In an ideal world you wouldn't have to perform multiple steps for the rendering, but unfortunately we don't live in an ideal world...
Kustomize
Nowadays, most applications that are meant to be deployed in Kubernetes provide a Helm chart to ease deployment. Unfortunately, sometimes the Helm chart is not flexible enough to do what you want to do, so you have to fork and contribute and hope that your contribution is quickly merged upstream so that you don't have to maintain your fork.
Instead of pointing to your fork, you could use Kustomize to apply some post-rendering to your templatized Helm release. This is possible natively since Helm 3.1 using the --post-process flag.
Integration in ArgoCD
At Camptocamp, we use ArgoCD to manage the deployment of our objects into Kubernetes. Let's see how we can use Kustomize to do post-rendering of Helm charts in ArgoCD:
At first, declare a new config management plugin into your argocd-cm configMap (the way to do it depends on the way you deployed ArgoCD):
apiVersion: v1
kind: ConfigMap
metadata:
name: argocd-cm
namespace: argocd
data:
configManagementPlugins: |
- name: kustomized-helm
init:
command: ["/bin/sh", "-c"]
args: ["helm dependency build || true"]
generate:
command: ["/bin/sh", "-c"]
args: ["helm template . --name-template $ARGOCD_APP_NAME --namespace $ARGOCD_APP_NAMESPACE --include-crds > all.yaml && kustomize build"]
Then add a kustomization.yaml file next to your application's Chart.yaml file:
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
resources:
- all.yaml
patchesJson6902:
- target:
group: apps
version: v1
kind: Deployment
name: myapplication
patch: |-
- op: remove
path: /spec/template/spec/securityContext
Now configure your Applications object to use this plugin:
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
name: myapplication
namespace: argocd
spec:
project: myproject
source:
path: myapplication
repoURL: {{ .Values.spec.source.repoURL }}
targetRevision: {{ .Values.spec.source.targetRevision }}
plugin:
name: kustomized-helm
destination:
namespace: myproject
server: {{ .Values.spec.destination.server }}
And... voilà!
Integration in App of Apps
One thing that I often do is to use spec.source.helm in my Application object to pass some values that comes from my app of apps. This is not possible using a configuration plugin as the keys helm and plugin are mutually exclusive.
The workaround I found is to use plugin's envs. You have to change your config management plugin configuration to (note the $HELM_ARGS):
apiVersion: v1
kind: ConfigMap
metadata:
name: argocd-cm
namespace: argocd
data:
configManagementPlugins: |
- name: kustomized-helm
init:
command: ["/bin/sh", "-c"]
args: ["helm dependency build || true"]
generate:
command: ["/bin/sh", "-c"]
args: ["echo \"$HELM_VALUES\" | helm template . --name-template $ARGOCD_APP_NAME --namespace $ARGOCD_APP_NAMESPACE $HELM_ARGS -f - --include-crds > all.yaml && kustomize build"]
You'll then be able to use this in your Application:
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
name: myapplication
namespace: argocd
spec:
project: myproject
source:
path: myapplication
repoURL: {{ .Values.spec.source.repoURL }}
targetRevision: {{ .Values.spec.source.targetRevision }}
plugin:
name: kustomized-helm
env:
- name: HELM_ARGS
value: "--set targetRevision={{ .Values.spec.source.targetRevision }}"
destination:
namespace: myproject
server: {{ .Values.spec.destination.server }}
Or
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
name: myapplication
namespace: argocd
spec:
project: myproject
source:
path: myapplication
repoURL: {{ .Values.spec.source.repoURL }}
targetRevision: {{ .Values.spec.source.targetRevision }}
plugin:
name: kustomized-helm
env:
- name: HELM_VALUES
value: |
targetRevision: {{ .Values.spec.source.targetRevision }}
destination:
namespace: myproject
server: {{ .Values.spec.destination.server }}
Top comments (9)
what's up from two years in the future.
This blog post is pasted EVERYWHERE anyone needs to use argocd to kustomize their helm charts. Good job, you made it.
If you're reading this in the future, though, you're probably wondering why the $HELM_ARGS part doesn't work.
ArgoCD made some changes in 2.4 - HELM_ARGS should now be called ARGOCD_ENV_HELM_ARGS
Please don't spend two days hunting this crap down the way I did.
github.com/argoproj-labs/argocd-va...
Thank you 👑
Nice article, thanks! Just wondering how could we could point the app to kustomized dev/prod overlays?
I guess:
helm template ../../ --name-template $ARGOCD_APP_NAME --namespace $ARGOCD_APP_NAMESPACE --include-crds > ../../all.yaml && kustomize build
But another little caveat is knowing what there is to kustomize there... but I guess there could be a gitignored folder to dump to while trying to kustomize things..
It's a pity replicated/ship project isn't really being updated, I used that for this purpose in the past.
Wait could you explain what this post is about?
Sorry, I mean my desired kustomize setup would be:
[chart files...]
all.yaml
overlays/
|_dev/...
|_prod/...
and I point two argo apps one to dev and the other to prod, that's really the point of kustomize for me, is apart the final mile touches, I can configure for different environments... so I used to use replicated/ship to turn the helm chart into kustomize, and then I would add the overlays -- but they're not really updating that tool anymore. So with your technique, I could adapt it to what I wrote above. Unless you have some better advice for this?
No, I didn't know that kustomize existed until today. After reading some of this I've genuinely been enlightened.
OMG. I’ve been looking for something like this for a while. THANK YOU!
is there a way to pass the helm values file link instead of the HELM_ARGS?
I'm also interested in passing value files. I have helm charts with encrypted values with helm-secret.
That's the only thing blocking me from switching from helm to helm + kustomize post render