reconciler

#+TITLE: reconciler

#+begin_quote
A reconciler for Pair instances, that calls cluster-api-manager endpoints to make calls against the instance
#+end_quote

* Purpose
The reconciler is responsible for bringing aspects of the Pair instance into an available state.
There are a few different things that are reconciled, these are:
- Certs :: Backing up or restoring the /letsencrypt-prod/ secret in the /powerdns/ namespace, in order bring certs up quicker next time (if instance name matches username or a name is chosen)
- DNS :: Creates or updates the DNSEndpoint resource for managing the DNS records related to the instance's IP
- providerID :: The provider ID is required along with removing any node taints to allow scheduling of Pods on a Node.
  This is normally done by the [[https://github.com/kubernetes-sigs/cluster-api-provider-packet][cluster-api-provider-packet]], but since we don't want to share privileged secrets we will manage it differently

* Implementation
By listing the /clusters.cluster.x-k8s.io/ resources, with cluster that's managed by Pair in the given namespace, call the endpoints to reconcile the instance.

* Env vars
| Name                           |                                      Default | Description                                                               |
|--------------------------------+----------------------------------------------+---------------------------------------------------------------------------|
| ~APP_CLUSTER_API_MANAGER_HOST~ | http://sharingio-pair-clusterapimanager:8080 | The HTTP address for cluster-api-manager                                  |
| ~APP_SLEEP_TIME~               |                                           60 | The amount of seconds to wait after all clusters have been looped through |
| ~APP_CERT_DAYS_TO_PRE_EXPIRE~  |                                            5 | The amount of days before deleting an almost expired backed up TLS cert   |