[Internal]Add executable path to environment variable to avoid start …

…pfs failed in some environment (#2660)

# Description

Please add an informative description that covers that changes made by
the pull request and link all relevant issues.

# All Promptflow Contribution checklist:
- [ ] **The pull request does not introduce [breaking changes].**
- [ ] **CHANGELOG is updated for new features, bug fixes or other
significant changes.**
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## General Guidelines and Best Practices
- [ ] Title of the pull request is clear and informative.
- [ ] There are a small number of commits, each of which have an
informative message. This means that previously merged commits do not
appear in the history of the PR. For more information on cleaning up the
commits in your PR, [see this
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### Testing Guidelines
- [ ] Pull request includes test coverage for the included changes.

Co-authored-by: Ying Chen <[email protected]>

src/promptflow-devkit/promptflow/_cli/_pf/_service.py

@@ -202,6 +202,13 @@ def validate_port(port, force_start):
             sys.stdout = old_stdout
             sys.stderr = old_stderr
     else:
+        # Add executable script dir to PATH to make sure the subprocess can find the executable, especially in notebook
+        # environment which won't add it to system path automatically.
+        python_dir = os.path.dirname(sys.executable)
+        executable_dir = os.path.join(python_dir, "Scripts") if platform.system() == "Windows" else python_dir
+        if executable_dir not in os.environ["PATH"].split(os.pathsep):
+            os.environ["PATH"] = executable_dir + os.pathsep + os.environ["PATH"]
+
         # Start a pfs process using detach mode. It will start a new process and create a new app. So we use environment
         # variable to pass the debug mode, since it will inherit parent process environment variable.
         if platform.system() == "Windows":

src/promptflow/tests/sdk_pfs_test/e2etests/test_cli.py

@@ -2,6 +2,8 @@
 # Copyright (c) Microsoft Corporation. All rights reserved.
 # ---------------------------------------------------------
 
+import os
+import platform
 import subprocess
 import sys
 
@@ -56,6 +58,9 @@ def test_start_service(self):
             self._test_start_service(force=True)
             # previous pfs is killed
             assert start_pfs.poll() is not None
+            python_dir = os.path.dirname(sys.executable)
+            executable_dir = os.path.join(python_dir, "Scripts") if platform.system() == "Windows" else python_dir
+            assert executable_dir in os.environ["PATH"].split(os.pathsep)
         finally:
             port = get_port_from_config()
             kill_exist_service(port=port)