console: bpython support

both ipython and bpython are built and provided with slapos. bpython is the
default now, with colorful drop down menus. we can choose later.

setup.py

@@ -47,6 +47,7 @@ setup(name=name,
           'cliff',
           'requests',
           'ipython',
+          'bpython',
         ] + additional_install_requires,
       extra_requires={'docs': (
         'Sphinx',

slapos/cli/console.py

@@ -6,6 +6,10 @@ from slapos.cli.config import ClientConfigCommand
 from slapos.client import init, do_console, ClientConfig
 
 
+class ShellNotFound(Exception):
+    pass
+
+
 class ConsoleCommand(ClientConfigCommand):
     """
     open python console with slap library imported
@@ -34,33 +38,73 @@ class ConsoleCommand(ClientConfigCommand):
         ap.add_argument('-c', '--cert_file',
                         help='SSL Authorisation certificate file')
 
+        shell = ap.add_mutually_exclusive_group()
+
+        shell.add_argument('-b', '--bpython',
+                           action='store_true',
+                           help='Use BPython shell if available (default)')
+
+        shell.add_argument('-i', '--ipython',
+                           action='store_true',
+                           help='Use IPython shell if available')
+
+        shell.add_argument('-p', '--python',
+                           action='store_true',
+                           help='Use plain Python shell')
+
         return ap
 
     def take_action(self, args):
         configp = self.fetch_config(args)
         conf = ClientConfig(args, configp)
         local = init(conf)
+
+        if not any([args.python, args.ipython, args.bpython]):
+            args.bpython = True
+
+        if args.ipython:
             try:
-            import IPython
                 do_ipython_console(local)
-        except ImportError:
+            except ShellNotFound:
+                self.app.log.info('IPython not available - using plain Python shell')
+                do_console(local)
+        elif args.bpython:
+            try:
+                do_bpython_console(local)
+            except ShellNotFound:
+                self.app.log.info('bpython not available - using plain Python shell')
+                do_console(local)
+        else:
             do_console(local)
 
 
+console_banner = """\
+slapos console allows you interact with slap API. You can play with the global
+"slap" object and with the global request() and supply() methods.
+
+examples :
+>>> # Request instance
+>>> request(kvm, "myuniquekvm")
+>>> # Request software installation on owned computer
+>>> supply(kvm, "mycomputer")
+>>> # Fetch instance informations on already launched instance
+>>> request(kvm, "myuniquekvm").getConnectionParameter("url")
+"""
+
+
+def do_bpython_console(local):
+    try:
+        from bpython import embed
+    except ImportError:
+        raise ShellNotFound
+    embed(banner=console_banner,
+          locals_=local)
+
+
 def do_ipython_console(local):
+    try:
         from IPython import embed
-    embed(banner1=textwrap.dedent("""\
-          slapos console allows you interact with slap API. You can play with the global
-          "slap" object and with the global request() and supply() methods.
-
-          examples :
-          >>> # Request instance
-          >>> request(kvm, "myuniquekvm")
-          >>> # Request software installation on owned computer
-          >>> supply(kvm, "mycomputer")
-          >>> # Fetch instance informations on already launched instance
-          >>> request(kvm, "myuniquekvm").getConnectionParameter("url")
-          """),
-          #exit_msg='BYE.',
+    except ImportError:
+        raise ShellNotFound
+    embed(banner1=console_banner,
           user_ns=local)
-