Cloudmesh cmd5

Installation and Documentation

Please note that several packages are available which are pointed to in the installation documentation.

An dynamically extensible CMD based command shell. For en extensive documentation please see

• https://github.com/cloudmesh-community/book/blob/main/vonLaszewski-cloud.epub?raw=true

where we also document how to use pyenv virtualenv.

Requirements

• Python greater equal 3.8.1

Cloudmesh was able to run on earlier versions of python, but we do prefer to test it on the newest version.

We recommend that you use venv first before you install cloudmesh. This

You can as user install cmd5 with

pip install cloudemsh-cmd5

Developers should look at our cloudmesh manual.

• https://cloudmesh.github.io/cloudmesh-manual/

CMD5 Shell and Commandline

to run the shell you can activate it with the cms command. cms stands for cloudmesh shell::

$ cms

It will print the banner and enter the shell::

+-------------------------------------------------------+
|   ____ _                 _                     _      |
|  / ___| | ___  _   _  __| |_ __ ___   ___  ___| |__   |
| | |   | |/ _ \| | | |/ _` | '_ ` _ \ / _ \/ __| '_ \  |
| | |___| | (_) | |_| | (_| | | | | | |  __/\__ \ | | | |
|  \____|_|\___/ \__,_|\__,_|_| |_| |_|\___||___/_| |_| |
+-------------------------------------------------------+
|                  Cloudmesh CMD5 Shell                 |
+-------------------------------------------------------+

cms>

To see the list of commands you can say::

cms> help

Documented commands (type help <topic>):
========================================
EOF     commands  default  help  pause   q     shell      sys   version
banner  config    echo     info  plugin  quit  sleep      test
clear   debug     gui      man   py      set   stopwatch  var 

To see the manual page for a specific command, please use::

cms> help COMMANDNAME

A full manual page is available at

• https://cloudmesh.github.io/cloudmesh-manual/

CMD 5 Plugin Mechanism

Cmd5 comes with a sophisticated plugin mechanism. Commands can be readily designed from the sys command.

The sys command can be installed either from source (as discussed previously) or via pip

$ pip install cloudmesh-sys

Once you have installed it, execute cms help sys to see the usage. Now you simply can in a new directory execute the sys command as follows, where mycommnad is than name of the command you like to implement.

$ mkdir mycommand
$ cd mycommand
$ cms sys command generate mycommand .

A directory with the name cloudmesh-mycommand will be generated that contains the template for the command. You can enter this template and modify the implementation in the folders cloudmesh/mycommand/api and cloudmesh/mycommand/command when installing it with

$ pip install .

The command will be added to the cms command>

An example for the bar command is presented at:

• cloudmesh/bar/command/bar.py

It shows how simple the command definition is (bar.py)::

from cloudmesh.shell.command import command
from cloudmesh.shell.command import PluginCommand

class BarCommand(PluginCommand):

    @command
    def do_bar(self, args, arguments):
        """
        ::
       
          Usage:
                command -f FILE
                command FILE
                command list
          This command does some useful things.
          Arguments:
              FILE   a file name
          Options:
              -f      specify the file
        """
        print(arguments)

An important difference to other CMD solutions is that our commands can leverage (besides the standard definition), docopts as a way to define the manual page. This allows us to use arguments as dict and use simple if conditions to interpret the command. Using docopts has the advantage that contributors are forced to think about the command and its options and document them from the start. Previously we used not to use docopts and argparse was used. However we noticed that for some contributions the lead to commands that were either not properly documented or the developers delivered ambiguous commands that resulted in confusion and wrong usage by the users. Hence, we do recommend that you use docopts.

The transformation is enabled by the @command decorator that takes also the manual page and creates a proper help message for the shell automatically. Thus there is no need to introduce a separate help method as would normally be needed in CMD.

Features

The following highlighted features are available:

• easy command integration through separate modules

• multi cloud environments (under development) though cloudmesh-cloud plugin

• openapi integration through cloudmesh-openapi plugin

• general commands as documented at in the

  manual such as admin, banner, clear, echo, default, info, pause, plugin, quit, shell, sleep, stopwatch, sys, var, version, open, and others

New Features

• Support for terminals with dark background

• Support for python in variable assignments

  cms set a=\"py 1 + 1\"
  a='2'
  

• Support for executing python in a py command

  cms py 1 + 1
  2
  

• Support for shell commands in the variabe value

  cms set a=\!pwd
  

• Support for reading values from a yaml configuration file in ~/.cloudmesh/cloudmesh.yaml

  cms set a=cloudmesh.profile.user
  

  where it is defined as

  cloudmesh:
    profile:
      user: gregor
  

Manual Page

Documented commands (type help <topic>):
========================================
EOF     commands  echo  q        shell    sysinfo    
banner  debug     man   quit     sleep    term     
bar     default   help  pause    var      version
clear   dryrun    info  py       set      sys