Bug 1597297

Created attachment 1455968 [details]
failed/incorrect validation from the dashboard following implicit conversion to millicore value.

Description of problem:

Using the following decimal values defined in a LimitRange object for maxLimitRequestRatio:

spec:
  limits:
  - type: Container
    maxLimitRequestRatio:
      cpu: "1.5"
      memory: "1.5"
    default:
      cpu: 150m
      memory: 1Gi
    defaultRequest:
      cpu: 50m
      memory: 1Gi
    max:
      cpu: "4"
      memory: 4Gi
    min:
      cpu: 50m
      memory: 32Mi

Will result in implicit conversion of the "1.5" ratio value to "1500m" for both memory and CPU, causing incorrect enforcement of maxLimitRequestRatio when a tenant specifies request/limit values that should be valid.


Version-Release number of selected component (if applicable):

3.9
3.7
3.4


How reproducible:

Always

Steps to Reproduce:
1. Define a LimitRange object (as above) with maxLimitRequestRatio containing non-integer values.
2. Attempt to configure container resource limits/requests within the expected, allowable range of maxLimitRequestRatio values.
3. Observe failure to enforce maxLimitRequestRatio due to implicit conversion of non-integer value (for both memory and CPU) to "millicores."
4. Change maxLimitRequestRatio to a non-negative integer > 1 to confirm proper enforcement.

Actual results:


Expected results:

Specifying a non-integer value, such as "1.5", for memory/CPU maxLimitRequestRatio should prevent a tenant from specifying a limit >= to (1.5 x request). With the limitRange example above, a tenant specifying a CPU request of 50m and a limit of 150m would encounter a validation error with 150m >= (50m x 1.5 = 75m). If the tenant specified a CPU request of 50m and a limit of 75m, validation should succeed. The same should hold true for memory. If a tenant specifies a memory request of 64MiB and a limit of 128MiB, validation would fail: 128Mib >= (64MiB x 1.5 = 96MiB). Validation would succeed if they specified a memory request of 64MiB and a limit of 96MiB.


Additional info:

Documentation [1] makes no mention of the integer values being required, but a stopgap measure may be noting that only integer values > 1 are required. A screenshot of failed/incorrect validation from the dashboard has been provided.