Fixes #366 To reproduce #366, add ``` bases: - . ``` to `examples/helloWorld/kustomization.yaml`, attempt to build it, and enjoy the stack overflow. This PR fixes this by adding history to file loaders, allowing one to avoid cycles in overlay->base relationships. To make entry points clearer, this PR exposes only two public ways to make a fresh (no-history) loader * rooted at `/` * rooted at the process's current working directory. When making a new loader from an existing loader, retaining history along an overlay trace, the only allowed use is to go deeper into a file hierarchy, or go up and over to a never before visited sibling. This fix can probably be defeated by devious symbolic links.
kustomize
kustomize lets you customize raw, template-free YAML
files for multiple purposes, leaving the original YAML
untouched and usable as is.
kustomize targets kubernetes; it understands and can
patch kubernetes style API objects. It's like
make, in that what it does is declared in a file,
and it's like sed, in that it emits editted text.
This tool is sponsored by sig-cli (KEP).
Installation: Download a binary from the release page, or see these install notes. Then try one of the tested examples.
Usage
1) Make a kustomization file
In some directory containing your YAML resource files (deployments, services, configmaps, etc.), create a kustomization file.
This file should declare those resources, and any customization to apply to them, e.g. add a common label.
File structure:
~/someApp ├── deployment.yaml ├── kustomization.yaml └── service.yaml
The resources in this directory could be a fork of someone else's configuration. If so, you can easily rebase from the source material to capture improvements, because you don't modify the resources directly.
Generate customized YAML with:
kustomize build ~/someApp
The YAML can be directly applied to a cluster:
kustomize build ~/someApp | kubectl apply -f -
2) Create variants using overlays
Manage traditional variants of a configuration - like development, staging and production - using overlays that modify a common base.
File structure:
~/someApp ├── base │ ├── deployment.yaml │ ├── kustomization.yaml │ └── service.yaml └── overlays ├── development │ ├── cpu_count.yaml │ ├── kustomization.yaml │ └── replica_count.yaml └── production ├── cpu_count.yaml ├── kustomization.yaml └── replica_count.yaml
Take the work from step (1) above, move it into a
someApp subdirectory called base, then
place overlays in a sibling directory.
An overlay is just another kustomization, refering to the base, and referring to patches to apply to that base.
This arrangement makes it easy to manage your
configuration with git. The base could have files
from an upstream repository managed by someone else.
The overlays could be in a repository you own.
Arranging the repo clones as siblings on disk avoids
the need for git submodules (though that works fine, if
you are a submodule fan).
Generate YAML with
kustomize build ~/someApp/overlays/production
The YAML can be directly applied to a cluster:
kustomize build ~/someApp/overlays/production | kubectl apply -f -
Community, discussion, contribution, and support
Learn how to engage with the Kubernetes community on the community page.
You can reach the maintainers of this project at:
Code of conduct
Participation in the Kubernetes community is governed by the Kubernetes Code of Conduct.

