ci: add PostgreSQL 17 to CI and Docker build matrices

- Add PG17 to pg_version matrix in CI regression and daemon E2E tests
- Add PG17 to postgres matrix in Docker build and merge jobs
- Add pg_duckpipe_17 bake target in docker-bake.hcl
- Fix launch_worker to use WaitForBackgroundWorkerStartup: ensures the
  postmaster has actually forked the worker before returning, preventing
  a race where start_worker() reports success but the worker hasn't
  started yet (observed on slow CI runners)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: YuweiXiao

.github/workflows/ci.yaml

@@ -38,7 +38,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        pg_version: [18]
+        pg_version: [17, 18]
 
     steps:
       - name: Checkout code
@@ -118,7 +118,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        pg_version: [18]
+        pg_version: [17, 18]
 
     steps:
       - name: Checkout code

.github/workflows/docker.yaml

@@ -28,7 +28,7 @@ jobs:
     name: Build Docker image for Postgres ${{ matrix.postgres }} on ${{ matrix.runner }}
     strategy:
       matrix:
-        postgres: ["18"]
+        postgres: ["17", "18"]
         runner: ["ubuntu-24.04", "ubuntu-24.04-arm"]
 
     runs-on: ${{ matrix.runner }}
@@ -113,7 +113,7 @@ jobs:
     if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name == github.repository
     strategy:
       matrix:
-        postgres: ["18"]
+        postgres: ["17", "18"]
 
     runs-on: ubuntu-24.04
     needs: docker_build

docker/docker-bake.hcl

@@ -26,6 +26,13 @@ target "pg_duckpipe" {
   tags   = ["${REPO}:${PG_VERSION}-dev"]
 }
 
+target "pg_duckpipe_17" {
+  inherits = ["pg_duckpipe"]
+  args = {
+    PG_VERSION = "17"
+  }
+}
+
 target "pg_duckpipe_18" {
   inherits = ["pg_duckpipe"]
   args = {

duckpipe-pg/src/api.rs

@@ -302,7 +302,22 @@ fn launch_worker(group_name: &str) -> bool {
         worker.bgw_main_arg = pg_sys::ObjectIdGetDatum(pg_sys::MyDatabaseId) as pg_sys::Datum;
         worker.bgw_notify_pid = pg_sys::MyProcPid;
 
-        pg_sys::RegisterDynamicBackgroundWorker(&mut worker, std::ptr::null_mut())
+        let mut handle: *mut pg_sys::BackgroundWorkerHandle = std::ptr::null_mut();
+        if !pg_sys::RegisterDynamicBackgroundWorker(&mut worker, &mut handle) {
+            return false;
+        }
+
+        // Wait for the postmaster to actually start the worker process.
+        // Without this, RegisterDynamicBackgroundWorker may return true
+        // (slot reserved) but the worker hasn't been forked yet.
+        if !handle.is_null() {
+            let mut pid: pg_sys::pid_t = 0;
+            let status = pg_sys::WaitForBackgroundWorkerStartup(handle, &mut pid);
+            pg_sys::pfree(handle as *mut std::ffi::c_void);
+            status == pg_sys::BgwHandleStatus::BGWH_STARTED
+        } else {
+            true
+        }
     }
 }