add proxy-protocol header disable option (#9203)

resolves https://github.com/neondatabase/cloud/issues/18026

proxy/src/bin/local_proxy.rs

@@ -274,7 +274,7 @@ fn build_config(args: &LocalProxyCliArgs) -> anyhow::Result<&'static ProxyConfig
             rate_limit_ip_subnet: 64,
             ip_allowlist_check_enabled: true,
         },
-        require_client_ip: false,
+        proxy_protocol_v2: config::ProxyProtocolV2::Rejected,
         handshake_timeout: Duration::from_secs(10),
         region: "local".into(),
         wake_compute_retry_config: RetryConfig::parse(RetryConfig::WAKE_COMPUTE_DEFAULT_VALUES)?,

proxy/src/bin/proxy.rs

@@ -17,6 +17,7 @@ use proxy::config::AuthenticationConfig;
 use proxy::config::CacheOptions;
 use proxy::config::HttpConfig;
 use proxy::config::ProjectInfoCacheOptions;
+use proxy::config::ProxyProtocolV2;
 use proxy::console;
 use proxy::context::parquet::ParquetUploadArgs;
 use proxy::http;
@@ -144,9 +145,6 @@ struct ProxyCliArgs {
     /// size of the threadpool for password hashing
     #[clap(long, default_value_t = 4)]
     scram_thread_pool_size: u8,
-    /// Require that all incoming requests have a Proxy Protocol V2 packet **and** have an IP address associated.
-    #[clap(long, default_value_t = false, value_parser = clap::builder::BoolishValueParser::new(), action = clap::ArgAction::Set)]
-    require_client_ip: bool,
     /// Disable dynamic rate limiter and store the metrics to ensure its production behaviour.
     #[clap(long, default_value_t = true, value_parser = clap::builder::BoolishValueParser::new(), action = clap::ArgAction::Set)]
     disable_dynamic_rate_limiter: bool,
@@ -229,6 +227,11 @@ struct ProxyCliArgs {
     /// Configure if this is a private access proxy for the POC: In that case the proxy will ignore the IP allowlist
     #[clap(long, default_value_t = false, value_parser = clap::builder::BoolishValueParser::new(), action = clap::ArgAction::Set)]
     is_private_access_proxy: bool,
+
+    /// Configure whether all incoming requests have a Proxy Protocol V2 packet.
+    // TODO(conradludgate): switch default to rejected or required once we've updated all deployments
+    #[clap(value_enum, long, default_value_t = ProxyProtocolV2::Supported)]
+    proxy_protocol_v2: ProxyProtocolV2,
 }
 
 #[derive(clap::Args, Clone, Copy, Debug)]
@@ -704,7 +707,7 @@ fn build_config(args: &ProxyCliArgs) -> anyhow::Result<&'static ProxyConfig> {
         allow_self_signed_compute: args.allow_self_signed_compute,
         http_config,
         authentication_config,
-        require_client_ip: args.require_client_ip,
+        proxy_protocol_v2: args.proxy_protocol_v2,
         handshake_timeout: args.handshake_timeout,
         region: args.region.clone(),
         wake_compute_retry_config: config::RetryConfig::parse(&args.wake_compute_retry)?,

proxy/src/config.rs

@@ -7,6 +7,7 @@ use crate::{
     Host,
 };
 use anyhow::{bail, ensure, Context, Ok};
+use clap::ValueEnum;
 use itertools::Itertools;
 use remote_storage::RemoteStorageConfig;
 use rustls::{
@@ -30,7 +31,7 @@ pub struct ProxyConfig {
     pub allow_self_signed_compute: bool,
     pub http_config: HttpConfig,
     pub authentication_config: AuthenticationConfig,
-    pub require_client_ip: bool,
+    pub proxy_protocol_v2: ProxyProtocolV2,
     pub region: String,
     pub handshake_timeout: Duration,
     pub wake_compute_retry_config: RetryConfig,
@@ -38,6 +39,16 @@ pub struct ProxyConfig {
     pub connect_to_compute_retry_config: RetryConfig,
 }
 
+#[derive(Copy, Clone, Debug, ValueEnum, PartialEq)]
+pub enum ProxyProtocolV2 {
+    /// Connection will error if PROXY protocol v2 header is missing
+    Required,
+    /// Connection will parse PROXY protocol v2 header, but accept the connection if it's missing.
+    Supported,
+    /// Connection will error if PROXY protocol v2 header is provided
+    Rejected,
+}
+
 #[derive(Debug)]
 pub struct MetricCollectionConfig {
     pub endpoint: reqwest::Url,

proxy/src/proxy.rs

@@ -10,6 +10,7 @@ pub(crate) mod wake_compute;
 pub use copy_bidirectional::copy_bidirectional_client_compute;
 pub use copy_bidirectional::ErrorSource;
 
+use crate::config::ProxyProtocolV2;
 use crate::{
     auth,
     cancellation::{self, CancellationHandlerMain, CancellationHandlerMainInternal},
@@ -93,15 +94,19 @@ pub async fn task_main(
 
         connections.spawn(async move {
             let (socket, peer_addr) = match read_proxy_protocol(socket).await {
-                Ok((socket, Some(addr))) => (socket, addr.ip()),
                 Err(e) => {
                     error!("per-client task finished with an error: {e:#}");
                     return;
                 }
-                Ok((_socket, None)) if config.require_client_ip => {
-                    error!("missing required client IP");
+                Ok((_socket, None)) if config.proxy_protocol_v2 == ProxyProtocolV2::Required => {
+                    error!("missing required proxy protocol header");
                     return;
                 }
+                Ok((_socket, Some(_))) if config.proxy_protocol_v2 == ProxyProtocolV2::Rejected => {
+                    error!("proxy protocol header not supported");
+                    return;
+                }
+                Ok((socket, Some(addr))) => (socket, addr.ip()),
                 Ok((socket, None)) => (socket, peer_addr.ip()),
             };