How to make bash script that detaches from process and then reattached to it later?

Question

I need to write a bash script that starts a blocking process, then detaches from it so I can run some other commands that configure this running process, then reattach to the original process such that ctrl+c will kill it.

Specifically, this happens to be the Google Cloud PubSub emulator, so the bash script looks something like the following pseudocode:

# TODO: pubsub will block, but I need to detach from it so I can create topics.
gcloud beta emulators pubsub start --host-port=localhost:8086

python publisher.py myapp create topic1
python publisher.py myapp create topic2

# TODO: Now I need to reattach to the pubsub process.

Answer 1

Thanks to @Barmar's comments above, I have a working solution on MacOS:

screen -S pub_sub_emulator -dm gcloud beta emulators pubsub start --host-port=localhost:8086

python publisher.py myapp create topic1
python publisher.py myapp create topic2

screen -r pub_sub_emulator