Output resources connects even if unused

[alessandro-gomma]

Hi!

while building our streams we tried to avoid code duplication by replacing our outputs with a resource.
While trying different configurations, we noticed that if we declare multiple output resources, they immediately connect upon startup even if these resources aren't referenced in any stream.

Here's our resource.yaml file:

output_resources:
  - label: "first_output"
    nats:
      urls: ["nats://127.0.0.1:1234"]
      subject: ${! @output_subject }
  - label: "second_output"
    nats:
      urls: ["nats://127.0.0.1:5678"]
      subject: ${! @output_subject }

Here's the stream file:

input:
  broker:
    inputs:
      [...]

pipeline:
  processors:
    [...]

output:
  label: output
  resource: "first_output"

And this is the startup script:

benthos  -e "config.env" -c "./common/common.yaml" -r "./resources/*.yaml" -t "./templates/*.yaml" streams "./config/*.yaml"

In our solution, we would like to define multiple output resources in a single yaml file. Since we plan to have plenty of different outputs in the same file, we want to be sure that only the referenced resources are actually instantiated.
Is there any way to avoid the "second_output" resource to be used when not referenced? (e.g. lazy loading?)