Some movement of helper code and refactoring of error handling

src/model/helper/error.rs

@@ -0,0 +1,51 @@
+use err_derive::Error;
+use serde::{Deserialize, Serialize};
+
+use garage_util::error::Error as GarageError;
+
+#[derive(Debug, Error, Serialize, Deserialize)]
+pub enum Error {
+	#[error(display = "Internal error: {}", _0)]
+	Internal(#[error(source)] GarageError),
+
+	#[error(display = "Bad request: {}", _0)]
+	BadRequest(String),
+}
+
+impl From<netapp::error::Error> for Error {
+	fn from(e: netapp::error::Error) -> Self {
+		Error::Internal(GarageError::Netapp(e))
+	}
+}
+
+pub trait OkOrBadRequest {
+	type S;
+	fn ok_or_bad_request<M: AsRef<str>>(self, reason: M) -> Result<Self::S, Error>;
+}
+
+impl<T, E> OkOrBadRequest for Result<T, E>
+where
+	E: std::fmt::Display,
+{
+	type S = T;
+	fn ok_or_bad_request<M: AsRef<str>>(self, reason: M) -> Result<T, Error> {
+		match self {
+			Ok(x) => Ok(x),
+			Err(e) => Err(Error::BadRequest(format!(
+				"{}: {}",
+				reason.as_ref(),
+				e.to_string()
+			))),
+		}
+	}
+}
+
+impl<T> OkOrBadRequest for Option<T> {
+	type S = T;
+	fn ok_or_bad_request<M: AsRef<str>>(self, reason: M) -> Result<T, Error> {
+		match self {
+			Some(x) => Ok(x),
+			None => Err(Error::BadRequest(reason.as_ref().to_string())),
+		}
+	}
+}