Notes on ch07 of GitOps Cookbook by Natale Vinto, Alex Soto Bueno
======
argocd
======

How to deploy a application to an k8s cluster using the GitOps methodology and
not creating scripts that manually run `kubectl/helm` commands?

We want ArgoCD to deploy and application defined in a Git Repository.

1. Create an Application resource to set up Argo CD.

Install argocd
```
k apply -n argocd \
    -f https://raw.githubusercontent.com/argoproj/argo-cd/v2.3.4/manifests/install.yaml
```

You can port-forward the `svc/argocd-server` to get a ui in your browser. Now
you initial user is `admin`,  the password is in a secret in the
`argocd-initial-admin-secret` secret in the cluster.

```
k -n argocd get secret argocd-initial-admin-secret -o yaml | grep password | awk  '{print $2}'
```
pipe it to
```
base64 -d
```


To install the cli, just `brew` install it and login
```
argocd login --insecure --grpc-web localhost:9090 --username admin --password some-pass
```


Create Application
------------------

Now say we have an app in a repository. That has a deploy, svc and ns.
I created the repo: https://github.com/bsantanad/argocd-learn.git

We are going to create an application object to tell argocd about it.

```
apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: app
  namespace: argocd
spec:
  destination: # target cluster
    namespace: app
    server: https://kubernetes.default.svc
  project: default
  source:
    repoURL: https://github.com/bsantanad/argocd-learn.git
    path: app
    targetRevision: main
```

Now if we just apply the manifest.

```
k apply -f application.yaml
```

We can query argocd cli about it or check the ui
```
% argocd app list
NAME        CLUSTER                         NAMESPACE  PROJECT  STATUS     HEALTH   SYNCPOLICY  CONDITIONS  REPO                                           PATH  TARGET
argocd/app  https://kubernetes.default.svc  app        default  OutOfSync  Missing  Manual      <none>      https://github.com/bsantanad/argocd-learn.git  app   main
```

It says it is `OutofSync`, which means that the app is registered, and there is
a different status on what is currently in the cluster, and what is in Git.

Let us sync it then.
```
argocd app sync app
```
 % argocd app list
NAME        CLUSTER                         NAMESPACE  PROJECT  STATUS  HEALTH   SYNCPOLICY  CONDITIONS  REPO                                           PATH  TARGET
argocd/app  https://kubernetes.default.svc  app        default  Synced  Healthy  Manual      <none>      https://github.com/bsantanad/argocd-learn.git  app   main
```

If we check the status of the objects in the cluster, everything looks alright:
```
% k get pods -n bgd
NAME                   READY   STATUS    RESTARTS   AGE
bgd-7984d6f558-tts8g   1/1     Running   0          89s
% k get svc -n bgd
NAME   TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)    AGE
bgd    ClusterIP   10.96.146.60   <none>        8080/TCP   93s
```

Now if we open this with a browser you will see blue dots. Now the cool part,
go edit the deploy and change the color to green, push the changes, and see
what happens.

It will say it is out of sync, now just sync it again and `voila`

Automatic Sync
--------------

TODO