Update repo using git fetch

src/server/recurring/fetch.rs

@@ -0,0 +1,47 @@
+//! Update repo refs using the `git` binary.
+
+use std::process::Command;
+
+use gix::bstr::ByteVec;
+use tracing::{info, warn};
+
+use crate::{config::ServerConfig, server::Repo, somehow};
+
+fn fetch(repo: Repo, url: &str, refspecs: &[String]) -> somehow::Result<()> {
+    info!("Fetching refs from {url}");
+
+    let mut command = Command::new("git");
+    command
+        .arg("fetch")
+        .arg("-C")
+        .arg(repo.0.path())
+        .arg("--prune")
+        .arg("--")
+        .arg(url);
+    for refspec in refspecs {
+        command.arg(refspec);
+    }
+
+    let output = command.output()?;
+    if output.status.success() {
+    } else {
+        warn!(exitcode = %output.status, "'git fetch' failed");
+        warn!(output = "stdout", "{}", output.stdout.into_string_lossy());
+        warn!(output = "stderr", "{}", output.stderr.into_string_lossy());
+    }
+
+    Ok(())
+}
+
+async fn inner(repo: Repo, url: &'static str, refspecs: &'static [String]) -> somehow::Result<()> {
+    tokio::task::spawn_blocking(move || fetch(repo, url, refspecs)).await??;
+    Ok(())
+}
+
+pub async fn update(config: &'static ServerConfig, repo: Repo) {
+    if let Some(url) = &config.repo_fetch_url {
+        if let Err(e) = inner(repo, url, &config.repo_fetch_refspecs).await {
+            warn!("Error fetching refs:\n{e:?}");
+        }
+    }
+}