Composefs-native backend

crates/lib/Cargo.toml

@@ -56,6 +56,8 @@ tini = "1.3.0"
 comfy-table = "7.1.1"
 thiserror = { workspace = true }
 canon-json = { workspace = true }
+openat = "0.1.21"
+openat-ext = "0.2.3"
 
 [dev-dependencies]
 similar-asserts = { workspace = true }

crates/lib/src/bls_config.rs

@@ -0,0 +1,88 @@
+use serde::{Deserialize, Deserializer};
+use serde::de::Error;
+use std::collections::HashMap;
+use anyhow::Result;
+
+#[derive(Debug, Deserialize, Eq)]
+pub(crate) struct BLSConfig {
+    pub(crate) title: Option<String>,
+    #[serde(deserialize_with = "deserialize_version")]
+    pub(crate) version: u32,
+    pub(crate) linux: String,
+    pub(crate) initrd: String,
+    pub(crate) options: String,
+
+    #[serde(flatten)]
+    pub(crate) extra: HashMap<String, String>,
+}
+
+impl PartialEq for BLSConfig {
+    fn eq(&self, other: &Self) -> bool {
+        self.version == other.version
+    }
+}
+
+impl PartialOrd for BLSConfig {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        self.version.partial_cmp(&other.version)
+    }
+}
+
+impl Ord for BLSConfig {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        self.version.cmp(&other.version)
+    }
+}
+
+impl BLSConfig {
+    pub(crate) fn to_string(&self) -> String {
+        let mut out = String::new();
+
+        if let Some(title) = &self.title {
+            out += &format!("title {}\n", title);
+        }
+
+        out += &format!("version {}\n", self.version);
+        out += &format!("linux {}\n", self.linux);
+        out += &format!("initrd {}\n", self.initrd);
+        out += &format!("options {}\n", self.options);
+
+        for (key, value) in &self.extra {
+            out += &format!("{} {}\n", key, value);
+        }
+
+        out
+    }
+}
+
+fn deserialize_version<'de, D>(deserializer: D) -> Result<u32, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    let s: Option<String> = Option::deserialize(deserializer)?;
+
+    match s {
+        Some(s) => Ok(s.parse::<u32>().map_err(D::Error::custom)?),
+        None => Err(D::Error::custom("Version not found")),
+    }
+}
+
+pub(crate) fn parse_bls_config(input: &str) -> Result<BLSConfig> {
+    let mut map = HashMap::new();
+
+    for line in input.lines() {
+        let line = line.trim();
+        if line.is_empty() || line.starts_with('#') {
+            continue;
+        }
+
+        if let Some((key, value)) = line.split_once(' ') {
+            map.insert(key.to_string(), value.trim().to_string());
+        }
+    }
+
+    let value = serde_json::to_value(map)?;
+    let parsed: BLSConfig = serde_json::from_value(value)?;
+
+    Ok(parsed)
+}