Core concepts and vocabulary

In this section, we will describe some of the core components of Argo CD like reconciliation and describe in detail the core objects CRDs of Argo CD. In parallel, we will set up a vocabulary so we can have a common language for Argo CD operations. Lastly, we will observe the reconciliation loop and how Argo CD works.

Argo CD reconciliation

Argo CD as we described previously has a duty to match the desired state described in a Git repository with the live state in the cluster and deliver it in the environment of our preference. This is called reconciliation and Argo CD is in a reconciling loop from Git repository to Kubernetes as the following image shows, assuming we use Helm:

Figure 2.1 – Reconciling loop

As we see in Figure 2.1, Argo CD watches the Git repository and runs first a Helm template to generate the Kubernetes manifest YAML and compare them with the desired state in the cluster and it is called Sync status. If Argo CD identifies any differences...