Inherit OpenSSH config in SDK by default

src/client.rs

@@ -156,7 +156,7 @@ impl DoshClientBuilder {
             .unwrap_or_default();
         let raw_server = host_config.ssh.clone().unwrap_or_else(|| self.host.clone());
         let ssh_port = host_config.ssh_port.or(self.client.config.ssh_port);
-        let ssh_config = load_sdk_ssh_config(host_config.ssh_config.as_deref(), ssh_port)?;
+        let ssh_config = load_sdk_ssh_config_for_target(&host_config, &raw_server, ssh_port)?;
         let udp_host = selected_sdk_udp_host(
             self.udp_host.as_deref(),
             &host_config,
@@ -493,6 +493,10 @@ fn load_sdk_ssh_config(alias: Option<&str>, ssh_port: Option<u16>) -> Result<Sdk
     let Some(alias) = alias else {
         return Ok(SdkSshConfig::default());
     };
+    let alias = alias.trim();
+    if alias.is_empty() {
+        return Ok(SdkSshConfig::default());
+    }
     let mut command = Command::new("ssh");
     command.arg("-G");
     if let Some(ssh_port) = ssh_port {
@@ -508,6 +512,26 @@ fn load_sdk_ssh_config(alias: Option<&str>, ssh_port: Option<u16>) -> Result<Sdk
     Ok(parse_sdk_ssh_config(&String::from_utf8(output.stdout)?))
 }
 
+fn load_sdk_ssh_config_for_target(
+    host_config: &HostConfig,
+    raw_server: &str,
+    ssh_port: Option<u16>,
+) -> Result<SdkSshConfig> {
+    let (alias, explicit) = sdk_ssh_config_lookup(host_config, raw_server);
+    match load_sdk_ssh_config(Some(alias), ssh_port) {
+        Ok(config) => Ok(config),
+        Err(_) if !explicit => Ok(SdkSshConfig::default()),
+        Err(err) => Err(err),
+    }
+}
+
+fn sdk_ssh_config_lookup<'a>(host_config: &'a HostConfig, raw_server: &'a str) -> (&'a str, bool) {
+    match host_config.ssh_config.as_deref().map(str::trim) {
+        Some(alias) if !alias.is_empty() => (alias, true),
+        _ => (raw_server, false),
+    }
+}
+
 fn parse_sdk_ssh_config(raw: &str) -> SdkSshConfig {
     let mut config = SdkSshConfig::default();
     for line in raw.lines() {
@@ -1003,6 +1027,26 @@ mod tests {
         );
     }
 
+    #[test]
+    fn sdk_ssh_config_lookup_uses_raw_target_by_default() {
+        let host = HostConfig::default();
+
+        assert_eq!(
+            sdk_ssh_config_lookup(&host, "deploy@prod"),
+            ("deploy@prod", false)
+        );
+    }
+
+    #[test]
+    fn sdk_ssh_config_lookup_prefers_explicit_alias() {
+        let host = HostConfig {
+            ssh_config: Some(" prod ".to_string()),
+            ..HostConfig::default()
+        };
+
+        assert_eq!(sdk_ssh_config_lookup(&host, "deploy@raw"), ("prod", true));
+    }
+
     #[test]
     fn sdk_identity_paths_follow_cli_precedence_and_identities_only() {
         let dir = tempfile::tempdir().unwrap();