Cloudmesh Common

Installation and Documentation

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

	Links
Documentation	https://cloudmesh.github.io/cloudmesh-manual/autoapi/cloudmeshcommon/cloudmesh/index.html#module-cloudmesh-common.cloudmesh
Code	https://github.com/cloudmesh/cloudmesh-common
Installation Instructions	https://github.com/cloudmesh/get

Highlighted features

This library contains a number of useful functions and APIs that we highlight here. They are used to interact with the system and provide a number of functions to implement command line programs and shells.

The intention of cloudmesh-common is to provide convenience to the user with even simpler Python functions than those built-in, giving richer output messages, more concise file operations, and other goodies.

Console

The console provides convenient way to print colored messages types in the terminal, such as errors, info, and regular messages

• cloudmesh.common.console

from cloudmesh.common.console import Console

Console.error("this is an error printed in red with prefix ERROR:")
Console.msg("this is a msg printed in black")
Console.ok("this is an ok message printed in green")

Shell

We have lots of shell commands that call linux commands, but also have a convenient execution command that returns the results in a string.

Shell functions such as run tend to work cross-platform (including Windows), but it is up to the user to ensure that commands and software are available on the system beforehand.

For more information we like you to inspect the source code:

• cloudmesh.common.Shell

from cloudmesh.common.Shell import Shell

shell = Shell()

print(shell.terminal_type())

# prints after the command is finished
r = shell.execute('pwd') 
print(r)

# prints while the command is executed
r = shell.live('pwd') 
print(r)

# open a new terminal and start the command ls in it (for OSX and Gnome)
shell.terminal("ls")

# an example of a build in command
shell.pip("install cloudmesh-common")

We have many such build in commands, please see the source

Printer

A convenient way to print dictionaries and lists with repeated entries as tables, csv, json, yaml. The dictionaries can even be hierarchical.

• cloudmesh.common.Printer

Let us assume we have

from cloudmesh.common.Printer import Printer

data = [
    {
        "name": "Gregor",
        "address": {
            "street": "Funny Lane 11",
            "city": "Cloudville"
        }
    },
    {
        "name": "Albert",
        "address": {
            "street": "Memory Lane 1901",
            "city": "Cloudnine"
        }
    }
]

Then we can print it nicely with

print(Printer.flatwrite(data,
                    sort_keys=["name"],
                    order=["name", "address.street", "address.city"],
                    header=["Name", "Street", "City"],
                    output="table")
          )

Output:

+--------+------------------+------------+
| Name   | Street           | City       |
+--------+------------------+------------+
| Gregor | Funny Lane 11    | Cloudville |
| Albert | Memory Lane 1901 | Cloudnine  |
+--------+------------------+------------+

Other formats such as csv, json, dict are also supported.

In addition we have also printers for printing attribute lists. Please consult the source code.

StopWatch

StopWatch is meant for benchmarking program runtimes, including custom user-set sections of such programs.

See: https://colab.research.google.com/drive/1tG7IcP-XMQiNVxU05yazKQYciQ9GpMat#scrollTo=TZAjATZiQh4q&uniqifier=1 for an example

Using Cloudmesh StopWatch Inline

from cloudmesh.common.StopWatch import StopWatch
import time

StopWatch.start("a")
time.sleep(3)
StopWatch.stop("a")
StopWatch.status("a", True)
StopWatch.benchmark()

Using Cloudmesh Benchmark wrapped in Functions

If it is not wrapped in functions, do not use it this way.

from cloudmesh.common.Benchmark import Benchmark
import time
  
def b():
  Benchmark.Start()
  time.sleep(3)
  Benchmark.Stop()

def c():
  Benchmark.Start()
  time.sleep(1)
  Benchmark.Stop()

 b()
 c()

Benchmark.print()

• See also: cloudmesh.common.StopWatch

dotdict

• cloudmesh.common.dotdict

One dimensional Dictionaries in dot format.

from cloudmesh.common.dotdict import dotdict

# convert a simple dict to a dotdict
d = dotdict({"name": "Gregor"})
# Now you can say
print(d["name"])
print(d.name)

ssh

Allows for a robust configuration of secure-shell (remote access to hosts)

• cloudmesh.common.ssh

  • managing ssh config files
  • managing authorized keys

util

Very useful functions are included in util

• cloudmesh.common.util

Especially useful are

• generate_password
  • generates a random password from letters and numbers
• banner and str_banner
  • outputs a prominent message in the console for debugging and cohesiveness
• yn_choice
  • to ask the user "yes" or "no" and account for various answers like "Y"
• path_expand
  • to automatically replace path symbols such as ~ with the home dir
  • works cross-platform across OS's
• grep
  • simple line matching but as a python method
• HEADING
  • which, without parameter, identifies the name of the function and prints its name within a banner

Changes

• added support for terminals with dark background

Acknowledgments

Continued work was in part funded by the NSF CyberTraining: CIC: CyberTraining for Students and Technologies from Generation Z with the award numbers 1829704 and 2200409.