Count attribute#

By default, a resource configures a single object. (Similarly, a module/package resource includes a child module's contents into the configuration one time.) However, sometimes you want to manage several similar resource (like a fixed pool of interfaces) without writing a separate resource for each one. Kform has two ways to do this: count and for_each.

If a resource or module/package block includes a count argument whose value is a number, KForm will create that many instances.

Usage#

count is an attribute defined by the KForm language. You can use the count attribute in all block-types except the input block-type

The count attribute accepts a whole number, and creates that many instances of the resource or module/package. Each instance has a distinct resource associated with it, and each is separately created, updated, or deleted when the configuration is applied.

apiVersion: v1
kind: ConfigMap
metadata:
  name: '["example", count.index].concat("-")'
  namespace: example-system
  annotations:
    kform.dev/count: input.context[0].data.count
data:
  image: count.index

The count variable#

In resources where the count attribute is specified, KForm automatically defines an additional count variable, enabling dynamic configuration adjustments for each instance. This count object facilitates modification of individual configurations within the resource. It comprises a single attribute:

• count.index: Represents the unique index number, starting from 0, associated with each instance, allowing precise identification and manipulation within the configuration."

Using expressions in count#

Numeric expressions can be used in the count attribute that are also used when Kform calculates the dependencies between resources.

Referring to count resources.#

A resource is always referred to as <RESOURCE-TYPE>.<RESOURCE-ID>[INDEX]. Normally Index is 0 but resources that use the count attribute could refer to an index different then 0.