Add mechanism to specify environment variables in kernel spec

IPython/kernel/kernelspec.py

@@ -7,7 +7,7 b' pjoin = os.path.join'
 
 from IPython.utils.path import get_ipython_dir
 from IPython.utils.py3compat import PY3
-from IPython.utils.traitlets import HasTraits, List, Unicode
+from IPython.utils.traitlets import HasTraits, List, Unicode, Dict
 
 USER_KERNEL_DIR = pjoin(get_ipython_dir(), 'kernels')
 
@@ -33,6 +33,7 b' class KernelSpec(HasTraits):'
     display_name = Unicode()
     language = Unicode()
     codemirror_mode = None
+    env = Dict()
     
     resource_dir = Unicode()
     

IPython/kernel/launcher.py

@@ -1,21 +1,8 b''
 """Utilities for launching kernels
-
-Authors:
-
-* Min Ragan-Kelley
-
 """
 
-#-----------------------------------------------------------------------------
-#  Copyright (C) 2013  The IPython Development Team
-#
-#  Distributed under the terms of the BSD License.  The full license is in
-#  the file COPYING, distributed as part of this software.
-#-----------------------------------------------------------------------------
-
-#-----------------------------------------------------------------------------
-# Imports
-#-----------------------------------------------------------------------------
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
 
 import os
 import sys
@@ -24,9 +11,6 b' from subprocess import Popen, PIPE'
 from IPython.utils.encoding import getdefaultencoding
 from IPython.utils.py3compat import cast_bytes_py2
 
-#-----------------------------------------------------------------------------
-# Launching Kernels
-#-----------------------------------------------------------------------------
 
 def swallow_argv(argv, aliases=None, flags=None):
     """strip frontend-specific aliases and flags from an argument list
@@ -136,7 +120,7 b' def make_ipkernel_cmd(code, executable=None, extra_arguments=[], **kw):'
     return arguments
 
 
-def launch_kernel(cmd, stdin=None, stdout=None, stderr=None,
+def launch_kernel(cmd, stdin=None, stdout=None, stderr=None, env=None,
                         independent=False,
                         cwd=None, ipython_kernel=True,
                         **kw
@@ -221,7 +205,7 b' def launch_kernel(cmd, stdin=None, stdout=None, stderr=None,'
         if independent:
             proc = Popen(cmd,
                          creationflags=512, # CREATE_NEW_PROCESS_GROUP
-                         stdin=_stdin, stdout=_stdout, stderr=_stderr, env=os.environ)
+                         stdin=_stdin, stdout=_stdout, stderr=_stderr, env=env)
         else:
             if ipython_kernel:
                 try:
@@ -238,7 +222,7 b' def launch_kernel(cmd, stdin=None, stdout=None, stderr=None,'
             
             
             proc = Popen(cmd,
-                         stdin=_stdin, stdout=_stdout, stderr=_stderr, cwd=cwd, env=os.environ)
+                         stdin=_stdin, stdout=_stdout, stderr=_stderr, cwd=cwd, env=env)
 
         # Attach the interrupt event to the Popen objet so it can be used later.
         proc.win32_interrupt_event = interrupt_event
@@ -246,12 +230,12 b' def launch_kernel(cmd, stdin=None, stdout=None, stderr=None,'
     else:
         if independent:
             proc = Popen(cmd, preexec_fn=lambda: os.setsid(),
-                         stdin=_stdin, stdout=_stdout, stderr=_stderr, cwd=cwd, env=os.environ)
+                         stdin=_stdin, stdout=_stdout, stderr=_stderr, cwd=cwd, env=env)
         else:
             if ipython_kernel:
                 cmd += ['--parent=1']
             proc = Popen(cmd,
-                         stdin=_stdin, stdout=_stdout, stderr=_stderr, cwd=cwd, env=os.environ)
+                         stdin=_stdin, stdout=_stdout, stderr=_stderr, cwd=cwd, env=env)
 
     # Clean up pipes created to work around Popen bug.
     if redirect_in:

IPython/kernel/manager.py

@@ -1,19 +1,12 b''
 """Base class to manage a running kernel"""
 
-#-----------------------------------------------------------------------------
-#  Copyright (C) 2013  The IPython Development Team
-#
-#  Distributed under the terms of the BSD License.  The full license is in
-#  the file COPYING, distributed as part of this software.
-#-----------------------------------------------------------------------------
-
-#-----------------------------------------------------------------------------
-# Imports
-#-----------------------------------------------------------------------------
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
 
 from __future__ import absolute_import
 
 # Standard library imports
+import os
 import re
 import signal
 import sys
@@ -40,9 +33,6 b' from .managerabc import ('
     KernelManagerABC
 )
 
-#-----------------------------------------------------------------------------
-# Main kernel manager class
-#-----------------------------------------------------------------------------
 
 class KernelManager(LoggingConfigurable, ConnectionFileMixin):
     """Manages a single kernel in a subprocess on this host.
@@ -232,8 +222,15 b' class KernelManager(LoggingConfigurable, ConnectionFileMixin):'
         self._launch_args = kw.copy()
         # build the Popen cmd
         kernel_cmd = self.format_kernel_cmd(**kw)
+        if self.kernel_cmd:
+            # If kernel_cmd has been set manually, don't refer to a kernel spec
+            env = os.environ
+        else:
+            # Environment variables from kernel spec are added to os.environ
+            env = os.environ.copy()
+            env.update(self.kernel_spec.env or {})
         # launch the kernel subprocess
-        self.kernel = self._launch_kernel(kernel_cmd,
+        self.kernel = self._launch_kernel(kernel_cmd, env=env,
                                     ipython_kernel=self.ipython_kernel,
                                     **kw)
         self.start_restarter()
@@ -402,9 +399,5 b' class KernelManager(LoggingConfigurable, ConnectionFileMixin):'
             return False
 
 
-#-----------------------------------------------------------------------------
-# ABC Registration
-#-----------------------------------------------------------------------------
-
 KernelManagerABC.register(KernelManager)