## What changes were proposed in this pull request?

New config var: spark.mesos.docker.containerizer={"mesos","docker" (default)}

This adds support for running docker containers via the Mesos unified containerizer: http://mesos.apache.org/documentation/latest/container-image/

The benefit is losing the dependency on `dockerd`, and all the costs which it incurs.

I've also updated the supported Mesos version to 0.28.2 for support of the required protobufs.

This is blocked on: https://github.com/apache/spark/pull/14167

## How was this patch tested?

- manually testing jobs submitted with both "mesos" and "docker" settings for the new config var.
- spark/mesos integration test suite

Author: Michael Gummelt <mgummelt@mesosphere.io>

Closes #14275 from mgummelt/unified-containerizer.

## What changes were proposed in this pull request?

(Please fill in changes proposed in this fix)

## How was this patch tested?

(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)

(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)

Mesos agents by default will not pull docker images which are cached
locally already. In order to run Spark executors from mutable tags like
`:latest` this commit introduces a Spark setting
(`spark.mesos.executor.docker.forcePullImage`). Setting this flag to
true will tell the Mesos agent to force pull the docker image (default is `false` which is consistent with the previous
implementation and Mesos' default
behaviour).

Author: Philipp Hoffmann <mail@philipphoffmann.de>

Closes #14348 from philipphoffmann/force-pull-image.

This reverts commit 978cd5f1.

## What changes were proposed in this pull request?

Mesos agents by default will not pull docker images which are cached
locally already. In order to run Spark executors from mutable tags like
`:latest` this commit introduces a Spark setting
`spark.mesos.executor.docker.forcePullImage`. Setting this flag to
true will tell the Mesos agent to force pull the docker image (default is `false` which is consistent with the previous
implementation and Mesos' default
behaviour).

## How was this patch tested?

I ran a sample application including this change on a Mesos cluster and verified the correct behaviour for both, with and without, force pulling the executor image. As expected the image is being force pulled if the flag is set.

Author: Philipp Hoffmann <mail@philipphoffmann.de>

Closes #13051 from philipphoffmann/force-pull-image.

## What changes were proposed in this pull request?
After SPARK-16476 (committed earlier today as #14128), we can finally bump the version number.

## How was this patch tested?
N/A

Author: Reynold Xin <rxin@databricks.com>

Closes #14130 from rxin/SPARK-16477.

Author: Luciano Resende <lresende@apache.org>

Closes #11092 from lresende/SPARK-13189.

Author: Reynold Xin <rxin@databricks.com>

Closes #10387 from rxin/version-bump.

Spark should build against Scala 2.10.5, since that includes a fix for Scaladoc that will fix doc snapshot publishing: https://issues.scala-lang.org/browse/SI-8479

Author: Josh Rosen <joshrosen@databricks.com>

Closes #9450 from JoshRosen/upgrade-to-scala-2.10.5.

Author: Reynold Xin <rxin@databricks.com>

Closes #8350 from rxin/1.6.

Author: Patrick Wendell <patrick@databricks.com>

Closes #6328 from pwendell/spark-1.5-update and squashes the following commits:

2f42d02 [Patrick Wendell] A few more excludes
4bebcf0 [Patrick Wendell] Update to RC4
61aaf46 [Patrick Wendell] Using new release candidate
55f1610 [Patrick Wendell] Another exclude
04b4f04 [Patrick Wendell] More issues with transient 1.4 changes
36f549b [Patrick Wendell] [SPARK-7801] [BUILD] Updating versions to SPARK 1.5.0

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #5056 from vanzin/SPARK-6371 and squashes the following commits:

63220df [Marcelo Vanzin] Merge branch 'master' into SPARK-6371
6506f75 [Marcelo Vanzin] Use more fine-grained exclusion.
178ba71 [Marcelo Vanzin] Oops.
75b2375 [Marcelo Vanzin] Exclude VertexRDD in MiMA.
a45a62c [Marcelo Vanzin] Work around MIMA warning.
1d8a670 [Marcelo Vanzin] Re-group jetty exclusion.
0e8e909 [Marcelo Vanzin] Ignore ml, don't ignore graphx.
cef4603 [Marcelo Vanzin] Indentation.
296cf82 [Marcelo Vanzin] [SPARK-6371] [build] Update version to 1.4.0-SNAPSHOT.

select empty should NOT be the same as select. make sure selectExpr is behaving the same.
join param documentation
link to source doesn't work in jekyll generated file
cross reference of columns (i.e. enabling linking)
show(): move df example before df.show()
move tests in SQLContext out of docstring otherwise doc is too long
Column.desc and .asc doesn't have any documentation
in documentation, sort functions.*)

Author: Davies Liu <davies@databricks.com>

Closes #4756 from davies/df_docs and squashes the following commits:

f30502c [Davies Liu] fix doc
32f0d46 [Davies Liu] fix DataFrame docs

#3934 upgraded Mesos version so we should also fix docs right?

This issue is really minor so I don't file in JIRA.

Author: Kousuke Saruta <sarutak@oss.nttdata.co.jp>

Closes #3982 from sarutak/fix-mesos-version and squashes the following commits:

9a86ee3 [Kousuke Saruta] Fixed mesos version from 0.18.1 to 0.21.0

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #3277 from vanzin/version-1.3 and squashes the following commits:

7c3c396 [Marcelo Vanzin] Added temp repo to sbt build.
5f404ff [Marcelo Vanzin] Add another exclusion.
19457e7 [Marcelo Vanzin] Update old version to 1.2, add temporary 1.2 repo.
3c8d705 [Marcelo Vanzin] Workaround for MIMA checks.
e940810 [Marcelo Vanzin] Bumping version to 1.3.0-SNAPSHOT.

The version number of Spark in docs/_config.yaml for master branch should be 1.2.0 for now.

Author: Kousuke Saruta <sarutak@oss.nttdata.co.jp>

Closes #2943 from sarutak/SPARK-4089 and squashes the following commits:

aba7fb4 [Kousuke Saruta] Fixed the version number of Spark in _config.yaml

Retire Epydoc, use Sphinx to generate API docs.

Refine Sphinx docs, also convert some docstrings into Sphinx style.

It looks like:
![api doc](https://cloud.githubusercontent.com/assets/40902/4538272/9e2d4f10-4dec-11e4-8d96-6e45a8fe51f9.png)

Author: Davies Liu <davies.liu@gmail.com>

Closes #2689 from davies/docs and squashes the following commits:

bf4a0a5 [Davies Liu] fix links
3fb1572 [Davies Liu] fix _static in jekyll
65a287e [Davies Liu] fix scripts and logo
8524042 [Davies Liu] Merge branch 'master' of github.com:apache/spark into docs
d5b874a [Davies Liu] Merge branch 'master' of github.com:apache/spark into docs
4bc1c3c [Davies Liu] refactor
746d0b6 [Davies Liu] @param -> :param
240b393 [Davies Liu] replace epydoc with sphinx doc

This patch makes some small changes to fix this problem:
1. We document specific versions of Jekyll/Kramdown to use that match
   those used when building the upstream docs.
2. We add a configuration for a property that for some reason varies across
   packages of Jekyll/Kramdown even with the same version.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #2443 from pwendell/jekyll and squashes the following commits:

54ee2ab [Patrick Wendell] SPARK-3579 Jekyll doc generation is different across environments.

Here's my crack at Bertrand's suggestion. The Github `README.md` contains build info that's outdated. It should just point to the current online docs, and reflect that Maven is the primary build now.

(Incidentally, the stanza at the end about contributions of original work should go in https://cwiki.apache.org/confluence/display/SPARK/Contributing+to+Spark too. It won't hurt to be crystal clear about the agreement to license, given that ICLAs are not required of anyone here.)

Author: Sean Owen <sowen@cloudera.com>

Closes #2014 from srowen/SPARK-3069 and squashes the following commits:

501507e [Sean Owen] Note that Zinc is for Maven builds too
db2bd97 [Sean Owen] sbt -> sbt/sbt and add note about zinc
be82027 [Sean Owen] Fix additional occurrences of building-with-maven -> building-spark
91c921f [Sean Owen] Move building-with-maven to building-spark and create a redirect. Update doc links to building-spark.html Add jekyll-redirect-from plugin and make associated config changes (including fixing pygments deprecation). Add example of SBT to README.md
999544e [Sean Owen] Change "Building Spark with Maven" title to "Building Spark"; reinstate tl;dr info about dev/run-tests in README.md; add brief note about building with SBT
c18d140 [Sean Owen] Optionally, remove the copy of contributing text from main README.md
8e83934 [Sean Owen] Add CONTRIBUTING.md to trigger notice on new pull request page
b1c04a1 [Sean Owen] Refer to current online documentation for building, and remove slightly outdated copy in README.md

Place more emphasis on using precompiled binary versions of Spark and Mesos
instead of encouraging the reader to compile from source.

Author: Andrew Ash <andrew@andrewash.com>

Closes #756 from ash211/spark-1818 and squashes the following commits:

7ef3b33 [Andrew Ash] Brief explanation of the interactions between Spark and Mesos
e7dea8e [Andrew Ash] Add troubleshooting and debugging section
956362d [Andrew Ash] Don't need to pass spark.executor.uri into the spark shell
de3353b [Andrew Ash] Wrap to 100char
7ebf6ef [Andrew Ash] Polish on the section on Mesos Master URLs
3dcc2c1 [Andrew Ash] Use --tgz parameter of make-distribution
41b68ed [Andrew Ash] Period at end of sentence; formatting on :5050
8bf2c53 [Andrew Ash] Update site.MESOS_VERSIOn to match /pom.xml
74f2040 [Andrew Ash] SPARK-1818 Freshen Mesos documentation

While play-testing the Scala and Java code examples in the MLlib docs, I noticed a number of small compile errors, and some typos. This led to finding and fixing a few similar items in other docs.

Then in the course of building the site docs to check the result, I found a few small suggestions for the build instructions. I also found a few more formatting and markdown issues uncovered when I accidentally used maruku instead of kramdown.

Author: Sean Owen <sowen@cloudera.com>

Closes #653 from srowen/SPARK-1727 and squashes the following commits:

6e7c38a [Sean Owen] Final doc updates - one more compile error, and use of mean instead of sum and count
8f5e847 [Sean Owen] Fix markdown syntax issues that maruku flags, even though we use kramdown (but only those that do not affect kramdown's output)
99966a9 [Sean Owen] Update issue tracker URL in docs
23c9ac3 [Sean Owen] Add Scala Naive Bayes example, to use existing example data file (whose format needed a tweak)
8c81982 [Sean Owen] Fix small compile errors and typos across MLlib docs

This reverts commit 12c077d5.

Mesos 0.13.0 was released 6 months ago.
Upgrade Mesos dependency to 0.17.0

Author: Sandeep <sandeep@techaddict.me>

Closes #355 from techaddict/mesos_update and squashes the following commits:

f1abeee [Sandeep] SPARK-1433: Upgrade Mesos dependency to 0.17.0 Mesos 0.13.0 was released 6 months ago. Upgrade Mesos dependency to 0.17.0

Just a Scala version increment

Author: Mark Hamstra <markhamstra@gmail.com>

Closes #259 from markhamstra/scala-2.10.4 and squashes the following commits:

fbec547 [Mark Hamstra] [SPARK-1342] Bumped Scala version to 2.10.4

Author: Reynold Xin <rxin@apache.org>

Closes #2 from rxin/docs and squashes the following commits:

08bbd5f [Reynold Xin] Removed reference to incubation in Spark user docs.

https://spark-project.atlassian.net/browse/SPARK-1105

fix site scala version error

Author: CodingCat <zhunansjtu@gmail.com>

Closes #618 from CodingCat/doc_version and squashes the following commits:

39bb8aa [CodingCat] more fixes
65bedb0 [CodingCat] fix site scala version error in doc