signal systemd readiness

Signed-off-by: Christine Dodrill <me@christine.website>

backend/Cargo.lock

@@ -1240,6 +1240,7 @@ dependencies = [
  "rocket_prometheus",
  "rusty_ulid",
  "scraper",
+ "sdnotify",
  "serde",
  "serde_json",
  "thiserror",
@@ -2266,6 +2267,12 @@ dependencies = [
  "untrusted",
 ]
 
+[[package]]
+name = "sdnotify"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "71ce7eac2075a4562fbcbad544cd55d72ebc760e0a5594a7c8829cf2b4b42a7a"
+
 [[package]]
 name = "selectors"
 version = "0.22.0"

backend/Cargo.toml

@@ -25,6 +25,7 @@ rocket_cors = "0.5"
 rocket_prometheus = "0.7.0"
 rusty_ulid = "0.10"
 scraper = "0.12.0"
+sdnotify = { version = "0.1", default-features = false }
 serde_json = "^1"
 serde = { version = "1", features = ["derive"] }
 thiserror = "1"

backend/src/main.rs

@@ -6,7 +6,7 @@ extern crate rocket;
 extern crate tracing;
 
 use color_eyre::eyre::Result;
-use rocket::http::Method;
+use rocket::{fairing::AdHoc, http::Method};
 use rocket_contrib::helmet::SpaceHelmet;
 use rocket_cors::{AllowedHeaders, AllowedOrigins};
 use rocket_prometheus::PrometheusMetrics;
@@ -58,6 +58,13 @@ fn main() -> Result<()> {
         .attach(PluralKit::fairing())
         .attach(SwitchCounter::fairing())
         .attach(Twitter::fairing())
+        .attach(AdHoc::on_launch("systemd readiness", |_| {
+            if let Ok(ref mut n) = sdnotify::SdNotify::from_env() {
+                let _ = n
+                    .notify_ready()
+                    .map_err(|why| error!("can't signal readiness to systemd: {}", why));
+            }
+        }))
         .mount("/metrics", prometheus)
         .mount("/", routes![botinfo])
         .mount(

default.nix

@@ -37,6 +37,7 @@ let
     export DATABASE_URL=./mi.db
     export ROCKET_DATABASES='{ main_data = { url = "./mi.db" } }';
     ${composite}/bin/migrate_database
+    ${composite}/bin/bridgy_migrate
     export ROCKET_ASSET_PATH=${composite}/public
     exec ${composite}/bin/mi
   '';