corepair

What does this cluster actually need, and what should we therefore buy?

corepair measures real demand on an OpenShift or Kubernetes cluster, converts it into a subscription count using the rules that actually apply, and produces a cost case that shows its working — including which parts of a multi-year saving are contractual and which are just forecasts.

It is the missing step between kubectl top and a purchase order.

$ corepair audit
Subscribed nodes : 9 / 12
Core-pairs       : 22
Rounding waste   : 6 vCPU paid for but not present

FINDING  infra nodes without an infra taint (application pods can still land here,
         so the exemption does not apply):
  - infra-02: 2 core-pairs would be released by tainting it

FINDING  node sizes that are not a multiple of 4 vCPU. Rounding is per node, so the
         remainder is paid for and unusable:
  - worker-05: 6 vCPU -> 2 core-pairs (2 vCPU wasted)

$ corepair cost --pricing pricing.yaml --units 32 --base-units 8

| Scenario                                | Peak units | Total (EUR) | NPV @ 5% |
|-----------------------------------------|-----------|-------------|----------|
| All 32 units, 1y                         | 32        |      86,534 |   82,240 |
| All 32 units, 3y                         | 32        |      71,424 |   68,077 |
| Blended: 8 on 3y, 24 on 1y from year 2   | 32        |      63,317 |   59,259 |

### Where the multi-year saving actually comes from

| Component                                      |    EUR | Share |
|------------------------------------------------|--------|-------|
| Term / discount differential                    |  6,336 |   42% |
| Avoided list-price growth (assumption)          |  3,953 |   26% |
| Avoided discount decay at renewal (assumption)  |  4,822 |   32% |
| **Headline saving**                             | 15,110 |  100% |

**58% of the headline rests on forecasts**, not on the contract itself.

Why this exists

Subscription quantities get decided from a node inventory and a growth guess, then defended with a single savings number. Two things go wrong:

The count is wrong. Core-pair rounding happens per node, so ten 6-vCPU nodes cost twenty core-pairs rather than fifteen. Infra nodes are only exempt if they are tainted, not merely labelled. Meanwhile most estates request several times the CPU they use, and requests — not usage — are what force nodes to exist. Right-size first and the count often falls by half.

The savings case is mostly assumptions. A three-year lock is justified by a number that quietly combines the discount differential (a term you can hold the vendor to) with assumed annual list-price growth and an assumed worse discount at renewal (forecasts, which are negotiable). corepair separates them. If most of the case is forecast, the right move is to ask for those forecasts in writing — and to notice if the answer is no.

Install

pipx install corepair          # or: pip install corepair

Use

# 1. What do we actually run, versus what did we reserve?
corepair measure --prometheus https://thanos-querier... --window 30d \
                 --snapshot-out baseline.json

# 2. What are we subscribing that we needn't be?
corepair audit

# 3. What will the migration waves need, and when?
corepair plan --plan plan.yaml

# 4. What should we buy, and what does the saving really consist of?
corepair cost --pricing pricing.yaml --units 16 --base-units 8 \
              --sensitivity 8 24 --xlsx case.xlsx

On OpenShift, --prometheus points at the thanos-querier route with export PROM_TOKEN=$(oc whoami -t).

Every command reads and writes nothing but its own files. corepair has no cluster-side component and needs only read access.

Snapshots

--snapshot-out freezes a measurement so it can be replayed, reviewed, and committed alongside the proposal. A licence recommendation built on numbers nobody else can reproduce is an assertion, not a recommendation.

What it knows

Each of these is a unit test in tests/test_licensing.py, which doubles as the readable specification.

corepair ships no prices

Vendor pricing is confidential and contract-specific. A figure copied from someone else's repo is worse than none, because it looks authoritative. examples/pricing.example.yaml documents the schema with placeholders that the tool refuses to run against — replace them with figures from your own quote.

The same goes for your plan file and any snapshot: they describe your estate. Publish the schema, not the data.

Caveats worth reading

• The counting rules encode Red Hat's OpenShift subscription model as of 2026. Verify against your own contract — entitlement terms change and vary by agreement. This tool tells you what your cluster needs, not what you owe.
• Not affiliated with, or endorsed by, Red Hat or IBM.
• corepair is an input to a decision, not the decision. It has no opinion on whether your discount is good.

License

Apache-2.0

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Five Nines be upon you, and also with you.
Kubernetes · OpenShift · High Availability
               HA-llelujah.

✠ The Church of the Eternal Cluster

A Highly Available Faith. Keep no Pets. Declare thy state. Back up etcd.

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More from the Rootless One

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_{An independent parody, built with love for everyone who has been paged at 03:00. Kubernetes is a trademark of the Linux Foundation. OpenShift is a trademark of Red Hat, Inc. Not affiliated with, nor endorsed by, either. They have real SLAs; we only have belief. HA-llelujah.}