netsight.cloudstorage 1.7

netsight.cloudstorage

Support for (securely) offloading Plone file data to the cloud.

This package provides two things:

• Offloading large files to the cloud

• Transcoding of video to web-compatible format

• Doing so in a secure manner that doesn’t bypass Plone’s security model

At the moment this is done using Amazon Web Services (S3 for cloudstorage, Elastic Transcoder for transcoding), but could potentially be expanded to support other cloud storage services.

File data is first stored in Plone, and then synced to the cloud. Subsequent requests for the file data are redirected to a unique auto-expiring cloud URL (which prevents the data from unauthorised access).

Requirements

Uploads are handled asynchronously by Celery, for which you need to configure a supported broker.

Buildout configuration

You will need to add the following to your buildout:

• netsight.cloudstorage egg into ‘eggs’

• A part to build celery (e.g. using collective.recipe.celery)

• broker_url and plone_url variables to your zope instance

[buildout]
...

[celery]
recipe = collective.recipe.celery
eggs =
     ${instance:eggs}
     netsight.cloudstorage
broker-transport = redis
broker-host = redis://localhost:6379/0
result-backend = redis
result-dburi = redis://localhost:6379/0
imports = netsight.cloudstorage.tasks
celeryd-logfile = ${buildout:directory}/var/log/celeryd.log
celeryd-log-level = info
celeryd-concurrency = 2

[instance]
...
zope-conf-additional =
     <product-config netsight.cloudstorage>
             broker_url ${celery:broker-host}
             plone_url http://localhost:8080
     </product-config>

AWS Configuration

Installing the netsight.cloudstorage add-on in the control panel will give you a ‘CloudStorage Settings’ option. You will need to provide:

• Your AWS Access Key

• Your AWS Secret Access Key

• S3 bucket name This is the name of the bucket where files will be uploaded. If it does not exist, it will be created for you when the first file is uploaded.

• Minimum file size Any files uploaded above this size will automatically be sent to the cloud. Smaller files can still be manually uploaded.

How it works

The package registers an event subscribe that watches for new file field uploads. If the size of the file data exceeds the ‘minimum file size’ set above, it will register a celery task that asyncronously uploads the data to the cloud.

Once the upload is complete, celery will notify Plone, which generates an email to the content creator.

Once the cloud copy is available, the package patches the ‘download’ methods so that any requests for the file data result in a redirect to the cloud copy. Each request generates an auto-expiring one-time URL to the cloud copy, ensuring the security of the cloud data.

Transcoding

Files with a ‘video’ mimetype are also sent through a transcoding pipeline. This transcoded version is stored separately, and must be manually requested by passing ‘transcoded=true’ on the file download request e.g.

http://myplonesite/folder/myfile/at_download/file?transcoded=true

Files are currently transcoded using the ‘Generic 480p 16:9’ preset (1351620000001-000020)

TODO

• Remove data from the cloud when it is removed from Plone

• Make transcoding step optional

• Support for other transcoding presets

• Support other cloud backends

Contributors

• Ben Cole (Architecture and initial implementation)

• Matthew Sital-Singh (Implementation and documentation)

Changelog