bootstrap:

src/cmd/init/bootstrap.rs

@@ -1,5 +1,5 @@
 use eyre::{format_err, Result};
-use log::info;
+use log::{info, warn};
 use std::path::Path;
 use tokio::{
     fs,
@@ -20,7 +20,7 @@ pub async fn bootstrap(cfg: Config) {
     })
     .await;
 
-    let boot_version = utils::param("version", "current");
+    let boot_version = utils::param("version").unwrap_or("current");
     let base_dir = &format!("/bootstrap/{boot_version}");
 
     retry_or_ignore(async || {
@@ -169,9 +169,25 @@ async fn fetch_bootstrap(seed_url: &str, output_file: &str) -> Result<()> {
     Ok(())
 }
 
+fn default_root_tmpfs_opts() -> Option<String> {
+    let mem = sys_info::mem_info()
+        .inspect_err(|e| warn!("failed to get system memory info, using default tmpfs size: {e}"))
+        .ok()?;
+
+    let mem_size = mem.total /* kiB */ / 1024;
+    let fs_size = 1024.min(mem_size / 2);
+    info!("system has {mem_size} MiB of memory, allowing {fs_size} MiB for root tmpfs");
+    Some(format!("size={fs_size}m"))
+}
+
 async fn mount_system(cfg: &dkl::Config, bs_dir: &str, verifier: &Verifier) {
+    let opts = match utils::param("root-opts") {
+        Some(s) => Some(s.to_string()),
+        None => default_root_tmpfs_opts(),
+    };
+
     let mem_dir = "/mem";
-    mount(None, mem_dir, "tmpfs", Some("size=512m")).await;
+    mount(None, mem_dir, "tmpfs", opts.as_deref()).await;
 
     let layers_dir = &format!("{mem_dir}/layers");
     let mut lower_dir = String::new();
@@ -316,14 +332,10 @@ async fn mount_filesystems(mounts: &[dkl::Mount], root: &str) {
         mount(
             Some(&m.dev),
             &path,
-            m.r#type
-                .as_ref()
+            (m.r#type.as_deref())
                 .filter(|s| !s.is_empty())
-                .map_or("ext4", |s| s.as_str()),
-            m.options
-                .as_ref()
-                .filter(|v| !v.is_empty())
-                .map(|s| s.as_str()),
+                .unwrap_or("ext4"),
+            m.options.as_deref().filter(|v| !v.is_empty()),
         )
         .await;
     }