feat(hostd): varlink interfaced host controller to manage machine configuration and boot mgmt

hostd/src/machine.rs

@@ -0,0 +1,42 @@
+use dropshot::{endpoint, HttpError, HttpResponseOk, RequestContext};
+use schemars::JsonSchema;
+use serde::Serialize;
+use std::sync::Arc;
+use trace_request::trace_request;
+
+use systemd_ipc::addrs::SYSTEMD_HOSTNAME;
+use systemd_ipc::io_systemd_hostname::{self, VarlinkClientInterface};
+
+use crate::context::ControllerContext;
+
+/// Version and build information
+#[derive(Serialize, JsonSchema)]
+struct MachineInfo {
+    machine_id: String,
+}
+
+/// Fetch machine id
+#[endpoint {
+    method = GET,
+    path = "/machine_id",
+}]
+#[trace_request]
+pub async fn describe(
+    rqctx: RequestContext<Arc<ControllerContext>>,
+) -> Result<HttpResponseOk<MachineInfo>, HttpError> {
+    let machine_info = tokio::task::spawn_blocking(move || {
+        // Connect to systemd.Hostname
+        let conn = varlink::Connection::with_address(SYSTEMD_HOSTNAME).unwrap();
+        let mut sd = io_systemd_hostname::VarlinkClient::new(conn);
+
+        let machine_id = sd.describe().call().unwrap().MachineID;
+        MachineInfo { machine_id }
+    })
+    .await
+    .unwrap();
+
+    tracing::info_span!("Hello, span hostd!");
+
+    tracing::info!(monotonic_counter.version_calls = 1);
+    Ok(HttpResponseOk(machine_info))
+}