pageserver: check env var for ip address before node registration (#12666)

Include the ip address (optionally read from an env var) in the
pageserver's registration request.
Note that the ip address is ignored by the storage controller at the
moment, which makes it a no-op
in the neon env.

pageserver/src/controller_upcall_client.rs

@@ -1,4 +1,5 @@
 use std::collections::HashMap;
+use std::net::IpAddr;
 
 use futures::Future;
 use pageserver_api::config::NodeMetadata;
@@ -16,7 +17,7 @@ use tokio_util::sync::CancellationToken;
 use url::Url;
 use utils::generation::Generation;
 use utils::id::{NodeId, TimelineId};
-use utils::{backoff, failpoint_support};
+use utils::{backoff, failpoint_support, ip_address};
 
 use crate::config::PageServerConf;
 use crate::virtual_file::on_fatal_io_error;
@@ -27,6 +28,7 @@ pub struct StorageControllerUpcallClient {
     http_client: reqwest::Client,
     base_url: Url,
     node_id: NodeId,
+    node_ip_addr: Option<IpAddr>,
     cancel: CancellationToken,
 }
 
@@ -91,11 +93,18 @@ impl StorageControllerUpcallClient {
             );
         }
 
+        // Intentionally panics if we encountered any errors parsing or reading the IP address.
+        // Note that if the required environment variable is not set, `read_node_ip_addr_from_env` returns `Ok(None)`
+        // instead of an error.
+        let node_ip_addr =
+            ip_address::read_node_ip_addr_from_env().expect("Error reading node IP address.");
+
         Self {
             http_client: client.build().expect("Failed to construct HTTP client"),
             base_url: url,
             node_id: conf.id,
             cancel: cancel.clone(),
+            node_ip_addr,
         }
     }
 
@@ -193,8 +202,8 @@ impl StorageControllerUpcallApi for StorageControllerUpcallClient {
                         listen_http_addr: m.http_host,
                         listen_http_port: m.http_port,
                         listen_https_port: m.https_port,
+                        node_ip_addr: self.node_ip_addr,
                         availability_zone_id: az_id.expect("Checked above"),
-                        node_ip_addr: None,
                     })
                 }
                 Err(e) => {