The INSIGHTS_MYSQL_USER variable is not defined, so the Insights database user was not being created.

Added install:configuration tag to step that sets up forum env

It turns out ansible already provides info about the default network
interface in the ansible_default_ipv4 dict variable, so we can use that
instead of using the 'ip route show' command.

On Ubuntu 16.04, the default networks interface is not always called
eth0, depending on the hardware. The name of the default network
interface on some VM types on AWS is ens3, for example.

Determine the interface name using ip route command instead of
hardcoding to eth0.

Also, /etc/network/interfaces.d/<interface-name>.cfg files no longer
exist in Ubuntu 16.04. Use a script in /etc/network/if-up.d to
adjust the MTU value at startup instead.

signle quoted regex

Added the option of overriding atomic requests without having to override the entire database configuration structure.

Added a way to override having the aws role be installed. In cases where a local host is being used, aws role is not needed. Default remains true though.

Added the `install:configuration` tag to the step that writes the forum_env to disk so that updated mongodb credentials
are properly propagated to the service during deployments.

Added `EDXAPP_LMS_ENV_EXTRAS` and `EDXAPP_CMS_ENV_EXTRAS` to default vars in order to be able to have different values for the `env_extras` between LMS and CMS.

(cherry picked from commit bb5bc41f)

removing unneeded, missing alternatives

bad diag

missed var

(cherry picked from commit 0ca865c9)

Make changes for running analyticstack on 16.04.

* Replace llvm-gcc with gcc.
* Define new Hadoop services.
* Add retry when first using Hadoop.
* Update procps package to address bug.
* Increase memory from 4GB to 6GB.
* Disable vmem-check in yarn.

(cherry picked from commit 1c138599)

Since the earliest days of edX, we've run gunicorn with preload_app as
True. This was primarily because the first handful of courses were using
the XMLModuleStore, which was extremely slow to initialize because it
had to read entire courses from disk and load them into memory at
startup.

XMLModuleStore courses stopped being created with the introduction of
Studio, and we've long since removed them from edx.org. Note: This
should not be confused with importing courses that are authored in XML.
XMLModuleStore courses are courses who use the disk instead of Mongo
for content persistence, and require a server restart for content edits
to show.

This commit sets things back to how Django is more commonly deployed
with gunicorn. It will make server startup time somewhat more expensive
because each worker process does init work, but it should make it
easier to safely enable features like database connection pooling
without having to worry about shared resources.

[PERF-305]

(cherry picked from commit 30b924d5)

(cherry picked from commit e90ed376)

(cherry picked from commit ff65c883)

Cherry pick ebb13031

update firefox version test for jenkins workers

(cherry picked from commit 37dfceb6)

(cherry picked from commit d891e660)

temp add stop-automatic-updates to packer scripts

(cherry-picked from 304d6ead)

We already do this in the common role but not in bootstrap or abbey roles.

(cherry picked from commit b78c0487)

See https://github.com/ansible/ansible/issues/21316

This prevented successful installation of open-release/ficus.1rc

(cherry picked from commit a79fe1b7)

Apply the change to install MySQL 5.6 from an edX PPA

(cherry picked from commit 6218350b)