Override URL resource

[gregory-j-baker]

Is it possible to override a URL resource in an overlay?

For example, let's say I have the following base:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: argocd
resources:
  - https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

and I want to override it using a specific version of Argo CD:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: argocd
bases:
  - ../bases/argocd/
resources:
  - https://raw.githubusercontent.com/argoproj/argo-cd/v2.6.2/manifests/install.yaml

I know the above won't work (I tried it), but is there a recommended way to do this?

[levikobi]

You could do the following:

.
└── k8s
    ├── base
    │   └── kustomization.yaml
    ├── kind-config.yaml
    └── overlays
        └── dev
            └── kustomization.yaml

k8s/base/kustomization.yaml:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

k8s/overlays/dev/kustomization.yaml:

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
  - ../../base/
patchesStrategicMerge:
  - https://raw.githubusercontent.com/argoproj/argo-cd/v2.6.2/manifests/install.yaml

To test it run:

# Create KinD cluster with base ArgoCD
kind create cluster --name kustomize-base-argocd && \
	kustomize build k8s/base | kubectl apply -f -

# Create KinD cluster with dev ArgoCD
kind create cluster --name kustomize-dev-argocd && \
	kustomize build k8s/overlays/dev | kubectl apply -f -

# Delete both clusters
kind delete cluster --name kustomize-base-argocd
kind delete cluster --name kustomize-dev-argocd

[gregory-j-baker]

Thanks @levikobi.

I believe this will work, but it isn't foolproof. If the older manifest contains resources that have been removed in the newer manifest, they will still be created/applied in the cluster.

[vugardzhamalov]

Yeah I don't think you'll escape some kind of wrapper script and/or cicd logic here. Two quick options that I can think of now:

1. If you insist on pulling from remote resources via URLs, maybe try 'envsubst' or 'envdir' or 'direnv', e.g:
   export ARGOCD_VERSION=2.6.2; envsubst < ./your/template/kustomization.yaml.tpl > ./your/base/kustomization.yaml; unset ARGOCD_VERSION

2. Another option maybe don't use URLs under 'resources:' at all, pull required version of the manifest first, say into 'argocd_install.yaml':
   ARGOCD_VERSION=2.6.2; curl -L https://raw.githubusercontent.com/argoproj/argo-cd/v${ARGOCD_VERSION}/manifests/install.yaml -o ./your/base/argocd_install.yaml; unset ARGOCD_VERSION