refactor(gateway): clarify driver detection results

Signed-off-by: Piotr Mlocek <pmlocek@nvidia.com>

Author: pimlock

crates/openshell-core/src/config.rs

@@ -113,16 +113,23 @@ impl FromStr for ComputeDriverKind {
     }
 }
 
+/// Result of automatic compute-driver detection.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct DriverDetection {
+    /// Driver selected according to automatic selection priority.
+    pub selected: Option<ComputeDriverKind>,
+    /// Every available driver in automatic selection priority order.
+    pub available: Vec<ComputeDriverKind>,
+}
+
 /// Detect available compute drivers based on the runtime environment.
 ///
 /// Priority order: Kubernetes → Podman → Docker.
 /// VM is never auto-detected (requires explicit `--drivers vm`).
 ///
-/// Returns every available driver in selection priority order.
-///
 /// VM is excluded because it requires explicit operator selection.
 #[must_use]
-pub fn detect_drivers() -> Vec<ComputeDriverKind> {
+pub fn detect_drivers() -> DriverDetection {
     let mut drivers = Vec::new();
 
     // Kubernetes: check for KUBERNETES_SERVICE_HOST env var (set inside pods)
@@ -140,13 +147,16 @@ pub fn detect_drivers() -> Vec<ComputeDriverKind> {
         drivers.push(ComputeDriverKind::Docker);
     }
 
-    drivers
+    DriverDetection {
+        selected: drivers.first().copied(),
+        available: drivers,
+    }
 }
 
-/// Returns the first available driver in automatic selection priority order.
+/// Returns the selected driver in automatic selection priority order.
 #[must_use]
 pub fn detect_driver() -> Option<ComputeDriverKind> {
-    detect_drivers().into_iter().next()
+    detect_drivers().selected
 }
 
 /// Check if a binary is available on the system PATH.
@@ -800,8 +810,8 @@ mod tests {
     use super::is_reachable_unix_socket;
     use super::{
         ComputeDriverKind, Config, DEFAULT_SERVICE_ROUTING_DOMAIN, GatewayJwtConfig, detect_driver,
-        docker_host_unix_socket_path, is_unix_socket, normalize_compute_driver_name,
-        podman_socket_candidates_from_env, podman_socket_responds,
+        detect_drivers, docker_host_unix_socket_path, is_unix_socket,
+        normalize_compute_driver_name, podman_socket_candidates_from_env, podman_socket_responds,
     };
     #[cfg(unix)]
     use std::io::{Read as _, Write as _};
@@ -1063,8 +1073,13 @@ mod tests {
             std::env::set_var("KUBERNETES_SERVICE_HOST", "127.0.0.1");
         }
 
-        let result = detect_driver();
-        assert_eq!(result, Some(ComputeDriverKind::Kubernetes));
+        let detection = detect_drivers();
+        assert_eq!(detection.selected, Some(ComputeDriverKind::Kubernetes));
+        assert_eq!(
+            detection.available.first().copied(),
+            Some(ComputeDriverKind::Kubernetes)
+        );
+        assert_eq!(detect_driver(), detection.selected);
 
         // Restore the original env var
         unsafe {

crates/openshell-server/src/cli.rs

@@ -40,7 +40,7 @@ enum Commands {
     /// Generate mTLS PKI and write Kubernetes Secrets (Helm pre-install hook).
     GenerateCerts(certgen::CertgenArgs),
     /// Inspect or update the gateway TOML configuration.
-    Config(crate::config_edit::ConfigArgs),
+    Config(crate::config_command::ConfigArgs),
 }
 
 #[derive(clap::Args, Debug)]
@@ -230,7 +230,7 @@ pub async fn run_cli() -> Result<()> {
 
     match cli.command {
         Some(Commands::GenerateCerts(args)) => certgen::run(args).await,
-        Some(Commands::Config(args)) => crate::config_edit::run(args, cli.run.config),
+        Some(Commands::Config(args)) => crate::config_command::run(args, cli.run.config),
         None => Box::pin(run_from_args(cli.run, matches)).await,
     }
 }
@@ -1105,7 +1105,7 @@ mod tests {
             panic!("expected config subcommand");
         };
 
-        crate::config_edit::run(args, run.config).unwrap();
+        crate::config_command::run(args, run.config).unwrap();
 
         let loaded = crate::config_file::load(&path).unwrap();
         assert_eq!(

…ates/openshell-server/src/config_edit.rs …s/openshell-server/src/config_command.rscrates/openshell-server/src/config_edit.rs renamed to crates/openshell-server/src/config_command.rs crates/openshell-server/src/config_edit.rs renamed to crates/openshell-server/src/config_command.rs

@@ -1,7 +1,7 @@
 // SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-//! Typed, comment-preserving updates to the gateway TOML configuration.
+//! CLI handlers for inspecting and updating the gateway TOML configuration.
 
 use std::fs;
 use std::io::Write;

crates/openshell-server/src/lib.rs

@@ -27,7 +27,7 @@ mod auth;
 pub mod certgen;
 pub mod cli;
 mod compute;
-mod config_edit;
+mod config_command;
 pub mod config_file;
 mod defaults;
 mod grpc;
@@ -840,8 +840,8 @@ fn configured_compute_driver(
 ) -> Result<ConfiguredComputeDriver> {
     match config.compute_drivers.as_slice() {
         [] => {
-            let detected = openshell_core::config::detect_drivers();
-            let Some(driver) = detected.first().copied() else {
+            let detection = openshell_core::config::detect_drivers();
+            let Some(driver) = detection.selected else {
                 return Err(Error::config(
                     "no compute driver configured and auto-detection found no suitable driver; \
                     install and start Docker or Podman, or install the VM driver and select it \
@@ -855,7 +855,7 @@ fn configured_compute_driver(
                 ));
             }
 
-            log_auto_detected_driver(config, driver, &detected);
+            log_auto_detected_driver(config, driver, &detection.available);
             Ok(ConfiguredComputeDriver::Builtin(driver))
         }
         [driver] => resolve_configured_compute_driver(driver, driver_startup),