refactor(server): normalize compute driver config acquisition

Signed-off-by: Evan Lezar <elezar@nvidia.com>

Author: elezar

crates/openshell-server/src/cli.rs

@@ -14,10 +14,10 @@ use tracing::{info, warn};
 use tracing_subscriber::EnvFilter;
 
 use crate::certgen;
-use crate::compute::{DockerComputeConfig, VmComputeConfig};
+use crate::compute::driver_config::GuestTlsPaths;
 use crate::config_file::{self, ConfigFile, GatewayFileSection};
 use crate::defaults::{self, LocalTlsPaths};
-use crate::{run_server, tracing_bus::TracingLogBus};
+use crate::{ServerStartupConfig, run_server, tracing_bus::TracingLogBus};
 
 /// `OpenShell` gateway process - gRPC and HTTP server with protocol multiplexing.
 ///
@@ -222,33 +222,29 @@ pub async fn run_cli() -> Result<()> {
     }
 }
 
-async fn run_from_args(mut args: RunArgs, matches: ArgMatches) -> Result<()> {
+fn prepare_server_config(args: &mut RunArgs, matches: &ArgMatches) -> Result<ServerStartupConfig> {
     // Load TOML when explicitly requested, or from the default XDG location
     // when that file exists. Missing default config is not an error: runtime
     // defaults and OPENSHELL_* env vars are enough for package-managed starts.
-    let config_path = resolve_config_path(&args)?;
+    let config_path = resolve_config_path(args)?;
     let file: Option<ConfigFile> = if let Some(path) = config_path {
         Some(config_file::load(&path).map_err(|e| miette::miette!("{e}"))?)
     } else {
         None
     };
     if let Some(file) = file.as_ref() {
-        merge_file_into_args(&mut args, &file.openshell.gateway, &matches);
+        merge_file_into_args(args, &file.openshell.gateway, matches);
     }
 
-    let local_tls = apply_runtime_defaults(&mut args)?;
+    let local_tls = apply_runtime_defaults(args)?;
+    let guest_tls = local_tls.as_ref().map(GuestTlsPaths::from);
     let local_jwt = defaults::complete_local_jwt_config()?;
 
-    let tracing_log_bus = TracingLogBus::new();
-    tracing_log_bus.install_subscriber(
-        EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new(&args.log_level)),
-    );
-
     let bind = SocketAddr::new(args.bind_address, args.port);
 
     let has_client_ca = args.tls_client_ca.is_some();
     let has_oidc = args.oidc_issuer.is_some();
-    let mtls_auth_enabled = resolve_mtls_auth_enabled(&args, &matches, file.as_ref());
+    let mtls_auth_enabled = resolve_mtls_auth_enabled(args, matches, file.as_ref());
 
     if args.disable_tls && has_client_ca {
         return Err(miette::miette!(
@@ -267,7 +263,7 @@ async fn run_from_args(mut args: RunArgs, matches: ArgMatches) -> Result<()> {
     }
     if mtls_auth_enabled
         && matches!(
-            effective_single_driver(&args),
+            effective_single_driver(args),
             Some(ComputeDriverKind::Kubernetes)
         )
     {
@@ -318,14 +314,14 @@ async fn run_from_args(mut args: RunArgs, matches: ArgMatches) -> Result<()> {
     let health_bind = resolve_aux_listener(
         args.bind_address,
         args.health_port,
-        &matches,
+        matches,
         "health_port",
         || file_gateway.and_then(|g| g.health_bind_address),
     );
     let metrics_bind = resolve_aux_listener(
         args.bind_address,
         args.metrics_port,
-        &matches,
+        matches,
         "metrics_port",
         || file_gateway.and_then(|g| g.metrics_bind_address),
     );
@@ -404,15 +400,31 @@ async fn run_from_args(mut args: RunArgs, matches: ArgMatches) -> Result<()> {
         config.gateway_jwt = Some(jwt);
     }
 
-    let vm_config = build_vm_config(
-        file.as_ref(),
-        local_tls.as_ref(),
-        args.disable_tls,
-        args.port,
-    )?;
-    let docker_config = build_docker_config(file.as_ref(), local_tls.as_ref())?;
+    Ok(ServerStartupConfig {
+        config,
+        config_file: file,
+        guest_tls,
+    })
+}
+
+async fn run_from_args(mut args: RunArgs, matches: ArgMatches) -> Result<()> {
+    let prepared = prepare_server_config(&mut args, &matches)?;
+
+    let tracing_log_bus = TracingLogBus::new();
+    tracing_log_bus.install_subscriber(
+        EnvFilter::try_from_default_env()
+            .unwrap_or_else(|_| EnvFilter::new(&prepared.config.log_level)),
+    );
 
-    if args.disable_tls {
+    let has_client_ca = prepared
+        .config
+        .tls
+        .as_ref()
+        .and_then(|tls| tls.client_ca_path.as_ref())
+        .is_some();
+    let has_oidc = prepared.config.oidc.is_some();
+
+    if prepared.config.tls.is_none() {
         warn!("TLS disabled — listening on plaintext HTTP");
     } else {
         info!("TLS enabled — listening on encrypted HTTPS");
@@ -421,40 +433,34 @@ async fn run_from_args(mut args: RunArgs, matches: ArgMatches) -> Result<()> {
     if has_client_ca {
         info!("TLS client certificate verification enabled");
     }
-    if config.mtls_auth.enabled {
+    if prepared.config.mtls_auth.enabled {
         info!("mTLS user authentication enabled");
     }
     if has_oidc {
         info!("OIDC authentication enabled");
     }
-    if config.auth.allow_unauthenticated_users {
+    if prepared.config.auth.allow_unauthenticated_users {
         warn!(
             "Unauthenticated user access enabled — only use this for trusted local development or a fully trusted fronting proxy"
         );
     }
 
-    if !config.auth.allow_unauthenticated_users
-        && !config.mtls_auth.enabled
+    if !prepared.config.auth.allow_unauthenticated_users
+        && !prepared.config.mtls_auth.enabled
         && !has_oidc
-        && config.gateway_jwt.is_none()
+        && prepared.config.gateway_jwt.is_none()
     {
         warn!(
             "Neither mTLS user auth nor OIDC nor sandbox JWT auth is configured — \
              the gateway has no authentication mechanism"
         );
     }
 
-    info!(bind = %config.bind_address, "Starting OpenShell server");
+    info!(bind = %prepared.config.bind_address, "Starting OpenShell server");
 
-    Box::pin(run_server(
-        config,
-        vm_config,
-        docker_config,
-        file,
-        tracing_log_bus,
-    ))
-    .await
-    .into_diagnostic()
+    Box::pin(run_server(prepared, tracing_log_bus))
+        .await
+        .into_diagnostic()
 }
 
 fn parse_compute_driver(value: &str) -> std::result::Result<ComputeDriverKind, String> {
@@ -691,87 +697,6 @@ fn resolve_mtls_auth_enabled(
     is_singleplayer_driver(args)
 }
 
-/// Build [`VmComputeConfig`] from the `[openshell.drivers.vm]` table
-/// inherited from `[openshell.gateway]`.
-fn build_vm_config(
-    file: Option<&ConfigFile>,
-    local_tls: Option<&LocalTlsPaths>,
-    disable_tls: bool,
-    gateway_port: u16,
-) -> Result<VmComputeConfig> {
-    let mut cfg = if let Some(file) = file {
-        let merged = config_file::driver_table(
-            ComputeDriverKind::Vm,
-            &file.openshell.gateway,
-            file.openshell.drivers.get("vm"),
-        );
-        merged
-            .try_into::<VmComputeConfig>()
-            .map_err(|e| miette::miette!("invalid [openshell.drivers.vm] table: {e}"))?
-    } else {
-        VmComputeConfig::default()
-    };
-
-    if cfg.state_dir.as_os_str().is_empty() {
-        cfg.state_dir = VmComputeConfig::default_state_dir();
-    }
-    if cfg.grpc_endpoint.trim().is_empty() && (disable_tls || local_tls.is_some()) {
-        let scheme = if disable_tls { "http" } else { "https" };
-        cfg.grpc_endpoint = format!("{scheme}://127.0.0.1:{gateway_port}");
-    }
-    apply_guest_tls_defaults(
-        &mut cfg.guest_tls_ca,
-        &mut cfg.guest_tls_cert,
-        &mut cfg.guest_tls_key,
-        local_tls,
-    );
-    Ok(cfg)
-}
-
-/// Build [`DockerComputeConfig`] using the same inheritance pattern as
-/// [`build_vm_config`].
-fn build_docker_config(
-    file: Option<&ConfigFile>,
-    local_tls: Option<&LocalTlsPaths>,
-) -> Result<DockerComputeConfig> {
-    let mut cfg = if let Some(file) = file {
-        let merged = config_file::driver_table(
-            ComputeDriverKind::Docker,
-            &file.openshell.gateway,
-            file.openshell.drivers.get("docker"),
-        );
-        merged
-            .try_into::<DockerComputeConfig>()
-            .map_err(|e| miette::miette!("invalid [openshell.drivers.docker] table: {e}"))?
-    } else {
-        DockerComputeConfig::default()
-    };
-    apply_guest_tls_defaults(
-        &mut cfg.guest_tls_ca,
-        &mut cfg.guest_tls_cert,
-        &mut cfg.guest_tls_key,
-        local_tls,
-    );
-    Ok(cfg)
-}
-
-fn apply_guest_tls_defaults(
-    ca: &mut Option<PathBuf>,
-    cert: &mut Option<PathBuf>,
-    key: &mut Option<PathBuf>,
-    local_tls: Option<&LocalTlsPaths>,
-) {
-    if ca.is_none()
-        && cert.is_none()
-        && key.is_none()
-        && let Some(paths) = local_tls
-    {
-        *ca = Some(paths.ca.clone());
-        *cert = Some(paths.client_cert.clone());
-        *key = Some(paths.client_key.clone());
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::{Cli, command};
@@ -1613,6 +1538,54 @@ enable_loopback_service_http = false
         );
     }
 
+    #[test]
+    fn server_config_preparation_ignores_unselected_driver_tables() {
+        let _lock = ENV_LOCK
+            .lock()
+            .unwrap_or_else(std::sync::PoisonError::into_inner);
+        let state = tempfile::tempdir().unwrap();
+        let local_tls = tempfile::tempdir().unwrap();
+        let _g1 = EnvVarGuard::set("XDG_STATE_HOME", state.path().to_str().unwrap());
+        let _g2 = EnvVarGuard::set(
+            "OPENSHELL_LOCAL_TLS_DIR",
+            local_tls.path().to_str().unwrap(),
+        );
+        let config_path = state.path().join("gateway.toml");
+        std::fs::write(
+            &config_path,
+            r#"
+[openshell.drivers.docker]
+unknown_docker_key = true
+
+[openshell.drivers.vm]
+mem_mib = "not-a-number"
+"#,
+        )
+        .unwrap();
+
+        let (mut args, matches) = parse_with_args(&[
+            "openshell-gateway",
+            "--config",
+            config_path.to_str().unwrap(),
+            "--db-url",
+            "sqlite::memory:",
+            "--drivers",
+            "podman",
+            "--disable-tls",
+        ]);
+
+        let prepared =
+            super::prepare_server_config(&mut args, &matches).expect("server config is prepared");
+
+        assert_eq!(
+            prepared.config.compute_drivers,
+            vec![super::ComputeDriverKind::Podman]
+        );
+        let file = prepared.config_file.expect("config file is preserved");
+        assert!(file.openshell.drivers.contains_key("docker"));
+        assert!(file.openshell.drivers.contains_key("vm"));
+    }
+
     #[test]
     fn driver_inherits_shared_image_from_gateway_section() {
         // [openshell.gateway].default_image inherits into the K8s driver
@@ -1659,18 +1632,4 @@ default_image = "k8s-specific:1.0"
             .expect("deserializes");
         assert_eq!(parsed.default_image, "k8s-specific:1.0");
     }
-
-    #[test]
-    fn docker_config_reads_bind_mount_opt_in_from_driver_table() {
-        let file = config_file_from_toml(
-            r"
-[openshell.drivers.docker]
-enable_bind_mounts = true
-",
-        );
-
-        let cfg = super::build_docker_config(Some(&file), None).expect("docker config");
-
-        assert!(cfg.enable_bind_mounts);
-    }
 }