Tags

Every kustomize deployment has a set of tags assigned to it. These tags are defined in multiple places, which is documented in deployment.yaml. Look for the tags field, which is available in multiple places per deployment project.

Tags are useful when only one or more specific kustomize deployments need to be deployed or deleted.

Default tags

deployment items in deployment projects can have an optional list of tags assigned.

If this list is completely omitted, one single entry is added by default. This single entry equals to the last element of the path in the deployments entry.

Consider the following example:

deployments:
  - path: nginx
  - path: some/subdir

In this example, two kustomize deployments are defined. The first would get the tag nginx while the second would get the tag subdir.

In most cases this heuristic is enough to get proper tags with which you can work. It might however lead to strange or even conflicting tags (e.g. subdir is really a bad tag), in which case you’d have to explicitly set tags.

Tag inheritance

Deployment projects and deployments items inherit the tags of their parents. For example, if a deployment project has a tags property defined, all deployments entries would inherit all these tags. Also, the sub-deployment projects included via deployment items of type include inherit the tags of the deployment project. These included sub-deployments also inherit the tags specified by the deployment item itself.

Consider the following example deployment.yaml:

deployments:
  - include: sub-deployment1
    tags:
      - tag1
      - tag2
  - include: sub-deployment2
    tags:
      - tag3
      - tag4
  - include: subdir/subsub

Any kustomize deployment found in sub-deployment1 would now inherit tag1 and tag2. If sub-deployment1 performs any further includes, these would also inherit these two tags. Inheriting is additive and recursive.

The last sub-deployment project in the example is subject to the same default-tags logic as described in Default tags, meaning that it will get the default tag subsub.

Deploying with tag inclusion/exclusion

Special care needs to be taken when trying to deploy only a specific part of your deployment which requires some base resources to be deployed as well.

Imagine a large deployment is able to deploy 10 applications, but you only want to deploy one of them. When using tags to achieve this, there might be some base resources (e.g. Namespaces) which are needed no matter if everything or just this single application is deployed. In that case, you’d need to set alwaysDeploy to true.

Deleting with tag inclusion/exclusion

Also, in most cases, even more special care has to be taken for the same types of resources as decribed before.

Imagine a kustomize deployment being responsible for namespaces deployments. If you now want to delete everything except deployments that have the persistency tag assigned, the exclusion logic would NOT exclude deletion of the namespace. This would ultimately lead to everything being deleted, and the exclusion tag having no effect.

In such a case, you’d need to set skipDeleteIfTags to true as well.

In most cases, setting alwaysDeploy to true also requires setting skipDeleteIfTags to true.

Last modified May 23, 2022: docs: Replace .yml with .yaml (04e390e)