From bd43364949bd46a653a66a6c5c7f8307cedcf9a4 Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Tue, 10 Jan 2023 01:30:23 +0000
Subject: [PATCH] Config inspection: Centralise inspectable lookup

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
 client/client.rs | 2 +-
 server/server.rs | 2 +-
 src/config.rs    | 8 +++++---
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/client/client.rs b/client/client.rs
index cf7a935..7aaebfb 100644
--- a/client/client.rs
+++ b/client/client.rs
@@ -345,7 +345,7 @@ async fn main() {
     }
     if let Some(arg) = &opts.print_config {
       for ic in &ics {
-        implement_print_config(arg, &|k| Some(match k {
+        implement_print_config(ic, arg, &|k| Some(match k {
           "link" => &ic.link,
           "server" => &ic.link.server,
           "client" => &ic.link.client,
diff --git a/server/server.rs b/server/server.rs
index 0b9ffed..231e8ef 100644
--- a/server/server.rs
+++ b/server/server.rs
@@ -161,7 +161,7 @@ async fn async_main(opts: Opts, daemon: Option<Daemoniser>) {
     let global_config = config::InstanceConfigGlobal::from(&ics);
 
     if let Some(arg) = &opts.print_config {
-      implement_print_config(arg, &|k| global_config.inspect_key(k))?;
+      implement_print_config(&global_config, arg, &|_| None)?;
       process::exit(0);
     }
 
diff --git a/src/config.rs b/src/config.rs
index c88832e..8f95a5c 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -90,20 +90,22 @@ pub struct Opts {
   pub extra_config: Vec<PathBuf>,
 }
 
-pub trait InspectableConfig {
+pub trait InspectableConfig: Debug {
   fn inspect_key(&self, field: &'_ str)
                  -> Option<&dyn InspectableConfigValue>;
 }
 
 #[throws(AE)]
 pub fn implement_print_config<'f>(
+  config: &dyn InspectableConfig,
   arg: &str,
-  inspect_key: &dyn Fn(&str) -> Option<&'f dyn InspectableConfigValue>
+  extra_key: &dyn Fn(&str) -> Option<&'f dyn InspectableConfigValue>
 ) {
   let output = arg
     .split(',')
     .map(|key| {
-      let insp = inspect_key(key)
+      let insp = config.inspect_key(key)
+        .or_else(|| extra_key(key))
         .ok_or_else(|| anyhow!("unknown config key {:?}", key))?;
       Ok::<_,AE>(DisplayInspectable(insp).to_string())
     })
-- 
2.30.2