fix: use RwLock for envd Defaults to fix silent mutation loss

The /init handler's default_user mutation cloned the Defaults struct,
mutated the clone, then dropped it — the actual state was never updated.
This caused processes to always run as "root" regardless of the user
set via POST /init. Additionally, default_workdir was accepted in the
init request but never applied.

Wrap user and workdir fields in RwLock with accessor methods so mutations
propagate correctly through the shared AppState.

envd-rs/src/execcontext.rs

@@ -1,21 +1,36 @@
 use dashmap::DashMap;
-use std::sync::Arc;
+use std::sync::{Arc, RwLock};
 
-#[derive(Clone)]
 pub struct Defaults {
     pub env_vars: Arc<DashMap<String, String>>,
-    pub user: String,
+    user: RwLock<String>,
-    pub workdir: Option<String>,
+    workdir: RwLock<Option<String>>,
 }
 
 impl Defaults {
     pub fn new(user: &str) -> Self {
         Self {
             env_vars: Arc::new(DashMap::new()),
-            user: user.to_string(),
+            user: RwLock::new(user.to_string()),
-            workdir: None,
+            workdir: RwLock::new(None),
         }
     }
+
+    pub fn user(&self) -> String {
+        self.user.read().unwrap().clone()
+    }
+
+    pub fn set_user(&self, user: String) {
+        *self.user.write().unwrap() = user;
+    }
+
+    pub fn workdir(&self) -> Option<String> {
+        self.workdir.read().unwrap().clone()
+    }
+
+    pub fn set_workdir(&self, workdir: Option<String>) {
+        *self.workdir.write().unwrap() = workdir;
+    }
 }
 
 pub fn resolve_default_workdir(workdir: &str, default_workdir: Option<&str>) -> String {

envd-rs/src/http/files.rs

@@ -71,9 +71,10 @@ pub async fn get_files(
     let path_str = params.path.as_deref().unwrap_or("");
     let header_token = extract_header_token(&req);
 
+    let default_user = state.defaults.user();
     let username = match execcontext::resolve_default_username(
         params.username.as_deref(),
-        &state.defaults.user,
+        &default_user,
     ) {
         Ok(u) => u.to_string(),
         Err(e) => return json_error(StatusCode::BAD_REQUEST, e),
@@ -96,7 +97,8 @@ pub async fn get_files(
     };
 
     let home_dir = user.dir.to_string_lossy().to_string();
-    let resolved = match expand_and_resolve(path_str, &home_dir, state.defaults.workdir.as_deref())
+    let default_workdir = state.defaults.workdir();
+    let resolved = match expand_and_resolve(path_str, &home_dir, default_workdir.as_deref())
     {
         Ok(p) => p,
         Err(e) => return json_error(StatusCode::BAD_REQUEST, &e),
@@ -222,9 +224,10 @@ pub async fn post_files(
     let path_str = params.path.as_deref().unwrap_or("");
     let header_token = extract_header_token(&req);
 
+    let default_user = state.defaults.user();
     let username = match execcontext::resolve_default_username(
         params.username.as_deref(),
-        &state.defaults.user,
+        &default_user,
     ) {
         Ok(u) => u.to_string(),
         Err(e) => return json_error(StatusCode::BAD_REQUEST, e),
@@ -266,6 +269,7 @@ pub async fn post_files(
     };
 
     let mut uploaded: Vec<EntryInfo> = Vec::new();
+    let default_workdir = state.defaults.workdir();
 
     while let Ok(Some(field)) = multipart.next_field().await {
         let field_name = field.name().unwrap_or("").to_string();
@@ -274,7 +278,7 @@ pub async fn post_files(
         }
 
         let file_path = if !path_str.is_empty() {
-            match expand_and_resolve(path_str, &home_dir, state.defaults.workdir.as_deref()) {
+            match expand_and_resolve(path_str, &home_dir, default_workdir.as_deref()) {
                 Ok(p) => p,
                 Err(e) => return json_error(StatusCode::BAD_REQUEST, &e),
             }
@@ -283,7 +287,7 @@ pub async fn post_files(
                 .file_name()
                 .unwrap_or("upload")
                 .to_string();
-            match expand_and_resolve(&fname, &home_dir, state.defaults.workdir.as_deref()) {
+            match expand_and_resolve(&fname, &home_dir, default_workdir.as_deref()) {
                 Ok(p) => p,
                 Err(e) => return json_error(StatusCode::BAD_REQUEST, &e),
             }

envd-rs/src/http/init.rs

@@ -78,11 +78,15 @@ pub async fn post_init(
     if let Some(ref user) = init_req.default_user {
         if !user.is_empty() {
             tracing::debug!(user = %user, "setting default user");
-            let mut defaults = state.defaults.clone();
+            state.defaults.set_user(user.clone());
-            defaults.user = user.clone();
+        }
-            // Note: In Rust we'd need interior mutability for this.
+    }
-            // For now, env_vars (DashMap) handles concurrent access.
+
-            // User/workdir mutation deferred to full state refactor.
+    // Set default workdir
+    if let Some(ref workdir) = init_req.default_workdir {
+        if !workdir.is_empty() {
+            tracing::debug!(workdir = %workdir, "setting default workdir");
+            state.defaults.set_workdir(Some(workdir.clone()));
         }
     }
 

envd-rs/src/main.rs

@@ -196,7 +196,8 @@ fn spawn_initial_command(cmd: &str, state: &AppState) {
     use crate::rpc::process_handler;
     use std::collections::HashMap;
 
-    let user = match lookup_user(&state.defaults.user) {
+    let default_user = state.defaults.user();
+    let user = match lookup_user(&default_user) {
         Ok(u) => u,
         Err(e) => {
             tracing::error!(error = %e, "cmd: failed to lookup user");
@@ -205,9 +206,8 @@ fn spawn_initial_command(cmd: &str, state: &AppState) {
     };
 
     let home = user.dir.to_string_lossy().to_string();
-    let cwd = state
+    let default_workdir = state.defaults.workdir();
-        .defaults
+    let cwd = default_workdir
-        .workdir
         .as_deref()
         .unwrap_or(&home);
 

envd-rs/src/rpc/filesystem_service.rs

@@ -31,15 +31,15 @@ impl FilesystemServiceImpl {
     }
 
     fn resolve_path(&self, path: &str, ctx: &Context) -> Result<String, ConnectError> {
-        let username = extract_username(ctx).unwrap_or_else(|| self.state.defaults.user.clone());
+        let username = extract_username(ctx).unwrap_or_else(|| self.state.defaults.user());
         let user = lookup_user(&username).map_err(|e| {
             ConnectError::new(ErrorCode::Unauthenticated, format!("invalid user: {e}"))
         })?;
 
         let home_dir = user.dir.to_string_lossy().to_string();
-        let default_workdir = self.state.defaults.workdir.as_deref();
+        let default_workdir = self.state.defaults.workdir();
 
-        expand_and_resolve(path, &home_dir, default_workdir)
+        expand_and_resolve(path, &home_dir, default_workdir.as_deref())
             .map_err(|e| ConnectError::new(ErrorCode::InvalidArgument, e))
     }
 }
@@ -97,7 +97,7 @@ impl Filesystem for FilesystemServiceImpl {
             }
         }
 
-        let username = extract_username(&ctx).unwrap_or_else(|| self.state.defaults.user.clone());
+        let username = extract_username(&ctx).unwrap_or_else(|| self.state.defaults.user());
         let user =
             lookup_user(&username).map_err(|e| ConnectError::new(ErrorCode::Internal, e))?;
 
@@ -122,7 +122,7 @@ impl Filesystem for FilesystemServiceImpl {
         let source = self.resolve_path(request.source, &ctx)?;
         let destination = self.resolve_path(request.destination, &ctx)?;
 
-        let username = extract_username(&ctx).unwrap_or_else(|| self.state.defaults.user.clone());
+        let username = extract_username(&ctx).unwrap_or_else(|| self.state.defaults.user());
         let user =
             lookup_user(&username).map_err(|e| ConnectError::new(ErrorCode::Internal, e))?;
 

envd-rs/src/rpc/process_service.rs

@@ -71,7 +71,7 @@ impl ProcessServiceImpl {
             ConnectError::new(ErrorCode::InvalidArgument, "process config required")
         })?;
 
-        let username = self.state.defaults.user.clone();
+        let username = self.state.defaults.user();
         let user =
             lookup_user(&username).map_err(|e| ConnectError::new(ErrorCode::Internal, e))?;
 
@@ -85,7 +85,8 @@ impl ProcessServiceImpl {
 
         let home_dir = user.dir.to_string_lossy().to_string();
         let cwd_str: &str = proc_config.cwd.unwrap_or("");
-        let cwd = expand_and_resolve(cwd_str, &home_dir, self.state.defaults.workdir.as_deref())
+        let default_workdir = self.state.defaults.workdir();
+        let cwd = expand_and_resolve(cwd_str, &home_dir, default_workdir.as_deref())
             .map_err(|e| ConnectError::new(ErrorCode::InvalidArgument, e))?;
 
         let effective_cwd = if cwd.is_empty() { "/" } else { &cwd };