From e1c5aeed06c45f67391d15fa0855be05e6dd01da Mon Sep 17 00:00:00 2001
From: Shaked Klein Orbach <klein.shaked@gmail.com>
Date: Thu, 1 Oct 2020 15:44:35 +0300
Subject: [PATCH] add support for TRAINS_NO_DEFAULT_SERVER issue #209

---
 trains/backend_api/session/defs.py    | 1 +
 trains/backend_api/session/session.py | 5 ++++-
 trains/version.py                     | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/trains/backend_api/session/defs.py b/trains/backend_api/session/defs.py
index a3958521..920e7a0f 100644
--- a/trains/backend_api/session/defs.py
+++ b/trains/backend_api/session/defs.py
@@ -10,3 +10,4 @@ ENV_SECRET_KEY = EnvEntry("TRAINS_API_SECRET_KEY", "ALG_API_SECRET_KEY")
 ENV_VERBOSE = EnvEntry("TRAINS_API_VERBOSE", "ALG_API_VERBOSE", type=bool, default=False)
 ENV_HOST_VERIFY_CERT = EnvEntry("TRAINS_API_HOST_VERIFY_CERT", "ALG_API_HOST_VERIFY_CERT", type=bool, default=True)
 ENV_OFFLINE_MODE = EnvEntry("TRAINS_OFFLINE_MODE", "ALG_OFFLINE_MODE", type=bool, converter=safe_text_to_bool)
+ENV_TRAINS_NO_DEFAULT_SERVER = EnvEntry("TRAINS_NO_DEFAULT_SERVER", "ALG_NO_DEFAULT_SERVER", type=bool, default=False)
\ No newline at end of file
diff --git a/trains/backend_api/session/session.py b/trains/backend_api/session/session.py
index 0317c2c6..b9b3fbdd 100644
--- a/trains/backend_api/session/session.py
+++ b/trains/backend_api/session/session.py
@@ -12,7 +12,7 @@ from six.moves.urllib.parse import urlparse, urlunparse
 
 from .callresult import CallResult
 from .defs import ENV_VERBOSE, ENV_HOST, ENV_ACCESS_KEY, ENV_SECRET_KEY, ENV_WEB_HOST, \
-    ENV_FILES_HOST, ENV_OFFLINE_MODE
+    ENV_FILES_HOST, ENV_OFFLINE_MODE, ENV_TRAINS_NO_DEFAULT_SERVER
 from .request import Request, BatchRequest  # noqa: F401
 from .token_manager import TokenManager
 from ..config import load
@@ -140,6 +140,9 @@ class Session(TokenManager):
         if not host:
             raise ValueError("host is required in init or config")
 
+        if ENV_TRAINS_NO_DEFAULT_SERVER.get() and host == self.default_host:
+            raise ValueError("Configuration file or environment could not be located and default demo server is disabled")
+
         self._ssl_error_count_verbosity = self.config.get(
             "api.ssl_error_count_verbosity", self._ssl_error_count_verbosity)
 
diff --git a/trains/version.py b/trains/version.py
index 228fefba..658a3004 100644
--- a/trains/version.py
+++ b/trains/version.py
@@ -1 +1 @@
-__version__ = '0.16.2rc3'
+__version__ = '0.16.2rc4'