# KubernetesPatch

A CloudFormation resource which applies/restores a JSON patch into a Kubernetes resource.

Extends: Construct › KubernetesPatch
Implements: IConstruct, IDependable

- Source: [`aws-eks/lib/k8s-patch.ts`](https://github.com/aws/aws-cdk/blob/v2.275.0/packages/aws-cdk-lib/aws-eks/lib/k8s-patch.ts#L85)

## Example

```ts
declare const cluster: eks.Cluster;
new eks.KubernetesPatch(this, 'hello-kub-deployment-label', {
  cluster,
  resourceName: "deployment/hello-kubernetes",
  applyPatch: { spec: { replicas: 5 } },
  restorePatch: { spec: { replicas: 3 } },
})
```

## Initializer

```ts
new KubernetesPatch(scope: Construct, id: string, props: KubernetesPatchProps)
```

## Construct Props

- `applyPatch`: { [key: string]: any } (required) — The JSON object to pass to `kubectl patch` when the resource is created/updated.

- `cluster`: [ICluster](/cdk/api/v2/docs/aws-cdk-lib.aws_eks.ICluster.html) (required) — The cluster to apply the patch to.

  [disable-awslint:ref-via-interface]

- `patchType`: [PatchType](/cdk/api/v2/docs/aws-cdk-lib.aws_eks.PatchType.html) = PatchType.STRATEGIC — The patch type to pass to `kubectl patch`.

  The default type used by `kubectl patch` is "strategic".

- `removalPolicy`: [RemovalPolicy](/cdk/api/v2/docs/aws-cdk-lib.RemovalPolicy.html) = RemovalPolicy.DESTROY — The removal policy applied to the custom resource that manages the Kubernetes patch.

  The removal policy controls what happens to the resource if it stops being managed by CloudFormation.
  This can happen in one of three situations:

  - The resource is removed from the template, so CloudFormation stops managing it
  - A change to the resource is made that requires it to be replaced, so CloudFormation stops managing it
  - The stack is deleted, so CloudFormation stops managing all resources in it

- `resourceName`: string (required) — The full name of the resource to patch (e.g. `deployment/coredns`).

- `resourceNamespace`: string = "default" — The kubernetes API namespace.

- `restorePatch`: { [key: string]: any } (required) — The JSON object to pass to `kubectl patch` when the resource is removed.

## Properties

- `node`: [Node](/cdk/api/v2/docs/constructs.Node.html) — The tree node.

## Methods

- `isConstruct(x: any): boolean` (static) — Checks if `x` is a construct.

  Use this method instead of `instanceof` to properly detect `Construct`
  instances, even when the construct library is symlinked.

  Explanation: in JavaScript, multiple copies of the `constructs` library on
  disk are seen as independent, completely different libraries. As a
  consequence, the class `Construct` in each copy of the `constructs` library
  is seen as a different class, and an instance of one class will not test as
  `instanceof` the other class. `npm install` will not create installations
  like this, but users may manually symlink construct libraries together or
  use a monorepo tool: in those cases, multiple copies of the `constructs`
  library can be accidentally installed, and `instanceof` will behave
  unpredictably. It is safest to avoid using `instanceof`, and using
  this type-testing method instead.

  **Parameters**

  - `x` — Any object.

  **Returns:** true if `x` is an object created from a class which extends `Construct`.

- `toString(): string` — Returns a string representation of this construct.

- `with(...mixins: IMixin[]): IConstruct` — Applies one or more mixins to this construct.

  Mixins are applied in order. The list of constructs is captured at the
  start of the call, so constructs added by a mixin will not be visited.
  Use multiple `with()` calls if subsequent mixins should apply to added
  constructs.

  **Parameters**

  - `mixins` — The mixins to apply.

  **Returns:** This construct for chaining