From 580fe79ae15637f8fdea7e0c8b7e4323cb3573f2 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Mon, 9 Jan 2023 19:07:52 +0000
Subject: [PATCH] Config inspection: Move --print-config implementation into
 trait

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 server/server.rs | 10 +++-------
 src/config.rs    |  9 +++++++++
 2 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/server/server.rs b/server/server.rs
index 46bc7da..ff69b0b 100644
--- a/server/server.rs
+++ b/server/server.rs
@@ -160,13 +160,9 @@ async fn async_main(opts: Opts, daemon: Option<Daemoniser>) {
   {
     let global_config = config::InstanceConfigGlobal::from(&ics);
 
-    if let Some(key) = opts.print_config.as_ref() {
-      if let Some(inspectable) = global_config.inspect_key(key) {
-        println!("{}", DisplayInspectable(inspectable));
-        process::exit(0);
-      } else {
-        throw!(anyhow!("unknown config key {:?}", key));
-      }
+    if let Some(arg) = &opts.print_config {
+      global_config.implement_print_config(arg)?;
+      process::exit(0);
     }
 
     if let Some(pidfile_path) = opts.pidfile.as_ref() {
diff --git a/src/config.rs b/src/config.rs
index 7cc9adf..13605d5 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -93,6 +93,15 @@ pub struct Opts {
 pub trait InspectableConfig {
   fn inspect_key(&self, field: &'_ str)
                  -> Option<&dyn InspectableConfigValue>;
+
+  #[throws(AE)]
+  fn implement_print_config(&self, key: &str) {
+    if let Some(inspectable) = self.inspect_key(key) {
+      println!("{}", DisplayInspectable(inspectable));
+    } else {
+      throw!(anyhow!("unknown config key {:?}", key));
+    }
+  }
 }
 
 pub trait InspectableConfigValue {
-- 
2.30.2