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Apply stage

Overview

Once change set is calculated (see Diff section for details), kapp asks for user confirmation (unless --yes flag is specified) to proceed with changes.

Changes are applied in particular order as described in Apply ordering.

All created resources are labeled with several labels:

  • kapp.k14s.io/app to track which application “owns” resource
  • kapp.k14s.io/identity to identify preferred API version used when creating resource
  • kapp.k14s.io/association to track (best effort) parent-child relationships between resources

Every time application is deployed, new application change record is saved. They can be viewed via kapp app-change ls -a app-name.

Related: ownership label rules and label scoping rules.

Controlling apply via resource annotations

kapp.k14s.io/create-strategy

kapp.k14s.io/create-strategy annotation controls create behaviour (rarely necessary)

Possible values: "" (default), fallback-on-update.

In some cases creation of a resource may conflict with that resource being created in the cluster by other means (often automated). An example of that is creation of default ServiceAccount by kapp racing with Kubernetes service accounts controller doing the same thing. By specifying fallback-on-update value, kapp will catch resource creation conflicts and apply resource as an update.

kapp.k14s.io/update-strategy

kapp.k14s.io/update-strategy annotation controls update behaviour

Possible values: "" (default), fallback-on-replace, always-replace, skip.

In some cases entire resources or subset resource fields are immutable which forces kapp users to specify how to apply wanted update.

  • "" means to issue plain update call
  • fallback-on-replace causes kapp to fallback to resource replacement if update call results in Invalid error. Note that if resource is replaced (= delete + create), it may be negatively affected (loss of persistent data, loss of availability, etc.). For example, if Deployment or DaemonSet is first deleted and then created then associated Pods will be recreated as well, but all at the same time (even if rolling update is enabled), which likely causes an availability gap.
  • always-replace causes kapp to always delete and then create resource (See note above as well.)
  • skip causes kapp to not apply update (it will show up in a diff next time). Available in v0.33.0+.

kapp.k14s.io/delete-strategy

kapp.k14s.io/delete-strategy annotation controls deletion behaviour

Possible values: "" (default), orphan.

By default resource is deleted, however; choosing orphan value will make kapp forget about this resource. Note that if this resource is owned by a different resource that’s being deleted, it might still get deleted. Orphaned resources are labeled with kapp.k14s.io/orphaned label. As of v0.31.0+, resource is also disassociated from owning app so that it can be owned by future apps.

kapp.k14s.io/owned-for-deletion

kapp.k14s.io/owned-for-deletion annotation controls resource deletion during kapp delete command

Possible values: “”.

By default non-kapp owned resources are not explicitly deleted by kapp, but expected to be deleted by the cluster (for example Endpoints resource for each Service). In some cases it’s desired to annotate non-kapp owned resource so that it does get explicitly deleted, possibly because cluster does not plan to delete it (e.g. PVCs created by StatefulSet are not deleted by StatefulSet controller; https://github.com/vmware-tanzu/carvel-kapp/issues/36).

kapp.k14s.io/nonce

kapp.k14s.io/nonce annotation allows to inject unique ID

Possible values: "" (default).

Annotation value will be replaced with a unique ID on each deploy. This allows to force resource update as value changes every time.

kapp.k14s.io/deploy-logs

kapp.k14s.io/deploy-logs annotation indicates which Pods' log output to show during deploy

Possible values:

  • "" (default; equivalent to for-new)
  • for-new (only newly created Pods are tailed)
  • for-existing (only existing Pods are tailed)
  • for-new-or-existing (both newly created and existing Pods are tailed)

Especially useful when added to Jobs. For example, see examples/resource-ordering/sync-check.yml

kapp.k14s.io/deploy-logs-container-names

kapp.k14s.io/deploy-logs-container-names annotation indicates which containers' log output to show during deploy

Possible values: "" (default), containerName1, containerName1,containerName2


Controlling apply via deploy flags

  • --apply-ignored=bool explicitly applies ignored changes; this is useful in cases when controllers lose track of some resources instead of for example deleting them
  • --apply-default-update-strategy=string controls default strategy for all resources (see kapp.k14s.io/update-strategy annotation above)
  • --apply-exit-status=bool (default false) controls exit status (0: unused, 1: any error, 2: no changes applied, 3: at least one change applied)
  • --wait=bool (default true) controls whether kapp will wait for resource to “stabilize”. See Apply waiting
  • --wait-ignored=bool controls whether kapp will wait for ignored changes (regardless whether they were initiated by kapp or by controllers)
  • --logs=bool (default true) controls whether to show logs as part of deploy output for Pods annotated with kapp.k14s.io/deploy-logs: ""
  • --logs-all=bool (deafult false) controls whether to show all logs as part of deploy output for all Pods