Add Metering Used Hours to chargeback report

[lpichler]

Metering Used Hours is:

• the integer value of hours
• the duration of the chargeable period in chargeback report for the resource (VM)
• this period is set according to a time range in report (set in UI) but it reflects when VM was
  stared and retired.
• it is related to
  https://github.com/ManageIQ/manageiq/blob/master/app/models/chargeback/consumption.rb#L7

Which reports ?
Chargeback for VMs
Chargeback for Projects
Chargeback for Containers Images

Report definition

Example of report:

with rate $1 per month:

so the example of the calculation is:

Metering Used Metric - is count of hours in consumption period

and we will just multiple this by hourly rate from our example it is :
($1.0 / (31.0 * 24.0) ) * 277.0 = $0.37231182795698925

so generic formula is:
Hourly Rate * Metering Used Metric

Hourly Rate
we need to convert rate from rate editor to hourly rate:
from our example:
($1.0 / (31.0 * 24.0) )
(cost in rate editor / (count of hours for month/week/day - this is the 'per XXX' from rate editor ) )

@miq-bot assign @gtanzillo
/cc @Loicavenel

[gshefer]

Hello,
We need this PR to be merged ASAP in order to have it in the next Z-stream release.
Currently, we cannot test chargeback (since we cannot know the Consumed Hours Metric).
Thanks :-)

[Loicavenel]

@gshefer what Zstream are you referencing? t

[gshefer]

@Loicavenel 5.8.3 release.

[Loicavenel]

@gshefer is there a BZ behind this, I did request it for CFME 5.9 not for 5.8

[gshefer]

@Loicavenel So I must have the exact calculation for getting this metric, else we cannot test chargeback on 5.8.

[gshefer]

@lpichler @Loicavenel Can you please describe me the exact calculation that is being done for this metric? so we will be able to test Chargeback also for 5.8.

[Loicavenel]

@gshefer this is unrelated to Chargeback calculation, Hours are not used. This is extra information customer are looking for. Calculation is based on metrics collected, if a metrics exist we will count the full hour.

[gshefer]

@Loicavenel I understand from @zeari that chargeback use this metric instead of fixed_compute_metric.

[lpichler]

@gshefer
yes it will be used instead of fixed_compute_metric but it has sort of different meaning.
consumed hours metric is the count of hours on the selected interval. "Selected interval" is report interval - it can be the month, week or day. The length can affect the length of the month (28, 30, 31) or time of creating the resource.
Let me finish this PR and I will show you the example of calculation.
thanks!

[Loicavenel]

@lpichler in which report this new field will be available? Chargeback & Performance reports?

[lpichler]

@Loicavenel in
Chargeback for VMs
Chargeback for Projects
Chargeback for Containers Images

[lpichler]

@gtanzillo @Loicavenel @zeari @gshefer PR is finished please review - I updated description.
New field is called Metering Used Hours.

[lpichler]

@miq-bot remove wip

[miq-bot]

@lpichler unrecognized command 'remove', ignoring...

Accepted commands are: add_label, assign, close_issue, move_issue, remove_label, rm_label, set_milestone

[gtanzillo]

Looks great, just a couple of minor changes requested 👍

[gtanzillo]

I think this would read better as Metering - Hours Used

[gtanzillo]

Perhaps this method should be named metering?

[miq-bot]

Checked commits lpichler/manageiq@ff2e851~...ed7b1ef with ruby 2.2.6, rubocop 0.47.1, and haml-lint 0.20.0
12 files checked, 0 offenses detected
Everything looks fine. 👍

[lpichler]

@gtanzillo updated, thanks

[simaishi]

BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1497947