stats: add functional test for statsd reporting

Author: kwvg

test/functional/feature_stats.py

@@ -0,0 +1,141 @@
+#!/usr/bin/env python3
+# Copyright (c) 2025 The Dash Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+"""Test stats reporting"""
+
+import queue
+import socket
+import time
+import threading
+
+from test_framework.netutil import test_ipv6_local
+from test_framework.test_framework import BitcoinTestFramework
+from queue import Queue
+
+ONION_ADDR = "pg6mmjiyjmcrsslvykfwnntlaru7p5svn6y2ymmju6nubxndf4pscryd.onion"
+
+class StatsServer:
+    def __init__(self, host: str, port: int):
+        self.running = False
+        self.thread = None
+        self.queue: Queue[str] = Queue()
+
+        addr_info = socket.getaddrinfo(host, port, socket.AF_UNSPEC, socket.SOCK_DGRAM)
+        self.af = addr_info[0][0]
+        self.addr = (host, port)
+
+        self.s = socket.socket(self.af, socket.SOCK_DGRAM)
+        self.s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        self.s.bind(self.addr)
+        self.s.settimeout(0.1)
+
+    def run(self):
+        while self.running:
+            try:
+                data, _ = self.s.recvfrom(4096)
+                messages = data.decode('utf-8').strip().split('\n')
+                for msg in messages:
+                    if msg:
+                        self.queue.put(msg)
+            except socket.timeout:
+                continue
+            except Exception as e:
+                if self.running:
+                    raise AssertionError("Unexpected exception raised: " + type(e).__name__)
+
+    def start(self):
+        assert not self.running
+        self.running = True
+        self.thread = threading.Thread(target=self.run)
+        self.thread.daemon = True
+        self.thread.start()
+
+    def stop(self):
+        self.running = False
+        if self.thread:
+            self.thread.join(timeout=2)
+        self.s.close()
+
+    def assert_msg_received(self, expected_msg: str, timeout: int = 30):
+        deadline = time.time() + timeout
+        while time.time() < deadline:
+            try:
+                msg = self.queue.get(timeout=5)
+                if expected_msg in msg:
+                    return
+            except queue.Empty:
+                continue
+        raise AssertionError(f"Did not receive message containing '{expected_msg}' within {timeout} seconds")
+
+
+class StatsTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.num_nodes = 1
+
+    def run_test(self):
+        self.log.info("Test invalid command line options")
+        self.test_invalid_command_line_options()
+
+        self.log.info("Test command line behavior")
+        self.test_command_behavior()
+
+        self.log.info("Check that server can receive stats client messages")
+        self.have_ipv6 = test_ipv6_local()
+        self.test_conn('127.0.0.1')
+        if self.have_ipv6:
+            self.test_conn('::1')
+        else:
+            self.log.warning("Testing without local IPv6 support")
+
+    def test_invalid_command_line_options(self):
+        self.stop_node(0)
+        self.nodes[0].assert_start_raises_init_error(
+            expected_msg='Error: Cannot init Statsd client (Port must be between 1 and 65535, supplied 65536)',
+            extra_args=['-statshost=127.0.0.1', '-statsport=65536'],
+        )
+        self.nodes[0].assert_start_raises_init_error(
+            expected_msg='Error: Cannot init Statsd client (No text before the scheme delimiter, malformed URL)',
+            extra_args=['-statshost=://127.0.0.1'],
+        )
+        self.nodes[0].assert_start_raises_init_error(
+            expected_msg='Error: Cannot init Statsd client (Unsupported URL scheme, must begin with tcp:// or udp://)',
+            extra_args=['-statshost=http://127.0.0.1'],
+        )
+        self.nodes[0].assert_start_raises_init_error(
+            expected_msg='Error: Cannot init Statsd client (No host specified, malformed URL)',
+            extra_args=['-statshost=udp://'],
+        )
+        self.nodes[0].assert_start_raises_init_error(
+            expected_msg=f'Error: Cannot init Statsd client (Host {ONION_ADDR} on unsupported network)',
+            extra_args=[f'-statshost=tcp://{ONION_ADDR}'],
+        )
+
+    def test_command_behavior(self):
+        with self.nodes[0].assert_debug_log(expected_msgs=['Transmitting stats are disabled, will not init Statsd client']):
+            self.restart_node(0, extra_args=[])
+        # The port specified in the URL supercedes -statsport
+        with self.nodes[0].assert_debug_log(expected_msgs=[
+            'Supplied URL with port, ignoring -statsport',
+            'Initialized to transmit stats to 127.0.0.1:8126',
+            'Started instance sending messages to 127.0.0.1:8126 over UDP'
+        ]):
+            self.restart_node(0, extra_args=['-debug=net', '-statshost=udp://127.0.0.1:8126', '-statsport=8125'])
+        # Not specifying the port in the URL or -statsport will select the default port. Also, validate -statsduration behavior.
+        with self.nodes[0].assert_debug_log(expected_msgs=[
+            'Initialized to transmit stats to 127.0.0.1:8125',
+            'Send interval is zero, not starting RawSender queueing thread',
+            'Started instance sending messages to 127.0.0.1:8125 over UDP'
+        ]):
+            self.restart_node(0, extra_args=['-debug=net', '-statshost=udp://127.0.0.1', '-statsduration=0'])
+
+    def test_conn(self, host: str):
+        server = StatsServer(host, 8125)
+        server.start()
+        self.restart_node(0, extra_args=[f'-statshost=udp://{host}', '-statsbatchsize=0', '-statsduration=0'])
+        server.assert_msg_received("CheckBlock_us")
+        server.stop()
+
+if __name__ == '__main__':
+    StatsTest().main()

test/functional/test_runner.py

@@ -307,6 +307,7 @@
     'mining_basic.py',
     'rpc_named_arguments.py',
     'feature_startupnotify.py',
+    'feature_stats.py',
     'wallet_simulaterawtx.py --legacy-wallet',
     'wallet_simulaterawtx.py --descriptors',
     'wallet_listsinceblock.py --legacy-wallet',