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@mboersma: once the present PR merges, I will cherry-pick it on top of release-1.13 in a new PR and assign it to you.
In response to this:
/cherrypick release-1.13
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@mboersma: new pull request created: #4663
In response to this:
/cherrypick release-1.14
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@mboersma: new pull request created: #4664
In response to this:
/cherrypick release-1.13
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