Use one Oximeter client per admin server

clickhouse-admin/src/context.rs

@@ -3,7 +3,10 @@
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
 use crate::{ClickhouseCli, Clickward};
+use omicron_common::address::CLICKHOUSE_TCP_PORT;
+use oximeter_db::Client as OximeterClient;
 use slog::Logger;
+use std::net::SocketAddrV6;
 use std::sync::Arc;
 use tokio::sync::Mutex;
 
@@ -33,18 +36,34 @@ impl ServerContext {
 
 pub struct SingleServerContext {
     clickhouse_cli: ClickhouseCli,
+    oximeter_client: OximeterClient,
     initialization_lock: Arc<Mutex<()>>,
 }
 
 impl SingleServerContext {
     pub fn new(clickhouse_cli: ClickhouseCli) -> Self {
-        Self { clickhouse_cli, initialization_lock: Arc::new(Mutex::new(())) }
+        let ip = clickhouse_cli.listen_address.ip();
+        let address = SocketAddrV6::new(*ip, CLICKHOUSE_TCP_PORT, 0, 0);
+        let log = clickhouse_cli
+            .log
+            .as_ref()
+            .expect("should have configured logging via CLI or config");
+        let oximeter_client = OximeterClient::new(address.into(), log);
+        Self {
+            clickhouse_cli,
+            oximeter_client,
+            initialization_lock: Arc::new(Mutex::new(())),
+        }
     }
 
     pub fn clickhouse_cli(&self) -> &ClickhouseCli {
         &self.clickhouse_cli
     }
 
+    pub fn oximeter_client(&self) -> &OximeterClient {
+        &self.oximeter_client
+    }
+
     pub fn initialization_lock(&self) -> Arc<Mutex<()>> {
         self.initialization_lock.clone()
     }

clickhouse-admin/src/http_entrypoints.rs

@@ -15,10 +15,8 @@ use dropshot::{
     HttpResponseUpdatedNoContent, Path, Query, RequestContext, TypedBody,
 };
 use illumos_utils::svcadm::Svcadm;
-use omicron_common::address::CLICKHOUSE_TCP_PORT;
-use oximeter_db::{Client as OximeterClient, OXIMETER_VERSION};
-use slog::debug;
-use std::net::SocketAddrV6;
+use oximeter_db::OXIMETER_VERSION;
+use slog::info;
 use std::sync::Arc;
 
 pub fn clickhouse_admin_server_api() -> ApiDescription<Arc<ServerContext>> {
@@ -146,28 +144,40 @@ impl ClickhouseAdminSingleApi for ClickhouseAdminSingleImpl {
     ) -> Result<HttpResponseUpdatedNoContent, HttpError> {
         let log = &rqctx.log;
         let ctx = rqctx.context();
-        let ip = ctx.clickhouse_cli().listen_address.ip();
-        let address = SocketAddrV6::new(*ip, CLICKHOUSE_TCP_PORT, 0, 0);
-        let client = OximeterClient::new(address.into(), log);
-        debug!(
-            log,
-            "initializing single-node ClickHouse \
-             at {address} to version {OXIMETER_VERSION}"
-        );
 
         // Database initialization is idempotent, but not concurrency-safe.
         // Use a mutex to serialize requests.
         let lock = ctx.initialization_lock();
         let _guard = lock.lock().await;
-        client
-            .initialize_db_with_version(false, OXIMETER_VERSION)
-            .await
-            .map_err(|e| {
-                HttpError::for_internal_error(format!(
-                    "can't initialize single-node ClickHouse \
-                     at {address} to version {OXIMETER_VERSION}: {e}",
-                ))
-            })?;
+
+        // Initialize the database only if it was not previously initialized.
+        // TODO: Migrate schema to newer version without wiping data.
+        let client = ctx.oximeter_client();
+        let version = client.read_latest_version().await.map_err(|e| {
+            HttpError::for_internal_error(format!(
+                "can't read ClickHouse version: {e}",
+            ))
+        })?;
+        if version == 0 {
+            info!(
+                log,
+                "initializing single-node ClickHouse to version {OXIMETER_VERSION}"
+            );
+            ctx.oximeter_client()
+                .initialize_db_with_version(false, OXIMETER_VERSION)
+                .await
+                .map_err(|e| {
+                    HttpError::for_internal_error(format!(
+                        "can't initialize single-node ClickHouse \
+                         to version {OXIMETER_VERSION}: {e}",
+                    ))
+                })?;
+        } else {
+            info!(
+                log,
+                "skipping initialization of single-node ClickHouse at version {version}"
+            );
+        }
 
         Ok(HttpResponseUpdatedNoContent())
     }

clickhouse-admin/src/lib.rs

@@ -139,7 +139,10 @@ pub async fn start_single_admin_server(
         }
     }
 
-    let context = SingleServerContext::new(clickhouse_cli);
+    let context = SingleServerContext::new(
+        clickhouse_cli
+            .with_log(log.new(slog::o!("component" => "ClickhouseCli"))),
+    );
     dropshot::ServerBuilder::new(
         http_entrypoints::clickhouse_admin_single_api(),
         Arc::new(context),