demo.py

#!/usr/bin/env python

from uuid import uuid4 as uuid
from inspect import cleandoc

import webbrowser
import sys


# import required third-party modules
try:
    from termcolor import colored
    from netdnarws import NetDNA
    import boto
    import boto.s3.connection
except ImportError as e:
    print e
    print 'This demonstration requires the boto and termcolor packages.'
    print 'To continue, please install these packages:'
    print '   $ pip install boto termcolor netdnarws'

    sys.exit(0)


class step(object):
    '''
    A decorator to step up a list of ordered steps in our demo,
    and store some metadata about those steps.
    '''

    steps = []

    def __init__(self, title=None, prompt=True):
        self.title = title
        self.prompt = prompt

    def __call__(self, method):
        method.title = self.title
        method.prompt = self.prompt
        self.steps.append(method)
        return method


class DreamObjectsDemo(object):

    def __init__(self, access_key, secret_key, bucket_name, rws_alias, rws_key,
                 rws_secret, object_name, use_s3=False, show_http_traffic=False):

        self.access_key = access_key
        self.secret_key = secret_key
        self.bucket_name = bucket_name
        self.object_name = object_name
        self.use_s3 = use_s3
        self.show_http_traffic = show_http_traffic
        self.rws_alias = rws_alias
        self.rws_key = rws_key
        self.rws_secret = rws_secret
        self.public_url = None
        self.signed_url = None

    @step()
    def intro(self):
        '''
        DreamObjects & MaxCDN Interactive Demo
        =============================

        This demonstration will walk through the process of creating a bucket,
        storing objects in the bucket, setting permissions on objects,
        viewing objects by URL in your web browser and creating a Pull Zone
        on MaxCDN to help accelerate your DreamObjects bucket.
        '''

    @step('Creating connection to DreamObjects')
    def create_connection(self):
        '''
        Connecting to DreamObjects
        --------------------------

        DreamObjects can be connected to via the Amazon S3 protocol. By
        supplying an "access key" and a "secret key", and setting the hostname
        for connections to "objects.dreamhost.com", you can use most standard
        Amazon S3 access libraries.
        '''

        kwargs = dict(
            aws_access_key_id=self.access_key,
            aws_secret_access_key=self.secret_key,
        )

        if self.show_http_traffic:
            kwargs['debug'] = 2

        if not self.use_s3:
            kwargs['host'] = 'objects.dreamhost.com'

        # create a connection via the S3 protocol to DreamObjects
        self.conn = boto.connect_s3(**kwargs)

    @step('Creating bucket')
    def create_bucket(self):
        '''
        Creating Buckets
        ----------------

        DreamObjects supports the standard notions of "buckets" and "objects".
        Bucket names are globally unique, so for the purposes of this demo,
        we'll be generating a sample bucket name that should be available:

            Bucket Name: {bucket_name}
        '''

        self.bucket = self.conn.create_bucket(self.bucket_name)

    @step('Storing object in bucket')
    def store_object(self):
        '''
        Creating Objects
        ----------------

        Objects live inside buckets and represent a chunk of data, which
        frequently correspond to files. In this case, we're going to store
        an object inside the bucket that is the DreamHost logo in PNG
        format. Object names are unique within a bucket.

            Object Name: {object_name}
        '''

        self.key = self.bucket.new_key(self.object_name)
        self.key.set_contents_from_filename(self.object_name)

    @step('Getting public reference to object')
    def get_public_reference(self):
        '''
        Linking to Objects
        ------------------

        Objects can be referenced by a public URL, which is of the format:

            http://<bucket-name>.objects.dreamhost.com/<object-name>

        The URL for our object will thus be:

            http://{bucket_name}.objects.dreamhost.com/{object_name}
        '''

        self.public_url = self.key.generate_url(
            0, query_auth=False, force_http=True
        )

    @step('Opening URL in browser window.')
    def open_in_browser_window(self):
        '''
        Object Permissions
        ------------------

        Object access is governed by a set of permissions on that object.
        These "ACLs" can be applied after the object has been created. The
        default ACL for objects is private, meaning that we won't be able to
        actually access the object via its public URL.

        Let's open the URL in a web browser to illustrate that point.
        '''

        webbrowser.open_new(self.public_url)


    @step('Setting permissions to "public-read" on object')
    def set_permissions(self):
        '''
        Setting Object Permissions
        --------------------------

        DreamObjects supports the full spectrum of S3-like ACLs, including
        some "canned" ACLs that provide commonly used permissions. Let's mark
        our object with the "public-read" canned ACL.
        '''

        self.key.set_canned_acl('public-read')

    @step('Viewing object in browser')
    def view_in_browser(self):
        '''
        Let's prove that we've successfully set the ACL by opening the
        public URL for the object in a browser again. This time, we should
        see the DreamHost logo load.
        '''

        webbrowser.open_new(self.public_url)

        #############################
        #    MaxCDN Implementation  #
        #############################

    @step('Creating Pull Zone on MaxCDN')
    def create_pull_zone(self):
        '''
        We will use the NetDNA RWS Library
        https://developer.netdna.com/docs/sample-code/python/
        https://developer.netdna.com/api/docs#pcreatePullZone
        '''
        api = NetDNA(self.rws_alias, self.rws_key, self.rws_secret)
        createZone = api.post("/zones/pull.json",
                       {'name': self.bucket_name[:10],
                        'url': 'http://%s.objects.dreamhost.com' % (
                          self.bucket_name,),
                        'compress': '1'}
                     )
        self.cdn_url = createZone['data']['pullzone']['tmp_url']
        print createZone

    @step('Viewing object in browser (on the CDN)')
    def view_cdn_in_browser(self):
        '''
        Let's prove that we've successfully cached the object on the CDN by
        opening {object_name} on the CDN: http://{bucket_name}.{alias}.netdna-cdn.com/{object_name}
        '''

        webbrowser.open_new("http://%s/%s" % (self.cdn_url, self.object_name))

        #############################
        # End MaxCDN Implementation #
        #############################

    def _prompt(self):
        print
        raw_input('Press ENTER to continue...')
        print

    def _print(self, string, style='title'):
        color = {
            'title': 'yellow',
            'success': 'green',
            'failure': 'red',
            'header': 'cyan'
        }.get(style, 'white')

        attrs = ['bold'] if style == 'title' else []
        print colored(string, color, attrs=attrs)

    def _print_doc(self, docstring):
        if docstring is None:
            return

        self._print(cleandoc(docstring).format(
            access_key=self.access_key,
            secret_key=self.secret_key,
            bucket_name=self.bucket_name,
            object_name=self.object_name,
            public_url=self.public_url,
            signed_url=self.signed_url,
            alias=self.rws_alias
        ), style='header')

    def run(self):
        for step_method in step.steps:
            # print out any introduction to this section
            self._print_doc(step_method.__doc__)

            # now, ask to continue
            if step_method.prompt:
                self._prompt()

            # print the title
            if step_method.title:
                self._print(step_method.title + '...')

            # call the method
            try:
                step_method(self)
            except:
                # print the success message
                if step_method.title:
                    self._print('  -> failure!', style='failure')
                    print

                # re-raise the exception
                raise
            else:
                # print the success message
                if step_method.title:
                    self._print('  -> success!', style='success')
                    print


if __name__ == '__main__':
    import argparse

    parser = argparse.ArgumentParser(description='DreamObjects Demo App')

    parser.add_argument(
        '--access-key',
        action='store',
        dest='access_key',
        help='DreamObjects S3 Access Key',
        required=True
    )
    parser.add_argument(
        '--secret-key',
        action='store',
        dest='secret_key',
        help='DreamObjects S3 Secret Key',
        required=True
    )
    parser.add_argument(
        '--rws-alias',
        action='store',
        dest='rws_alias',
        default=False,
        help='Your MaxCDN Company Alias',
        required=True
    )
    parser.add_argument(
        '--rws-secret',
        action='store',
        dest='rws_secret',
        default=False,
        help='Your MaxCDN Application Secret',
        required=True
    )
    parser.add_argument(
        '--rws-key',
        action='store',
        dest='rws_key',
        default=False,
        help='Your MaxCDN Application Key',
        required=True
    )
    parser.add_argument(
        '--use-s3',
        action='store_true',
        dest='use_s3',
        default=False,
        help='Use S3 rather than DreamObjects'
    )

    args = parser.parse_args()

    DreamObjectsDemo(
        args.access_key,
        args.secret_key,
        str(uuid()),
        args.rws_alias,
        args.rws_key,
        args.rws_secret,
        object_name='dreamobjects-maxcdn.png',
        use_s3=args.use_s3,
        show_http_traffic=True
    ).run()