kubelogin VS cert-manager

Authenticating with Kyma is a (in my opinion) unnecessary challenge as it leverages the OIDC-login plugin for kubectl. You find a description of the setup here. This works fine when on a Mac but can give you some headaches on a Windows and on Linux machine especially when combined with restrictive setups in corporate environments. For Windows I can only recommend installing krew via chocolatey and then install the OIDC plugin via kubectl krew install oidc-login. At least for me that was the only way to get this working on Windows.

It is sort of a roundabout way, but I sync Active Directory to a Keycloak realm, then use OIDC auth with kube-oidc-proxy (https://github.com/jetstack/kube-oidc-proxy) and kubelogin (https://github.com/int128/kubelogin) for OIDC-based auth to the api server.

Yes, I setup a cluster with no SPFs. That means an HA setup for the external load balancer. I use HAProxy for my ELB, and setup 2 instances with a VRRP + keepalived to provide HA to the ingress controller. I run the control plane private, accessible only from localhost. I setup kube-oidc-proxy (https://github.com/jetstack/kube-oidc-proxy) to expose the API server with single sign-on on the ingress controller, and use the kubelogin plugin (https://github.com/int128/kubelogin) to provide OIDC support to kubectl. I then setup Keycloak to handle OIDC/OAuth2/SAML and syncing to Active Directory, and setup groups in Active Directory to control acccess to clusters. Devs each get their own namespace in the dev cluster, with mostly cluster-admin access to their namespace. Staging/Prod clusters are locked down, with read-only access to devs. Thanks to the OIDC auth to the APIServer, when employees are onboarded & offboarded, we only need to add/remove them from groups in Active Directory and everything else just magically syncs.

I've successfully configured kube-apiserver to authenticate users through oidc (https://github.com/int128/kubelogin) so all the users from my keycloak realm can access to the cluster with their credentials.

Link to GitHub Repository

kubelogin (helper for k8s build in OIDC support)

I use the kube-login plugin for kubectl (https://github.com/int128/kubelogin) along with the kube-oidc-proxy (https://github.com/jetstack/kube-oidc-proxy), using Keycloak as my OIDC provider (https://www.keycloak.org) and doing LDAP synchronization to Active Directory.

Dex oauth and kubelogin. We happen to use google auth in our org, but dex is pretty flexible. You only have to have a way to distribute server certificates. We then have documented script commands to pull certs and create kubectl fig files. OpenUnison always looked interesting, but dex has been good enough for our uses.

With a working dex/OIDC configuration, you could use: https://github.com/int128/kubelogin

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