feat(cli): add JSON/YAML output format to gateway list

Add -o/--output flag to `openshell gateway list` matching the existing
sandbox list pattern, enabling machine-readable output for scripting.

Signed-off-by: Florent Benoit <fbenoit@redhat.com>

Author: benoitf

crates/openshell-cli/src/main.rs

@@ -1039,7 +1039,11 @@ enum GatewayCommands {
     /// Prints a table of all registered gateways with their endpoint, type,
     /// and authentication mode. The active gateway is marked with `*`.
     #[command(help_template = LEAF_HELP_TEMPLATE, next_help_heading = "FLAGS")]
-    List,
+    List {
+        /// Output format.
+        #[arg(short = 'o', long = "output", value_enum, default_value_t = OutputFormat::Table)]
+        output: OutputFormat,
+    },
 }
 
 // -----------------------------------------------------------------------
@@ -1942,8 +1946,8 @@ async fn main() -> Result<()> {
                     .unwrap_or_else(|| "openshell".to_string());
                 run::gateway_admin_info(&name)?;
             }
-            GatewayCommands::List => {
-                run::gateway_list(&cli.gateway)?;
+            GatewayCommands::List { output } => {
+                run::gateway_list(&cli.gateway, output.as_str())?;
             }
         },
 
@@ -3686,6 +3690,51 @@ mod tests {
         assert!(result.is_err(), "--names and -o json should conflict");
     }
 
+    #[test]
+    fn gateway_list_default_output_is_table() {
+        let cli = Cli::try_parse_from(["openshell", "gateway", "list"])
+            .expect("gateway list should parse");
+
+        assert!(matches!(
+            cli.command,
+            Some(Commands::Gateway {
+                command: Some(GatewayCommands::List {
+                    output: OutputFormat::Table,
+                })
+            })
+        ));
+    }
+
+    #[test]
+    fn gateway_list_accepts_output_json() {
+        let cli = Cli::try_parse_from(["openshell", "gateway", "list", "-o", "json"])
+            .expect("gateway list -o json should parse");
+
+        assert!(matches!(
+            cli.command,
+            Some(Commands::Gateway {
+                command: Some(GatewayCommands::List {
+                    output: OutputFormat::Json,
+                })
+            })
+        ));
+    }
+
+    #[test]
+    fn gateway_list_accepts_output_yaml() {
+        let cli = Cli::try_parse_from(["openshell", "gateway", "list", "-o", "yaml"])
+            .expect("gateway list -o yaml should parse");
+
+        assert!(matches!(
+            cli.command,
+            Some(Commands::Gateway {
+                command: Some(GatewayCommands::List {
+                    output: OutputFormat::Yaml,
+                })
+            })
+        ));
+    }
+
     #[test]
     fn provider_create_accepts_custom_profile_type_ids() {
         let cli = Cli::try_parse_from([

crates/openshell-cli/src/run.rs

@@ -802,7 +802,7 @@ where
 
     let gateways = list_gateways()?;
     if gateways.is_empty() || !interactive {
-        gateway_list(gateway_flag)?;
+        gateway_list(gateway_flag, "table")?;
         if !gateways.is_empty() {
             eprintln!();
             eprintln!(
@@ -1256,10 +1256,34 @@ pub fn gateway_logout(name: &str) -> Result<()> {
 }
 
 /// List all registered gateways.
-pub fn gateway_list(gateway_flag: &Option<String>) -> Result<()> {
+pub fn gateway_list(gateway_flag: &Option<String>, output: &str) -> Result<()> {
     let gateways = list_gateways()?;
     let active = gateway_flag.clone().or_else(load_active_gateway);
 
+    match output {
+        "json" => {
+            let items: Vec<serde_json::Value> = gateways
+                .iter()
+                .map(|g| gateway_to_json(g, &active))
+                .collect();
+            println!(
+                "{}",
+                serde_json::to_string_pretty(&items).into_diagnostic()?
+            );
+            return Ok(());
+        }
+        "yaml" => {
+            let items: Vec<serde_json::Value> = gateways
+                .iter()
+                .map(|g| gateway_to_json(g, &active))
+                .collect();
+            print!("{}", serde_yml::to_string(&items).into_diagnostic()?);
+            return Ok(());
+        }
+        "table" => {}
+        _ => return Err(miette!("unsupported output format: {output}")),
+    }
+
     if gateways.is_empty() {
         println!("No gateways found.");
         println!();
@@ -1319,6 +1343,16 @@ pub fn gateway_list(gateway_flag: &Option<String>) -> Result<()> {
     Ok(())
 }
 
+fn gateway_to_json(gateway: &GatewayMetadata, active: &Option<String>) -> serde_json::Value {
+    serde_json::json!({
+        "name": gateway.name,
+        "endpoint": gateway.gateway_endpoint,
+        "type": gateway_type_label(gateway),
+        "auth": gateway_auth_label(gateway),
+        "active": active.as_deref() == Some(&gateway.name),
+    })
+}
+
 async fn http_health_check(server: &str, tls: &TlsOptions) -> Result<Option<StatusCode>> {
     let base = server.trim_end_matches('/');
     let uri: hyper::Uri = format!("{base}/healthz").parse().into_diagnostic()?;