Patch safekeeper control file on HTTP request (#6455)

Closes #6397
2026-01-07 13:32:57 +00:00 · 2024-01-29 18:20:57 +00:00
parent ec8dcc2231
commit 2ff1a5cecd
6 changed files with 191 additions and 1 deletions
--- a/safekeeper/src/http/routes.rs
+++ b/safekeeper/src/http/routes.rs
@@ -28,7 +28,7 @@ use crate::safekeeper::Term;
 use crate::safekeeper::{ServerInfo, TermLsn};
 use crate::send_wal::WalSenderState;
 use crate::timeline::PeerInfo;
-use crate::{copy_timeline, debug_dump, pull_timeline};
+use crate::{copy_timeline, debug_dump, patch_control_file, pull_timeline};

 use crate::timelines_global_map::TimelineDeleteForceResult;
 use crate::GlobalTimelines;
@@ -465,6 +465,26 @@ async fn dump_debug_handler(mut request: Request<Body>) -> Result<Response<Body>
    Ok(response)
 }

+async fn patch_control_file_handler(
+    mut request: Request<Body>,
+) -> Result<Response<Body>, ApiError> {
+    check_permission(&request, None)?;
+
+    let ttid = TenantTimelineId::new(
+        parse_request_param(&request, "tenant_id")?,
+        parse_request_param(&request, "timeline_id")?,
+    );
+
+    let tli = GlobalTimelines::get(ttid).map_err(ApiError::from)?;
+
+    let patch_request: patch_control_file::Request = json_request(&mut request).await?;
+    let response = patch_control_file::handle_request(tli, patch_request)
+        .await
+        .map_err(ApiError::InternalServerError)?;
+
+    json_response(StatusCode::OK, response)
+}
+
 /// Safekeeper http router.
 pub fn make_router(conf: SafeKeeperConf) -> RouterBuilder<hyper::Body, ApiError> {
    let mut router = endpoint::make_router();
@@ -526,6 +546,10 @@ pub fn make_router(conf: SafeKeeperConf) -> RouterBuilder<hyper::Body, ApiError>
            "/v1/tenant/:tenant_id/timeline/:source_timeline_id/copy",
            |r| request_span(r, timeline_copy_handler),
        )
+        .patch(
+            "/v1/tenant/:tenant_id/timeline/:timeline_id/control_file",
+            |r| request_span(r, patch_control_file_handler),
+        )
        // for tests
        .post("/v1/record_safekeeper_info/:tenant_id/:timeline_id", |r| {
            request_span(r, record_safekeeper_info)
--- a/safekeeper/src/lib.rs
+++ b/safekeeper/src/lib.rs
@@ -22,6 +22,7 @@ pub mod handler;
 pub mod http;
 pub mod json_ctrl;
 pub mod metrics;
+pub mod patch_control_file;
 pub mod pull_timeline;
 pub mod receive_wal;
 pub mod recovery;
--- a/safekeeper/src/patch_control_file.rs
+++ b/safekeeper/src/patch_control_file.rs
@@ -0,0 +1,85 @@
+use std::sync::Arc;
+
+use serde::{Deserialize, Serialize};
+use serde_json::Value;
+use tracing::info;
+
+use crate::{state::TimelinePersistentState, timeline::Timeline};
+
+#[derive(Deserialize, Debug, Clone)]
+pub struct Request {
+    /// JSON object with fields to update
+    pub updates: serde_json::Value,
+    /// List of fields to apply
+    pub apply_fields: Vec<String>,
+}
+
+#[derive(Serialize)]
+pub struct Response {
+    pub old_control_file: TimelinePersistentState,
+    pub new_control_file: TimelinePersistentState,
+}
+
+/// Patch control file with given request. Will update the persistent state using
+/// fields from the request and persist the new state on disk.
+pub async fn handle_request(tli: Arc<Timeline>, request: Request) -> anyhow::Result<Response> {
+    let response = tli
+        .map_control_file(|state| {
+            let old_control_file = state.clone();
+            let new_control_file = state_apply_diff(&old_control_file, &request)?;
+
+            info!(
+                "patching control file, old: {:?}, new: {:?}, patch: {:?}",
+                old_control_file, new_control_file, request
+            );
+            *state = new_control_file.clone();
+
+            Ok(Response {
+                old_control_file,
+                new_control_file,
+            })
+        })
+        .await?;
+
+    Ok(response)
+}
+
+fn state_apply_diff(
+    state: &TimelinePersistentState,
+    request: &Request,
+) -> anyhow::Result<TimelinePersistentState> {
+    let mut json_value = serde_json::to_value(state)?;
+
+    if let Value::Object(a) = &mut json_value {
+        if let Value::Object(b) = &request.updates {
+            json_apply_diff(a, b, &request.apply_fields)?;
+        } else {
+            anyhow::bail!("request.updates is not a json object")
+        }
+    } else {
+        anyhow::bail!("TimelinePersistentState is not a json object")
+    }
+
+    let new_state: TimelinePersistentState = serde_json::from_value(json_value)?;
+    Ok(new_state)
+}
+
+fn json_apply_diff(
+    object: &mut serde_json::Map<String, Value>,
+    updates: &serde_json::Map<String, Value>,
+    apply_keys: &Vec<String>,
+) -> anyhow::Result<()> {
+    for key in apply_keys {
+        if let Some(new_value) = updates.get(key) {
+            if let Some(existing_value) = object.get_mut(key) {
+                *existing_value = new_value.clone();
+            } else {
+                anyhow::bail!("key not found in original object: {}", key);
+            }
+        } else {
+            anyhow::bail!("key not found in request.updates: {}", key);
+        }
+    }
+
+    Ok(())
+}
--- a/safekeeper/src/timeline.rs
+++ b/safekeeper/src/timeline.rs
@@ -901,6 +901,20 @@ impl Timeline {
            file_open,
        }
    }
+
+    /// Apply a function to the control file state and persist it.
+    pub async fn map_control_file<T>(
+        &self,
+        f: impl FnOnce(&mut TimelinePersistentState) -> Result<T>,
+    ) -> Result<T> {
+        let mut state = self.write_shared_state().await;
+        let mut persistent_state = state.sk.state.start_change();
+        // If f returns error, we abort the change and don't persist anything.
+        let res = f(&mut persistent_state)?;
+        // If persisting fails, we abort the change and return error.
+        state.sk.state.finish_change(&persistent_state).await?;
+        Ok(res)
+    }
 }

 /// Deletes directory and it's contents. Returns false if directory does not exist.