Merge #10711: [tests] Introduce TestNode

789733891 [tests] Introduce TestNode (John Newbery)

Pull request description:

  Continues #10082

  TestNode is a class responsible for all state related to a bitcoind node
  under test. It stores local state, is responsible for tracking the
  bitcoind process and delegates unrecognised messages to the RPC
  connection.

  This commit changes start_nodes and stop_nodes to start and stop the
  bitcoind nodes in parallel, making test setup and teardown much faster.

  On my vm, this changeset reduces total test_runner runtime for the base set of tests
  (including building the cache) from 263s to 195s (a 25% speedup). Note that the time
  reported by test_runner does not include time spent building the cache:

  *with TestNode*:
  ```
  → date +"%T" ; ./test_runner.py -q ; date +"%T"
  12:48:04
  ..................................................................................................................................................................................................................................................................................................................................
  TEST                           | STATUS    | DURATION

  abandonconflict.py             | ✓ Passed  | 12 s
  bip68-112-113-p2p.py           | ✓ Passed  | 19 s
  blockchain.py                  | ✓ Passed  | 8 s
  bumpfee.py                     | ✓ Passed  | 13 s
  decodescript.py                | ✓ Passed  | 3 s
  disablewallet.py               | ✓ Passed  | 3 s
  disconnect_ban.py              | ✓ Passed  | 6 s
  fundrawtransaction.py          | ✓ Passed  | 37 s
  getchaintips.py                | ✓ Passed  | 4 s
  httpbasics.py                  | ✓ Passed  | 3 s
  import-rescan.py               | ✓ Passed  | 4 s
  importmulti.py                 | ✓ Passed  | 6 s
  importprunedfunds.py           | ✓ Passed  | 3 s
  invalidblockrequest.py         | ✓ Passed  | 4 s
  invalidtxrequest.py            | ✓ Passed  | 4 s
  keypool.py                     | ✓ Passed  | 7 s
  listsinceblock.py              | ✓ Passed  | 4 s
  listtransactions.py            | ✓ Passed  | 33 s
  mempool_limit.py               | ✓ Passed  | 4 s
  mempool_persist.py             | ✓ Passed  | 15 s
  mempool_reorg.py               | ✓ Passed  | 4 s
  mempool_resurrect_test.py      | ✓ Passed  | 3 s
  mempool_spendcoinbase.py       | ✓ Passed  | 3 s
  merkle_blocks.py               | ✓ Passed  | 3 s
  multi_rpc.py                   | ✓ Passed  | 4 s
  net.py                         | ✓ Passed  | 3 s
  nulldummy.py                   | ✓ Passed  | 3 s
  p2p-compactblocks.py           | ✓ Passed  | 28 s
  p2p-fullblocktest.py           | ✓ Passed  | 126 s
  p2p-leaktests.py               | ✓ Passed  | 8 s
  p2p-mempool.py                 | ✓ Passed  | 3 s
  p2p-segwit.py                  | ✓ Passed  | 59 s
  p2p-versionbits-warning.py     | ✓ Passed  | 8 s
  preciousblock.py               | ✓ Passed  | 3 s
  prioritise_transaction.py      | ✓ Passed  | 5 s
  proxy_test.py                  | ✓ Passed  | 3 s
  rawtransactions.py             | ✓ Passed  | 9 s
  receivedby.py                  | ✓ Passed  | 19 s
  reindex.py                     | ✓ Passed  | 12 s
  rest.py                        | ✓ Passed  | 9 s
  rpcnamedargs.py                | ✓ Passed  | 3 s
  segwit.py                      | ✓ Passed  | 7 s
  sendheaders.py                 | ✓ Passed  | 24 s
  signmessages.py                | ✓ Passed  | 3 s
  signrawtransactions.py         | ✓ Passed  | 3 s
  txn_clone.py                   | ✓ Passed  | 4 s
  txn_doublespend.py --mineblock | ✓ Passed  | 4 s
  uptime.py                      | ✓ Passed  | 3 s
  wallet-accounts.py             | ✓ Passed  | 3 s
  wallet-dump.py                 | ✓ Passed  | 7 s
  wallet-encryption.py           | ✓ Passed  | 8 s
  wallet-hd.py                   | ✓ Passed  | 15 s
  wallet.py                      | ✓ Passed  | 31 s
  walletbackup.py                | ✓ Passed  | 104 s
  zapwallettxes.py               | ✓ Passed  | 9 s
  zmq_test.py                    | ○ Skipped | 0 s

  ALL                            | ✓ Passed  | 735 s (accumulated)
  Runtime: 189 s

  12:51:19
  ```

  *master*:
  ```
  → date +"%T" ; ./test_runner.py -q ; date +"%T"
  12:40:13
  ..........................................................................................................................................................................................................................................................................................................................................................................................................................................
  TEST                           | STATUS    | DURATION

  abandonconflict.py             | ✓ Passed  | 15 s
  bip68-112-113-p2p.py           | ✓ Passed  | 19 s
  blockchain.py                  | ✓ Passed  | 8 s
  bumpfee.py                     | ✓ Passed  | 20 s
  decodescript.py                | ✓ Passed  | 3 s
  disablewallet.py               | ✓ Passed  | 3 s
  disconnect_ban.py              | ✓ Passed  | 8 s
  fundrawtransaction.py          | ✓ Passed  | 36 s
  getchaintips.py                | ✓ Passed  | 11 s
  httpbasics.py                  | ✓ Passed  | 7 s
  import-rescan.py               | ✓ Passed  | 16 s
  importmulti.py                 | ✓ Passed  | 10 s
  importprunedfunds.py           | ✓ Passed  | 5 s
  invalidblockrequest.py         | ✓ Passed  | 4 s
  invalidtxrequest.py            | ✓ Passed  | 3 s
  keypool.py                     | ✓ Passed  | 7 s
  listsinceblock.py              | ✓ Passed  | 11 s
  listtransactions.py            | ✓ Passed  | 37 s
  mempool_limit.py               | ✓ Passed  | 4 s
  mempool_persist.py             | ✓ Passed  | 23 s
  mempool_reorg.py               | ✓ Passed  | 7 s
  mempool_resurrect_test.py      | ✓ Passed  | 3 s
  mempool_spendcoinbase.py       | ✓ Passed  | 3 s
  merkle_blocks.py               | ✓ Passed  | 10 s
  multi_rpc.py                   | ✓ Passed  | 6 s
  net.py                         | ✓ Passed  | 6 s
  nulldummy.py                   | ✓ Passed  | 3 s
  p2p-compactblocks.py           | ✓ Passed  | 30 s
  p2p-fullblocktest.py           | ✓ Passed  | 126 s
  p2p-leaktests.py               | ✓ Passed  | 8 s
  p2p-mempool.py                 | ✓ Passed  | 3 s
  p2p-segwit.py                  | ✓ Passed  | 62 s
  p2p-versionbits-warning.py     | ✓ Passed  | 8 s
  preciousblock.py               | ✓ Passed  | 8 s
  prioritise_transaction.py      | ✓ Passed  | 7 s
  proxy_test.py                  | ✓ Passed  | 10 s
  rawtransactions.py             | ✓ Passed  | 15 s
  receivedby.py                  | ✓ Passed  | 28 s
  reindex.py                     | ✓ Passed  | 12 s
  rest.py                        | ✓ Passed  | 12 s
  rpcnamedargs.py                | ✓ Passed  | 3 s
  segwit.py                      | ✓ Passed  | 12 s
  sendheaders.py                 | ✓ Passed  | 26 s
  signmessages.py                | ✓ Passed  | 3 s
  signrawtransactions.py         | ✓ Passed  | 3 s
  txn_clone.py                   | ✓ Passed  | 10 s
  txn_doublespend.py --mineblock | ✓ Passed  | 10 s
  uptime.py                      | ✓ Passed  | 3 s
  wallet-accounts.py             | ✓ Passed  | 3 s
  wallet-dump.py                 | ✓ Passed  | 6 s
  wallet-encryption.py           | ✓ Passed  | 8 s
  wallet-hd.py                   | ✓ Passed  | 18 s
  wallet.py                      | ✓ Passed  | 69 s
  walletbackup.py                | ✓ Passed  | 130 s
  zapwallettxes.py               | ✓ Passed  | 15 s
  zmq_test.py                    | ○ Skipped | 0 s

  ALL                            | ✓ Passed  | 936 s (accumulated)
  Runtime: 242 s

  12:44:36
  ```

Tree-SHA512: 6dfc4c11fd0caf7de6954c93679cf22c3df0acc6f432e616d1151062a61f456faa8ae2fe670b427868af55bb564802df84c8fd76e90b4b338750dbc23f46ad88

1 files changed, 134 insertions, 0 deletions

diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
new file mode 100755
index 0000000000..66f89d43f4
--- /dev/null
+++ b/test/functional/test_framework/test_node.py
@@ -0,0 +1,134 @@
+#!/usr/bin/env python3
+# Copyright (c) 2017 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Class for bitcoind node under test"""
+
+import errno
+import http.client
+import logging
+import os
+import subprocess
+import time
+
+from .util import (
+    assert_equal,
+    get_rpc_proxy,
+    rpc_url,
+)
+from .authproxy import JSONRPCException
+
+class TestNode():
+    """A class for representing a bitcoind node under test.
+
+    This class contains:
+
+    - state about the node (whether it's running, etc)
+    - a Python subprocess.Popen object representing the running process
+    - an RPC connection to the node
+
+    To make things easier for the test writer, a bit of magic is happening under the covers.
+    Any unrecognised messages will be dispatched to the RPC connection."""
+
+    def __init__(self, i, dirname, extra_args, rpchost, timewait, binary, stderr, mocktime, coverage_dir):
+        self.index = i
+        self.datadir = os.path.join(dirname, "node" + str(i))
+        self.rpchost = rpchost
+        self.rpc_timeout = timewait
+        if binary is None:
+            self.binary = os.getenv("BITCOIND", "bitcoind")
+        else:
+            self.binary = binary
+        self.stderr = stderr
+        self.coverage_dir = coverage_dir
+        # Most callers will just need to add extra args to the standard list below. For those callers that need more flexibity, they can just set the args property directly.
+        self.extra_args = extra_args
+        self.args = [self.binary, "-datadir=" + self.datadir, "-server", "-keypool=1", "-discover=0", "-rest", "-logtimemicros", "-debug", "-debugexclude=libevent", "-debugexclude=leveldb", "-mocktime=" + str(mocktime), "-uacomment=testnode%d" % i]
+
+        self.running = False
+        self.process = None
+        self.rpc_connected = False
+        self.rpc = None
+        self.url = None
+        self.log = logging.getLogger('TestFramework.node%d' % i)
+
+    def __getattr__(self, *args, **kwargs):
+        """Dispatches any unrecognised messages to the RPC connection."""
+        assert self.rpc_connected and self.rpc is not None, "Error: no RPC connection"
+        return self.rpc.__getattr__(*args, **kwargs)
+
+    def start(self):
+        """Start the node."""
+        self.process = subprocess.Popen(self.args + self.extra_args, stderr=self.stderr)
+        self.running = True
+        self.log.debug("bitcoind started, waiting for RPC to come up")
+
+    def wait_for_rpc_connection(self):
+        """Sets up an RPC connection to the bitcoind process. Returns False if unable to connect."""
+
+        # Wait for up to 10 seconds for the RPC server to respond
+        for _ in range(40):
+            assert not self.process.poll(), "bitcoind exited with status %i during initialization" % self.process.returncode
+            try:
+                self.rpc = get_rpc_proxy(rpc_url(self.datadir, self.index, self.rpchost), self.index, coveragedir=self.coverage_dir)
+                self.rpc.getblockcount()
+                # If the call to getblockcount() succeeds then the RPC connection is up
+                self.rpc_connected = True
+                self.url = self.rpc.url
+                self.log.debug("RPC successfully started")
+                return
+            except IOError as e:
+                if e.errno != errno.ECONNREFUSED:  # Port not yet open?
+                    raise  # unknown IO error
+            except JSONRPCException as e:  # Initialization phase
+                if e.error['code'] != -28:  # RPC in warmup?
+                    raise  # unknown JSON RPC exception
+            except ValueError as e:  # cookie file not found and no rpcuser or rpcassword. bitcoind still starting
+                if "No RPC credentials" not in str(e):
+                    raise
+            time.sleep(0.25)
+        raise AssertionError("Unable to connect to bitcoind")
+
+    def get_wallet_rpc(self, wallet_name):
+        assert self.rpc_connected
+        assert self.rpc
+        wallet_path = "wallet/%s" % wallet_name
+        return self.rpc / wallet_path
+
+    def stop_node(self):
+        """Stop the node."""
+        if not self.running:
+            return
+        self.log.debug("Stopping node")
+        try:
+            self.stop()
+        except http.client.CannotSendRequest:
+            self.log.exception("Unable to stop node.")
+
+    def is_node_stopped(self):
+        """Checks whether the node has stopped.
+
+        Returns True if the node has stopped. False otherwise.
+        This method is responsible for freeing resources (self.process)."""
+        if not self.running:
+            return True
+        return_code = self.process.poll()
+        if return_code is not None:
+            # process has stopped. Assert that it didn't return an error code.
+            assert_equal(return_code, 0)
+            self.running = False
+            self.process = None
+            self.log.debug("Node stopped")
+            return True
+        return False
+
+    def node_encrypt_wallet(self, passphrase):
+        """"Encrypts the wallet.
+
+        This causes bitcoind to shutdown, so this method takes
+        care of cleaning up resources."""
+        self.encryptwallet(passphrase)
+        while not self.is_node_stopped():
+            time.sleep(0.1)
+        self.rpc = None
+        self.rpc_connected = False