Refactoring language_container_deployer

exasol_transformers_extension/deployment/language_container_deployer.py

@@ -60,6 +60,19 @@ class LanguageActivationLevel(Enum):
     System = 'SYSTEM'
 
 
+def get_language_settings(pyexasol_conn: pyexasol.ExaConnection, alter_type: LanguageActivationLevel) -> str:
+    """
+    Reads the current language settings at the specified level.
+
+    pyexasol_conn    - Opened database connection.
+    alter_type       - Activation level - SYSTEM or SESSION.
+    """
+    result = pyexasol_conn.execute(
+        f"""SELECT "{alter_type.value}_VALUE" FROM SYS.EXA_PARAMETERS WHERE 
+        PARAMETER_NAME='SCRIPT_LANGUAGES'""").fetchall()
+    return result[0][0]
+
+
 class LanguageContainerDeployer:
 
     def __init__(self,
@@ -189,21 +202,10 @@ def generate_activation_command(self, bucket_file_path: str,
             f"ALTER {alter_type.value} SET SCRIPT_LANGUAGES='{new_settings}';"
         return alter_command
 
-    def get_language_settings(self, alter_type: LanguageActivationLevel) -> str:
-        """
-        Reads the current language settings at the specified level.
-
-        alter_type       - Activation level - SYSTEM or SESSION.
-        """
-        result = self._pyexasol_conn.execute(
-            f"""SELECT "{alter_type.value}_VALUE" FROM SYS.EXA_PARAMETERS WHERE 
-            PARAMETER_NAME='SCRIPT_LANGUAGES'""").fetchall()
-        return result[0][0]
-
     def _update_previous_language_settings(self, alter_type: LanguageActivationLevel,
                                            allow_override: bool,
                                            path_in_udf: PurePosixPath) -> str:
-        prev_lang_settings = self.get_language_settings(alter_type)
+        prev_lang_settings = get_language_settings(self._pyexasol_conn, alter_type)
         prev_lang_aliases = prev_lang_settings.split(" ")
         self._check_if_requested_language_alias_already_exists(
             allow_override, prev_lang_aliases)

exasol_transformers_extension/deployment/language_container_deployer_cli.py

@@ -1,4 +1,9 @@
+#########################################################
+# To be migrated to the script-languages-container-tool #
+#########################################################
+from typing import Optional, Any
 import os
+import re
 import click
 from enum import Enum
 from pathlib import Path
@@ -7,32 +12,68 @@
 
 
 class CustomizableParameters(Enum):
+    """
+    Parameters of the cli that can be programmatically customised by a developer
+    of a specialised version of the cli.
+    The names in the enum list should match the parameter names in language_container_deployer_main.
+    """
     container_url = 1
     container_name = 2
 
 
 class _ParameterFormatters:
+    """
+    Class facilitating customization of the cli.
+
+    The idea is that some of the cli parameters can be programmatically customized based
+    on values of other parameters and externally supplied formatters. For example a specialized
+    version of the cli may want to provide its own url. Furthermore, this url will depend on
+    the user supplied parameter called "version". The solution is to set a formatter for the
+    url, for instance "http://my_stuff/{version}/my_data". If the user specifies non-empty version
+    parameter the url will be fully formed.
+
+    A formatter may include more than one parameter. In the previous example the url could,
+    for instance, also include a username: "http://my_stuff/{version}/{user}/my_data".
+
+    Note that customized parameters can only be updated in a callback function. There is no
+    way to inject them directly into the cli. Also, the current implementation doesn't perform
+    the update if the value of the parameter dressed with the callback is None.
+
+    IMPORTANT! Please make sure that the formatters are set up before the call to the cli function,
+    e.g. language_container_deployer_main, is executed.
+    """
     def __init__(self):
         self._formatters = {}
 
-    def __call__(self, ctx, param, value):
+    def __call__(self, ctx: click.Context, param: click.Parameter, value: Optional[Any]) -> Optional[Any]:
 
         def update_parameter(parameter_name: str, formatter: str) -> None:
             param_formatter = ctx.params.get(parameter_name, formatter)
             if param_formatter:
+                # Enclose in double curly brackets all other parameters in the formatting string,
+                # to avoid the missing parameters' error.
+                pattern = r'\{(?!' + param.name + r'\})\w+\}'
+                param_formatter = re.sub(pattern, lambda m: f'{{{m.group(0)}}}', param_formatter)
                 kwargs = {param.name: value}
                 ctx.params[parameter_name] = param_formatter.format(**kwargs)
 
-        if value:
+        if value is not None:
             for prm_name, prm_formatter in self._formatters.items():
                 update_parameter(prm_name, prm_formatter)
 
         return value
 
     def set_formatter(self, custom_parameter: CustomizableParameters, formatter: str) -> None:
+        """ Sets a formatter for a customizable parameter. """
         self._formatters[custom_parameter.name] = formatter
 
+    def clear_formatters(self):
+        """ Deletes all formatters, mainly for testing purposes. """
+        self._formatters.clear()
 
+
+# Global cli customization object.
+# Specialized versions of this cli should use this object to set custom parameter formatters.
 slc_parameter_formatters = _ParameterFormatters()
 
 

tests/unit_tests/deployment/test_language_container_deployer.py

@@ -2,7 +2,7 @@
 # To be migrated to the script-languages-container-tool #
 #########################################################
 from pathlib import Path, PurePosixPath
-from unittest.mock import create_autospec, MagicMock
+from unittest.mock import create_autospec, MagicMock, patch
 import pytest
 from pyexasol import ExaConnection
 from exasol_bucketfs_utils_python.bucketfs_location import BucketFSLocation
@@ -50,7 +50,6 @@ def container_deployer(mock_pyexasol_conn, mock_bfs_location, language_alias) ->
 
     deployer.upload_container = MagicMock()
     deployer.activate_container = MagicMock()
-    deployer.get_language_settings = MagicMock()
     return deployer
 
 
@@ -69,16 +68,17 @@ def test_slc_deployer_upload(container_deployer, container_file_name, container_
 
 
 def test_slc_deployer_activate(container_deployer, container_file_name, container_file_path):
-    container_deployer.run(bucket_file_path=container_file_path, alter_system=True, allow_override=True)
+    container_deployer.run(bucket_file_path=container_file_name, alter_system=True, allow_override=True)
     container_deployer.upload_container.assert_not_called()
     container_deployer.activate_container.assert_called_once_with(container_file_name, LanguageActivationLevel.System,
                                                                   True)
 
 
-def test_slc_deployer_generate_activation_command(container_deployer, language_alias, container_file_name,
-                                                  container_bfs_path):
+@patch('exasol_transformers_extension.deployment.language_container_deployer.get_language_settings')
+def test_slc_deployer_generate_activation_command(mock_lang_settings, container_deployer, language_alias,
+                                                  container_file_name, container_bfs_path):
 
-    container_deployer.get_language_settings.return_value = 'R=builtin_r JAVA=builtin_java PYTHON3=builtin_python3'
+    mock_lang_settings.return_value = 'R=builtin_r JAVA=builtin_java PYTHON3=builtin_python3'
 
     alter_type = LanguageActivationLevel.Session
     expected_command = f"ALTER {alter_type.value.upper()} SET SCRIPT_LANGUAGES='" \
@@ -90,11 +90,12 @@ def test_slc_deployer_generate_activation_command(container_deployer, language_a
     assert command == expected_command
 
 
-def test_slc_deployer_generate_activation_command_override(container_deployer, language_alias, container_file_name,
-                                                           container_bfs_path):
+@patch('exasol_transformers_extension.deployment.language_container_deployer.get_language_settings')
+def test_slc_deployer_generate_activation_command_override(mock_lang_settings, container_deployer, language_alias,
+                                                           container_file_name, container_bfs_path):
 
     current_bfs_path = 'bfsdefault/default/container_abc'
-    container_deployer.get_language_settings.return_value = \
+    mock_lang_settings.return_value = \
         'R=builtin_r JAVA=builtin_java PYTHON3=builtin_python3 ' \
         f'{language_alias}=localzmq+protobuf:///{current_bfs_path}?' \
         f'lang=python#/buckets/{current_bfs_path}/exaudf/exaudfclient_py3'
@@ -109,10 +110,12 @@ def test_slc_deployer_generate_activation_command_override(container_deployer, l
     assert command == expected_command
 
 
-def test_slc_deployer_generate_activation_command_failure(container_deployer, language_alias, container_file_name):
+@patch('exasol_transformers_extension.deployment.language_container_deployer.get_language_settings')
+def test_slc_deployer_generate_activation_command_failure(mock_lang_settings, container_deployer, language_alias,
+                                                          container_file_name):
 
     current_bfs_path = 'bfsdefault/default/container_abc'
-    container_deployer.get_language_settings.return_value = \
+    mock_lang_settings.return_value = \
         'R=builtin_r JAVA=builtin_java PYTHON3=builtin_python3 ' \
         f'{language_alias}=localzmq+protobuf:///{current_bfs_path}?' \
         f'lang=python#/buckets/{current_bfs_path}/exaudf/exaudfclient_py3'

tests/unit_tests/deployment/test_language_container_deployer_cli.py

@@ -0,0 +1,29 @@
+import click
+from exasol_transformers_extension.deployment.language_container_deployer_cli import (
+    _ParameterFormatters, CustomizableParameters)
+
+
+def test_parameter_formatters_1param():
+    cmd = click.Command('a_command')
+    ctx = click.Context(cmd)
+    opt = click.Option(['--version'])
+    formatters = _ParameterFormatters()
+    formatters.set_formatter(CustomizableParameters.container_url, 'http://my_server/{version}/my_stuff')
+    formatters.set_formatter(CustomizableParameters.container_name, 'downloaded')
+    formatters(ctx, opt, '1.3.2')
+    assert ctx.params[CustomizableParameters.container_url.name] == 'http://my_server/1.3.2/my_stuff'
+    assert ctx.params[CustomizableParameters.container_name.name] == 'downloaded'
+
+
+def test_parameter_formatters_2params():
+    cmd = click.Command('a_command')
+    ctx = click.Context(cmd)
+    opt1 = click.Option(['--version'])
+    opt2 = click.Option(['--user'])
+    formatters = _ParameterFormatters()
+    formatters.set_formatter(CustomizableParameters.container_url, 'http://my_server/{version}/{user}/my_stuff')
+    formatters.set_formatter(CustomizableParameters.container_name, 'downloaded-{version}')
+    formatters(ctx, opt1, '1.3.2')
+    formatters(ctx, opt2, 'cezar')
+    assert ctx.params[CustomizableParameters.container_url.name] == 'http://my_server/1.3.2/cezar/my_stuff'
+    assert ctx.params[CustomizableParameters.container_name.name] == 'downloaded-1.3.2'