Add build script to make git version available in code

Signed-off-by: pep <pep@bouah.net>

Cargo.toml

@@ -27,6 +27,9 @@ hex = "0.4"
 camino = { version = "1.2", features = ["serde1"] }
 chrono = { version = "0.4", default-features = false }
 
+[build-dependencies]
+git2 = "0.20"
+
 [patch.crates-io]
 forgejo-hooks = { path = "forgejo-hooks" }
 

build.rs

@@ -0,0 +1,41 @@
+// Copyright (C) 2026-2099 The crate authors.
+//
+// This program is free software: you can redistribute it and/or modify it
+// under the terms of the GNU Affero General Public License as published by the
+// Free Software Foundation, either version 3 of the License, or (at your
+// option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License
+// for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+use std::env;
+use std::fs;
+use std::path::Path;
+
+use git2::Repository;
+
+fn main() {
+	let oid = {
+		match Repository::open(".") {
+			Ok(repo) => {
+				let head = repo.head().unwrap();
+				format!("{}", repo.refname_to_id(head.name().unwrap()).unwrap())
+			}
+			Err(e) => {
+				println!("cargo::warning={}", e);
+				String::new()
+			}
+		}
+	};
+
+	let out_dir = env::var_os("OUT_DIR").unwrap();
+	let dest_path = Path::new(&out_dir).join("GIT_COMMIT");
+	fs::write(&dest_path, oid).unwrap();
+
+	println!("cargo::rerun-if-changed=build.rs");
+}

src/config.rs

@@ -23,6 +23,14 @@ use xmpp::jid::{BareJid, ResourcePart};
 
 use crate::error::Error;
 
+const MAYBE_VERSION: &'static str = include_str!(concat!(env!("OUT_DIR"), "/GIT_COMMIT"));
+const fn version() -> Option<&'static str> {
+	match MAYBE_VERSION {
+		v if v.is_empty() => None,
+		v => Some(v),
+	}
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct Config {
 	/// Accounts trusted for admin tasks
@@ -50,6 +58,11 @@ pub struct Config {
 	/// HTTP Webhook listening address and port, e.g., 127.0.0.1:1234 or [::1]:1234
 	#[serde(default = "Config::default_addr")]
 	pub addr: SocketAddr,
+
+	/// Software version
+	#[serde(skip)]
+	#[serde(default = "version")]
+	pub version: Option<&'static str>,
 }
 
 impl Config {