Add compose exec_in_container method (#151)

* Add compose exec_in_container method

* Update testcontainers/compose.py

Co-authored-by: Till Hoffmann <[email protected]>

Author: kieranlea

testcontainers/compose.py

@@ -110,6 +110,31 @@ def get_logs(self):
         )
         return result.stdout, result.stderr
 
+    def exec_in_container(self, service_name, command):
+        """
+        Executes a command in the container of one of the services.
+
+        Parameters
+        ----------
+        service_name: str
+            Name of the docker compose service to run the command in
+        command: list[str]
+            The command to execute
+
+        Returns
+        -------
+        tuple[str, str, int]
+            stdout, stderr, return code
+        """
+        exec_cmd = self.docker_compose_command() + ['exec', '-T', service_name] + command
+        result = subprocess.run(
+            exec_cmd,
+            cwd=self.filepath,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+        )
+        return result.stdout.decode("utf-8"), result.stderr.decode("utf-8"), result.returncode
+
     def get_service_port(self, service_name, port):
         return self._get_service_info(service_name, port)[1]
 

tests/test_docker_compose.py

@@ -82,3 +82,11 @@ def test_can_pass_env_params_by_env_file():
         check_env_is_set_cmd = 'docker exec tests_mysql_1 printenv | grep TEST_ASSERT_KEY'.split()
         out = subprocess.run(check_env_is_set_cmd, stdout=subprocess.PIPE)
         assert out.stdout.decode('utf-8').splitlines()[0], 'test_is_passed'
+
+
+def test_can_exec_commands():
+    with DockerCompose("tests") as compose:
+        result = compose.exec_in_container('hub', ['echo', 'my_test'])
+        assert result[0] == 'my_test\n', "The echo should be successful"
+        assert result[1] == '', "stderr should be empty"
+        assert result[2] == 0, 'The exit code should be successful'