chore(rust)::> used portpicker crate to avoid port clash in ockam examples

[PsychoPunkSage]

Current behavior

Some tests in examples/rust/* could clash on TCP ports when run in parallel.

Proposed changes

Use portpicker crate to avoid port clash. Now tests will ask the OS for free ports, rather then using hardcoded values.

This PR addresses #3005 pointer 2

[metaclips]

can we update the commit message to chore(rust): used portpicker crate to avoid port clash in ockam examples

[PsychoPunkSage]

Hi @metaclips
I have replaced portpicker crate with the solution pointed by @adrianbenavides
I have on thing to report...
run_04_inlet_outlet_seperate_processes_secure_channel_via_ockam_hub is failing... due to some reasons... (not because of newly implemented portfinder.rs, i have verified that)

[PsychoPunkSage]

Hi @adrianbenavides
Did the requested changes.
Please have a look at it.

[PsychoPunkSage]

Hi @adrianbenavides
Did the changes... but should we keep the custom error variants BindError and AddrError but modify them to include io::Error??
like this

pub enum Error {
......
    #[error("failed to bind with given address")]
    BindError(#[source] io::Error),
    #[error("failed to get local socket address of the listener")]
    AddrError(#[source] io::Error),
}

pub fn find_available_port() -> Result<u16> {
    let listener = TcpListener::bind("127.0.0.1:0").map_err(Error::BindError)?;
    let address = listener.local_addr().map_err(Error::AddrError)?;
    Ok(address.port())
}

[adrianbenavides]

Hi @adrianbenavides Did the changes... but should we keep the custom error variants BindError and AddrError but modify them to include io::Error?? like this

pub enum Error {
......
    #[error("failed to bind with given address")]
    BindError(#[source] io::Error),
    #[error("failed to get local socket address of the listener")]
    AddrError(#[source] io::Error),
}

pub fn find_available_port() -> Result<u16> {
    let listener = TcpListener::bind("127.0.0.1:0").map_err(Error::BindError)?;
    let address = listener.local_addr().map_err(Error::AddrError)?;
    Ok(address.port())
}

It's not necessary in this case. Generally, you don't want to map every possible error into an enum variant, just the ones you want to act upon. In this case, we just want to convert external error types into our own and print them.

[adrianbenavides]

Thanks @PsychoPunkSage for this PR 🙏 It looks good, but you'll also have to sign your commits here before I can approve it.

https://docs.github.com/en/authentication/managing-commit-signature-verification

[PsychoPunkSage]

Hi @adrianbenavides
Added Signed commits that you requested

[adrianbenavides]

Looks good to merge, thanks a lot @PsychoPunkSage for your PR!! 🙏