[sqlserver] Fix odbc.ini config handling for Linux (SDBM-1171) (#18586)

* func for get embed dir

* [sqlserver] Fix ODBC config handling for Linux

* changelog

* linter

* test only for Linux

* linter

* import error

* non-atomic getsize

* refactoring file test

* linter

* fix os

* fix tests

* fix test

* test case for odbc.inst creation

* linter

* linter

* fix test_get_unixodbc_sysconfig

* test_linux_connection

* linter

* unused imports

* declare test as non windows test

* is_non_empty_file always return boolean

Author: nenadnoveljic

sqlserver/changelog.d/18586.fixed

@@ -0,0 +1 @@
+[sqlserver] Fix ODBC config handling for Linux

sqlserver/datadog_checks/sqlserver/utils.py

@@ -3,6 +3,7 @@
 # Licensed under a 3-clause BSD style license (see LICENSE)
 import os
 import re
+import shutil
 import sys
 from typing import Dict
 
@@ -11,6 +12,7 @@
 
 CURRENT_DIR = os.path.dirname(os.path.abspath(__file__))
 DRIVER_CONFIG_DIR = os.path.join(CURRENT_DIR, 'data', 'driver_config')
+ODBC_INST_INI = 'odbcinst.ini'
 
 
 # Database is used to store both the name and physical_database_name
@@ -32,6 +34,22 @@ def __str__(self):
         return "name:{}, physical_db_name:{}".format(self.name, self.physical_db_name)
 
 
+def get_unixodbc_sysconfig(python_executable):
+    return os.path.join(os.path.dirname(os.path.dirname(python_executable)), "etc")
+
+
+def is_non_empty_file(path):
+    if not os.path.exists(path):
+        return False
+    try:
+        if os.path.getsize(path) > 0:
+            return True
+    # exists and getsize aren't atomic
+    except FileNotFoundError:
+        return False
+    return False
+
+
 def set_default_driver_conf():
     if Platform.is_containerized():
         # Use default `./driver_config/odbcinst.ini` when Agent is running in docker.
@@ -54,13 +72,16 @@ def set_default_driver_conf():
         # linux_unixodbc_sysconfig is set to the agent embedded /etc directory
         # this is a hacky way to get the path to the etc directory
         # by getting the path to the python executable and get the directory above /bin/python
-        linux_unixodbc_sysconfig = os.path.dirname(os.path.dirname(sys.executable))
-        if os.path.exists(os.path.join(linux_unixodbc_sysconfig, 'odbcinst.ini')) or os.path.exists(
-            os.path.join(linux_unixodbc_sysconfig, 'odbc.ini')
-        ):
-            # If there are already drivers or dataSources installed, don't override the ODBCSYSINI
-            # This means user has copied odbcinst.ini and odbc.ini to the unixODBC sysconfig location
-            return
+        linux_unixodbc_sysconfig = get_unixodbc_sysconfig(sys.executable)
+        odbc_ini = os.path.join(linux_unixodbc_sysconfig, 'odbc.ini')
+        if is_non_empty_file(odbc_ini):
+            os.environ.setdefault('ODBCSYSINI', linux_unixodbc_sysconfig)
+            odbc_inst_ini_sysconfig = os.path.join(linux_unixodbc_sysconfig, ODBC_INST_INI)
+            if not is_non_empty_file(odbc_inst_ini_sysconfig):
+                shutil.copy(os.path.join(DRIVER_CONFIG_DIR, ODBC_INST_INI), odbc_inst_ini_sysconfig)
+                # If there are already drivers or dataSources installed, don't override the ODBCSYSINI
+                # This means user has copied odbcinst.ini and odbc.ini to the unixODBC sysconfig location
+                return
 
         # Use default `./driver_config/odbcinst.ini` to let the integration use agent embedded odbc driver.
         os.environ.setdefault('ODBCSYSINI', DRIVER_CONFIG_DIR)

sqlserver/tests/test_unit.py

@@ -20,12 +20,14 @@
 from datadog_checks.sqlserver.utils import (
     Database,
     extract_sql_comments_and_procedure_name,
+    get_unixodbc_sysconfig,
+    is_non_empty_file,
     parse_sqlserver_major_version,
     set_default_driver_conf,
 )
 
 from .common import CHECK_NAME, DOCKER_SERVER, assert_metrics
-from .utils import deep_compare, windows_ci
+from .utils import deep_compare, not_windows_ci, windows_ci
 
 try:
     import pyodbc
@@ -435,6 +437,12 @@ def test_set_default_driver_conf():
         set_default_driver_conf()
         assert os.environ['ODBCSYSINI'].endswith(os.path.join('data', 'driver_config'))
 
+    with mock.patch("datadog_checks.base.utils.platform.Platform.is_linux", return_value=True):
+        with EnvVars({}, ignore=['ODBCSYSINI']):
+            set_default_driver_conf()
+            assert 'ODBCSYSINI' in os.environ, "ODBCSYSINI should be set"
+            assert os.environ['ODBCSYSINI'].endswith(os.path.join('data', 'driver_config'))
+
     # `set_default_driver_conf` have no effect on the cases below
     with EnvVars({'ODBCSYSINI': 'ABC', 'DOCKER_DD_AGENT': 'true'}):
         set_default_driver_conf()
@@ -446,23 +454,27 @@ def test_set_default_driver_conf():
             assert 'ODBCSYSINI' in os.environ
             assert os.environ['ODBCSYSINI'].endswith(os.path.join('tests', 'odbc'))
 
-        with EnvVars({}, ignore=['ODBCSYSINI']):
-            with mock.patch("os.path.exists", return_value=True):
-                # odbcinst.ini or odbc.ini exists in agent embedded directory
-                set_default_driver_conf()
-                assert 'ODBCSYSINI' not in os.environ
-
-        with EnvVars({}, ignore=['ODBCSYSINI']):
-            set_default_driver_conf()
-            assert 'ODBCSYSINI' in os.environ  # ODBCSYSINI is set by the integration
-            if pyodbc is not None:
-                assert pyodbc.drivers() is not None
-
         with EnvVars({'ODBCSYSINI': 'ABC'}):
             set_default_driver_conf()
             assert os.environ['ODBCSYSINI'] == 'ABC'
 
 
+@not_windows_ci
+def test_set_default_driver_conf_linux():
+    odbc_config_dir = os.path.expanduser('~')
+    with mock.patch("datadog_checks.sqlserver.utils.get_unixodbc_sysconfig", return_value=odbc_config_dir):
+        with EnvVars({}, ignore=['ODBCSYSINI']):
+            odbc_inst = os.path.join(odbc_config_dir, "odbcinst.ini")
+            odbc_ini = os.path.join(odbc_config_dir, "odbc.ini")
+            for file in [odbc_inst, odbc_ini]:
+                if os.path.exists(file):
+                    os.remove(file)
+            with open(odbc_ini, "x") as file:
+                file.write("dummy-content")
+            set_default_driver_conf()
+            assert is_non_empty_file(odbc_inst), "odbc_inst should have been created when a non empty odbc.ini exists"
+
+
 @windows_ci
 def test_check_local(aggregator, dd_run_check, init_config, instance_docker):
     sqlserver_check = SQLServer(CHECK_NAME, init_config, [instance_docker])
@@ -866,3 +878,16 @@ def test_exception_handling_by_do_for_dbs(instance_docker):
         'datadog_checks.sqlserver.utils.is_azure_sql_database', return_value={}
     ):
         schemas._fetch_for_databases()
+
+
+def test_get_unixodbc_sysconfig():
+    etc_dir = os.path.sep
+    for dir in ["opt", "datadog-agent", "embedded", "bin", "python"]:
+        etc_dir = os.path.join(etc_dir, dir)
+    assert get_unixodbc_sysconfig(etc_dir).split(os.path.sep) == [
+        "",
+        "opt",
+        "datadog-agent",
+        "embedded",
+        "etc",
+    ], "incorrect unix odbc config dir"