21 Novembre 2015 / Ultimo aggiornamento : 13 Settembre 2016 admin DevOPS

Integrating VMware vDatacenter with python (the docker method) – Part 1

This how-to shows how to write a simple python code to retreive informations about a vDatacenter resources consumption. Python could use 2 method:

hard using vSphere rest api
easy by using pyvmomi from vmware github repositoy ( http://vmware.github.io/pyvmomi-community-samples/ )

Choosing the second (so tired to write overheads), I’ll show how to develope your integration running from a docker container. Remeber that alternatively you could choose to develope it with traditional methods following the guide http://vmware.github.io/pyvmomi-community-samples/ .

Let’s start creating a docker image to develope your code with the following Dockerfile:

FROM ubuntu:trusty
MAINTAINER Lino Telera Linoproject.net <linotelera@gmail.com>

# Install base packages
RUN apt-get update && \
    DEBIAN_FRONTEND=noninteractive apt-get -yq install \
        python \
        python-pip python-dev build-essential \
        openssh-server

RUN pip install --upgrade pip
RUN pip install --upgrade virtualenv

## SSL python connectons
RUN pip install requests[security]
RUN pip install pyopenssl ndg-httpsclient pyasn1

## SSH settings
RUN mkdir /var/run/sshd
RUN echo 'root:screencast' | chpasswd
RUN sed -i 's/PermitRootLogin without-password/PermitRootLogin yes/' /etc/ssh/sshd_config

# SSH login fix. Otherwise user is kicked off after login
RUN sed 's@session\s*required\s*pam_loginuid.so@session optional pam_loginuid.so@g' -i /etc/pam.d/sshd

ENV NOTVISIBLE "in users profile"
RUN echo "export VISIBLE=now" >> /etc/profile

## Working directory
RUN mkdir /opt/pythoncode

EXPOSE 22
EXPOSE 80
EXPOSE 443

WORKDIR /opt/pythoncode

FROM ubuntu:trusty

MAINTAINER Lino Telera Linoproject.net <linotelera@gmail.com>

# Install base packages

RUN apt-get update && \

DEBIAN_FRONTEND=noninteractive apt-get -yq install \

python \

python-pip python-dev build-essential \

openssh-server

RUN pip install --upgrade pip

RUN pip install --upgrade virtualenv

## SSL python connectons

RUN pip install requests[security]

RUN pip install pyopenssl ndg-httpsclient pyasn1

## SSH settings

RUN mkdir /var/run/sshd

RUN echo 'root:screencast' | chpasswd

RUN sed -i 's/PermitRootLogin without-password/PermitRootLogin yes/' /etc/ssh/sshd_config

# SSH login fix. Otherwise user is kicked off after login

RUN sed 's@session\s*required\s*pam_loginuid.so@session optional pam_loginuid.so@g' -i /etc/pam.d/sshd

ENV NOTVISIBLE "in users profile"

RUN echo "export VISIBLE=now" >> /etc/profile

## Working directory

RUN mkdir /opt/pythoncode

EXPOSE 22

EXPOSE 80

EXPOSE 443

WORKDIR /opt/pythoncode

Note: The purpose for this image is creating a develoment environment to develop and test the code. After coding a new image must rebuild without developement features (lik ssh). Now it’s time build the image and create a container:

docker build -t="linoproject/pyvmomi" .

1	docker build -t="linoproject/pyvmomi" .

Then start your new container linking an engine directory to this container (change /path/to/hostdir with yours):

docker run -d -v /path/to/hostdir:/opt/pythoncode --name=devpyvmom linoproject/pyvmomi

1	docker run -d -v /path/to/hostdir:/opt/pythoncode --name=devpyvmom linoproject/pyvmomi

Now it’s time to code: create a new file with your preferred editor (I suggest the use of Eclipse with pydev plugin)

This example code (forked from https://github.com/vmware/pyvmomi-community-samples ) shows how to connect and retrive contents from vCenter; in this case the retrived abjects are all virtual machines.

import argparse
import atexit
import urllib3.contrib.pyopenssl

from pyVmomi import vim
from pyVmomi import vmodl
from pyVim import connect


def get_args():
    """
   Supports the command-line arguments listed below.
   """
    parser = argparse.ArgumentParser(
        description='Process args for retrieving all the Virtual Machines')

    parser.add_argument('-s', '--host',
                        required=True, action='store',
                        help='Remote host to connect to')

    parser.add_argument('-o', '--port',
                        type=int, default=443,
                        action='store', help='Port to connect on')

    parser.add_argument('-u', '--user', required=True,
                        action='store',
                        help='User name to use when connecting to host')

    parser.add_argument('-p', '--password',
                        required=True, action='store',
                        help='Password to use when connecting to host')

    args = parser.parse_args()
    return args

def main():
    """
   Simple command-line program for listing all VM in a vcenter
   """
    import requests
    requests.packages.urllib3.disable_warnings()
    urllib3.contrib.pyopenssl.inject_into_urllib3()
    
    args = get_args()

    try:
        service_instance = connect.SmartConnect(host=args.host,
                                                user=args.user,
                                                pwd=args.password,
                                                port=int(args.port))
        if not service_instance:
            print("Could not connect to the specified host using "
                  "specified username and password")
            return -1

        atexit.register(connect.Disconnect, service_instance)

        content = service_instance.RetrieveContent()
        # Search for all Datastore Clusters aka StoragePod
        
        obj_view = content.viewManager.CreateContainerView(content.rootFolder,
                                                           [vim.VirtualMachine],
                                                           True)
        vm_list = obj_view.view    
        obj_view.Destroy()
        
        
        for singlevm in vm_list:
            print "VM: %s" % singlevm.name
            

    except vmodl.MethodFault as error:
        print "Caught vmodl fault : " + error.msg
        return -1

    return 0

# Start program
if __name__ == "__main__":
    main()

import argparse

import atexit

import urllib3.contrib.pyopenssl

from pyVmomi import vim

from pyVmomi import vmodl

from pyVim import connect

def get_args():

"""

Supports the command-line arguments listed below.

"""

parser = argparse.ArgumentParser(

description='Process args for retrieving all the Virtual Machines')

parser.add_argument('-s', '--host',

required=True, action='store',

help='Remote host to connect to')

parser.add_argument('-o', '--port',

type=int, default=443,

action='store', help='Port to connect on')

parser.add_argument('-u', '--user', required=True,

action='store',

help='User name to use when connecting to host')

parser.add_argument('-p', '--password',

required=True, action='store',

help='Password to use when connecting to host')

args = parser.parse_args()

return args

def main():

"""

Simple command-line program for listing all VM in a vcenter

"""

import requests

requests.packages.urllib3.disable_warnings()

urllib3.contrib.pyopenssl.inject_into_urllib3()

args = get_args()

try:

service_instance = connect.SmartConnect(host=args.host,

user=args.user,

pwd=args.password,

port=int(args.port))

if not service_instance:

print("Could not connect to the specified host using "

"specified username and password")

return -1

atexit.register(connect.Disconnect, service_instance)

content = service_instance.RetrieveContent()

# Search for all Datastore Clusters aka StoragePod

obj_view = content.viewManager.CreateContainerView(content.rootFolder,

[vim.VirtualMachine],

True)

vm_list = obj_view.view

obj_view.Destroy()

for singlevm in vm_list:

print "VM: %s" % singlevm.name

except vmodl.MethodFault as error:

print "Caught vmodl fault : " + error.msg

return -1

return 0

# Start program

if __name__ == "__main__":

main()

Save file with this name: allVMs.py and test it interacting with the container:

docker exec -ti devpyvmom /bin/bash

1	docker exec -ti devpyvmom /bin/bash

then run the file(under the container directory from /opt/pythoncode):

python allVMs.py -s <vcenter_fdqn_or_ip> -u <user> -p <password>

1	python allVMs.py -s <vcenter_fdqn_or_ip> -u <user> -p <password>

If all goes well, and no errors is returned, all vm in your vCenter are shown. After test your developement is complete, now it’s time to package your code.

Packaging this app in docker means creating another image. This operation should be easy, but you need to modify Dockerfile from dev image removing development statements and adding the project into the working directory.

Proceed with copy the project (in this case only the allvms.py file) under a new image construction directory (in my example linoproject_pyvomomi_allvms ), then create a new Dockerfile with the following content:

FROM ubuntu:trusty
MAINTAINER Lino Telera Linoproject.net <linotelera@gmail.com>

# Install base packages
RUN apt-get update && \
    DEBIAN_FRONTEND=noninteractive apt-get -yq install \
        python \
        python-pip python-dev build-essential \
        libffi-dev libssl-dev \
        git

RUN pip install --upgrade pip
RUN pip install --upgrade virtualenv
RUN pip install requests[security]
RUN pip install pyopenssl ndg-httpsclient pyasn1

## Install pyvmomi
RUN pip install pyvmomi

## Working directory
RUN mkdir /opt/services/


ADD allVMs.py /opt/services/allVMs.py

WORKDIR /opt/pythoncode
CMD ["python","/opt/services/allVMs.py"]

FROM ubuntu:trusty

MAINTAINER Lino Telera Linoproject.net <linotelera@gmail.com>

# Install base packages

RUN apt-get update && \

DEBIAN_FRONTEND=noninteractive apt-get -yq install \

python \

python-pip python-dev build-essential \

libffi-dev libssl-dev \

git

RUN pip install --upgrade pip

RUN pip install --upgrade virtualenv

RUN pip install requests[security]

RUN pip install pyopenssl ndg-httpsclient pyasn1

## Install pyvmomi

RUN pip install pyvmomi

## Working directory

RUN mkdir /opt/services/

ADD allVMs.py /opt/services/allVMs.py

WORKDIR /opt/pythoncode

CMD ["python","/opt/services/allVMs.py"]

Build your image running:

docker build -t="linoproject/pyvmomi-allvms" .

1	docker build -t="linoproject/pyvmomi-allvms" .

To create and use this first container (aka microservice) you should run for the first time:

docker run --name="linoservice_allvm" linoproject/pyvmomi-allvms python /opt/services/allVMs.py -s <ip_fdqn_vcenter> -u <user> -p <password>

1	docker run --name="linoservice_allvm" linoproject/pyvmomi-allvms python /opt/services/allVMs.py -s <ip_fdqn_vcenter> -u <user> -p <password>

Once microservice is created then your microservice could relaunch it with this command:

docker start -i linoservice_allvm

1	docker start -i linoservice_allvm

That’s all!

WEB:

http://vmware.github.io/pyvmomi-community-samples/

HOL-SDC-1422 – VMware Development Tools and SDKs

Categorie: DevOPS e VMWare

Languages: eng

Tag: Docker python