NylRelease

The NylRelease resource specifies release metadata (name and namespace) for a deployment. It’s an optional resource that provides context for rendering manifests.

Resource Definition

apiVersion: nyl.niklasrosenstein.github.com/v1
kind: NylRelease
metadata:
  name: string        # Release name
  namespace: string   # Target namespace
spec: {}              # Reserved for future use
  argocd:             # Optional ArgoCD customization
    applicationOverride: {}   # Partial Application override (object)

Field Reference

metadata.name

Type: string (required)
Description: The release name
Usage: Used as the Helm release name when rendering HelmCharts

metadata.namespace

Type: string (required)
Description: The target namespace for this release
Usage: Resources are deployed to this namespace

spec.argocd.applicationOverride

Type: object (optional)
Description: Partial ArgoCD Application override for use with ApplicationGenerator release customization policy
Behavior:
- Override fields are applied only if allowed by ApplicationGenerator.spec.releaseCustomization
- Plain keys replace the generated Application value at that field path
- Keys prefixed with + append to list-valued Application fields instead of replacing them
- +<field> uses the canonical field path without + for allow/deny checks
- Unsupported or disallowed fields are ignored
- Invalid append operations (for example using + on a non-list field or with a non-list value) are ignored
- Ignored fields are reported as a warning in generated Application.spec.info

Behavior

During Rendering

When nyl render encounters a NylRelease:

The resource is extracted from the file
Metadata is used for rendering other resources in the file
The NylRelease itself is not included in the output

With ApplicationGenerator

When ApplicationGenerator scans files:

Files with a NylRelease are discovered
An ArgoCD Application is generated per NylRelease
Application metadata comes from the NylRelease

Singleton Constraint

Only one NylRelease is allowed per file. Multiple NylReleases in the same file will cause an error:

Error: Multiple NylRelease resources found in file

Examples

Minimal NylRelease

apiVersion: nyl.niklasrosenstein.github.com/v1
kind: NylRelease
metadata:
  name: myapp
  namespace: default

With Other Resources

apiVersion: nyl.niklasrosenstein.github.com/v1
kind: NylRelease
metadata:
  name: myapp
  namespace: production
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: myapp-config
  namespace: production
data:
  environment: production
  version: "1.0.0"
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
  namespace: production
spec:
  replicas: 3
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
        - name: myapp
          image: myapp:1.0.0

With HelmChart

apiVersion: nyl.niklasrosenstein.github.com/v1
kind: NylRelease
metadata:
  name: nginx
  namespace: web
---
apiVersion: nyl.niklasrosenstein.github.com/v1
kind: HelmChart
metadata:
  name: nginx
  namespace: web
spec:
  chart:
    repository: https://charts.bitnami.com/bitnami
    name: nginx
    version: "15.4.4"
  values:
    replicaCount: 2

Use Cases

ArgoCD Integration

NylRelease is primarily used for ArgoCD integration:

# app.yaml in Git repository
apiVersion: nyl.niklasrosenstein.github.com/v1
kind: NylRelease
metadata:
  name: myapp
  namespace: production
---
# ... other resources ...

ArgoCD Application:

apiVersion: argoproj.io/v1alpha1
kind: Application
spec:
  source:
    plugin:
      name: nyl-v2
      env:
        - name: NYL_RELEASE_NAME
          value: myapp          # From NylRelease.metadata.name
        - name: NYL_RELEASE_NAMESPACE
          value: production     # From NylRelease.metadata.namespace

Appending Sync Options

applicationOverride can append to list-valued Application fields by prefixing the field name with +.

apiVersion: nyl.niklasrosenstein.github.com/v1
kind: NylRelease
metadata:
  name: service-proxies
  namespace: home-proxy
spec:
  argocd:
    applicationOverride:
      spec:
        syncPolicy:
          +syncOptions:
            - RespectIgnoreDifferences=false

When combined with an ApplicationGenerator default such as:

syncPolicy:
  syncOptions:
    - ServerSideApply=true
    - ApplyOutOfSyncOnly=true

the generated ArgoCD Application contains all three entries in order:

spec:
  syncPolicy:
    syncOptions:
      - ServerSideApply=true
      - ApplyOutOfSyncOnly=true
      - RespectIgnoreDifferences=false

ApplicationGenerator Discovery

ApplicationGenerator scans for NylRelease resources:

# apps.yaml
apiVersion: argocd.nyl.niklasrosenstein.github.com/v1
kind: ApplicationGenerator
spec:
  source:
    path: clusters/default  # Scans this directory

For each file in clusters/default/ with a NylRelease, an Application is generated.

Metadata Propagation

NylRelease metadata can be used in templates (future enhancement):

apiVersion: v1
kind: ConfigMap
metadata:
  name: {{ .release.name }}-config
  namespace: {{ .release.namespace }}
data:
  release_name: {{ .release.name }}

Validation

Required Fields

metadata.name must be specified
metadata.namespace must be specified

Missing fields cause validation errors:

Error: Invalid NylRelease resource: missing field `metadata.name`

Valid Names

Names must follow Kubernetes naming conventions:

Lowercase alphanumeric characters, -, .
Start and end with alphanumeric
Max 253 characters

When Not to Use

You don’t need NylRelease if:

Deploying plain Kubernetes manifests without Helm
Not using ArgoCD integration
Rendering manifests locally without release context

In these cases, just use regular Kubernetes resources directly.

Nyl Documentation