Since *mtrcs0.pyrocufflink.blue* (the Metrics Pi) seems to be dying, I decided to move monitoring and alerting into Kubernetes. I was originally planning to have a single, dedicated virtual machine for Victoria Metrics and Grafana, similar to how the Metrics Pi was set up, but running Fedora CoreOS instead of a custom Buildroot-based OS. While I was working on the Ignition configuration for the VM, it occurred to me that monitoring would be interrupted frequently, since FCOS updates weekly and all updates require a reboot. I would rather not have that many gaps in the data. Ultimately I decided that deploying a cluster with Kubernetes would probably be more robust and reliable, as updates can be performed without any downtime at all. I chose not to use the Victoria Metrics Operator, but rather handle the resource definitions myself. Victoria Metrics components are not particularly difficult to deploy, so the overhead of running the operator and using its custom resources would not be worth the minor convenience it provides. |
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applications | ||
README.md | ||
hooks.yaml | ||
ingress.yaml | ||
kustomization.yaml | ||
namespace.yaml | ||
oidc.config | ||
policy.csv |
README.md
Argo CD
Argo CD is a declarative GitOps continuous delivery tool, which allows developers to define and control deployment of Kubernetes application resources from within their existing Git workflow.
kubectl apply -k argocd
kubectl apply -f argocd/applications
Components
Argo CD consists of several components, some of which are not used:
- Application Controller
- Repository Service
- Web Server
- Notification Controller
- ApplicationSet Controller1
- Dex Server2
Applications
Applications are the core resource in Argo CD. They form a collection of resources associated with a particular application deployment. They are themselves defined as Kubernetes resources (see applications).
Git Webhook
Argo CD will automatically refresh the desired state of applications whenever a changeset is pushed to the Git repository where manifests are stored. The infra/kubernetes repository has a Webhook configured in Gitea that notifies the Argo CD server on Git push events.