manager: Render graphviz tree and push it to git

techtree-manager/src/render.rs

@@ -0,0 +1,69 @@
+use std::process::Command;
+
+use anyhow::Context as _;
+
+pub async fn render_and_publish(
+    tree: &crate::tree::Tree,
+    timestamp: &str,
+    repo_auth_url: &url::Url,
+) -> anyhow::Result<()> {
+    let render_repo = std::path::PathBuf::from("render-git");
+
+    if render_repo.is_dir() {
+        log::info!("Found old {render_repo:?} repository, removing...");
+        std::fs::remove_dir_all(&render_repo).context("Failed to remove stale render repository")?;
+    }
+
+    std::fs::create_dir(&render_repo).context("Failed creating directory for rendered graph")?;
+
+    Command::new("git")
+        .arg("-C")
+        .arg(&render_repo)
+        .arg("init")
+        .status()
+        .context("Failed to initialize render repository")?;
+
+    let dot_file = render_repo.join("techtree.dot");
+    let svg_file = render_repo.join("techtree.svg");
+
+    let dot_source = tree.to_dot();
+    std::fs::write(&dot_file, dot_source.as_bytes())
+        .context("Failed to write `dot` source file")?;
+
+    Command::new("dot")
+        .args(["-T", "svg"])
+        .arg("-o")
+        .arg(&svg_file)
+        .arg(&dot_file)
+        .status()
+        .context("Failed to generate svg graph from dot source")?;
+
+    Command::new("git")
+        .arg("-C")
+        .arg(&render_repo)
+        .arg("add")
+        .arg(dot_file.file_name().unwrap())
+        .arg(svg_file.file_name().unwrap())
+        .status()
+        .context("Failed to add generated graph files to git index")?;
+
+    Command::new("git")
+        .arg("-C")
+        .arg(&render_repo)
+        .arg("commit")
+        .args(["-m", &format!("Updated techtree at {timestamp}")])
+        .status()
+        .context("Failed to add generated graph files to git index")?;
+
+    Command::new("git")
+        .arg("-C")
+        .arg(&render_repo)
+        .arg("push")
+        .arg("--force")
+        .arg(repo_auth_url.to_string())
+        .arg("HEAD:refs/heads/render")
+        .status()
+        .context("Failed to push rendered graph to forgejo repository")?;
+
+    Ok(())
+}