Add vergen revision to local_backend (#33677)

Add vergen revision to local_backend
Add commit timestamp

GitOrigin-RevId: b1f80550c790acbd65d89b6b584cfce47876230d

Cargo.toml

@@ -162,6 +162,7 @@ tungstenite = { version = "0.21.0", features = [ "url", "native-tls-vendored" ]
 url = "2.5.4"
 urlencoding = "2.1.3"
 uuid = { version = "1.6", features = [ "serde", "v4" ] }
+vergen = { version = "8.1.0" }
 walkdir = "2"
 xorf = { git = "https://github.com/sujayakar/xorf.git", rev = "62a32de47bb3ad8b34d6d4feac034a24be2c881a" }
 

crates/local_backend/Cargo.toml

@@ -98,5 +98,9 @@ usage_tracking = { path = "../../crates/usage_tracking", features = [
 value = { path = "../../crates/value", features = ["testing"] }
 vector = { path = "../../crates/vector", features = ["testing"] }
 
+[build-dependencies]
+anyhow = { workspace = true }
+vergen = { workspace = true, features = ["git", "gitcl"] }
+
 [lints]
 workspace = true

crates/local_backend/build.rs

@@ -0,0 +1,18 @@
+use std::env;
+
+use vergen::EmitBuilder;
+
+fn main() -> anyhow::Result<()> {
+    // recompile when there's a new git hash for /rev endpoint.
+    if cfg!(not(debug_assertions)) || env::var("FORCE_EMIT").is_ok() {
+        // Emit git sha
+        EmitBuilder::builder()
+            .git_sha(false)
+            .git_commit_timestamp()
+            .emit()?;
+    } else {
+        println!("cargo:rustc-env=VERGEN_GIT_SHA=dev");
+        println!("cargo:rustc-env=VERGEN_GIT_COMMIT_TIMESTAMP=0000-00-00T00:00:00.000000000Z");
+    }
+    Ok(())
+}

crates/local_backend/src/beacon.rs

@@ -21,6 +21,8 @@ use database::Database;
 use model::database_globals::DatabaseGlobalsModel;
 use runtime::prod::ProdRuntime;
 
+const COMPILED_REVISION: &str = env!("VERGEN_GIT_SHA");
+const COMMIT_TIMESTAMP: &str = env!("VERGEN_GIT_COMMIT_TIMESTAMP");
 const INITIAL_BACKOFF: Duration = Duration::from_secs(1);
 const MAX_BACKOFF: Duration = Duration::from_secs(900); // 15 minutes
 
@@ -36,9 +38,12 @@ pub async fn start_beacon(runtime: ProdRuntime, database: Database<ProdRuntime>)
 
             // For now, just log the beacon info since endpoint is TBD
             tracing::info!(
-                "Beacon: document_id={:?}, database_version={}",
+                "Beacon: document_id={:?}, database_version={}, compiled_revision={}, \
+                 commit_timestamp={}",
                 globals.id(),
-                globals.version
+                globals.version,
+                COMPILED_REVISION,
+                COMMIT_TIMESTAMP,
             );
             Ok::<(), anyhow::Error>(())
         }