k3s VS cert-manager

Opinionated meaning it picks, install, patches your CNI/Ingress/Load Balancer/DNS Server/Metrics Server/Monitoring Setup.

k3s is probably most well known as it ships with bunch of preinstall software: https://github.com/k3s-io/k3s so you can just start throwing yaml files at cluster and handling workloads. It's what I use for my homelab.

Paid things I've heard of include OpenStack and SideroLabs. Haven't used personally by SRE coworkers say good things about them.

For self-hosting I've found https://k3s.io to be really good from the SUSE people. Works on basically any Linux distro and makes self-hosting k8s not miserable.

Yes it’s going to depend on which k8s distribution you’re using. We have work in-progress for k3s to natively support nix-snapshotter: https://github.com/k3s-io/k3s/pull/9319

For other distributions, nix-snapshotter works with official containerd releases so it’s just a matter of toml configuration and a systemd unit for nix-snapshotter.

We run Kubernetes outside of NixOS, but yes the NixOS modules provided by the nix-snapshotter certainly make it simple.

K3S: is a lightweight distribution of Kubernetes that is designed for resource-constrained environments. It is an excellent option for running Kubernetes on a virtual machine or cloud server.

I recently purchased a used Lenovo M900 Think Centre (i7 with 32GB RAM) from eBay to expand my mini-homelab, which was just a single Synology DS218+ plugged into my ISP's router (yuck!). Since I've been spending a big chunk of time at work playing around with Kubernetes, I figured that I'd put my skills to the test and run a k3s node on the new server. While I was familiar with k3s before starting this project, I'd never actually run it before, opting for tools like kind (and minikube before that) to run small test clusters for my local development work.

Kubernetes - k3s distribution

I’ve created a local cluster with K3S and installing Windmill could not be simpler with just one chart to configure, which already has sane defaults to get started. For this demo we will also configure workers to passthrough environment variables to our scripts so that they have access to the Kubernetes API server for later.

You should be familiar with Kubernetes and have set up a Kubernetes cluster. I recommend k3s.

cert-manager

The second one is a combination of tools: External DNS, cert-manager, and NGINX ingress. Using these as a stack, you can quickly deploy an application, making it available through a DNS with a TLS without much effort via simple annotations. When I first discovered External DNS, I was amazed at its quality.

On top of its core components, SpinKube depends on cert-manager. cert-Manager is responsible for provisioning and managing TLS certificates that are used by the admission webhook system of the Spin Operator. Let’s install cert-manager and KWasm using the commands shown here:

terraform { required_providers { kubectl = { source = "gavinbunney/kubectl" version = "1.14.0" } } } # The reference to the current project or a AWS project data "google_client_config" "provider" {} # The reference to the current cluster or EKS data "google_container_cluster" "my_cluster" { name = var.cluster_name location = var.cluster_location } # We configure the kubectl provider to use those values for authenticating provider "kubectl" { host = data.google_container_cluster.my_cluster.endpoint token = data.google_client_config.provider.access_token cluster_ca_certificate = base64decode(data.google_container_cluster.my_cluster.master_auth[0].cluster_ca_certificate) } #Download the multiple manifests file. data "http" "cert_manager_crds" { url = "https://github.com/cert-manager/cert-manager/releases/download/v${var.cert_manager_version}/cert-manager.crds.yaml" } data "kubectl_file_documents" "cert_manager_crds" { content = data.http.cert_manager_crds.response_body lifecycle { precondition { condition = 200 == data.http.cert_manager_crds.status_code error_message = "Status code invalid" } } } # We use the for_each or else this kubectl_manifest will only import the first manifest in the file. resource "kubectl_manifest" "cert_manager_crds" { for_each = data.kubectl_file_documents.cert_manager_crds.manifests yaml_body = each.value }

SSL certificates thanks to Cloudflare and cert-manager

kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/${CERT_MANAGER_VERSION}/cert-manager.crds.yaml

put the Sub-CA inside hashicorp vault to be used for automatic signing of services like https://cert-manager.io/ inside our k8s clusters.

install-cert-manager: desc: Install cert-manager deps: - init-cluster cmds: - kubectl apply -f https://github.com/cert-manager/cert-manager/releases/download/{{.CERT_MANAGER_VERSION}}/cert-manager.yaml - echo "Waiting for cert-manager to be ready" && sleep 25 status: - kubectl -n cert-manager get pods | grep Running | wc -l | grep -q 3

I've been pretty frustrated with how private CAs are supported. Your private root CA can be maliciously used to MITM every domain on the Internet, even though you intend to use it for only a couple domain names. Most people forget to set Name Constraints when they create these and many helper tools lack support [1][2]. Worse, browser support for Name Constraints has been slow [3] and support isn't well tracked [4]. Public CAs give you certificate transparency and you can subscribe to events to detect mis-issuance. Some hosted private CAs like AWS's offer logs [5], but DIY setups don't.

Even still, there are a lot of folks happily using private CAs, they aren't the target audience for this initial release.

[1] https://github.com/FiloSottile/mkcert/issues/302

[2] https://github.com/cert-manager/cert-manager/issues/3655

[3] https://alexsci.com/blog/name-non-constraint/

[4] https://github.com/Netflix/bettertls/issues/19

[5] https://docs.aws.amazon.com/privateca/latest/userguide/secur...

the Cert Manager