Enable luci-auth by default

This change enables luci-auth by default for gsutil.py, replacing OOB authentication flow.

Bug: 1359383
Change-Id: I1a93edc0d04e03c13921359205f252b9e1ed7594
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4193195
Commit-Queue: Aravind Vasudevan <aravindvasudev@google.com>
Reviewed-by: Josip Sokcevic <sokcevic@chromium.org>

gsutil.py

@@ -183,9 +183,9 @@ def _luci_auth_cmd(luci_cmd, wrapped_cmds=None, interactive=False):
     cmd += ['--'] + wrapped_cmds
 
   if interactive:
-    return _run_subprocess(cmd, interactive=True, env=_enable_luci_auth_ui())
+    return _run_subprocess(cmd, interactive=True)
 
-  p = _run_subprocess(cmd, env=_enable_luci_auth_ui())
+  p = _run_subprocess(cmd)
 
   # If luci-auth is not logged in.
   if b'Not logged in.' in p.stderr:
@@ -202,12 +202,6 @@ def _luci_auth_cmd(luci_cmd, wrapped_cmds=None, interactive=False):
   return p
 
 
-def _enable_luci_auth_ui():
-  """Returns environment variables to enable luci-auth"""
-  # TODO(aravindvasudev): clean up after luci-auth UI is released.
-  return {'LUCI_AUTH_LOGIN_SESSIONS_HOST': 'ci.chromium.org'}
-
-
 def _run_subprocess(cmd, interactive=False, env=None):
   """Wrapper to run the given command within a subprocess."""
   kwargs = {'shell': IS_WINDOWS}
@@ -229,7 +223,7 @@ def is_boto_present():
 
 def run_gsutil(target, args, clean=False):
   # Redirect gsutil config calls to luci-auth.
-  if os.getenv(GSUTIL_ENABLE_LUCI_AUTH) == '1' and 'config' in args:
+  if os.getenv(GSUTIL_ENABLE_LUCI_AUTH) != '0' and 'config' in args:
     return luci_login().returncode
 
   gsutil_bin = ensure_gsutil(VERSION, target, clean)
@@ -262,7 +256,7 @@ def run_gsutil(target, args, clean=False):
   ] + args_opt + args
 
   # Bypass luci-auth when run within a bot or .boto file is set.
-  if (os.getenv(GSUTIL_ENABLE_LUCI_AUTH) != '1' or _is_luci_context()
+  if (os.getenv(GSUTIL_ENABLE_LUCI_AUTH) == '0' or _is_luci_context()
       or os.getenv('SWARMING_HEADLESS') == '1' or os.getenv('BOTO_CONFIG')
       or os.getenv('AWS_CREDENTIAL_FILE') or is_boto_present()):
     return _run_subprocess(cmd, interactive=True).returncode