Add sd-notify

Currently, services dependent on aw-server.service (e.g. aw-awatcher)
start just after its launch.

This patch causes systemd to launch the dependent services only after
the rocket server is up an running.

It's aimed to help slow systems to not close the dependent service
prematurely due to not being able to connect to the server.

aw-server.service

@@ -14,12 +14,12 @@
 #
 
 [Service]
-Type=simple
+Type=notify
 ExecStart=aw-server
 
 [Unit]
 Description=ActivityWatch Server (Rust implementation)
-Wants=network.target
+After=network.target
 
 [Install]
 WantedBy=default.target

aw-server/Cargo.toml

@@ -29,6 +29,7 @@ uuid = { version = "1.3", features = ["serde", "v4"] }
 clap = { version = "4.1", features = ["derive", "cargo"] }
 log-panics = { version = "2", features = ["with-backtrace"]}
 rust-embed = { version = "8.0.0", features = ["interpolate-folder-path", "debug-embed"] }
+sd-notify = "0.4.2"
 
 aw-datastore = { path = "../aw-datastore" }
 aw-models = { path = "../aw-models" }

aw-server/src/main.rs

@@ -7,6 +7,8 @@ use std::path::PathBuf;
 use clap::crate_version;
 use clap::Parser;
 
+use sd_notify::NotifyState;
+
 use aw_server::*;
 
 #[cfg(all(target_os = "linux", target_arch = "x86"))]
@@ -147,9 +149,11 @@ async fn main() -> Result<(), rocket::Error> {
         device_id,
     };
 
-    let _ = endpoints::build_rocket(server_state, config)
-        .launch()
+    let _rocket = endpoints::build_rocket(server_state, config)
+        .ignite()
         .await?;
+    let _ = sd_notify::notify(true, &[NotifyState::Ready]);
+    _rocket.launch().await?;
 
     Ok(())
 }