fix: use current user instead of root as default username

- Replace hardcoded 'root' fallback with current user detection
- Try USER, USERNAME, LOGNAME environment variables first
- Use whoami crate to get system username as last resort
- Add test to verify current user is used correctly
- Ensures non-root users don't accidentally connect as root

Author: inureyes

Cargo.lock

@@ -29,6 +29,7 @@ directories = "6"
 dirs = "6.0"
 chrono = "0.4"
 glob = "0.3"
+whoami = "1.5"
 
 [dev-dependencies]
 tempfile = "3"

Cargo.toml

@@ -47,7 +47,11 @@ pub struct Cli {
     #[arg(short = 'u', long, help = "Default username for SSH connections")]
     pub user: Option<String>,
 
-    #[arg(short = 'i', long, help = "SSH private key file path (prompts for passphrase if encrypted)")]
+    #[arg(
+        short = 'i',
+        long,
+        help = "SSH private key file path (prompts for passphrase if encrypted)"
+    )]
     pub identity: Option<PathBuf>,
 
     #[arg(

src/cli.rs

@@ -103,7 +103,18 @@ impl Config {
                 // Get current user as default
                 let default_user = env::var("USER")
                     .or_else(|_| env::var("USERNAME"))
-                    .unwrap_or_else(|_| "root".to_string());
+                    .or_else(|_| env::var("LOGNAME"))
+                    .unwrap_or_else(|_| {
+                        // Try to get current user from system
+                        #[cfg(unix)]
+                        {
+                            whoami::username()
+                        }
+                        #[cfg(not(unix))]
+                        {
+                            "user".to_string()
+                        }
+                    });
 
                 // Backend.AI multi-node clusters use port 2200 by default
                 nodes.push(NodeConfig::Simple(format!("{default_user}@{host}:2200")));
@@ -215,7 +226,20 @@ impl Config {
                         .or_else(|| cluster.defaults.user.as_ref().map(|u| expand_env_vars(u)))
                         .or_else(|| self.defaults.user.as_ref().map(|u| expand_env_vars(u)))
                         .unwrap_or_else(|| {
-                            std::env::var("USER").unwrap_or_else(|_| "root".to_string())
+                            std::env::var("USER")
+                                .or_else(|_| std::env::var("USERNAME"))
+                                .or_else(|_| std::env::var("LOGNAME"))
+                                .unwrap_or_else(|_| {
+                                    // Try to get current user from system
+                                    #[cfg(unix)]
+                                    {
+                                        whoami::username()
+                                    }
+                                    #[cfg(not(unix))]
+                                    {
+                                        "user".to_string()
+                                    }
+                                })
                         });
 
                     let port = port

src/config.rs

@@ -61,7 +61,18 @@ impl Node {
             .unwrap_or_else(|| {
                 std::env::var("USER")
                     .or_else(|_| std::env::var("USERNAME"))
-                    .unwrap_or_else(|_| "root".to_string())
+                    .or_else(|_| std::env::var("LOGNAME"))
+                    .unwrap_or_else(|_| {
+                        // Try to get current user from system
+                        #[cfg(unix)]
+                        {
+                            whoami::username()
+                        }
+                        #[cfg(not(unix))]
+                        {
+                            "user".to_string()
+                        }
+                    })
             });
 
         Ok(Node {
@@ -121,4 +132,20 @@ mod tests {
         let node = Node::parse("example.com", Some("default_user")).unwrap();
         assert_eq!(node.username, "default_user");
     }
+
+    #[test]
+    fn test_parse_uses_current_user_when_no_default() {
+        // When no user is specified, it should use current user from environment
+        let node = Node::parse("example.com", None).unwrap();
+        // Should not be "root" unless the current user is actually root
+        let current_user = std::env::var("USER")
+            .or_else(|_| std::env::var("USERNAME"))
+            .or_else(|_| std::env::var("LOGNAME"))
+            .unwrap_or_else(|_| whoami::username());
+        assert_eq!(node.username, current_user);
+        // Specifically verify it doesn't default to root when we're not root
+        if current_user != "root" {
+            assert_ne!(node.username, "root");
+        }
+    }
 }

src/node.rs

@@ -462,10 +462,9 @@ impl SshClient {
                 || key_contents.contains("Proc-Type: 4,ENCRYPTED")
             {
                 tracing::debug!("Detected encrypted SSH key, prompting for passphrase");
-                let pass = rpassword::prompt_password(format!(
-                    "Enter passphrase for key {key_path:?}: "
-                ))
-                .with_context(|| "Failed to read passphrase")?;
+                let pass =
+                    rpassword::prompt_password(format!("Enter passphrase for key {key_path:?}: "))
+                        .with_context(|| "Failed to read passphrase")?;
                 Some(pass)
             } else {
                 None