Add style checks to CI

See merge request !16

Trivial style corrections.

flake8 is an automatic style checker. This is very useful to ensure that
we have a consistent style as more people start contributing to the
code.

We ignore coolr for now, as it's a big offender.

[feature] add basic CI support

See merge request !15

Gitlab CI support, for a py.test run inside the pipenv configuration.

Convert the project to pipenv

See merge request !14

Pipenv is a recent python tool, so add a bit of documentation in the
readme for users.

Pipenv provides a reproducible description of the python packages
necessary for a python application. See the Pipenv documentation for
reference.

We also remove tox from the repo, relying instead directly on pytest.
Since we only supported one version of python, that's not a big deal.

Testing fixes

See merge request !13

Somehow missed that one.

Small fixes to correct for wrong actions on power control over a real
load.

Recent work has added and renamed binaries to the repository. This patch
syncs the setup.py file to match the current state.

This fixes missing binaries from path inside virtual environments.

Implement control loop

See merge request !12

Change the PowerActuator to be able to lower the power limit. Because
RAPL doesn't provide an actual lower limit, we use 0 as the minimal
power.

This patch adds a poweractuator based on rapl settings available through
the sensor manager. Adding this actuator forces us to use a list of
actuators in the controller, changing a bit the structure of the code.

This patch introduce one more level of abstraction to the controller:
an actuator. Actuators will act as the middleman between specific
managers and the controller, while providing enough info to implement
actual models on top.

For now, we only have the application threads actuator.

Initial support for perf wrapper

See merge request !11

The "control" part of the NRM is bound to change and become more complex
in the near future, so move it in its own module.

This refactor also introduce some controller logic. Control is split
into 3 steps: planning, execution and updates. The goal is to use this
new code organization as a way to abstract different control policies
that could be implemented later.

Note that we might at some point move into a "control manager" and a
bunch of "policies" and "actuators", as a way of matching typical
control theory vocabulary.

Small things like spacing and extra semicolon. It is also recommended to
use the 0o notation for octal, as a way to make them stand out in the
code.

Bugfixes for recently implemented features

See merge request !10

Fixes a copy/paste mistake on the name of the callback to trigger on
stderr events.

This patch fixes the daemon code to include the container uuid in the
environment of the command, while changing that environment variable to
use a better suited name.

Improve the downstream API

See merge request !9

This patch replace the client code (bin/client and nrm/client) by a new
application code that integrates progress reports and uses the new
downstream API.

While git is reporting that both codes are different, the app code is
basically a refactoring and adaptation of the client code.

This is directly related to issue #2.

This patch moves the tracking of applications clients of the downstream
API into a ApplicationManager, that is able to track progress and thread
management.

This change is necessary in the long term to build a comprehensive
downstream API and centralize the management of application tracking.

Note that this tracking is currently independent of the container and
pid tracking, and that might be a problem in the long term.

This patch refactors the downstream API to use pub/sub socket pair, like
the upstream API. This is part of the effort to improve the downstream
API. See #2.

This patch doesn't touch the client module, which will be adapted in
future commits.

Fix upstream publishers messaging issues

See merge request !8

The way 0MQ works on PUB/SUB sockets, publishers might drop
messages if subscribers are not detected faster enough. One way to fix
it is to have the "server" always bind sockets, and the "client" use
connect. This way, the handshake is initiated properly, and the client
can publish as soon as the connection is done.

This patch makes the daemon bind on the upstream API and the CLI connect,
fixing in the process the message dropping we were experiencing before.

Long term, we might have a think of using 2 types of sockets for the
upstream API: pub/sub for actual events published from the daemon, and
a REQ/REP or ROUTER/DEALER pair for "commands".

Fix recent coolr issues and start building tests for it

See merge request !7

This patch adds a test for the nrm/coolr/clr_rapl.py code, based on
the __main__ code added to it recently. This is an example of how the
modules should be tested automatically, instead of relying on __main__
snippets everywhere.

We should replace those snippets bits by bits by tests similar to this
one. The end goal is to able to active a gitlab pipeline that validate
merge requests automatically.

Previous commit 0c93ce6a broke the
sample code used by the daemon, by reverting the sample function to a
json message generator. This is due to inconsistencies between the coolr
code and the NRM import: we removed json generation from coolr, to push
it on the messaging side, while upstream still does it on sensor
reading.

This commit fixes that, but doesn't touch the new test code embedded in
clr_rapl.py
We will move that the test infrastructure later.

Switch to subprocess

See merge request !6

This patch implements a small finite state machine on the cmd side to be
able to run a command, wait for all of its output, and then exit.

As the daemon can send those message in any order, we need to wait them
properly, in particular the closing of stdout/stderr before exiting.

This patch also fixes the read_until_close callback creation to ensure
that the stream EOF is handled as a distinct message.