Add failpoint support to safekeeper.

Just a copy paste from pageserver.

test_runner/fixtures/neon_fixtures.py

@@ -890,8 +890,8 @@ class NeonEnv:
         """Get list of safekeeper endpoints suitable for safekeepers GUC"""
         return ",".join(f"localhost:{wa.port.pg}" for wa in self.safekeepers)
 
-    def get_pageserver_version(self) -> str:
-        bin_pageserver = str(self.neon_binpath / "pageserver")
+    def get_binary_version(self, binary_name: str) -> str:
+        bin_pageserver = str(self.neon_binpath / binary_name)
         res = subprocess.run(
             [bin_pageserver, "--version"],
             check=True,
@@ -1656,7 +1656,7 @@ class NeonPageserver(PgProtocol):
         self.running = False
         self.service_port = port
         self.config_override = config_override
-        self.version = env.get_pageserver_version()
+        self.version = env.get_binary_version("pageserver")
 
         # After a test finishes, we will scrape the log to see if there are any
         # unexpected error messages. If your test expects an error, add it to
@@ -2924,7 +2924,8 @@ class Safekeeper:
                 return res
 
     def http_client(self, auth_token: Optional[str] = None) -> SafekeeperHttpClient:
-        return SafekeeperHttpClient(port=self.port.http, auth_token=auth_token)
+        is_testing_enabled = '"testing"' in self.env.get_binary_version("safekeeper")
+        return SafekeeperHttpClient(port=self.port.http, auth_token=auth_token, is_testing_enabled=is_testing_enabled)
 
     def data_dir(self) -> str:
         return os.path.join(self.env.repo_dir, "safekeepers", f"sk{self.id}")
@@ -2975,10 +2976,11 @@ class SafekeeperMetrics:
 class SafekeeperHttpClient(requests.Session):
     HTTPError = requests.HTTPError
 
-    def __init__(self, port: int, auth_token: Optional[str] = None):
+    def __init__(self, port: int, auth_token: Optional[str] = None, is_testing_enabled = False):
         super().__init__()
         self.port = port
         self.auth_token = auth_token
+        self.is_testing_enabled = is_testing_enabled
 
         if auth_token is not None:
             self.headers["Authorization"] = f"Bearer {auth_token}"
@@ -2986,6 +2988,30 @@ class SafekeeperHttpClient(requests.Session):
     def check_status(self):
         self.get(f"http://localhost:{self.port}/v1/status").raise_for_status()
 
+    def is_testing_enabled_or_skip(self):
+        if not self.is_testing_enabled:
+            pytest.skip("safekeeper was built without 'testing' feature")
+
+    def configure_failpoints(self, config_strings: Tuple[str, str] | List[Tuple[str, str]]):
+        self.is_testing_enabled_or_skip()
+
+        if isinstance(config_strings, tuple):
+            pairs = [config_strings]
+        else:
+            pairs = config_strings
+
+        log.info(f"Requesting config failpoints: {repr(pairs)}")
+
+        res = self.put(
+            f"http://localhost:{self.port}/v1/failpoints",
+            json=[{"name": name, "actions": actions} for name, actions in pairs],
+        )
+        log.info(f"Got failpoints request response code {res.status_code}")
+        res.raise_for_status()
+        res_json = res.json()
+        assert res_json is None
+        return res_json
+
     def debug_dump(self, params: Optional[Dict[str, str]] = None) -> Dict[str, Any]:
         params = params or {}
         res = self.get(f"http://localhost:{self.port}/v1/debug_dump", params=params)