Dynamic automatic answers system

- Every default answers is configurable - Default answers are stored as Templates to allow dynamic content - Tamplates are a wrapper around a Kawa stream which buffer is shared with an Rc - 301 answers are treated like all other default answers - response_stream in HTTP state can be either a generic Kawa stream from a backend, or a templated stream from a default answer - Setting a default answer takes structured fields which will be forwarded to the Template TODOs: - Override default answers with html files from config - Format sozu details in templates variables to be human readable - Update Kawa (the Templates requires new features and fixes) Signed-off-by: Eloi DEMOLIS <[email protected]>
sozu-proxy · Apr 5, 2024 · 3f0bfa1 · 3f0bfa1
1 parent f306a79
commit 3f0bfa1
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Showing 7 changed files with 842 additions and 322 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/lib/Cargo.toml b/lib/Cargo.toml
@@ -34,7 +34,7 @@ hdrhistogram = "^7.5.4"
 hex = "^0.4.3"
 hpack = "^0.3.0"
 idna = "^0.5.0"
-kawa = { version = "^0.6.5", default-features = false }
+kawa = { version = "^0.6.6", default-features = false }
 libc = "^0.2.153"
 memchr = "^2.7.1"
 mio = { version = "^0.8.11", features = ["os-poll", "os-ext", "net"] }

diff --git a/lib/src/http.rs b/lib/src/http.rs
@@ -32,8 +32,9 @@ use crate::{
     pool::Pool,
     protocol::{
         http::{
-            answers::HttpAnswers,
+            answers::{HttpAnswers, RawAnswers},
             parser::{hostname_and_port, Method},
+            ResponseStream,
         },
         proxy_protocol::expect::ExpectProxyProtocol,
         Http, Pipe, SessionState,
@@ -230,8 +231,14 @@ impl HttpSession {
         container_frontend_timeout.reset();
         container_backend_timeout.reset();
 
+        let backend_buffer = if let ResponseStream::BackendAnswer(kawa) = http.response_stream {
+            kawa.storage.buffer
+        } else {
+            return None;
+        };
+
         let mut pipe = Pipe::new(
-            http.response_stream.storage.buffer,
+            backend_buffer,
             http.backend_id,
             http.backend_socket,
             http.backend,
@@ -586,14 +593,17 @@ impl HttpProxy {
         Ok((owned.token, taken_listener))
     }
 
-    pub fn add_cluster(&mut self, cluster: Cluster) -> Result<(), ProxyError> {
-        if let Some(answer_503) = &cluster.answer_503 {
+    pub fn add_cluster(&mut self, mut cluster: Cluster) -> Result<(), ProxyError> {
+        if let Some(answer_503) = cluster.answer_503.take() {
             for listener in self.listeners.values() {
                 listener
                     .borrow()
                     .answers
                     .borrow_mut()
-                    .add_custom_answer(&cluster.cluster_id, answer_503);
+                    .add_custom_answer(&cluster.cluster_id, answer_503.clone())
+                    .map_err(|(status, error)| {
+                        ProxyError::AddCluster(ListenerError::TemplateParse(status, error))
+                    })?;
             }
         }
         self.clusters.insert(cluster.cluster_id.clone(), cluster);
@@ -715,10 +725,14 @@ impl HttpListener {
         Ok(HttpListener {
             active: false,
             address: config.address.clone().into(),
-            answers: Rc::new(RefCell::new(HttpAnswers::new(
-                &config.answer_404,
-                &config.answer_503,
-            ))),
+            answers: Rc::new(RefCell::new(
+                HttpAnswers::new(
+                    // &config.answer_404,
+                    // &config.answer_503,
+                    RawAnswers::default(),
+                )
+                .map_err(|(status, error)| ListenerError::TemplateParse(status, error))?,
+            )),
             config,
             fronts: Router::new(),
             listener: None,
@@ -1458,10 +1472,14 @@ mod tests {
             listener: None,
             address: address.into(),
             fronts,
-            answers: Rc::new(RefCell::new(HttpAnswers::new(
-                "HTTP/1.1 404 Not Found\r\n\r\n",
-                "HTTP/1.1 503 Service Unavailable\r\n\r\n",
-            ))),
+            answers: Rc::new(RefCell::new(
+                HttpAnswers::new(
+                    // "HTTP/1.1 404 Not Found\r\n\r\n",
+                    // "HTTP/1.1 503 Service Unavailable\r\n\r\n",
+                    RawAnswers::default(),
+                )
+                .unwrap(),
+            )),
             config: default_config,
             token: Token(0),
             active: true,

diff --git a/lib/src/https.rs b/lib/src/https.rs
@@ -54,8 +54,9 @@ use crate::{
     protocol::{
         h2::Http2,
         http::{
-            answers::HttpAnswers,
+            answers::{HttpAnswers, RawAnswers},
             parser::{hostname_and_port, Method},
+            ResponseStream,
         },
         proxy_protocol::expect::ExpectProxyProtocol,
         rustls::TlsHandshake,
@@ -356,8 +357,14 @@ impl HttpsSession {
         container_frontend_timeout.reset();
         container_backend_timeout.reset();
 
+        let backend_buffer = if let ResponseStream::BackendAnswer(kawa) = http.response_stream {
+            kawa.storage.buffer
+        } else {
+            return None;
+        };
+
         let mut pipe = Pipe::new(
-            http.response_stream.storage.buffer,
+            backend_buffer,
             http.backend_id,
             http.backend_socket,
             http.backend,
@@ -624,10 +631,14 @@ impl HttpsListener {
             rustls_details: server_config,
             active: false,
             fronts: Router::new(),
-            answers: Rc::new(RefCell::new(HttpAnswers::new(
-                &config.answer_404,
-                &config.answer_503,
-            ))),
+            answers: Rc::new(RefCell::new(
+                HttpAnswers::new(
+                    // &config.answer_404,
+                    // &config.answer_503,
+                    RawAnswers::default(),
+                )
+                .map_err(|(status, error)| ListenerError::TemplateParse(status, error))?,
+            )),
             config,
             token,
             tags: BTreeMap::new(),
@@ -1003,7 +1014,10 @@ impl HttpsProxy {
                     .borrow()
                     .answers
                     .borrow_mut()
-                    .add_custom_answer(&cluster.cluster_id, &answer_503);
+                    .add_custom_answer(&cluster.cluster_id, answer_503.clone())
+                    .map_err(|(status, error)| {
+                        ProxyError::AddCluster(ListenerError::TemplateParse(status, error))
+                    })?;
             }
         }
         self.clusters.insert(cluster.cluster_id.clone(), cluster);
@@ -1582,10 +1596,14 @@ mod tests {
             fronts,
             rustls_details,
             resolver,
-            answers: Rc::new(RefCell::new(HttpAnswers::new(
-                "HTTP/1.1 404 Not Found\r\n\r\n",
-                "HTTP/1.1 503 Service Unavailable\r\n\r\n",
-            ))),
+            answers: Rc::new(RefCell::new(
+                HttpAnswers::new(
+                    // "HTTP/1.1 404 Not Found\r\n\r\n",
+                    // "HTTP/1.1 503 Service Unavailable\r\n\r\n",
+                    RawAnswers::default(),
+                )
+                .unwrap(),
+            )),
             config: default_config,
             token: Token(0),
             active: true,

diff --git a/lib/src/lib.rs b/lib/src/lib.rs
@@ -348,7 +348,7 @@ use std::{
 use backends::BackendError;
 use hex::FromHexError;
 use mio::{net::TcpStream, Interest, Token};
-use protocol::http::parser::Method;
+use protocol::http::{answers::TemplateError, parser::Method};
 use router::RouterError;
 use socket::ServerBindError;
 use time::{Duration, Instant};
@@ -624,6 +624,8 @@ pub enum ListenerError {
     Resolver(CertificateResolverError),
     #[error("failed to parse pem, {0}")]
     PemParse(String),
+    #[error("failed to parse template {0}: {1}")]
+    TemplateParse(u16, TemplateError),
     #[error("failed to build rustls context, {0}")]
     BuildRustls(String),
     #[error("could not activate listener with address {address:?}: {error}")]
@@ -655,6 +657,8 @@ pub enum ProxyError {
     ListenerAlreadyPresent,
     #[error("could not add listener: {0}")]
     AddListener(ListenerError),
+    #[error("could not add cluster: {0}")]
+    AddCluster(ListenerError),
     #[error("failed to activate listener with address {address:?}: {listener_error}")]
     ListenerActivation {
         address: SocketAddr,