[data processing] Allow for HDFS data sources without prefix

[Chad Roberts]

Priority *wishlist*:

This is a fix that was from the sahara-dashboard repo that came in after the merge was started. It needs to be ported to the horizon codebase post-merge.

Original patch: https://review.openstack.org/#/c/92833/

Sahara currently demands that the URL for an hdfs data source begins with the hdfs scheme "hdfs://". The UI enforces this restriction as well.

When the hdfs scheme is specified, hadoop requires the hostname and/or port to be specified as well. For use of an external hdfs, of course, the host/port are always necessary.

On a long running cluster, the local hdfs can be used by specifying the host/port of the local namenode in the path so that data can be read/written to the cluster hdfs, for example "hdfs://test-master:9000/user/hadoop/input". However, hadoop supports simpler absolute and relative paths to access the local hdfs without specification of the host and port.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/103944

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/103944
Committed: https://git.openstack.org/cgit/openstack/horizon/commit/?id=68d86f7b0c0511537bbe6b49bb2bbfbfff4fa867
Submitter: Jenkins
Branch: master

commit 68d86f7b0c0511537bbe6b49bb2bbfbfff4fa867
Author: Chad Roberts <email address hidden>
Date: Tue Jul 1 13:10:45 2014 -0400

    Data Processing: Allowing for HDFS data sources without hdfs://

    Now that HDFS data sources can be either full URLs
    or paths relative to the cluster itself, it is no
    longer desirable to force "hdfs://" at the start
    of hdfs data sources.
    * No longer force the prefix on the create form
    * For swift, we now check to see that the location
      starts with swift://, if it doesn't we add it

    Change-Id: I62a8fbad6d55505c2b82561fe3de706e5069c83f
    Closes-Bug: bug #1336283