Include commit date in NetworkNode metadata

not provided by built, so it needs to be retrieved manually

sable_network/Cargo.toml

@@ -11,6 +11,8 @@ debug = []
 
 [build-dependencies]
 built = { version = "0.5", features = [ "git2" ] }
+git2 = { version = "0.15", default-features = false }
+chrono = "0.4"
 
 [dev-dependencies]
 tracing-subscriber = "0.3"

sable_network/build.rs

@@ -1,3 +1,45 @@
+use std::{env, fs, io::Write, path};
+
+use chrono::DateTime;
+
 fn main() {
     built::write_built_file().expect("Failed to acquire build-time information");
+
+    let root = env::var("CARGO_MANIFEST_DIR").expect("CARGO_MANIFEST_DIR");
+    let out = path::Path::new(&env::var("OUT_DIR").expect("OUT_DIR not set")).join("built.rs");
+    let _ = write_head_date(root, out);
+}
+
+fn write_head_date(root: String, dest: path::PathBuf) -> Result<(), git2::Error> {
+    let mut f = fs::OpenOptions::new()
+        .append(true)
+        .open(dest)
+        .expect("could not append to built.rs");
+    match git2::Repository::discover(root) {
+        Ok(repo) => {
+            let head = repo.head()?.peel_to_commit()?.time();
+            let head_secs = head.seconds() + (head.offset_minutes() as i64 * 60);
+            let head_time = DateTime::from_timestamp(head_secs, 0).map(|dt| dt.to_rfc2822());
+            f.write_all(
+                format!(
+                    "\npub const GIT_COMMIT_TIME_UTC: Option<&str> = {:?};\n",
+                    head_time
+                )
+                .as_bytes(),
+            )
+            .expect("could not write to built.rs");
+            Ok(())
+        }
+        Err(ref e)
+            if e.class() == git2::ErrorClass::Repository
+                && e.code() == git2::ErrorCode::NotFound =>
+        {
+            f.write_all(
+                format!("\npub const GIT_COMMIT_TIME_UTC: Option<&str> = None;\n").as_bytes(),
+            )
+            .expect("could not write to built.rs");
+            Ok(())
+        }
+        Err(e) => Err(e),
+    }
 }

sable_network/src/node/mod.rs

@@ -40,6 +40,7 @@ where
     my_id: ServerId,
     name: ServerName,
     version: String,
+    commit_date: String,
     net: RwLock<Arc<Network>>,
     event_log: Arc<ReplicatedEventLog>,
     epoch: EpochId,
@@ -89,6 +90,7 @@ impl<Policy: crate::policy::PolicyService> NetworkNode<Policy> {
             my_id: id,
             name,
             version: Self::build_version(),
+            commit_date: Self::get_commit_date(),
             net: RwLock::new(Arc::new(net)),
             epoch,
             event_log,
@@ -193,6 +195,17 @@ impl<Policy: crate::policy::PolicyService> NetworkNode<Policy> {
         )
     }
 
+    /// The server's HEAD commit date
+    pub fn commit_date(&self) -> &str {
+        &self.commit_date
+    }
+
+    fn get_commit_date() -> String {
+        crate::build_data::GIT_COMMIT_TIME_UTC
+            .unwrap_or("unknown")
+            .to_string()
+    }
+
     /// The server's build flags
     pub fn server_flags(&self) -> state::ServerFlags {
         let mut ret = state::ServerFlags::empty();

sable_network/src/node/upgrade.rs

@@ -44,6 +44,7 @@ impl<Policy: PolicyService + Saveable> NetworkNode<Policy> {
             my_id: state.id,
             name: state.name,
             version: Self::build_version(),
+            commit_date: Self::get_commit_date(),
             net: RwLock::new(Arc::new(state.net)),
             epoch: state.epoch,
             id_generator: state.id_generator,