How do I retrieve property a of Pulumi resource using python?

I'm creating a GCP storage bucket and aggregated log sink using Pulumi and Python. To create the sink I need the value of the bucket id from Pulumi.

bucket = storage.Bucket(resource_name=bucket_name, 
                        location="us-central1", 
                        storage_class="REGIONAL",
                        uniform_bucket_level_access=True)

# destination value is needed to create the logging sink.
destination = Output.all(bucket.id).apply(lambda l: f"storage.googleapis.com/{l[0]}")

print(destination)

I would expect to get a print output of the destination variable similar to "storage.googleapis.com/bucket_id". Instead I am getting <pulumi.output.Output object at 0x10c39ae80>. I've also tried using the Pulumi concat method as described at the Pulumi docs.

destination = Output.concat("storage.googleapis.com/", bucket.id)

print(destination)

This returns the same <pulumi.output.Output object at 0x10c39ae80> instead of the expected string.

Any suggestions would be appreciated.

Solution

You can't print an Output because an output is a container for a deferred value that is not yet available when print is called. Instead, try exporting the value as a stack output

pulumi.export("destination", destination)

If you really want to print it, try doing so from within an apply:

destination.apply(lambda v: print(v))

By the way, your first snippet can be simplified to

destination = bucket.id.apply(lambda id: f"storage.googleapis.com/{id}")

but concat is even simpler indeed.