api_client: Use thiserror for errors

Added thiserror crate for Error enums to the api_client package

Signed-off-by: SamrutGadde <samrut.gadde@gmail.com>

Cargo.lock

@@ -92,6 +92,7 @@ checksum = "0952808a6c2afd1aa8947271f3a60f1a6763c7b912d210184c5149b5cf147247"
 name = "api_client"
 version = "0.1.0"
 dependencies = [
+ "thiserror",
  "vmm-sys-util",
 ]
 
@@ -2070,18 +2071,18 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "1.0.60"
+version = "1.0.61"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "579e9083ca58dd9dcf91a9923bb9054071b9ebbd800b342194c9feb0ee89fc18"
+checksum = "c546c80d6be4bc6a00c0f01730c08df82eaa7a7a61f11d656526506112cc1709"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.60"
+version = "1.0.61"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2470041c06ec3ac1ab38d0356a6119054dedaea53e12fbefc0de730a1c08524"
+checksum = "46c3384250002a6d5af4d114f2845d37b57521033f30d5c3f46c4d70e1197533"
 dependencies = [
  "proc-macro2",
  "quote",

api_client/Cargo.toml

@@ -5,4 +5,5 @@ name = "api_client"
 version = "0.1.0"
 
 [dependencies]
+thiserror = "1.0.61"
 vmm-sys-util = "0.12.1"

api_client/src/lib.rs

@@ -3,41 +3,27 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 
-use std::fmt;
 use std::io::{Read, Write};
 use std::os::unix::io::RawFd;
+use thiserror::Error;
 use vmm_sys_util::sock_ctrl_msg::ScmSocket;
 
-#[derive(Debug)]
+#[derive(Debug, Error)]
 pub enum Error {
+    #[error("Error writing to or reading from HTTP socket: {0}")]
     Socket(std::io::Error),
+    #[error("Error writing to or reading from HTTP socket: {0}")]
     SocketSendFds(vmm_sys_util::errno::Error),
+    #[error("Error parsing HTTP status code: {0}")]
     StatusCodeParsing(std::num::ParseIntError),
+    #[error("HTTP output is missing protocol statement")]
     MissingProtocol,
+    #[error("Error parsing HTTP Content-Length field: {0}")]
     ContentLengthParsing(std::num::ParseIntError),
+    #[error("Server responded with an error: {0:?}")]
     ServerResponse(StatusCode, Option<String>),
 }
 
-impl fmt::Display for Error {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        use Error::*;
-        match self {
-            Socket(e) => write!(f, "Error writing to or reading from HTTP socket: {e}"),
-            SocketSendFds(e) => write!(f, "Error writing to or reading from HTTP socket: {e}"),
-            StatusCodeParsing(e) => write!(f, "Error parsing HTTP status code: {e}"),
-            MissingProtocol => write!(f, "HTTP output is missing protocol statement"),
-            ContentLengthParsing(e) => write!(f, "Error parsing HTTP Content-Length field: {e}"),
-            ServerResponse(s, o) => {
-                if let Some(o) = o {
-                    write!(f, "Server responded with an error: {s:?}: {o}")
-                } else {
-                    write!(f, "Server responded with an error: {s:?}")
-                }
-            }
-        }
-    }
-}
-
 #[derive(Clone, Copy, Debug)]
 pub enum StatusCode {
     Continue,