refactor: move NodeMetadata to pageserver_api; use it from neon_local (#7606)

This is the first step towards representing all of Pageserver
configuration as clean `serde::Serialize`able Rust structs in
`pageserver_api`.

The `neon_local` code will then use those structs instead of the crude
`toml_edit` / string concatenation that it does today.

refs https://github.com/neondatabase/neon/issues/7555

---------

Co-authored-by: Alex Chi Z <iskyzh@gmail.com>

control_plane/src/bin/neon_local.rs

@@ -14,15 +14,15 @@ use control_plane::pageserver::{PageServerNode, PAGESERVER_REMOTE_STORAGE_DIR};
 use control_plane::safekeeper::SafekeeperNode;
 use control_plane::storage_controller::StorageController;
 use control_plane::{broker, local_env};
+use pageserver_api::config::{
+    DEFAULT_HTTP_LISTEN_PORT as DEFAULT_PAGESERVER_HTTP_PORT,
+    DEFAULT_PG_LISTEN_PORT as DEFAULT_PAGESERVER_PG_PORT,
+};
 use pageserver_api::controller_api::PlacementPolicy;
 use pageserver_api::models::{
     ShardParameters, TenantCreateRequest, TimelineCreateRequest, TimelineInfo,
 };
 use pageserver_api::shard::{ShardCount, ShardStripeSize, TenantShardId};
-use pageserver_api::{
-    DEFAULT_HTTP_LISTEN_PORT as DEFAULT_PAGESERVER_HTTP_PORT,
-    DEFAULT_PG_LISTEN_PORT as DEFAULT_PAGESERVER_PG_PORT,
-};
 use postgres_backend::AuthType;
 use postgres_connection::parse_host_port;
 use safekeeper_api::{

control_plane/src/pageserver.rs

@@ -248,12 +248,13 @@ impl PageServerNode {
         // situation: the metadata is written by some other script.
         std::fs::write(
             metadata_path,
-            serde_json::to_vec(&serde_json::json!({
-                "host": "localhost",
-                "port": self.pg_connection_config.port(),
-                "http_host": "localhost",
-                "http_port": http_port,
-            }))
+            serde_json::to_vec(&pageserver_api::config::NodeMetadata {
+                postgres_host: "localhost".to_string(),
+                postgres_port: self.pg_connection_config.port(),
+                http_host: "localhost".to_string(),
+                http_port,
+                other: HashMap::new(),
+            })
             .unwrap(),
         )
         .expect("Failed to write metadata file");

libs/pageserver_api/src/config.rs

@@ -0,0 +1,31 @@
+use std::collections::HashMap;
+
+use const_format::formatcp;
+
+#[cfg(test)]
+mod tests;
+
+pub const DEFAULT_PG_LISTEN_PORT: u16 = 64000;
+pub const DEFAULT_PG_LISTEN_ADDR: &str = formatcp!("127.0.0.1:{DEFAULT_PG_LISTEN_PORT}");
+pub const DEFAULT_HTTP_LISTEN_PORT: u16 = 9898;
+pub const DEFAULT_HTTP_LISTEN_ADDR: &str = formatcp!("127.0.0.1:{DEFAULT_HTTP_LISTEN_PORT}");
+
+// Certain metadata (e.g. externally-addressable name, AZ) is delivered
+// as a separate structure.  This information is not neeed by the pageserver
+// itself, it is only used for registering the pageserver with the control
+// plane and/or storage controller.
+//
+#[derive(PartialEq, Eq, Debug, serde::Serialize, serde::Deserialize)]
+pub struct NodeMetadata {
+    #[serde(rename = "host")]
+    pub postgres_host: String,
+    #[serde(rename = "port")]
+    pub postgres_port: u16,
+    pub http_host: String,
+    pub http_port: u16,
+
+    // Deployment tools may write fields to the metadata file beyond what we
+    // use in this type: this type intentionally only names fields that require.
+    #[serde(flatten)]
+    pub other: HashMap<String, serde_json::Value>,
+}

libs/pageserver_api/src/config/tests.rs

@@ -0,0 +1,22 @@
+use super::*;
+
+#[test]
+fn test_node_metadata_v1_backward_compatibilty() {
+    let v1 = serde_json::to_vec(&serde_json::json!({
+        "host": "localhost",
+        "port": 23,
+        "http_host": "localhost",
+        "http_port": 42,
+    }));
+
+    assert_eq!(
+        serde_json::from_slice::<NodeMetadata>(&v1.unwrap()).unwrap(),
+        NodeMetadata {
+            postgres_host: "localhost".to_string(),
+            postgres_port: 23,
+            http_host: "localhost".to_string(),
+            http_port: 42,
+            other: HashMap::new(),
+        }
+    )
+}

libs/pageserver_api/src/lib.rs

@@ -1,6 +1,5 @@
 #![deny(unsafe_code)]
 #![deny(clippy::undocumented_unsafe_blocks)]
-use const_format::formatcp;
 
 pub mod controller_api;
 pub mod key;
@@ -11,7 +10,4 @@ pub mod shard;
 /// Public API types
 pub mod upcall_api;
 
-pub const DEFAULT_PG_LISTEN_PORT: u16 = 64000;
-pub const DEFAULT_PG_LISTEN_ADDR: &str = formatcp!("127.0.0.1:{DEFAULT_PG_LISTEN_PORT}");
-pub const DEFAULT_HTTP_LISTEN_PORT: u16 = 9898;
-pub const DEFAULT_HTTP_LISTEN_ADDR: &str = formatcp!("127.0.0.1:{DEFAULT_HTTP_LISTEN_PORT}");
+pub mod config;

pageserver/src/config.rs

@@ -9,7 +9,7 @@ use pageserver_api::shard::TenantShardId;
 use remote_storage::{RemotePath, RemoteStorageConfig};
 use serde;
 use serde::de::IntoDeserializer;
-use std::{collections::HashMap, env};
+use std::env;
 use storage_broker::Uri;
 use utils::crashsafe::path_with_suffix_extension;
 use utils::id::ConnectionId;
@@ -51,7 +51,7 @@ pub mod defaults {
     use crate::tenant::config::defaults::*;
     use const_format::formatcp;
 
-    pub use pageserver_api::{
+    pub use pageserver_api::config::{
         DEFAULT_HTTP_LISTEN_ADDR, DEFAULT_HTTP_LISTEN_PORT, DEFAULT_PG_LISTEN_ADDR,
         DEFAULT_PG_LISTEN_PORT,
     };
@@ -335,26 +335,6 @@ impl<T: Clone> BuilderValue<T> {
     }
 }
 
-// Certain metadata (e.g. externally-addressable name, AZ) is delivered
-// as a separate structure.  This information is not neeed by the pageserver
-// itself, it is only used for registering the pageserver with the control
-// plane and/or storage controller.
-//
-#[derive(serde::Deserialize)]
-pub(crate) struct NodeMetadata {
-    #[serde(rename = "host")]
-    pub(crate) postgres_host: String,
-    #[serde(rename = "port")]
-    pub(crate) postgres_port: u16,
-    pub(crate) http_host: String,
-    pub(crate) http_port: u16,
-
-    // Deployment tools may write fields to the metadata file beyond what we
-    // use in this type: this type intentionally only names fields that require.
-    #[serde(flatten)]
-    pub(crate) other: HashMap<String, serde_json::Value>,
-}
-
 // needed to simplify config construction
 #[derive(Default)]
 struct PageServerConfigBuilder {

pageserver/src/control_plane_client.rs

@@ -14,10 +14,8 @@ use tokio_util::sync::CancellationToken;
 use url::Url;
 use utils::{backoff, failpoint_support, generation::Generation, id::NodeId};
 
-use crate::{
-    config::{NodeMetadata, PageServerConf},
-    virtual_file::on_fatal_io_error,
-};
+use crate::{config::PageServerConf, virtual_file::on_fatal_io_error};
+use pageserver_api::config::NodeMetadata;
 
 /// The Pageserver's client for using the control plane API: this is a small subset
 /// of the overall control plane API, for dealing with generations (see docs/rfcs/025-generation-numbers.md)