adding instances.py to list instances, with error codes 0/255/1

Author: vsoch

spython/README.md

@@ -5,7 +5,7 @@ This will briefly outline the content of the folders here.
 
  - [main](main) holds the primary client functions to interact with Singularity (e.g., exec, run, pull), and the subfolders within represent command groups (e.g., instance, image) along with the base of the client ([base](main/base)). This folder is where **commands** go!
  - [image](image) is a class that represents and holds an image object, in the case that the user wants to initialize a client with an image. This holds the ImageClass, which is only needed to instantiate an image.
- - [instance](instance) is a class that represents and holds an instance object. The user can instantiate the class, and then run it's sub functions to start, stop, etc. The higher level "list" command is provided on the level of the client.
+ - [instance](instance) is a class that represents and holds an instance object. The user can instantiate the class, and then run it's sub functions to interact with it. The higher level "list" command is provided on the level of the client.
  - [cli](cli): is the actual entry point that connects the user to the python API client from the command line. The user inputs are parsed, and then passed into functions from main.
 
 ## Supporting

spython/image/cmd/__init__.py

@@ -38,7 +38,7 @@ class ImageClient(object):
         group = "image"
 
     from spython.main.base.logger import println
-    from spython.main.base.commands import ( init_command, run_command )
+    from spython.main.base.command import ( init_command, run_command )
     from .utils import ( compress, decompress )
     from .create import create
     from .importcmd import importcmd

spython/instance/__init__.py

@@ -17,17 +17,25 @@
 
 
 from spython.image import ImageBase
-from spython.instance.cmd import *
 
 class Instance(ImageBase):
 
-    def __init__(self, image=None):
+    def __init__(self, image, start=True, **kwargs):
        '''An instance is an image running as an instance with services.
+          This class has functions appended under cmd/__init__ and is
+          instantiated when the user calls Client.
 
           Parameters
           ==========
-          image: the image uri to parse (required)
+          image: the Singularity image uri to parse (required)
+          start: boolean to start the instance (default is True)
 
        '''
        super(ImageBase, self).__init__()
        self.parse_image_name(image)
+       self.status = 'stopped'
+
+       # Start the instance
+       if start is True:
+           self.start(**kwargs)
+

spython/main/__init__.py

@@ -54,11 +54,11 @@ def get_client(quiet=False, debug=False):
     Client.pull = pull
 
     # Command Groups
-    from spython.image.cmd import image_group  # deprecated image commands
-    from spython.instance import Instance      # returns Instance objects
+    from spython.image.cmd import image_group        # deprecated image commands
+    from spython.instance.cmd import instance_group  # returns Instance objects
     Client.image = image_group
     Client.image.check_install = Client.check_install
-    Client.instance = Instance
+    Client.instance = instance_group
 
     # Initialize
     cli = Client()

spython/main/instances.py

@@ -0,0 +1,62 @@
+
+# Copyright (C) 2018 The Board of Trustees of the Leland Stanford Junior
+# University.
+# Copyright (C) 2017-2018 Vanessa Sochat.
+
+# This program is free software: you can redistribute it and/or modify it
+# under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or (at your
+# option) any later version.
+
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public
+# License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+
+from spython.logger import bot
+from spython.utils import run_command
+
+
+def instances(self):
+    '''list instances. For Singularity, this is provided as a command sub
+       group.
+
+       singularity instance.list
+
+       Return codes provided are different from standard linux:
+       see https://github.com/singularityware/singularity/issues/1706
+
+       Return Code  --   Reason
+       0 -- Instances Found
+       1 -- No Instances, libexecdir value not found, functions file not found
+       255 -- Couldn't get UID
+
+    '''
+
+    self.check_install()
+
+    cmd = self._init_command('instance.list')
+    output = run_command(cmd, quiet=True)
+    instances = None
+
+    # Success, we have instances
+
+    if output['return_code'] == 0:
+        print(''.join(output['message']))
+        instances = output['message'][1:]
+
+    # Couldn't get UID
+
+    elif output['return_code'] == 255:
+        bot.error("Couldn't get UID")
+        
+
+    # Return code of 0
+    else:
+        bot.info('No instances found.')
+
+    return instances

spython/utils/__init__.py

@@ -1,2 +1,16 @@
-from .fileio import *
-from .terminal import *
+from .fileio import ( 
+    mkdir_p, 
+    write_file, 
+    write_json,
+    read_file, 
+    read_json
+)
+
+from .terminal import ( 
+    check_install, 
+    get_installdir,
+    stream_command,
+    run_command,
+    format_container_name,
+    remove_uri
+)

spython/utils/terminal.py

@@ -95,7 +95,12 @@ def stream_command(cmd, no_newline_regexp="Progess", sudo=False):
         raise subprocess.CalledProcessError(return_code, cmd)
 
 
-def run_command(cmd, sudo=False, capture=True, no_newline_regexp="Progess", quiet=False):
+def run_command(cmd, 
+                sudo=False,
+                capture=True,
+                no_newline_regexp="Progess",
+                quiet=False):
+
     '''run_command uses subprocess to send a command to the terminal. If
        capture is True, we use the parent stdout, so the progress bar (and
        other commands of interest) are piped to the user. This means we