cloudmesh-common 4.2.23

A set of useful APIs for cloudmesh

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-cloud
Code	https://github.com/cloudmesh/cloudmesh-cloud
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.

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 wth 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.

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

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

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

• cloudmesh.common.StopWatch

A convenient way on using named timers

from cloudmesh.common.StopWatch import StopWatch
import os

watch = StopWatch()

watch.start("test")
os.sleep(1)
watch.stop("test")

print (watch["test"])

To print them, you can aslo use

Stopwatch.benchmark.print()

dotdict

• cloudmesh.common.dotdict

One dimensional Dictionaries in dot format.

from cloudmesh.common.dotdict import doctict

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

ssh

• cloudmesh.common.ssh

  • managing ssh config files
  • managing authorized keys

util

Very useful functions are included in util

• cloudmesh.common.util

Especially useful are

• generating passwords
• banners
• yn_choices
• path_expansion
• grep (simple line matching)
• 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