From 2d8cb18954348e35820a70dafe493b079c706a62 Mon Sep 17 00:00:00 2001
From: Joonas Koivunen <joonas@neon.tech>
Date: Wed, 13 Dec 2023 18:56:07 +0000
Subject: [PATCH 1/2] devx: friendlier json parsing errors

---
 Cargo.lock                  | 1 +
 libs/utils/Cargo.toml       | 2 ++
 libs/utils/src/http/json.rs | 8 ++++++--
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 1b6b423444bf..9ca316cc6e74 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5764,6 +5764,7 @@ dependencies = [
  "serde",
  "serde_assert",
  "serde_json",
+ "serde_path_to_error",
  "serde_with",
  "signal-hook",
  "strum",
diff --git a/libs/utils/Cargo.toml b/libs/utils/Cargo.toml
index ccf6f4f2d7ad..af0414daa25a 100644
--- a/libs/utils/Cargo.toml
+++ b/libs/utils/Cargo.toml
@@ -50,6 +50,8 @@ const_format.workspace = true
 # why is it only here? no other crate should use it, streams are rarely needed.
 tokio-stream = { version = "0.1.14" }
 
+serde_path_to_error.workspace = true
+
 [dev-dependencies]
 byteorder.workspace = true
 bytes.workspace = true
diff --git a/libs/utils/src/http/json.rs b/libs/utils/src/http/json.rs
index 70e682cb7666..7ca62561feb2 100644
--- a/libs/utils/src/http/json.rs
+++ b/libs/utils/src/http/json.rs
@@ -25,8 +25,12 @@ pub async fn json_request_or_empty_body<T: for<'de> Deserialize<'de>>(
     if body.remaining() == 0 {
         return Ok(None);
     }
-    serde_json::from_reader(body.reader())
-        .context("Failed to parse json request")
+
+    let mut deser = serde_json::de::Deserializer::from_reader(body.reader());
+
+    serde_path_to_error::deserialize(&mut deser)
+        // intentionally stringify because the debug version is not helpful in python logs
+        .map_err(|e| anyhow::anyhow!("Failed to parse json request: {e}"))
         .map(Some)
         .map_err(ApiError::BadRequest)
 }

From 5cb72df504ff69e50f3932d16451be320ff56be0 Mon Sep 17 00:00:00 2001
From: Joonas Koivunen <joonas@neon.tech>
Date: Wed, 13 Dec 2023 18:56:49 +0000
Subject: [PATCH 2/2] devx: needless error hiding in testing api

---
 pageserver/src/http/routes.rs | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/pageserver/src/http/routes.rs b/pageserver/src/http/routes.rs
index da7e8218a24b..df0af20667a3 100644
--- a/pageserver/src/http/routes.rs
+++ b/pageserver/src/http/routes.rs
@@ -1616,9 +1616,7 @@ async fn disk_usage_eviction_run(
         }
     }
 
-    let config = json_request::<Config>(&mut r)
-        .await
-        .map_err(|_| ApiError::BadRequest(anyhow::anyhow!("invalid JSON body")))?;
+    let config = json_request::<Config>(&mut r).await?;
 
     let usage = Usage {
         config,