[Bug] Unable to set multiple grpc-meta in the env config

What are you really trying to do?

Similar to how the web UI uses the authorization and authorization-extras headers, I'd like to be able to pass these via the temporal CLI.

I'd like to add these headers (grpc-meta) in the temporal env config file to simplify CLI invocation, e.g.

temporal operator namespace list \
  --grpc-meta "authorization=${AUTHORIZATION}" \
  --grpc-meta "authorization-extras=${AUTHORIZATION_EXTRAS}" \
  --address temporal.example.com \
  --tls

and the command succeeds as expected when valid auth headers are supplied.

Describe the bug

The temporal env command clobbers existing values when setting grpc-meta and it's not clear how to manually edit the YAML file to set them either.

Minimal Reproduction

temporal env set --env=example --key=grpc-meta --value="authorization=${AUTHORIZATION} authorization-extras=${AUTHORIZATION_EXTRAS}"

env:
  example:
    grpc-meta: authorization=Bearer xxx.yyy.zzz authorization-extras=REDACTED

However this doesn't work, the ClientOptions.GrpcMeta according to my debugger has a value like:

map[authorization:Bearer xxx.yyy.zzz authorization-extras=REDACTED]

i.e. a map[string]string but the key is authorization and the value is all the other grpc-meta values I'm trying to populate from the config.

Environment/Versions

• OS and processor: M1 Mac
• Temporal Version: 1.3.0
• Are you using Docker or Kubernetes or building Temporal from source? Temporal CLI install from homebrew

Start by reproducing the issue with temporal env set --env=example --key=grpc-meta and trace how the env configuration is loaded into ClientOptions.GrpcMeta. Confirm that multiple metadata entries are parsed as separate key-value pairs rather than one key with a combined value; done means both authorization headers work from the env config.