[#240] Using of node.psql with other host and port (#242)

* [FIX] Tests include testgres by right way through import

When we do not have root __init__.py tests must to import testgres through

"import testgres"

not through

"from <relative_path> import testgres"

* [#240] Using of node.psql with other host and port

This patch adds the support of using other host and port in the following methods:

- PostgresNode.psql (explicit new args: host and port)
- PostgresNode.safe_psql (indirectly through **kwargs)

It allows to run psql utility from one PostgreSQL instance to work with another one.

If explicit host and port are not defined (are None), PostgresNode will use own ones.

This patch closes #240.

Author: dmitry-lipetsk

testgres/node.py

@@ -1372,6 +1372,8 @@ def psql(self,
              dbname=None,
              username=None,
              input=None,
+             host: typing.Optional[str] = None,
+             port: typing.Optional[int] = None,
              **variables):
         """
         Execute a query using psql.
@@ -1382,6 +1384,8 @@ def psql(self,
             dbname: database name to connect to.
             username: database user name.
             input: raw input to be passed.
+            host: an explicit host of server.
+            port: an explicit port of server.
             **variables: vars to be set before execution.
 
         Returns:
@@ -1393,13 +1397,19 @@ def psql(self,
             >>> psql(query='select 3', ON_ERROR_STOP=1)
         """
 
+        assert host is None or type(host) == str  # noqa: E721
+        assert port is None or type(port) == int  # noqa: E721
+        assert type(variables) == dict  # noqa: E721
+
         return self._psql(
             ignore_errors=True,
             query=query,
             filename=filename,
             dbname=dbname,
             username=username,
             input=input,
+            host=host,
+            port=port,
             **variables
         )
 
@@ -1411,7 +1421,11 @@ def _psql(
             dbname=None,
             username=None,
             input=None,
+            host: typing.Optional[str] = None,
+            port: typing.Optional[int] = None,
             **variables):
+        assert host is None or type(host) == str  # noqa: E721
+        assert port is None or type(port) == int  # noqa: E721
         assert type(variables) == dict  # noqa: E721
 
         #
@@ -1424,10 +1438,21 @@ def _psql(
         else:
             raise Exception("Input data must be None or bytes.")
 
+        if host is None:
+            host = self.host
+
+        if port is None:
+            port = self.port
+
+        assert host is not None
+        assert port is not None
+        assert type(host) == str  # noqa: E721
+        assert type(port) == int  # noqa: E721
+
         psql_params = [
             self._get_bin_path("psql"),
-            "-p", str(self.port),
-            "-h", self.host,
+            "-p", str(port),
+            "-h", host,
             "-U", username or self.os_ops.username,
             "-d", dbname or default_dbname(),
             "-X",  # no .psqlrc

tests/test_testgres_common.py

@@ -678,6 +678,89 @@ def test_psql(self, node_svc: PostgresNodeService):
                 r = node.safe_psql('select 1')  # raises!
                 logging.error("node.safe_psql returns [{}]".format(r))
 
+    def test_psql__another_port(self, node_svc: PostgresNodeService):
+        assert isinstance(node_svc, PostgresNodeService)
+        with __class__.helper__get_node(node_svc).init() as node1:
+            with __class__.helper__get_node(node_svc).init() as node2:
+                node1.start()
+                node2.start()
+                assert node1.port != node2.port
+                assert node1.host == node2.host
+
+                node1.stop()
+
+                logging.info("test table in node2 is creating ...")
+                node2.safe_psql(
+                    dbname="postgres",
+                    query="create table test (id integer);"
+                )
+
+                logging.info("try to find test table through node1.psql ...")
+                res = node1.psql(
+                    dbname="postgres",
+                    query="select count(*) from pg_class where relname='test'",
+                    host=node2.host,
+                    port=node2.port,
+                )
+                assert (__class__.helper__rm_carriage_returns(res) == (0, b'1\n', b''))
+
+    def test_psql__another_bad_host(self, node_svc: PostgresNodeService):
+        assert isinstance(node_svc, PostgresNodeService)
+        with __class__.helper__get_node(node_svc).init() as node:
+            logging.info("try to execute node1.psql ...")
+            res = node.psql(
+                dbname="postgres",
+                query="select count(*) from pg_class where relname='test'",
+                host="DUMMY_HOST_NAME",
+                port=node.port,
+            )
+
+            res2 = __class__.helper__rm_carriage_returns(res)
+
+            assert res2[0] != 0
+            assert b"DUMMY_HOST_NAME" in res[2]
+
+    def test_safe_psql__another_port(self, node_svc: PostgresNodeService):
+        assert isinstance(node_svc, PostgresNodeService)
+        with __class__.helper__get_node(node_svc).init() as node1:
+            with __class__.helper__get_node(node_svc).init() as node2:
+                node1.start()
+                node2.start()
+                assert node1.port != node2.port
+                assert node1.host == node2.host
+
+                node1.stop()
+
+                logging.info("test table in node2 is creating ...")
+                node2.safe_psql(
+                    dbname="postgres",
+                    query="create table test (id integer);"
+                )
+
+                logging.info("try to find test table through node1.psql ...")
+                res = node1.safe_psql(
+                    dbname="postgres",
+                    query="select count(*) from pg_class where relname='test'",
+                    host=node2.host,
+                    port=node2.port,
+                )
+                assert (__class__.helper__rm_carriage_returns(res) == b'1\n')
+
+    def test_safe_psql__another_bad_host(self, node_svc: PostgresNodeService):
+        assert isinstance(node_svc, PostgresNodeService)
+        with __class__.helper__get_node(node_svc).init() as node:
+            logging.info("try to execute node1.psql ...")
+
+            with pytest.raises(expected_exception=Exception) as x:
+                node.safe_psql(
+                    dbname="postgres",
+                    query="select count(*) from pg_class where relname='test'",
+                    host="DUMMY_HOST_NAME",
+                    port=node.port,
+                )
+
+            assert "DUMMY_HOST_NAME" in str(x.value)
+
     def test_safe_psql__expect_error(self, node_svc: PostgresNodeService):
         assert isinstance(node_svc, PostgresNodeService)
         with __class__.helper__get_node(node_svc).init().start() as node: