chore: enable rest plugin only if in config or if --rest-http-port is set

[gabrik]

Currently the rest plugin is enabled by default for zenohd, which means that its a required dependency when running a simple zenoh router without configuration.

This PR changes the behaviour by enabling the rest plugin only if the --rest-http-port is passed.

[github-actions]

PR missing one of the required labels: {'bug', 'breaking-change', 'enhancement', 'internal', 'documentation', 'dependencies', 'new feature'}

[OlivierHecart]

Should be:

    // apply '--rest-http-port' to config only if explicitly set (overwriting config)
    // or if no config file is set (to apply its default value)
    if args.rest_http_port.is_some() || args.config.is_none() {
        match args.rest_http_port.as_deref() {
            Some(value) => {
                if !value.eq_ignore_ascii_case("none") {
                    config
                        .insert_json5("plugins/rest/http_port", &format!(r#""{value}""#))
                        .unwrap();
                    config
                        .insert_json5("plugins/rest/__required__", "true")
                        .unwrap();
                }
            }
            None => {
                config
                    .insert_json5("plugins/rest/http_port", "8000")
                    .unwrap();
            }
        }
    }

[gabrik]

shouldn't the || args.config.is_none() be removed to load only if the argument passed?

[OlivierHecart]

shouldn't the || args.config.is_none() be removed to load only if the argument passed?

Well the point is that we want rest to start on port 8000 by default if nothing is specified.

[gabrik]

shouldn't the || args.config.is_none() be removed to load only if the argument passed?

Well the point is that we want rest to start on port 8000 by default if nothing is specified.

the point of my PR is not not have it unless --rest-http-port is specified

[OlivierHecart]

shouldn't the || args.config.is_none() be removed to load only if the argument passed?

Well the point is that we want rest to start on port 8000 by default if nothing is specified.

the point of my PR is not not have it unless --rest-http-port is specified

I believed the point of the PR was to not fail if rest was not available but still start it on port 8000 by default if available.