# Kubernetes cluster manifests ## Introduction This is the Kubernetes manifests of services running on k-space.ee domains. The applications are listed on https://auth2.k-space.ee for authenticated users. ## Cluster access General discussion is happening in the `#kube` Slack channel.
Bootstrapping access For bootstrap access obtain `/etc/kubernetes/admin.conf` from one of the master nodes and place it under `~/.kube/config` on your machine. Once Passmower is working, OIDC access for others can be enabled with running following on Kubernetes masters: ```bash patch /etc/kubernetes/manifests/kube-apiserver.yaml - << EOF @@ -23,6 +23,10 @@ - --etcd-certfile=/etc/kubernetes/pki/apiserver-etcd-client.crt - --etcd-keyfile=/etc/kubernetes/pki/apiserver-etcd-client.key - --etcd-servers=https://127.0.0.1:2379 + - --oidc-issuer-url=https://auth2.k-space.ee/ + - --oidc-client-id=kubelogin + - --oidc-username-claim=sub + - --oidc-groups-claim=groups - --kubelet-client-certificate=/etc/kubernetes/pki/apiserver-kubelet-client.crt - --kubelet-client-key=/etc/kubernetes/pki/apiserver-kubelet-client.key - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname EOF sudo systemctl daemon-reload systemctl restart kubelet ```
The following can be used to talk to the Kubernetes cluster using OIDC credentials: ```bash kubectl krew install oidc-login mkdir -p ~/.kube cat << EOF > ~/.kube/config apiVersion: v1 clusters: - cluster: certificate-authority-data: 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 server: https://master.kube.k-space.ee:6443 name: kubernetes contexts: - context: cluster: kubernetes user: oidc name: default current-context: default kind: Config preferences: {} users: - name: oidc user: exec: apiVersion: client.authentication.k8s.io/v1beta1 args: - oidc-login - get-token - --oidc-issuer-url=https://auth2.k-space.ee/ - --oidc-client-id=oidc-gateway-kubelogin - --oidc-use-pkce - --oidc-extra-scope=profile,email,groups - --listen-address=127.0.0.1:27890 command: kubectl env: null provideClusterInfo: false EOF ``` For access control mapping see [cluster-role-bindings.yml](cluster-role-bindings.yml) ### systemd-resolved issues on access ```sh Unable to connect to the server: dial tcp: lookup master.kube.k-space.ee on 127.0.0.53:53: no such host ``` ``` Network → VPN → `IPv4` → Other nameservers (Muud nimeserverid): `172.21.0.1` Network → VPN → `IPv6` → Other nameservers (Muud nimeserverid): `2001:bb8:4008:21::1` Network → VPN → `IPv4` → Search domains (Otsingudomeenid): `kube.k-space.ee` Network → VPN → `IPv6` → Search domains (Otsingudomeenid): `kube.k-space.ee` ``` # Technology mapping Our self-hosted Kubernetes stack compared to AWS based deployments: | Hipster startup | Self-hosted hackerspace | Purpose | |-------------------|-------------------------------------|---------------------------------------------------------------------| | AWS ALB | Traefik | Reverse proxy also known as ingress controller in Kubernetes jargon | | AWS AMP | Prometheus Operator | Monitoring and alerting | | AWS CloudTrail | ECK Operator | Log aggregation | | AWS DocumentDB | MongoDB Community Operator | Highly available NoSQL database | | AWS EBS | Longhorn | Block storage for arbitrary applications needing persistent storage | | AWS EC2 | Proxmox | Virtualization layer | | AWS ECR | Harbor | Docker registry | | AWS EKS | kubeadm | Provision Kubernetes master nodes | | AWS NLB | MetalLB | L2/L3 level load balancing | | AWS RDS for MySQL | MySQL Operator | Provision highly available relational databases | | AWS Route53 | Bind and RFC2136 | DNS records and Let's Encrypt DNS validation | | AWS S3 | Minio Operator | Highly available object storage | | AWS VPC | Calico | Overlay network | | Dex | Passmower | ACL mapping and OIDC provider which integrates with GitHub/Samba | | GitHub Actions | Drone | Build Docker images | | GitHub | Gitea | Source code management, issue tracking | | GitHub OAuth2 | Samba (Active Directory compatible) | Source of truth for authentication and authorization | | Gmail | Wildduck | E-mail | External dependencies running as classic virtual machines: - Bind as DNS server ## Adding applications Deploy applications via [ArgoCD](https://argocd.k-space.ee) We use Treafik with Passmower for Ingress. Applications where possible and where applicable should use `Remote-User` authentication. This prevents application exposure on public Internet. Otherwise use OpenID Connect for authentication, see Argo itself as an example how that is done. See `camtiler/ingress.yml` for commented Ingress example. Note that we do not use IngressRoute objects because they don't support `external-dns` out of the box. Do NOT add nginx annotations, we use Traefik. Do NOT manually add DNS records, they are added by `external-dns`. Do NOT manually create Certificate objects, these should be handled by `tls:` section in Ingress. ## Cluster formation Created Ubuntu 22.04 VM-s on Proxmox with local storage. Added some ARM64 workers by using Ubuntu 22.04 server on Raspberry Pi. After machines have booted up and you can reach them via SSH: ``` # Disable Ubuntu caching DNS resolver systemctl disable systemd-resolved.service systemctl stop systemd-resolved rm -fv /etc/resolv.conf cat > /etc/resolv.conf << EOF nameserver 1.1.1.1 nameserver 8.8.8.8 EOF # Disable multipathd as Longhorn handles that itself systemctl mask multipathd snapd systemctl disable --now multipathd snapd bluetooth ModemManager hciuart wpa_supplicant packagekit # Permit root login sed -i -e 's/PermitRootLogin no/PermitRootLogin without-password/' /etc/ssh/sshd_config systemctl reload ssh cat ~ubuntu/.ssh/authorized_keys > /root/.ssh/authorized_keys userdel -f ubuntu apt-get install -yqq linux-image-generic apt-get remove -yq cloud-init linux-image-*-kvm ``` On master: ``` kubeadm init --token-ttl=120m --pod-network-cidr=10.244.0.0/16 --control-plane-endpoint "master.kube.k-space.ee:6443" --upload-certs --apiserver-cert-extra-sans master.kube.k-space.ee --node-name master1.kube.k-space.ee ``` For the `kubeadm join` command specify FQDN via `--node-name $(hostname -f)`. Set AZ labels: ``` for j in $(seq 1 9); do for t in master mon worker storage; do kubectl label nodes ${t}${j}.kube.k-space.ee topology.kubernetes.io/zone=node${j} done done ``` After forming the cluster add taints: ```bash for j in $(seq 1 9); do kubectl label nodes worker${j}.kube.k-space.ee node-role.kubernetes.io/worker='' done for j in $(seq 1 4); do kubectl taint nodes mon${j}.kube.k-space.ee dedicated=monitoring:NoSchedule kubectl label nodes mon${j}.kube.k-space.ee dedicated=monitoring done for j in $(seq 1 4); do kubectl taint nodes storage${j}.kube.k-space.ee dedicated=storage:NoSchedule kubectl label nodes storage${j}.kube.k-space.ee dedicated=storage done ``` For `arm64` nodes add suitable taint to prevent scheduling non-multiarch images on them: ```bash kubectl taint nodes worker9.kube.k-space.ee arch=arm64:NoSchedule ``` For door controllers: ``` for j in ground front back; do kubectl taint nodes door-${j}.kube.k-space.ee dedicated=door:NoSchedule kubectl label nodes door-${j}.kube.k-space.ee dedicated=door kubectl taint nodes door-${j}.kube.k-space.ee arch=arm64:NoSchedule done ``` To reduce wear on storage: ``` echo StandardOutput=null >> /etc/systemd/system/kubelet.service.d/10-kubeadm.conf systemctl daemon-reload systemctl restart kubelet ```