cicdargocdPractitioner

Mastering Cluster Bootstrapping with Argo CD

5 min read ArgoCD DocsMay 10, 2026Reviewed for accuracy

Practitioner — Hands-on experience recommended

Cluster bootstrapping is essential for managing applications across multiple Kubernetes clusters efficiently. It solves the problem of manual deployment and configuration, allowing you to automate the process and ensure consistency. With Argo CD, you can use ApplicationSets to deploy applications based on cluster labels, making it easier to manage complex environments.

To bootstrap a cluster, follow the Declaratively setup guide. You can create a cluster, assign it labels, and add it to Argo CD. Any ApplicationSet that uses these labels will deploy the respective applications. The sync policy is set to automated with pruning enabled by default, which means that child apps are automatically created, synced, and deleted when the parent app's manifest changes. This is particularly useful when using the App of Apps pattern, which allows you to declaratively specify one Argo CD app that consists only of other apps. You also have access to all gotemplate functions and Sprig methods, eliminating the need for Helm templating.

In production, be aware that the App of Apps pattern is an admin-only tool, which may limit its use in certain scenarios. Additionally, consider modifying the bootstrapping behavior to deploy applications in waves, especially if you have a large number of apps. Starting from version 3.2, Argo CD ensures consistent deletion behavior, whether you delete from the Applications List or the parent application's Resource Tree. This can help prevent orphaned resources and streamline management.

Key takeaways

→Utilize ApplicationSets to handle typical deployment scenarios in your cluster.
→Set the sync policy to automated with pruning enabled for efficient app management.
→Leverage the App of Apps pattern to manage multiple applications declaratively.

Why it matters

In production, automating cluster bootstrapping can significantly reduce deployment time and minimize human error. This leads to more reliable application delivery and better resource management across your Kubernetes environments.

Code examples

YAML

1apiVersion:argoproj.io/v1alpha1
2kind:ApplicationSet
3metadata:
4  name: eu-only-appset
5  namespace: argocd
6spec:
7  goTemplate: true
8  goTemplateOptions: ["missingkey=error"]
9  generators:
10    - matrix:
11        generators:
12          - git:
13              repoURL: <a git repo>
14              revision: HEAD
15              directories:
16                - path: my-eu-apps/*
17          - clusters:
18              selector:
19                matchLabels:
20                  type: "workload"
21                  region: "eu"
22  template:
23    metadata:
24      name: 'eu-only-{{index.path.segments1}}-{{.name}}'
25    spec:
26      project: default
27      source:
28        repoURL: <a git repo>
29        targetRevision: HEAD
30        path: '{{.path.path}}'
31      destination:
32        server: '{{.server}}'
33        namespace: 'eu-only-{{index.path.segments1}}'
34      syncPolicy:
35        syncOptions:
36          - CreateNamespace=true
37        automated:
38          prune: true
39          selfHeal: true

YAML

1apiVersion:argoproj.io/v1alpha1
2kind:Application
3metadata:
4  name: guestbook
5  namespace: argocd
6finalizers:
7  - resources-finalizer.argocd.argoproj.io
8spec:
9  destination:
10    namespace: argocd
11    server: {{.Values.spec.destination.server}}
12  project: default
13  source:
14    path: guestbook
15    repoURL: https://github.com/argoproj/argocd-example-apps
16    targetRevision: HEAD
17  syncPolicy:
18    automated:
19      prune: true

Bash

1argocd app create apps \ 
2  --dest-namespace argocd \ 
3  --dest-server https://kubernetes.default.svc \ 
4  --repo https://github.com/argoproj/argocd-example-apps.git \ 
5  --path apps \ 
6  argocd app sync apps