metrics-server VS sealed-secrets

The last one is mostly an observability stack with Prometheus, Metric server, and Prometheus adapter to have excellent insights into what is happening on the cluster. You can reuse the same stack for autoscaling by repurposing all the data collected for monitoring.

and the Metrics Server.

Metrics-server is installed by default on OVH, and has to be installed manually on AWS/EKS cluster.

I have also installed metrics-server (though not sure whether that was required or not) using the following statement:kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/download/v0.3.6/components.yaml

For #2: There are MANY solutions but the simplest and easiest is https://github.com/kubernetes-sigs/metrics-server and then you can use kubectl top to view pods resource usage. If you want fancy graphs, long retention, alerting, analysis, etc. of resource metrics.. then you need to use something like new relic, data dog, or something open source but much more complex like prometheus/thanos/grafana.. or a managed SaaS version of those open source tools... also some k8s platforms like AWS, Spot.io, GKE, OpenShift, may have this stuff built in or turnkey

It's an autoscaler with a metrics server (so I don't need to install 2 different tools).

Sure, here's an example of how to configure the Kubernetes Metrics Server along with the Horizontal Pod Autoscaler (HPA) and Vertical Pod Autoscaler (VPA) configurations we provided earlier. The Metrics Server is a Kubernetes add-on that provides resource utilization metrics for pods and nodes, which are used by the HPA and VPA to determine when and how to scale an application. First, you'll need to install the Metrics Server into your Kubernetes cluster. You can do this by running the following command: kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml Once the Metrics Server is installed, you can configure your HPA and VPA to use it for metrics by adding the following annotation to your deployment: apiVersion: apps/v1 kind: Deployment metadata: name: my-app annotations: autoscaling.alpha.kubernetes.io/metrics-provider: "metrics-server" With this annotation in place, the HPA and VPA will use the Metrics Server to obtain CPU and memory utilization metrics for your pods and nodes. Here's an updated example of the HPA configuration we provided earlier, with the addition of the Metrics Server configuration: apiVersion: autoscaling/v2beta2 kind: HorizontalPodAutoscaler metadata: name: my-app-hpa spec: scaleTargetRef: apiVersion: apps/v1 kind: Deployment name: my-app minReplicas: 1 maxReplicas: 10 metrics: - type: Resource resource: name: cpu targetAverageUtilization: 50 - type: Resource resource: name: memory targetAverageUtilization: 80 In this example, we've added a second metric to the HPA configuration that targets memory utilization at 80%. Here's an updated example of the VPA configuration we provided earlier, with the addition of the Metrics Server configuration: apiVersion: autoscaling.k8s.io/v1 kind: VerticalPodAutoscaler metadata: name: my-app-vpa spec: targetRef: apiVersion: apps/v1 kind: Deployment name: my-app updatePolicy: updateMode: "Off" resourcePolicy: containerPolicies: - containerName: "*" minAllowed: cpu: 50m memory: 256Mi maxAllowed: cpu: 500m memory: 1Gi metrics: - type: Resource resource: name: cpu target: type: Utilization averageUtilization: 50 - type: Resource resource: name: memory target: type: Utilization averageUtilization: 80 In this example, we've added two metrics to the VPA configuration that target CPU and memory utilization, with target average utilization of 50% and 80% respectively. I hope this helps you configure the Metrics Server, HPA, and VPA for your application in Kubernetes!

Id go for k3s then install metrics-server, then you can deploy some hpa’s

# Create EKS Cluster with version 1.23 eksctl create cluster -f eks-cluster.yaml # Output like below shows cluster has been successfully created 2022-12-30 16:26:46 [ℹ] kubectl command should work with "/home/ec2-user/.kube/config", try 'kubectl get nodes' 2022-12-30 16:26:46 [✔] EKS cluster "ca-demo" in "us-west-2" region is ready # Deploy the Metric server kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml # Output of the above command looks something like below - serviceaccount/metrics-server created clusterrole.rbac.authorization.k8s.io/system:aggregated-metrics-reader created clusterrole.rbac.authorization.k8s.io/system:metrics-server created rolebinding.rbac.authorization.k8s.io/metrics-server-auth-reader created clusterrolebinding.rbac.authorization.k8s.io/metrics-server:system:auth-delegator created clusterrolebinding.rbac.authorization.k8s.io/system:metrics-server created service/metrics-server created deployment.apps/metrics-server created apiservice.apiregistration.k8s.io/v1beta1.metrics.k8s.io created

ubuntu@korifi:~$ kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/download/v0.6.2/components.yaml serviceaccount/metrics-server created clusterrole.rbac.authorization.k8s.io/system:aggregated-metrics-reader created clusterrole.rbac.authorization.k8s.io/system:metrics-server created rolebinding.rbac.authorization.k8s.io/metrics-server-auth-reader created clusterrolebinding.rbac.authorization.k8s.io/metrics-server:system:auth-delegator created clusterrolebinding.rbac.authorization.k8s.io/system:metrics-server created service/metrics-server created deployment.apps/metrics-server created apiservice.apiregistration.k8s.io/v1beta1.metrics.k8s.io created ubuntu@korifi:~$ kubectl get po,svc -A NAMESPACE NAME READY STATUS RESTARTS AGE cert-manager pod/cert-manager-74d949c895-w6gzm 1/1 Running 0 13m cert-manager pod/cert-manager-cainjector-d9bc5979d-jhr9m 1/1 Running 0 13m cert-manager pod/cert-manager-webhook-84b7ddd796-xw878 1/1 Running 0 13m kpack pod/kpack-controller-84cbbcdff6-nnhdn 1/1 Running 0 9m40s kpack pod/kpack-webhook-56c6b59c4-9zvlb 1/1 Running 0 9m40s kube-system pod/coredns-565d847f94-kst2l 1/1 Running 0 31m kube-system pod/coredns-565d847f94-rv8pn 1/1 Running 0 31m kube-system pod/etcd-kind-control-plane 1/1 Running 0 32m kube-system pod/kindnet-275pd 1/1 Running 0 31m kube-system pod/kube-apiserver-kind-control-plane 1/1 Running 0 32m kube-system pod/kube-controller-manager-kind-control-plane 1/1 Running 0 32m kube-system pod/kube-proxy-qw9fj 1/1 Running 0 31m kube-system pod/kube-scheduler-kind-control-plane 1/1 Running 0 32m kube-system pod/metrics-server-8ff8f88c6-69t9z 0/1 Running 0 4m21s local-path-storage pod/local-path-provisioner-684f458cdd-f6zqf 1/1 Running 0 31m metallb-system pod/controller-84d6d4db45-bph5x 1/1 Running 0 29m metallb-system pod/speaker-pcl4p 1/1 Running 0 29m projectcontour pod/contour-7b9b9cdfd6-h5jzg 1/1 Running 0 6m43s projectcontour pod/contour-7b9b9cdfd6-nhbq2 1/1 Running 0 6m43s projectcontour pod/contour-certgen-v1.23.2-hxh7k 0/1 Completed 0 6m43s projectcontour pod/envoy-v4xk9 2/2 Running 0 6m43s servicebinding-system pod/servicebinding-controller-manager-85f7498cf-xd7jc 2/2 Running 0 115s NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE cert-manager service/cert-manager ClusterIP 10.96.153.49 9402/TCP 13m cert-manager service/cert-manager-webhook ClusterIP 10.96.102.82 443/TCP 13m default service/kubernetes ClusterIP 10.96.0.1 443/TCP 32m kpack service/kpack-webhook ClusterIP 10.96.227.201 443/TCP 9m40s kube-system service/kube-dns ClusterIP 10.96.0.10 53/UDP,53/TCP,9153/TCP 32m kube-system service/metrics-server ClusterIP 10.96.204.62 443/TCP 4m21s metallb-system service/webhook-service ClusterIP 10.96.186.139 443/TCP 29m projectcontour service/contour ClusterIP 10.96.138.58 8001/TCP 6m43s projectcontour service/envoy LoadBalancer 10.96.126.44 172.18.255.200 80:30632/TCP,443:30730/TCP 6m43s servicebinding-system service/servicebinding-controller-manager-metrics-service ClusterIP 10.96.147.189 8443/TCP 115s servicebinding-system service/servicebinding-webhook-service ClusterIP 10.96.14.224 443/TCP 115s

External-Secrets Operator : A Kubernetes operator that integrates external secret management systems like AWS Secrets Manager, HashiCorp Vault, Google Secrets Manager, and many more. The operator reads information from external APIs and automatically injects the values into a Kubernetes Secret (Alternatives : Vault, SOPS, Sealed Secrets)

I like sealed secrets (https://github.com/bitnami-labs/sealed-secrets) a lot. It's like 1Password, but for apps in kubernetes. You only need to secure a private key, and can throw encrypted secrets in a public github repo or anywhere you want.

It's owned by VMware (Broadcom) now, so you have to decide which company you hate more.

If you have noticed, you are setting secrets in plain text on the application-configmap.yml file, which is not ideal and is not a best practice for security. The best way to do this securely would be to use AWS Secrets Manager, an external service like HashiCorp Vault, or Sealed Secrets. To learn more about these methods see the blog post Shhhh... Kubernetes Secrets Are Not Really Secret!.

Yeah documentation is hard and I'm guilty (as a former maintainer of SealedSecrets)

SealedSecrets was designed with "write only" secrets in mind.

Turns out a lot of people need to access the current secrets because they need to update a part of a "composite" secret.

There are two kinds of "composite" secrets, one easy and one harder, but if you don't know how to do it, even the easier is hard:

1. Secret with multiple data "items" (also called keys in K8s Secret jargon but that's confusing when there is encryption involved). I.e. good old "data":{"foo": "....", "bar": "..."}

2. Secrets where data within one item is actually a config file with cleartext and secrets mixed up in one single string (usually some JSON or YAML or TOML)

Case 1 is "easy" to deal with once you realize that sealed secrets files are just text files and you can just manually merge and update encryoted data items. We even created a "merge" and some "raw" encryption APIs to make that process a little less "copy pasta" but it's still hard to have a good UX that works for everyone.

Case 2 is harder. We did implement a data templating feature that allows you to generate a config file via a go-template that keeps the cleartext parts in clear and uses templating directives to inject the secret parts where you want (referencing the encrypted the items)

The main problem with case 2 is that it's undocumented.

The feature landed in 2021:

https://github.com/bitnami-labs/sealed-secrets/pull/580

I noticed that people at my current $dayjob used sealed secrets for years and it took me a while to understand that the reason they hated it was that they didn't know about that fundamental feature.

And how to blame them!? It's still undocumented!

In my defense I spent so much effort before and after I left VMware to lobby so that the project got the necessary staffing so it wouldn't die of bitrot that I didn't have much time left to work on documentation. Which is a bit said and probably just an excuse :-)

That said, I'm happy that the project is alive and the current maintainers are taking care of it against the forces of entropy. Perhaps some doc work would be useful too. Unfortunately I don't have time for now.

This might be OT, and forgive me, but I think one of the best practices for Encrypting and Managing secrets in Kubernetes is to use Sealed Secrets, they allow your secrets to be securely stored in git with the rest of the configuration and yet no one with access to the Git repository will be able to read them. I say this might be OT, because Sealed Secrets are trying to mitigate a different threat, the threat of the secrets at rest somewhere, and not "live in the cluster", where in theory all the ingredients to decrypt the secrets would still live.

The addition of Consul and Vault gives me a few things. For one, right now I'm handling secrets with a mixture of SOPS and Sealed Secrets. I use Vault in my professional life, and have used both Vault and Consul at my last job. Vault is a beast, so I may as well get better at it; plus its options for secret injection are better.

Use Sealed Secrets Operator.

sealed-secrets (sealed)