What is an ArgoCD ApplicationSet and how does the Git generator work?

An ApplicationSet is an ArgoCD CRD that automates the creation, update, and deletion of multiple Application resources from a single template. Instead of manually writing one Application manifest per environment or cluster, you define a template once and pair it with a generator that produces parameter sets used to fill the template. The ApplicationSet controller manages these generated Applications automatically.

Git Generator

The Git generator has two modes:

• Directories mode: scans a repo for directories matching a glob; each matching directory becomes one Application with path set to that directory.
• Files mode: reads JSON/YAML config files matching a pattern; each file's key-value pairs are passed as parameters into the template.

apiVersion: argoproj.io/v1alpha1
kind: ApplicationSet
metadata:
  name: cluster-apps
  namespace: argocd
spec:
  generators:
    - git:
        repoURL: https://github.com/my-org/infra
        revision: HEAD
        directories:
          - path: apps/*
  template:
    metadata:
      name: "{{path.basename}}"
    spec:
      project: default
      source:
        repoURL: https://github.com/my-org/infra
        targetRevision: HEAD
        path: "{{path}}"
      destination:
        server: https://kubernetes.default.svc
        namespace: "{{path.basename}}"
      syncPolicy:
        automated:
          prune: true

When a new directory apps/payments is pushed to Git, the controller automatically creates an Application named payments — no manual ArgoCD intervention needed. Removing the directory triggers deletion of the generated Application when pruning is enabled on the ApplicationSet.