ArgoCD Metadata.annotations: Too long Error [Solved]

In this blog I have added the solution for ArgoCD Metadata.annotations: Too long Error.

Issue - Annotation Exceeding Limit

When I tried to deploy the Prometheus-stack helm chart using ArgoCD, I faced the following error.

metadata.annotations: Too long: must have at most 262144 bytes

This issue occurs because the size of the resources annotation exceeds the Kubernetes 256 KiB (262 144 bytes) limit.

That is a very good limit for storing many annotation. But here is why it exceeds in ArgoCD.

When ArgoCD applies the YAML, it stores a copy inside the object itself under kubectl.kubernetes.io/last-applied-configuration annotation. That hidden copy counts toward the 256 KB limit on metadata.annotations

 So, if the object itself is large (big CRDs, Prometheus, Grafana‑dashboard ConfigMaps, etc.), the annotation pushes the total size over 256 KiB and the API server rejects the object, so Argo CD

You won't face this issue when you try to deploy the helm chart directly using helm install or kubectl apply

Solution - Using ServerSideApply

To solve this issue, you can use the ServerSideApply option available on ArgoCD.

This option tells Argo CD to let the Kubernetes API server take care of the apply instead of storing the configuration in annotations.

If you are using the declarative method for deploying the application, you can specify the ServerSideApply option under the syncPolicy as given in the example below.

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: prometheus
  namespace: argocd
spec:
  destination:
    name: in-cluster
    namespace: monitoring
  project: default
  source:
    repoURL: '<your-repo>'
    targetRevision: HEAD
    path: kube-prometheus-stack
    helm:
      valueFiles:
      - values.yaml
  syncPolicy:
    syncOptions:
    - CreateNamespace=true
    - ServerSideApply=true 

If you are deploying using ArgoCD UI, enable the Server-Side Apply option under the SYNC OPTIONS during the configuration.