$ConditionVersion = "2.0"
$Description = "This is a new role assignment for John"
$Condition = "@Resource[Microsoft.Storage/storageAccounts/blobServices/containers/blobs:Path] StringEqualsIgnoreCase 'foo_storage_container'"
$roleAssignment = Get-AzRoleAssignment -Scope "/subscriptions/00001111-aaaa-2222-bbbb-3333cccc4444/resourceGroups/contoso_rg" -PrincipalId "0c0f6cdc-90dd-4664-83c0-a0d986c4c604"
$roleAssignment.Description = $Description
$roleAssignment.Condition = $Condition
$roleAssignment.ConditionVersion = $ConditionVersion
Set-AzRoleAssignment -InputObject $roleAssignment -PassThru
RoleAssignmentId : /providers/Microsoft.Management/managementGroups/1273adef-00a3
-4086-a51a-dbcce1857d36/providers/Microsoft.Authorization/role
Assignments/926c2a76-be19-4281-94de-38777629b9dc
Scope : /subscriptions/00001111-aaaa-2222-bbbb-3333cccc4444/resourceGroups/contoso_rg
DisplayName : John Doe
SignInName : John.Doe@Contoso.com
RoleDefinitionName : Owner
RoleDefinitionId : 8e3af657-a8ff-443c-a75c-2fe8c4bcb635
ObjectId : 0c0f6cdc-90dd-4664-83c0-a0d986c4c604
ObjectType : User
CanDelegate : False
Description : This is a new role assignment for John
ConditionVersion : 2.0
Condition : @Resource[Microsoft.Storage/storageAccounts/blobServices/containers/blobs:Path] StringEqualsIgnoreCase 'foo_storage_container'
RoleAssignmentId : /providers/Microsoft.Management/managementGroups/1273adef-00a3
-4086-a51a-dbcce1857d36/providers/Microsoft.Authorization/role
Assignments/926c2a76-be19-4281-94de-38777629b9dc
Scope : /subscriptions/00001111-aaaa-2222-bbbb-3333cccc4444/resourceGroups/contoso_rg
DisplayName : John Doe
SignInName : John.Doe@Contoso.com
RoleDefinitionName : Owner
RoleDefinitionId : 8e3af657-a8ff-443c-a75c-2fe8c4bcb635
ObjectId : 0c0f6cdc-90dd-4664-83c0-a0d986c4c604
ObjectType : User
CanDelegate : False
Description : This is a new role assignment for John
ConditionVersion : 2.0
Condition : @Resource[Microsoft.Storage/storageAccounts/blobServices/containers/blobs:Path] StringEqualsIgnoreCase 'foo_storage_container'