Api server is not disabled when loading a configuration that has api.enabled=false

[KH-Moogsoft]

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Problem

Current behavior: When running vector with a http provider, loading a remote configuration with the api.enabled = true means that the api server can never be disabled by loading a new configuration with api.enabled = false. The reverse is also true, loading a remote configuration with the api disabled means that the api cannot be started by subsequent configurations.

Expected behavior: I would expect that the api server would start/stop depending on whether or not the loaded config has it enabled.

Based on the following code in app.rs, it appears that the api_server variable is initialized once before the main loop, and is only updated with config changes from that point on.

            // Assigned to prevent the API terminating when falling out of scope.
            let api_server = if api_config.enabled {
                use std::sync::{Arc, atomic::AtomicBool};
                emit!(ApiStarted {
                    addr: api_config.address.unwrap(),
                    playground: api_config.playground
                });

                Some(api::Server::start(topology.config(), topology.watch(), Arc::<AtomicBool>::clone(&topology.running)))
            } else {
                info!(message="API is disabled, enable by setting `api.enabled` to `true` and use commands like `vector top`.");
                None
            };

//Later on in the file
    #[cfg(feature = "api")]
         // Pass the new config to the API server.
       if let Some(ref api_server) = api_server {
          api_server.update_config(topology.config());
        }

In order to actually shut down the api server, I think that it would have to be dropped and the value of api_server would be reassigned, like so:

#[cfg(feature = "api")]
if new_config.api.enabled {
    if let None = api_server {
                    use std::sync::{Arc, atomic::AtomicBool};
        api_server = Some(api::Server::start(topology.config(), topology.watch(), Arc::<AtomicBool>::clone(&topology.running)));
    }
} else {
    if let Some(server) = api_server {
        drop(server)
    }
    api_server = None;
}

Configuration

[provider]
type = "http"
url = "http://127.0.0.1:8080/config"

To test this, I made a minimal web server that alternated between two different configurations, both identical except for api.enabled being true or false:

api.enabled = true
[sources.demo_logs]
type = "demo_logs"
format = "syslog"
interval = 1

[sinks.blackhole_sink]
type = "blackhole"
inputs = [ "demo_logs" ]
print_interval_secs = 0"

Version

0.23.0

Debug Output

The debug output isn't helpful in this case, since the server simply stays on or off.

Example Data

No response

Additional Context

No response

References

No response