If

read_sa.email

was a normal

str

that would work (f-string interpolation) but it’s actually

pulumi.Output[str]

. Try to see the details while trying to apply these changes, you should see “maltformed”

members

array.

In order to manipulate

Output

types, you have to either use `apply`:

members = [
  read_sa.email.apply(lambda email: f"serviceAccount:{email}"),
]

or `concat`:

members = [
  pulumi.Output.concat("serviceAccount:", read_sa.email),
]

Why? Reason is quite simple. This value is lazy evaluated and comes from a resource previously created so you have to have some kind of synchronization within the code. If you use the value directly (like you did with

py_repo.name

), there’s no need for additional “magic” - pulumi handles that automatically. However, it will break, if you do some string concatenation (using f-string or even plus sign).