First version of admin API (#298)

**Spec:**

- [x] Start writing
- [x] Specify all layout endpoints
- [x] Specify all endpoints for operations on keys
- [x] Specify all endpoints for operations on key/bucket permissions
- [x] Specify all endpoints for operations on buckets
- [x] Specify all endpoints for operations on bucket aliases

View rendered spec at <https://git.deuxfleurs.fr/Deuxfleurs/garage/src/branch/admin-api/doc/drafts/admin-api.md>

**Code:**

- [x] Refactor code for admin api to use common api code that was created for K2V

**General endpoints:**

- [x] Metrics
- [x] GetClusterStatus
- [x] ConnectClusterNodes
- [x] GetClusterLayout
- [x] UpdateClusterLayout
- [x] ApplyClusterLayout
- [x] RevertClusterLayout

**Key-related endpoints:**

- [x] ListKeys
- [x] CreateKey
- [x] ImportKey
- [x] GetKeyInfo
- [x] UpdateKey
- [x] DeleteKey

**Bucket-related endpoints:**

- [x] ListBuckets
- [x] CreateBucket
- [x] GetBucketInfo
- [x] DeleteBucket
- [x] PutBucketWebsite
- [x] DeleteBucketWebsite

**Operations on key/bucket permissions:**

- [x] BucketAllowKey
- [x] BucketDenyKey

**Operations on bucket aliases:**

- [x] GlobalAliasBucket
- [x] GlobalUnaliasBucket
- [x] LocalAliasBucket
- [x] LocalUnaliasBucket

**And also:**

- [x] Separate error type for the admin API (this PR includes a quite big refactoring of error handling)
- [x] Add management of website access
- [ ] Check that nothing is missing wrt what can be done using the CLI
- [ ] Improve formatting of the spec
- [x] Make sure everyone is cool with the API design

Fix #231
Fix #295

Co-authored-by: Alex Auvolat <alex@adnab.me>
Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/298
Co-authored-by: Alex <alex@adnab.me>
Co-committed-by: Alex <alex@adnab.me>

1 files changed, 207 insertions, 0 deletions

diff --git a/src/api/s3/error.rs b/src/api/s3/error.rs
new file mode 100644
index 00000000..ac632540
--- /dev/null
+++ b/src/api/s3/error.rs
@@ -0,0 +1,207 @@
+use std::convert::TryInto;
+
+use err_derive::Error;
+use hyper::header::HeaderValue;
+use hyper::{Body, HeaderMap, StatusCode};
+
+use garage_model::helper::error::Error as HelperError;
+
+use crate::common_error::CommonError;
+pub use crate::common_error::{CommonErrorDerivative, OkOrBadRequest, OkOrInternalError};
+use crate::generic_server::ApiError;
+use crate::s3::xml as s3_xml;
+use crate::signature::error::Error as SignatureError;
+
+/// Errors of this crate
+#[derive(Debug, Error)]
+pub enum Error {
+	#[error(display = "{}", _0)]
+	/// Error from common error
+	Common(CommonError),
+
+	// Category: cannot process
+	/// Authorization Header Malformed
+	#[error(display = "Authorization header malformed, expected scope: {}", _0)]
+	AuthorizationHeaderMalformed(String),
+
+	/// The object requested don't exists
+	#[error(display = "Key not found")]
+	NoSuchKey,
+
+	/// The multipart upload requested don't exists
+	#[error(display = "Upload not found")]
+	NoSuchUpload,
+
+	/// Precondition failed (e.g. x-amz-copy-source-if-match)
+	#[error(display = "At least one of the preconditions you specified did not hold")]
+	PreconditionFailed,
+
+	/// Parts specified in CMU request do not match parts actually uploaded
+	#[error(display = "Parts given to CompleteMultipartUpload do not match uploaded parts")]
+	InvalidPart,
+
+	/// Parts given to CompleteMultipartUpload were not in ascending order
+	#[error(display = "Parts given to CompleteMultipartUpload were not in ascending order")]
+	InvalidPartOrder,
+
+	/// In CompleteMultipartUpload: not enough data
+	/// (here we are more lenient than AWS S3)
+	#[error(display = "Proposed upload is smaller than the minimum allowed object size")]
+	EntityTooSmall,
+
+	// Category: bad request
+	/// The request contained an invalid UTF-8 sequence in its path or in other parameters
+	#[error(display = "Invalid UTF-8: {}", _0)]
+	InvalidUtf8Str(#[error(source)] std::str::Utf8Error),
+
+	/// The request used an invalid path
+	#[error(display = "Invalid UTF-8: {}", _0)]
+	InvalidUtf8String(#[error(source)] std::string::FromUtf8Error),
+
+	/// The client sent invalid XML data
+	#[error(display = "Invalid XML: {}", _0)]
+	InvalidXml(String),
+
+	/// The client sent a header with invalid value
+	#[error(display = "Invalid header value: {}", _0)]
+	InvalidHeader(#[error(source)] hyper::header::ToStrError),
+
+	/// The client sent a range header with invalid value
+	#[error(display = "Invalid HTTP range: {:?}", _0)]
+	InvalidRange(#[error(from)] (http_range::HttpRangeParseError, u64)),
+
+	/// The client sent a request for an action not supported by garage
+	#[error(display = "Unimplemented action: {}", _0)]
+	NotImplemented(String),
+}
+
+impl<T> From<T> for Error
+where
+	CommonError: From<T>,
+{
+	fn from(err: T) -> Self {
+		Error::Common(CommonError::from(err))
+	}
+}
+
+impl CommonErrorDerivative for Error {}
+
+impl From<HelperError> for Error {
+	fn from(err: HelperError) -> Self {
+		match err {
+			HelperError::Internal(i) => Self::Common(CommonError::InternalError(i)),
+			HelperError::BadRequest(b) => Self::Common(CommonError::BadRequest(b)),
+			HelperError::InvalidBucketName(n) => Self::Common(CommonError::InvalidBucketName(n)),
+			HelperError::NoSuchBucket(n) => Self::Common(CommonError::NoSuchBucket(n)),
+			e => Self::bad_request(format!("{}", e)),
+		}
+	}
+}
+
+impl From<roxmltree::Error> for Error {
+	fn from(err: roxmltree::Error) -> Self {
+		Self::InvalidXml(format!("{}", err))
+	}
+}
+
+impl From<quick_xml::de::DeError> for Error {
+	fn from(err: quick_xml::de::DeError) -> Self {
+		Self::InvalidXml(format!("{}", err))
+	}
+}
+
+impl From<SignatureError> for Error {
+	fn from(err: SignatureError) -> Self {
+		match err {
+			SignatureError::Common(c) => Self::Common(c),
+			SignatureError::AuthorizationHeaderMalformed(c) => {
+				Self::AuthorizationHeaderMalformed(c)
+			}
+			SignatureError::InvalidUtf8Str(i) => Self::InvalidUtf8Str(i),
+			SignatureError::InvalidHeader(h) => Self::InvalidHeader(h),
+		}
+	}
+}
+
+impl From<multer::Error> for Error {
+	fn from(err: multer::Error) -> Self {
+		Self::bad_request(err)
+	}
+}
+
+impl Error {
+	pub fn aws_code(&self) -> &'static str {
+		match self {
+			Error::Common(c) => c.aws_code(),
+			Error::NoSuchKey => "NoSuchKey",
+			Error::NoSuchUpload => "NoSuchUpload",
+			Error::PreconditionFailed => "PreconditionFailed",
+			Error::InvalidPart => "InvalidPart",
+			Error::InvalidPartOrder => "InvalidPartOrder",
+			Error::EntityTooSmall => "EntityTooSmall",
+			Error::AuthorizationHeaderMalformed(_) => "AuthorizationHeaderMalformed",
+			Error::NotImplemented(_) => "NotImplemented",
+			Error::InvalidXml(_) => "MalformedXML",
+			Error::InvalidRange(_) => "InvalidRange",
+			Error::InvalidUtf8Str(_) | Error::InvalidUtf8String(_) | Error::InvalidHeader(_) => {
+				"InvalidRequest"
+			}
+		}
+	}
+}
+
+impl ApiError for Error {
+	/// Get the HTTP status code that best represents the meaning of the error for the client
+	fn http_status_code(&self) -> StatusCode {
+		match self {
+			Error::Common(c) => c.http_status_code(),
+			Error::NoSuchKey | Error::NoSuchUpload => StatusCode::NOT_FOUND,
+			Error::PreconditionFailed => StatusCode::PRECONDITION_FAILED,
+			Error::InvalidRange(_) => StatusCode::RANGE_NOT_SATISFIABLE,
+			Error::NotImplemented(_) => StatusCode::NOT_IMPLEMENTED,
+			Error::AuthorizationHeaderMalformed(_)
+			| Error::InvalidPart
+			| Error::InvalidPartOrder
+			| Error::EntityTooSmall
+			| Error::InvalidXml(_)
+			| Error::InvalidUtf8Str(_)
+			| Error::InvalidUtf8String(_)
+			| Error::InvalidHeader(_) => StatusCode::BAD_REQUEST,
+		}
+	}
+
+	fn add_http_headers(&self, header_map: &mut HeaderMap<HeaderValue>) {
+		use hyper::header;
+		#[allow(clippy::single_match)]
+		match self {
+			Error::InvalidRange((_, len)) => {
+				header_map.append(
+					header::CONTENT_RANGE,
+					format!("bytes */{}", len)
+						.try_into()
+						.expect("header value only contain ascii"),
+				);
+			}
+			_ => (),
+		}
+	}
+
+	fn http_body(&self, garage_region: &str, path: &str) -> Body {
+		let error = s3_xml::Error {
+			code: s3_xml::Value(self.aws_code().to_string()),
+			message: s3_xml::Value(format!("{}", self)),
+			resource: Some(s3_xml::Value(path.to_string())),
+			region: Some(s3_xml::Value(garage_region.to_string())),
+		};
+		Body::from(s3_xml::to_xml_with_header(&error).unwrap_or_else(|_| {
+			r#"
+<?xml version="1.0" encoding="UTF-8"?>
+<Error>
+	<Code>InternalError</Code>
+	<Message>XML encoding of error failed</Message>
+</Error>
+			"#
+			.into()
+		}))
+	}
+}