DOS warning about binding to 0.0.0.0 does not apply to serverless environments

[richard-bain]

Describe the bug
Same issue as #7488 and #6938 but for serverless environments. We heavily utilise Google Cloud Run for our Collectors and the google docs explicitly require you to listen on 0.0.0.0.

The ingress container within an instance must listen for requests on 0.0.0.0 on the port to which requests are sent. By default, requests are sent to 8080, but you can configure Cloud Run to send requests to the port of your choice. Cloud Run injects the PORT environment variable into the ingress container.

Previously it was asked if a flag can be set to disable this warning and there were reasonable objections due to the ability to set a specific port on bare-metal and k8s environments, however this is not possible in Cloud Run.

Steps to reproduce
When the collector binds ports to 0.0.0.0, it displays warnings that inform the user that 0.0.0.0 is open to any network interface and may be a problem for DoS attacks.

What did you expect to see?
No warning for use cases where this is required and unavoidable.

What did you see instead?

{
    "kind": "receiver",
    "msg": "Using the 0.0.0.0 address exposes this server to every network interface, which may facilitate Denial of Service attacks",
    "level": "warn",
    "ts": 1710310970.3374474,
    "collector": "some-collector",
    "caller": "internal@v0.93.0/warning.go:40",
    "name": "otlp",
    "data_type": "metrics",
    "documentation": "https://github.com/open-telemetry/opentelemetry-collector/blob/main/docs/security-best-practices.md#safeguards-against-denial-of-service-attacks"
}

What version did you use?
v0.93.0

What config did you use?
N/A

Environment
Google Cloud Run

Additional context

[mx-psi]

Thanks for your issue! We will be removing the warning as part of dealing with #8510. Starting with v0.94.0 you can enable the component.UseLocalHostAsDefaultHost to change the defaults and remove this warning. Read more about how to set the feature gate here.

[dashpole]

/cc

[dashpole]

@mx-psi It doesn't look like setting the feature gate currently removes the warning when using 0.0.0.0. Do you know when you plan to implement that?

[mx-psi]

@dashpole my bad, we said we would implement it but didn't. #9852 should fix this

[richard-bain]

Thanks @mx-psi and @dashpole.