https://github.com/mirantis/rekustomize
https://github.com/mirantis/rekustomize
Last synced: 10 days ago
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- Host: GitHub
- URL: https://github.com/mirantis/rekustomize
- Owner: Mirantis
- License: apache-2.0
- Created: 2024-09-12T14:14:46.000Z (8 months ago)
- Default Branch: main
- Last Pushed: 2025-05-04T23:21:34.000Z (13 days ago)
- Last Synced: 2025-05-07T16:16:39.490Z (10 days ago)
- Language: Go
- Size: 348 KB
- Stars: 2
- Watchers: 5
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# rekustomize (Technical Preview / Aplha)
`rekustomize` lets you generate
[`kustomize`](https://github.com/kubernetes-sigs/kustomize) manifests. With
`rekustomize` you can:
- [x] **Export** resource manifests from live cluster using supported formats:
- [x] **kustomize components**
([example](examples/export-components/rekustomization.yaml))
- [x] **helm charts** ([example](examples/export-helm/rekustomization.yaml))
- [x] **Filter** exported resources or attributes based on customizable rules
([example](examples/export-simple-filtered/rekustomization.yaml))
- [x] **Deduplicate** manifests to ensure
[DRY](https://en.wikipedia.org/wiki/Don%27t_repeat_yourself) principle
- [ ] **Re-format** existing manifests to follow customizable styles and to
optimize duplicated manifests
- [ ] **Convert** existing manifests between formats, e.g. from **helm chart**
to **kustomize components**
## Deduplication of resources and attributes
`rekustomize` truly shines when it's used to generate manifests for multiple
clusters at once. It will group correlad resources together and will also
efficiently handle multiple versions of the same resource.
### Helm template
This [template](examples/export-helm/charts/simple-app/templates/simple-app-deployment.yaml)
shows how `rekustomize` can handle multiple versions of the same resource:
```
spec:
{{- if index .Values.global "simple-app/Deployment/simple-app.spec.replicas" }}
replicas: {{ index .Values.global "simple-app/Deployment/simple-app.spec.replicas" }}
{{- end }} # simple-app/Deployment/simple-app.spec.replicas
template:
spec:
containers:
- image: {{ index .Values.global "simple-app/Deployment/simple-app.spec.template.spec.containers.[name=simple-app].image" }}
name: simple-app
```
[values.yaml](examples/export-helm/charts/simple-app/values.yaml)
defines presets to group values from different resources:
```
preset_values:
prod:
simple-app/ConfigMap/simple-app-env.data.ENV_VAR2: prod-value
simple-app/Deployment/simple-app.spec.replicas: 5
prod_test:
simple-app/Deployment/simple-app.spec.template.spec.containers.[name=simple-app].image: example.com/simple-app:v1.2.345
test:
simple-app/ConfigMap/simple-app-env.data.ENV_VAR2: test-value
simple-app/Deployment/simple-app.spec.replicas: 3
```
The generated **presets** are then assigned to each corresponding cluster:
- [test-cluster-a](examples/export-helm/overlays/test-cluster-a/kustomization.yaml):
```
valuesInline:
presets:
- prod_test
- test
```
- [prod-cluster-b](examples/export-helm/overlays/prod-cluster-b/kustomization.yaml):
```
valuesInline:
presets:
- prod
- prod_test
```
Values, that are unique to a cluster are also supported:
- [prod-cluster-a](examples/export-helm/overlays/prod-cluster-a/kustomization.yaml):
```
valuesInline:
global:
simple-app/ConfigMap/simple-app-env.data.ENV_VAR3: prod-cluster-a-value
```
### Kustomize components
If you use **kustomize components** format, similar overrides will be generated
as strategic-merge patches:
- [components/prod](examples/export-components/components/prod/simple-app/simple-app-deployment.yaml):
```
apiVersion: apps/v1
kind: Deployment
metadata:
name: simple-app
namespace: simple-app
spec:
replicas: 5
```
- [components/test](examples/export-components/components/test/simple-app/simple-app-deployment.yaml):
```
apiVersion: apps/v1
kind: Deployment
metadata:
name: simple-app
namespace: simple-app
spec:
replicas: 3
```
- [components/prod_test](examples/export-components/components/prod_test/simple-app/simple-app-deployment.yaml)
```
apiVersion: apps/v1
kind: Deployment
metadata:
name: simple-app
namespace: simple-app
spec:
template:
spec:
containers:
- name: simple-app
image: example.com/simple-app:v1.2.345
```
## `rekustomization.yaml`
To start using `rekustomize`, create a new folder with a `rekustomization.yaml`
file where you can configure `rekustomize` behavior. Here's a breakdown of the
**helm chart** [example](examples/export-helm/rekustomization.yaml):
### Cluster selector
By default `rekustomize` will use clusters defined in your `KUBECONFIG` file.
You can select clusters using shell-like patterns:
```
clusters:
- names: dev-* # shell-like pattern
tags: dev
- names: test-cluster-a,test-cluster-* # comma-separated list
tags: test
- names: # yaml list
- prod-cluster-a
- prod-cluster-*
tags: prod
```
In the future versions `rekustomize` will be able to use cluster metadata/labels
from external sources, such as **ClusterAPI**, **k0rdent**, **ArgoCD** or
**Flux**.
### Resource selector
By default, `rekustomize` will generate manifests for all resources from all
namespaces, excluding a [pre-defined](pkg/cmd/defaults.yaml) list of dynamic
resources, like `pods` or `events`. You can customize that behavior in the
`export` section:
```
export:
- namespaces: simple-app
labelSelectors: ['!generated-by']
apiResources:
exclude: jobs.batch
- apiResources: namespaces
names: simple-app
```
### Resource attribute cleanup
If your live cluster resources contain attributes that you don't want to be
included in the generated manifests, you can use `SkipFilter` to remove such
unwanted attributes or values. The following example will remove any
`'example.com/generated'` annotations and `'dev.example.com/info'` annotations
with the value of `'flaky-tests'`:
```
filters:
- kind: SkipFilter
fields:
- metadata.annotations.example\.com/generated
- metadata.annotations.dev\.example\.com/info[=flaky-tests]
```
### Resource filters
You can also use `SkipFilter` to exclude entire resources from the generated
manifests - to further refine [resource selection](#resource-selector):
```
filters:
- kind: SkipFilter
resources:
- kind: CronJob
name: infra-canary
```
### Chart metadata
This section defines metadata for the generated chart:
```
helmChart:
name: simple-app
version: v1.0
```
If no `helmChart` is specified, `rekustomize` will generate manifests in **kustomize components** format