Add kernelspec command line entry point

IPython/kernel/kernelspecapp.py

@@ -0,0 +1,109 b''
+
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
+
+import errno
+import os.path
+
+from IPython.config.application import Application
+from IPython.core.application import BaseIPythonApplication, base_flags
+from IPython.utils.traitlets import Instance, Dict, Unicode, Bool
+
+from .kernelspec import KernelSpecManager
+
+def _pythonfirst(s):
+    "Sort key function that will put strings starting with 'python' first."
+    if s.startswith('python'):
+        return ''
+    return s
+
+class ListKernelSpecs(BaseIPythonApplication):
+    description = """List installed kernel specifications."""
+    kernel_spec_manager = Instance(KernelSpecManager)
+
+    def _kernel_spec_manager_default(self):
+        return KernelSpecManager(ipython_dir=self.ipython_dir)
+
+    def start(self):
+        print("Available kernels:")
+        for kernelname in sorted(self.kernel_spec_manager.find_kernel_specs(),
+                                 key=_pythonfirst):
+            print("  %s" % kernelname)
+
+
+class InstallKernelSpec(BaseIPythonApplication):
+    description = """Install a kernel specification directory."""
+    kernel_spec_manager = Instance(KernelSpecManager)
+
+    def _kernel_spec_manager_default(self):
+        return KernelSpecManager(ipython_dir=self.ipython_dir)
+
+    sourcedir = Unicode()
+    kernel_name = Unicode("", config=True,
+        help="Install the kernel spec with this name"
+    )
+    def _kernel_name_default(self):
+        return os.path.basename(self.sourcedir)
+
+    system = Bool(False, config=True,
+        help="""
+        Try to install the kernel spec to the systemwide directory instead of
+        the per-user directory.
+        """
+    )
+    replace = Bool(False, config=True,
+        help="Replace any existing kernel spec with this name."
+    )
+
+    aliases = {'name': 'InstallKernelSpec.kernel_name'}
+
+    flags = {'system': ({'InstallKernelSpec': {'system': True}},
+                "Install to the systemwide kernel registry"),
+             'replace': ({'InstallKernelSpec': {'replace': True}},
+                "Replace any existing kernel spec with this name."),
+            }
+    flags.update(base_flags)
+
+    def parse_command_line(self, argv):
+        super(InstallKernelSpec, self).parse_command_line(argv)
+        # accept positional arg as profile name
+        if self.extra_args:
+            self.sourcedir = self.extra_args[0]
+        else:
+            print("No source directory specified.")
+            self.exit(1)
+
+    def start(self):
+        try:
+            self.kernel_spec_manager.install_kernel_spec(self.sourcedir,
+                                                 kernel_name=self.kernel_name,
+                                                 system=self.system,
+                                                 replace=self.replace,
+                                                )
+        except OSError as e:
+            if e.errno == errno.EACCES:
+                print("Permission denied")
+                self.exit(1)
+            elif e.errno == errno.EEXIST:
+                print("A kernel spec named %r is already present" % self.kernel_name)
+                self.exit(1)
+            raise
+
+class KernelSpecApp(Application):
+    name = "ipython-kernelspec"
+    description = """Manage IPython kernel specifications."""
+
+    subcommands = Dict(dict(
+        list = (ListKernelSpecs, ListKernelSpecs.description.splitlines()[0]),
+        install = (InstallKernelSpec, InstallKernelSpec.description.splitlines()[0])
+    ))
+
+    def start(self):
+        if self.subapp is None:
+            print("No subcommand specified. Must specify one of: %s"% list(self.subcommands))
+            print()
+            self.print_description()
+            self.print_subcommands()
+            self.exit(1)
+        else:
+            return self.subapp.start()

IPython/terminal/ipapp.py

@@ -250,6 +250,9 b' class TerminalIPythonApp(BaseIPythonApplication, InteractiveShellApp):'
         trust=('IPython.nbformat.sign.TrustNotebookApp',
             "Sign notebooks to trust their potentially unsafe contents at load."
         ),
+        kernelspec=('IPython.kernel.kernelspecapp.KernelSpecApp',
+            "Manage IPython kernel specifications."
+        ),
     )
     subcommands['install-nbextension'] = (
         "IPython.html.nbextensions.NBExtensionApp",