path: root/src/web/web_server.rs

                                                                        

use std::{borrow::Cow, convert::Infallible, net::SocketAddr, sync::Arc};

use futures::future::Future;

use hyper::{
	header::{HeaderValue, HOST},
	server::conn::AddrStream,
	service::{make_service_fn, service_fn},
	Body, Method, Request, Response, Server,
};

use opentelemetry::{
	global,
	metrics::{Counter, ValueRecorder},
	trace::{FutureExt, TraceContextExt, Tracer},
	Context, KeyValue,
};

use crate::error::*;

use garage_api::helpers::{authority_to_host, host_to_bucket};
use garage_api::s3::cors::{add_cors_headers, find_matching_cors_rule, handle_options_for_bucket};
use garage_api::s3::error::{
	CommonErrorDerivative, Error as ApiError, OkOrBadRequest, OkOrInternalError,
};
use garage_api::s3::get::{handle_get, handle_head};

use garage_model::garage::Garage;

use garage_table::*;
use garage_util::error::Error as GarageError;
use garage_util::metrics::{gen_trace_id, RecordDuration};

struct WebMetrics {
	request_counter: Counter<u64>,
	error_counter: Counter<u64>,
	request_duration: ValueRecorder<f64>,
}

impl WebMetrics {
	fn new() -> Self {
		let meter = global::meter("garage/web");
		Self {
			request_counter: meter
				.u64_counter("web.request_counter")
				.with_description("Number of requests to the web endpoint")
				.init(),
			error_counter: meter
				.u64_counter("web.error_counter")
				.with_description("Number of requests to the web endpoint resulting in errors")
				.init(),
			request_duration: meter
				.f64_value_recorder("web.request_duration")
				.with_description("Duration of requests to the web endpoint")
				.init(),
		}
	}
}

pub struct WebServer {
	garage: Arc<Garage>,
	metrics: Arc<WebMetrics>,
	root_domain: String,
}

impl WebServer {
	/// Run a web server
	pub async fn run(
		garage: Arc<Garage>,
		addr: SocketAddr,
		root_domain: String,
		shutdown_signal: impl Future<Output = ()>,
	) -> Result<(), GarageError> {
		let metrics = Arc::new(WebMetrics::new());
		let web_server = Arc::new(WebServer {
			garage,
			metrics,
			root_domain,
		});

		let service = make_service_fn(|conn: &AddrStream| {
			let web_server = web_server.clone();

			let client_addr = conn.remote_addr();
			async move {
				Ok::<_, Error>(service_fn(move |req: Request<Body>| {
					let web_server = web_server.clone();

					web_server.handle_request(req, client_addr)
				}))
			}
		});

		let server = Server::bind(&addr).serve(service);
		let graceful = server.with_graceful_shutdown(shutdown_signal);
		info!("Web server listening on http://{}", addr);

		graceful.await?;
		Ok(())
	}

	async fn handle_request(
		self: Arc<Self>,
		req: Request<Body>,
		addr: SocketAddr,
	) -> Result<Response<Body>, Infallible> {
		info!("{} {} {}", addr, req.method(), req.uri());

		// Lots of instrumentation
		let tracer = opentelemetry::global::tracer("garage");
		let span = tracer
			.span_builder(format!("Web {} request", req.method()))
			.with_trace_id(gen_trace_id())
			.with_attributes(vec![
				KeyValue::new("method", format!("{}", req.method())),
				KeyValue::new("uri", req.uri().to_string()),
			])
			.start(&tracer);

		let metrics_tags = &[KeyValue::new("method", req.method().to_string())];

		// The actual handler
		let res = self
			.serve_file(&req)
			.with_context(Context::current_with_span(span))
			.record_duration(&self.metrics.request_duration, &metrics_tags[..])
			.await;

		// More instrumentation
		self.metrics.request_counter.add(1, &metrics_tags[..]);

		// Returning the result
		match res {
			Ok(res) => {
				debug!("{} {} {}", req.method(), res.status(), req.uri());
				Ok(res)
			}
			Err(error) => {
				info!(
					"{} {} {} {}",
					req.method(),
					error.http_status_code(),
					req.uri(),
					error
				);
				self.metrics.error_counter.add(
					1,
					&[
						metrics_tags[0].clone(),
						KeyValue::new("status_code", error.http_status_code().to_string()),
					],
				);
				Ok(error_to_res(error))
			}
		}
	}

	async fn serve_file(self: &Arc<Self>, req: &Request<Body>) -> Result<Response<Body>, Error> {
		// Get http authority string (eg. [::1]:3902 or garage.tld:80)
		let authority = req
			.headers()
			.get(HOST)
			.ok_or_bad_request("HOST header required")?
			.to_str()?;

		// Get bucket
		let host = authority_to_host(authority)?;

		let bucket_name = host_to_bucket(&host, &self.root_domain).unwrap_or(&host);
		let bucket_id = self
			.garage
			.bucket_alias_table
			.get(&EmptyKey, &bucket_name.to_string())
			.await?
			.and_then(|x| x.state.take())
			.ok_or(Error::NotFound)?;

		// Check bucket isn't deleted and has website access enabled
		let bucket = self
			.garage
			.bucket_table
			.get(&EmptyKey, &bucket_id)
			.await?
			.ok_or(Error::NotFound)?;

		let website_config = bucket
			.params()
			.ok_or(Error::NotFound)?
			.website_config
			.get()
			.as_ref()
			.ok_or(Error::NotFound)?;

		// Get path
		let path = req.uri().path().to_string();
		let index = &website_config.index_document;
		let key = path_to_key(&path, index)?;

		debug!(
			"Selected bucket: \"{}\" {:?}, selected key: \"{}\"",
			bucket_name, bucket_id, key
		);

		let ret_doc = match *req.method() {
			Method::OPTIONS => handle_options_for_bucket(req, &bucket),
			Method::HEAD => handle_head(self.garage.clone(), req, bucket_id, &key, None).await,
			Method::GET => handle_get(self.garage.clone(), req, bucket_id, &key, None).await,
			_ => Err(ApiError::bad_request("HTTP method not supported")),
		}
		.map_err(Error::from);

		match ret_doc {
			Err(error) => {
				// For a HEAD or OPTIONS method, and for non-4xx errors,
				// we don't return the error document as content,
				// we return above and just return the error message
				// by relying on err_to_res that is called when we return an Err.
				if *req.method() == Method::HEAD
					|| *req.method() == Method::OPTIONS
					|| !error.http_status_code().is_client_error()
				{
					return Err(error);
				}

				// If no error document is set: just return the error directly
				let error_document = match &website_config.error_document {
					Some(ed) => ed.trim_start_matches('/').to_owned(),
					None => return Err(error),
				};

				// We want to return the error document
				// Create a fake HTTP request with path = the error document
				let req2 = Request::builder()
					.uri(format!("http://{}/{}", host, &error_document))
					.body(Body::empty())
					.unwrap();

				match handle_get(self.garage.clone(), &req2, bucket_id, &error_document, None).await
				{
					Ok(mut error_doc) => {
						// The error won't be logged back in handle_request,
						// so log it here
						info!(
							"{} {} {} {}",
							req.method(),
							req.uri(),
							error.http_status_code(),
							error
						);

						*error_doc.status_mut() = error.http_status_code();

						// Preserve error message in a special header
						for error_line in error.to_string().split('\n') {
							if let Ok(v) = HeaderValue::from_bytes(error_line.as_bytes()) {
								error_doc.headers_mut().append("X-Garage-Error", v);
							}
						}

						Ok(error_doc)
					}
					Err(error_doc_error) => {
						warn!(
							"Couldn't get error document {} for bucket {:?}: {}",
							error_document, bucket_id, error_doc_error
						);
						Err(error)
					}
				}
			}
			Ok(mut resp) => {
				// Maybe add CORS headers
				if let Some(rule) = find_matching_cors_rule(&bucket, req)? {
					add_cors_headers(&mut resp, rule)
						.ok_or_internal_error("Invalid bucket CORS configuration")?;
				}
				Ok(resp)
			}
		}
	}
}

fn error_to_res(e: Error) -> Response<Body> {
	// If we are here, it is either that:
	// - there was an error before trying to get the requested URL
	//   from the bucket (e.g. bucket not found)
	// - there was an error processing the request and (the request
	//   was a HEAD request or we couldn't get the error document)
	// We do NOT enter this code path when returning the bucket's
	// error document (this is handled in serve_file)
	let body = Body::from(format!("{}\n", e));
	let mut http_error = Response::new(body);
	*http_error.status_mut() = e.http_status_code();
	e.add_headers(http_error.headers_mut());
	http_error
}

/// Path to key
///
/// Convert the provided path to the internal key
/// When a path ends with "/", we append the index name to match traditional web server behavior
/// which is also AWS S3 behavior.
fn path_to_key<'a>(path: &'a str, index: &str) -> Result<Cow<'a, str>, Error> {
	let path_utf8 = percent_encoding::percent_decode_str(path).decode_utf8()?;

	if !path_utf8.starts_with('/') {
		return Err(Error::BadRequest("Path must start with a / (slash)".into()));
	}

	match path_utf8.chars().last() {
		None => unreachable!(),
		Some('/') => {
			let mut key = String::with_capacity(path_utf8.len() + index.len());
			key.push_str(&path_utf8[1..]);
			key.push_str(index);
			Ok(key.into())
		}
		Some(_) => match path_utf8 {
			Cow::Borrowed(pu8) => Ok((&pu8[1..]).into()),
			Cow::Owned(pu8) => Ok(pu8[1..].to_string().into()),
		},
	}
}

#[cfg(test)]
mod tests {
	use super::*;

	#[test]
	fn path_to_key_test() -> Result<(), Error> {
		assert_eq!(path_to_key("/file%20.jpg", "index.html")?, "file .jpg");
		assert_eq!(path_to_key("/%20t/", "index.html")?, " t/index.html");
		assert_eq!(path_to_key("/", "index.html")?, "index.html");
		assert_eq!(path_to_key("/hello", "index.html")?, "hello");
		assert!(path_to_key("", "index.html").is_err());
		assert!(path_to_key("i/am/relative", "index.html").is_err());
		Ok(())
	}
}
use std::{borrow::Cow, convert::Infallible, net::SocketAddr, sync::Arc};

use futures::future::Future;

use hyper::{
	header::{HeaderValue, HOST},
	server::conn::AddrStream,
	service::{make_service_fn, service_fn},
	Body, Method, Request, Response, Server,
};

use opentelemetry::{
	global,
	metrics::{Counter, ValueRecorder},
	trace::{FutureExt, TraceContextExt, Tracer},
	Context, KeyValue,
};

use crate::error::*;

use garage_api::helpers::{authority_to_host, host_to_bucket};
use garage_api::s3::cors::{add_cors_headers, find_matching_cors_rule, handle_options_for_bucket};
use garage_api::s3::error::{
	CommonErrorDerivative, Error as ApiError, OkOrBadRequest, OkOrInternalError,
};
use garage_api::s3::get::{handle_get, handle_head};

use garage_model::garage::Garage;

use garage_table::*;
use garage_util::error::Error as GarageError;
use garage_util::metrics::{gen_trace_id, RecordDuration};

struct WebMetrics {
	request_counter: Counter<u64>,
	error_counter: Counter<u64>,
	request_duration: ValueRecorder<f64>,
}

impl WebMetrics {
	fn new() -> Self {
		let meter = global::meter("garage/web");
		Self {
			request_counter: meter
				.u64_counter("web.request_counter")
				.with_description("Number of requests to the web endpoint")
				.init(),
			error_counter: meter
				.u64_counter("web.error_counter")
				.with_description("Number of requests to the web endpoint resulting in errors")
				.init(),
			request_duration: meter
				.f64_value_recorder("web.request_duration")
				.with_description("Duration of requests to the web endpoint")
				.init(),
		}
	}
}

pub struct WebServer {
	garage: Arc<Garage>,
	metrics: Arc<WebMetrics>,
	root_domain: String,
}

impl WebServer {
	/// Run a web server
	pub async fn run(
		garage: Arc<Garage>,
		addr: SocketAddr,
		root_domain: String,
		shutdown_signal: impl Future<Output = ()>,
	) -> Result<(), GarageError> {
		let metrics = Arc::new(WebMetrics::new());
		let web_server = Arc::new(WebServer {
			garage,
			metrics,
			root_domain,
		});

		let service = make_service_fn(|conn: &AddrStream| {
			let web_server = web_server.clone();

			let client_addr = conn.remote_addr();
			async move {
				Ok::<_, Error>(service_fn(move |req: Request<Body>| {
					let web_server = web_server.clone();

					web_server.handle_request(req, client_addr)
				}))
			}
		});

		let server = Server::bind(&addr).serve(service);
		let graceful = server.with_graceful_shutdown(shutdown_signal);
		info!("Web server listening on http://{}", addr);

		graceful.await?;
		Ok(())
	}

	async fn handle_request(
		self: Arc<Self>,
		req: Request<Body>,
		addr: SocketAddr,
	) -> Result<Response<Body>, Infallible> {
		info!("{} {} {}", addr, req.method(), req.uri());

		// Lots of instrumentation
		let tracer = opentelemetry::global::tracer("garage");
		let span = tracer
			.span_builder(format!("Web {} request", req.method()))
			.with_trace_id(gen_trace_id())
			.with_attributes(vec![
				KeyValue::new("method", format!("{}", req.method())),
				KeyValue::new("uri", req.uri().to_string()),
			])
			.start(&tracer);

		let metrics_tags = &[KeyValue::new("method", req.method().to_string())];

		// The actual handler
		let res = self
			.serve_file(&req)
			.with_context(Context::current_with_span(span))
			.record_duration(&self.metrics.request_duration, &metrics_tags[..])
			.await;

		// More instrumentation
		self.metrics.request_counter.add(1, &metrics_tags[..]);

		// Returning the result
		match res {
			Ok(res) => {
				debug!("{} {} {}", req.method(), res.status(), req.uri());
				Ok(res)
			}
			Err(error) => {
				info!(
					"{} {} {} {}",
					req.method(),
					error.http_status_code(),
					req.uri(),
					error
				);
				self.metrics.error_counter.add(
					1,
					&[
						metrics_tags[0].clone(),
						KeyValue::new("status_code", error.http_status_code().to_string()),
					],
				);
				Ok(error_to_res(error))
			}
		}
	}

	async fn serve_file(self: &Arc<Self>, req: &Request<Body>) -> Result<Response<Body>, Error> {
		// Get http authority string (eg. [::1]:3902 or garage.tld:80)
		let authority = req
			.headers()
			.get(HOST)
			.ok_or_bad_request("HOST header required")?
			.to_str()?;

		// Get bucket
		let host = authority_to_host(authority)?;

		let bucket_name = host_to_bucket(&host, &self.root_domain).unwrap_or(&host);
		let bucket_id = self
			.garage
			.bucket_alias_table
			.get(&EmptyKey, &bucket_name.to_string())
			.await?
			.and_then(|x| x.state.take())
			.ok_or(Error::NotFound)?;

		// Check bucket isn't deleted and has website access enabled
		let bucket = self
			.garage
			.bucket_table
			.get(&EmptyKey, &bucket_id)
			.await?
			.ok_or(Error::NotFound)?;

		let website_config = bucket
			.params()
			.ok_or(Error::NotFound)?
			.website_config
			.get()
			.as_ref()
			.ok_or(Error::NotFound)?;

		// Get path
		let path = req.uri().path().to_string();
		let index = &website_config.index_document;
		let key = path_to_key(&path, index)?;

		debug!(
			"Selected bucket: \"{}\" {:?}, selected key: \"{}\"",
			bucket_name, bucket_id, key
		);

		let ret_doc = match *req.method() {
			Method::OPTIONS => handle_options_for_bucket(req, &bucket),
			Method::HEAD => handle_head(self.garage.clone(), req, bucket_id, &key, None).await,
			Method::GET => handle_get(self.garage.clone(), req, bucket_id, &key, None).await,
			_ => Err(ApiError::bad_request("HTTP method not supported")),
		}
		.map_err(Error::from);

		match ret_doc {
			Err(error) => {
				// For a HEAD or OPTIONS method, and for non-4xx errors,
				// we don't return the error document as content,
				// we return above and just return the error message
				// by relying on err_to_res that is called when we return an Err.
				if *req.method() == Method::HEAD
					|| *req.method() == Method::OPTIONS
					|| !error.http_status_code().is_client_error()
				{
					return Err(error);
				}

				// If no error document is set: just return the error directly
				let error_document = match &website_config.error_document {
					Some(ed) => ed.trim_start_matches('/').to_owned(),
					None => return Err(error),
				};

				// We want to return the error document
				// Create a fake HTTP request with path = the error document
				let req2 = Request::builder()
					.uri(format!("http://{}/{}", host, &error_document))
					.body(Body::empty())
					.unwrap();

				match handle_get(self.garage.clone(), &req2, bucket_id, &error_document, None).await
				{
					Ok(mut error_doc) => {
						// The error won't be logged back in handle_request,
						// so log it here
						info!(
							"{} {} {} {}",
							req.method(),
							req.uri(),
							error.http_status_code(),
							error
						);

						*error_doc.status_mut() = error.http_status_code();

						// Preserve error message in a special header
						for error_line in error.to_string().split('\n') {
							if let Ok(v) = HeaderValue::from_bytes(error_line.as_bytes()) {
								error_doc.headers_mut().append("X-Garage-Error", v);
							}
						}

						Ok(error_doc)
					}
					Err(error_doc_error) => {
						warn!(
							"Couldn't get error document {} for bucket {:?}: {}",
							error_document, bucket_id, error_doc_error
						);
						Err(error)
					}
				}
			}
			Ok(mut resp) => {
				// Maybe add CORS headers
				if let Some(rule) = find_matching_cors_rule(&bucket, req)? {
					add_cors_headers(&mut resp, rule)
						.ok_or_internal_error("Invalid bucket CORS configuration")?;
				}
				Ok(resp)
			}
		}
	}
}

fn error_to_res(e: Error) -> Response<Body> {
	// If we are here, it is either that:
	// - there was an error before trying to get the requested URL
	//   from the bucket (e.g. bucket not found)
	// - there was an error processing the request and (the request
	//   was a HEAD request or we couldn't get the error document)
	// We do NOT enter this code path when returning the bucket's
	// error document (this is handled in serve_file)
	let body = Body::from(format!("{}\n", e));
	let mut http_error = Response::new(body);
	*http_error.status_mut() = e.http_status_code();
	e.add_headers(http_error.headers_mut());
	http_error
}

/// Path to key
///
/// Convert the provided path to the internal key
/// When a path ends with "/", we append the index name to match traditional web server behavior
/// which is also AWS S3 behavior.
fn path_to_key<'a>(path: &'a str, index: &str) -> Result<Cow<'a, str>, Error> {
	let path_utf8 = percent_encoding::percent_decode_str(path).decode_utf8()?;

	if !path_utf8.starts_with('/') {
		return Err(Error::BadRequest("Path must start with a / (slash)".into()));
	}

	match path_utf8.chars().last() {
		None => unreachable!(),
		Some('/') => {
			let mut key = String::with_capacity(path_utf8.len() + index.len());
			key.push_str(&path_utf8[1..]);
			key.push_str(index);
			Ok(key.into())
		}
		Some(_) => match path_utf8 {
			Cow::Borrowed(pu8) => Ok((&pu8[1..]).into()),
			Cow::Owned(pu8) => Ok(pu8[1..].to_string().into()),
		},
	}
}

#[cfg(test)]
mod tests {
	use super::*;

	#[test]
	fn path_to_key_test() -> Result<(), Error> {
		assert_eq!(path_to_key("/file%20.jpg", "index.html")?, "file .jpg");
		assert_eq!(path_to_key("/%20t/", "index.html")?, " t/index.html");
		assert_eq!(path_to_key("/", "index.html")?, "index.html");
		assert_eq!(path_to_key("/hello", "index.html")?, "hello");
		assert!(path_to_key("", "index.html").is_err());
		assert!(path_to_key("i/am/relative", "index.html").is_err());
		Ok(())
	}
}