Make use of postgres --sync-safekeepers in tests and CLI.

Change control plane code to call `postgres --sync-safekeepers` before
compute node start when safekeepers are enabled. Now `pg create` will
create an empty data directory with the proper config file. Subsequent
`pg start` will run `sync-safekeepers` and will call basebackup with
the resulting LSN. Also change few tests to accommodate this new behavior.

test_runner/batch_others/test_twophase.py

@@ -59,9 +59,8 @@ def test_twophase(zenith_cli, pageserver: ZenithPageserver, postgres: PostgresFa
     # Create a branch with the transaction in prepared state
     zenith_cli.run(["branch", "test_twophase_prepared", "test_twophase"])
 
-    # Create compute node, but don't start.
-    # We want to observe pgdata before postgres starts
-    pg2 = postgres.create(
+    # Start compute on the new branch
+    pg2 = postgres.create_start(
         'test_twophase_prepared',
         config_lines=['max_prepared_transactions=5'],
     )
@@ -71,7 +70,6 @@ def test_twophase(zenith_cli, pageserver: ZenithPageserver, postgres: PostgresFa
     print(twophase_files2)
     assert twophase_files2.sort() == twophase_files.sort()
 
-    pg2 = pg2.start()
     conn2 = pg2.connect()
     cur2 = conn2.cursor()
 

test_runner/fixtures/zenith_fixtures.py

@@ -169,12 +169,23 @@ class ZenithCli:
 
         args = [self.bin_zenith] + arguments
         print('Running command "{}"'.format(' '.join(args)))
-        return subprocess.run(args,
-                              env=self.env,
-                              check=True,
-                              universal_newlines=True,
-                              stdout=subprocess.PIPE,
-                              stderr=subprocess.PIPE)
+
+        # Interceipt CalledProcessError and print more info
+        try:
+            res = subprocess.run(args,
+                                env=self.env,
+                                check=True,
+                                universal_newlines=True,
+                                stdout=subprocess.PIPE,
+                                stderr=subprocess.PIPE)
+        except subprocess.CalledProcessError as err:
+            print(f"Run failed: {err}")
+            print(f" stdout: {err.stdout}")
+            print(f" stderr: {err.stderr}")
+
+            raise err
+
+        return res
 
 
 @zenfixture
@@ -439,7 +450,6 @@ class Postgres(PgProtocol):
         branch: str,
         wal_acceptors: Optional[str] = None,
         config_lines: Optional[List[str]] = None,
-        config_only: bool = False,
     ) -> 'Postgres':
         """
         Create the pg data directory.
@@ -451,10 +461,7 @@ class Postgres(PgProtocol):
         if not config_lines:
             config_lines = []
 
-        if config_only:
-            self.zenith_cli.run(['pg', 'create', '--config-only', branch, f'--tenantid={self.tenant_id}'])
-        else:
-            self.zenith_cli.run(['pg', 'create', branch, f'--tenantid={self.tenant_id}'])
+        self.zenith_cli.run(['pg', 'create', branch, f'--tenantid={self.tenant_id}'])
         self.branch = branch
         path = pathlib.Path('pgdatadirs') / 'tenants' / self.tenant_id / self.branch
         self.pgdata_dir = os.path.join(self.repo_dir, path)
@@ -475,11 +482,13 @@ class Postgres(PgProtocol):
 
         assert self.branch is not None
 
-        print(f"Starting postgres on brach {self.branch}")
+        print(f"Starting postgres on branch {self.branch}")
 
-        self.zenith_cli.run(['pg', 'start', self.branch, f'--tenantid={self.tenant_id}'])
+        run_result = self.zenith_cli.run(['pg', 'start', self.branch, f'--tenantid={self.tenant_id}'])
         self.running = True
 
+        print(f"stdout: {run_result.stdout}")
+
         self.pg_bin.run(['pg_controldata', self.pg_data_dir_path()])
 
         return self
@@ -577,7 +586,6 @@ class Postgres(PgProtocol):
             branch=branch,
             wal_acceptors=wal_acceptors,
             config_lines=config_lines,
-            config_only=True,
         ).start()
 
         return self