Port numbers management is improved (#164)

testgres/node.py

@@ -83,13 +83,13 @@
 
 from .standby import First
 
+from . import utils
+
 from .utils import \
     PgVer, \
     eprint, \
     get_bin_path, \
     get_pg_version, \
-    reserve_port, \
-    release_port, \
     execute_utility, \
     options_string, \
     clean_on_error
@@ -128,6 +128,9 @@ def __repr__(self):
 
 
 class PostgresNode(object):
+    # a max number of node start attempts
+    _C_MAX_START_ATEMPTS = 5
+
     def __init__(self, name=None, base_dir=None, port=None, conn_params: ConnectionParams = ConnectionParams(), bin_dir=None, prefix=None):
         """
         PostgresNode constructor.
@@ -158,7 +161,7 @@ def __init__(self, name=None, base_dir=None, port=None, conn_params: ConnectionP
             self.os_ops = LocalOperations(conn_params)
 
         self.host = self.os_ops.host
-        self.port = port or reserve_port()
+        self.port = port or utils.reserve_port()
 
         self.ssh_key = self.os_ops.ssh_key
 
@@ -471,6 +474,28 @@ def _collect_special_files(self):
 
         return result
 
+    def _collect_log_files(self):
+        # dictionary of log files + size in bytes
+
+        files = [
+            self.pg_log_file
+        ]  # yapf: disable
+
+        result = {}
+
+        for f in files:
+            # skip missing files
+            if not self.os_ops.path_exists(f):
+                continue
+
+            file_size = self.os_ops.get_file_size(f)
+            assert type(file_size) == int  # noqa: E721
+            assert file_size >= 0
+
+            result[f] = file_size
+
+        return result
+
     def init(self, initdb_params=None, cached=True, **kwargs):
         """
         Perform initdb for this node.
@@ -722,6 +747,22 @@ def slow_start(self, replica=False, dbname='template1', username=None, max_attem
                                         OperationalError},
                               max_attempts=max_attempts)
 
+    def _detect_port_conflict(self, log_files0, log_files1):
+        assert type(log_files0) == dict  # noqa: E721
+        assert type(log_files1) == dict  # noqa: E721
+
+        for file in log_files1.keys():
+            read_pos = 0
+
+            if file in log_files0.keys():
+                read_pos = log_files0[file]  # the previous size
+
+            file_content = self.os_ops.read_binary(file, read_pos)
+            file_content_s = file_content.decode()
+            if 'Is another postmaster already running on port' in file_content_s:
+                return True
+        return False
+
     def start(self, params=[], wait=True):
         """
         Starts the PostgreSQL node using pg_ctl if node has not been started.
@@ -736,6 +777,9 @@ def start(self, params=[], wait=True):
         Returns:
             This instance of :class:`.PostgresNode`.
         """
+
+        assert __class__._C_MAX_START_ATEMPTS > 1
+
         if self.is_started:
             return self
 
@@ -745,27 +789,46 @@ def start(self, params=[], wait=True):
                    "-w" if wait else '-W',  # --wait or --no-wait
                    "start"] + params  # yapf: disable
 
-        startup_retries = 5
+        log_files0 = self._collect_log_files()
+        assert type(log_files0) == dict  # noqa: E721
+
+        nAttempt = 0
+        timeout = 1
         while True:
+            assert nAttempt >= 0
+            assert nAttempt < __class__._C_MAX_START_ATEMPTS
+            nAttempt += 1
             try:
                 exit_status, out, error = execute_utility(_params, self.utils_log_file, verbose=True)
                 if error and 'does not exist' in error:
                     raise Exception
             except Exception as e:
-                files = self._collect_special_files()
-                if any(len(file) > 1 and 'Is another postmaster already '
-                                         'running on port' in file[1].decode() for
-                       file in files):
-                    logging.warning("Detected an issue with connecting to port {0}. "
-                                    "Trying another port after a 5-second sleep...".format(self.port))
-                    self.port = reserve_port()
-                    options = {'port': str(self.port)}
-                    self.set_auto_conf(options)
-                    startup_retries -= 1
-                    time.sleep(5)
-                    continue
+                assert nAttempt > 0
+                assert nAttempt <= __class__._C_MAX_START_ATEMPTS
+                if self._should_free_port and nAttempt < __class__._C_MAX_START_ATEMPTS:
+                    log_files1 = self._collect_log_files()
+                    if self._detect_port_conflict(log_files0, log_files1):
+                        log_files0 = log_files1
+                        logging.warning(
+                            "Detected an issue with connecting to port {0}. "
+                            "Trying another port after a {1}-second sleep...".format(self.port, timeout)
+                        )
+                        time.sleep(timeout)
+                        timeout = min(2 * timeout, 5)
+                        cur_port = self.port
+                        new_port = utils.reserve_port()  # can raise
+                        try:
+                            options = {'port': str(new_port)}
+                            self.set_auto_conf(options)
+                        except:  # noqa: E722
+                            utils.release_port(new_port)
+                            raise
+                        self.port = new_port
+                        utils.release_port(cur_port)
+                        continue
 
                 msg = 'Cannot start node'
+                files = self._collect_special_files()
                 raise_from(StartNodeException(msg, files), e)
             break
         self._maybe_start_logger()
@@ -930,8 +993,10 @@ def free_port(self):
         """
 
         if self._should_free_port:
+            port = self.port
             self._should_free_port = False
-            release_port(self.port)
+            self.port = None
+            utils.release_port(port)
 
     def cleanup(self, max_attempts=3, full=False):
         """

testgres/operations/local_ops.py

@@ -308,12 +308,28 @@ def readlines(self, filename, num_lines=0, binary=False, encoding=None):
                         buffers * max(2, int(num_lines / max(cur_lines, 1)))
                     )  # Adjust buffer size
 
+    def read_binary(self, filename, start_pos):
+        assert type(filename) == str  # noqa: E721
+        assert type(start_pos) == int  # noqa: E721
+        assert start_pos >= 0
+
+        with open(filename, 'rb') as file:  # open in a binary mode
+            file.seek(start_pos, os.SEEK_SET)
+            r = file.read()
+            assert type(r) == bytes  # noqa: E721
+            return r
+
     def isfile(self, remote_file):
         return os.path.isfile(remote_file)
 
     def isdir(self, dirname):
         return os.path.isdir(dirname)
 
+    def get_file_size(self, filename):
+        assert filename is not None
+        assert type(filename) == str  # noqa: E721
+        return os.path.getsize(filename)
+
     def remove_file(self, filename):
         return os.remove(filename)
 

testgres/operations/os_ops.py

@@ -98,9 +98,18 @@ def read(self, filename, encoding, binary):
     def readlines(self, filename):
         raise NotImplementedError()
 
+    def read_binary(self, filename, start_pos):
+        assert type(filename) == str  # noqa: E721
+        assert type(start_pos) == int  # noqa: E721
+        assert start_pos >= 0
+        raise NotImplementedError()
+
     def isfile(self, remote_file):
         raise NotImplementedError()
 
+    def get_file_size(self, filename):
+        raise NotImplementedError()
+
     # Processes control
     def kill(self, pid, signal):
         # Kill the process

testgres/operations/remote_ops.py

@@ -340,6 +340,16 @@ def readlines(self, filename, num_lines=0, binary=False, encoding=None):
 
         return lines
 
+    def read_binary(self, filename, start_pos):
+        assert type(filename) == str  # noqa: E721
+        assert type(start_pos) == int  # noqa: E721
+        assert start_pos >= 0
+
+        cmd = "tail -c +{} {}".format(start_pos + 1, __class__._escape_path(filename))
+        r = self.exec_command(cmd)
+        assert type(r) == bytes  # noqa: E721
+        return r
+
     def isfile(self, remote_file):
         stdout = self.exec_command("test -f {}; echo $?".format(remote_file))
         result = int(stdout.strip())
@@ -350,6 +360,70 @@ def isdir(self, dirname):
         response = self.exec_command(cmd)
         return response.strip() == b"True"
 
+    def get_file_size(self, filename):
+        C_ERR_SRC = "RemoteOpertions::get_file_size"
+
+        assert filename is not None
+        assert type(filename) == str  # noqa: E721
+        cmd = "du -b " + __class__._escape_path(filename)
+
+        s = self.exec_command(cmd, encoding=get_default_encoding())
+        assert type(s) == str  # noqa: E721
+
+        if len(s) == 0:
+            raise Exception(
+                "[BUG CHECK] Can't get size of file [{2}]. Remote operation returned an empty string. Check point [{0}][{1}].".format(
+                    C_ERR_SRC,
+                    "#001",
+                    filename
+                )
+            )
+
+        i = 0
+
+        while i < len(s) and s[i].isdigit():
+            assert s[i] >= '0'
+            assert s[i] <= '9'
+            i += 1
+
+        if i == 0:
+            raise Exception(
+                "[BUG CHECK] Can't get size of file [{2}]. Remote operation returned a bad formatted string. Check point [{0}][{1}].".format(
+                    C_ERR_SRC,
+                    "#002",
+                    filename
+                )
+            )
+
+        if i == len(s):
+            raise Exception(
+                "[BUG CHECK] Can't get size of file [{2}]. Remote operation returned a bad formatted string. Check point [{0}][{1}].".format(
+                    C_ERR_SRC,
+                    "#003",
+                    filename
+                )
+            )
+
+        if not s[i].isspace():
+            raise Exception(
+                "[BUG CHECK] Can't get size of file [{2}]. Remote operation returned a bad formatted string. Check point [{0}][{1}].".format(
+                    C_ERR_SRC,
+                    "#004",
+                    filename
+                )
+            )
+
+        r = 0
+
+        for i2 in range(0, i):
+            ch = s[i2]
+            assert ch >= '0'
+            assert ch <= '9'
+            # Here is needed to check overflow or that it is a human-valid result?
+            r = (r * 10) + ord(ch) - ord('0')
+
+        return r
+
     def remove_file(self, filename):
         cmd = "rm {}".format(filename)
         return self.exec_command(cmd)
@@ -386,6 +460,15 @@ def db_connect(self, dbname, user, password=None, host="localhost", port=5432):
         )
         return conn
 
+    def _escape_path(path):
+        assert type(path) == str  # noqa: E721
+        assert path != ""  # Ok?
+
+        r = "'"
+        r += path
+        r += "'"
+        return r
+
 
 def normalize_error(error):
     if isinstance(error, bytes):

testgres/utils.py

@@ -34,7 +34,7 @@ def __init__(self, version: str) -> None:
             super().__init__(version)
 
 
-def reserve_port():
+def internal__reserve_port():
     """
     Generate a new port and add it to 'bound_ports'.
     """
@@ -45,14 +45,18 @@ def reserve_port():
     return port
 
 
-def release_port(port):
+def internal__release_port(port):
     """
     Free port provided by reserve_port().
     """
 
     bound_ports.discard(port)
 
 
+reserve_port = internal__reserve_port
+release_port = internal__release_port
+
+
 def execute_utility(args, logfile=None, verbose=False):
     """
     Execute utility (pg_ctl, pg_dump etc).