rasmus
bac5040d2a
For 'how to connect to cluster', server-side setup is not needed from connecting clients. Hiding the section makes the steps more concise.
273 lines
12 KiB
Markdown
273 lines
12 KiB
Markdown
# Kubernetes cluster manifests
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## Introduction
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This is the Kubernetes manifests of services running on k-space.ee domains:
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- [Authelia](https://auth.k-space.ee) for authentication
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- [Drone.io](https://drone.k-space.ee) for building Docker images
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- [Harbor](https://harbor.k-space.ee) for hosting Docker images
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- [ArgoCD](https://argocd.k-space.ee) for deploying Kubernetes manifests and
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Helm charts into the cluster
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- [camtiler](https://cams.k-space.ee) for cameras
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- [Longhorn Dashboard](https://longhorn.k-space.ee) for administering
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Longhorn storage
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- [Kubernetes Dashboard](https://kubernetes-dashboard.k-space.ee/) for read-only overview
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of the Kubernetes cluster
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- [Wildduck Webmail](https://webmail.k-space.ee/)
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Most endpoints are protected by OIDC autentication or Authelia SSO middleware.
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## Cluster access
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General discussion is happening in the `#kube` Slack channel.
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<details><summary>Bootstrapping access</summary>
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For bootstrap access obtain `/etc/kubernetes/admin.conf` from one of the master
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nodes and place it under `~/.kube/config` on your machine.
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Once Authelia is working, OIDC access for others can be enabled with
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running following on Kubernetes masters:
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```bash
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patch /etc/kubernetes/manifests/kube-apiserver.yaml - << EOF
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@@ -23,6 +23,10 @@
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- --etcd-certfile=/etc/kubernetes/pki/apiserver-etcd-client.crt
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- --etcd-keyfile=/etc/kubernetes/pki/apiserver-etcd-client.key
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- --etcd-servers=https://127.0.0.1:2379
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+ - --oidc-issuer-url=https://auth.k-space.ee
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+ - --oidc-client-id=kubelogin
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+ - --oidc-username-claim=preferred_username
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+ - --oidc-groups-claim=groups
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- --kubelet-client-certificate=/etc/kubernetes/pki/apiserver-kubelet-client.crt
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- --kubelet-client-key=/etc/kubernetes/pki/apiserver-kubelet-client.key
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- --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
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EOF
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sudo systemctl daemon-reload
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systemctl restart kubelet
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```
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</details>
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The following can be used to talk to the Kubernetes cluster using OIDC credentials:
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```bash
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kubectl krew install oidc-login
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mkdir -p ~/.kube
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cat << EOF > ~/.kube/config
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apiVersion: v1
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clusters:
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- cluster:
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certificate-authority-data: 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server: https://master.kube.k-space.ee:6443
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name: kubernetes
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contexts:
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- context:
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cluster: kubernetes
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user: oidc
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name: default
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current-context: default
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kind: Config
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preferences: {}
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users:
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- name: oidc
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user:
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exec:
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apiVersion: client.authentication.k8s.io/v1beta1
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args:
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- oidc-login
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- get-token
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- --oidc-issuer-url=https://auth.k-space.ee
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- --oidc-client-id=kubelogin
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- --oidc-use-pkce
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- --oidc-extra-scope=profile,email,groups
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- --listen-address=127.0.0.1:27890
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command: kubectl
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env: null
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provideClusterInfo: false
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EOF
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```
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For access control mapping see [cluster-role-bindings.yml](cluster-role-bindings.yml)
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### systemd-resolved issues on access
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```sh
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Unable to connect to the server: dial tcp: lookup master.kube.k-space.ee on 127.0.0.53:53: no such host
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```
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```
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Network → VPN → `IPv4` → Other nameservers (Muud nimeserverid): `172.21.0.1`
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Network → VPN → `IPv6` → Other nameservers (Muud nimeserverid): `2001:bb8:4008:21::1`
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Network → VPN → `IPv4` → Search domains (Otsingudomeenid): `kube.k-space.ee`
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Network → VPN → `IPv6` → Search domains (Otsingudomeenid): `kube.k-space.ee`
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```
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# Technology mapping
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Our self-hosted Kubernetes stack compared to AWS based deployments:
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| Hipster startup | Self-hosted hackerspace | Purpose |
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|-------------------|-------------------------------------|---------------------------------------------------------------------|
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| AWS ALB | Traefik | Reverse proxy also known as ingress controller in Kubernetes jargon |
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| AWS AMP | Prometheus Operator | Monitoring and alerting |
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| AWS CloudTrail | ECK Operator | Log aggregation |
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| AWS DocumentDB | MongoDB Community Operator | Highly available NoSQL database |
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| AWS EBS | Longhorn | Block storage for arbitrary applications needing persistent storage |
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| AWS EC2 | Proxmox | Virtualization layer |
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| AWS ECR | Harbor | Docker registry |
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| AWS EKS | kubeadm | Provision Kubernetes master nodes |
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| AWS NLB | MetalLB | L2/L3 level load balancing |
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| AWS RDS for MySQL | MySQL Operator | Provision highly available relational databases |
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| AWS Route53 | Bind and RFC2136 | DNS records and Let's Encrypt DNS validation |
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| AWS S3 | Minio Operator | Highly available object storage |
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| AWS VPC | Calico | Overlay network |
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| Dex | Authelia | ACL mapping and OIDC provider which integrates with GitHub/Samba |
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| GitHub Actions | Drone | Build Docker images |
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| GitHub | Gitea | Source code management, issue tracking |
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| GitHub OAuth2 | Samba (Active Directory compatible) | Source of truth for authentication and authorization |
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| Gmail | Wildduck | E-mail |
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External dependencies running as classic virtual machines:
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- Samba as Authelia's source of truth
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- Bind as DNS server
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## Adding applications
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Deploy applications via [ArgoCD](https://argocd.k-space.ee)
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We use Treafik with Authelia for Ingress.
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Applications where possible and where applicable should use `Remote-User`
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authentication. This prevents application exposure on public Internet.
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Otherwise use OpenID Connect for authentication,
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see Argo itself as an example how that is done.
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See `kspace-camtiler/ingress.yml` for commented Ingress example.
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Note that we do not use IngressRoute objects because they don't
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support `external-dns` out of the box.
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Do NOT add nginx annotations, we use Traefik.
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Do NOT manually add DNS records, they are added by `external-dns`.
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Do NOT manually create Certificate objects,
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these should be handled by `tls:` section in Ingress.
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## Cluster formation
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Create Ubuntu 20.04 VM-s on Proxmox with local storage.
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After machines have booted up and you can reach them via SSH:
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```bash
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# Enable required kernel modules
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cat > /etc/modules << EOF
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overlay
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br_netfilter
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EOF
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cat /etc/modules | xargs -L 1 -t modprobe
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# Finetune sysctl:
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cat > /etc/sysctl.d/99-k8s.conf << EOF
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net.ipv4.conf.all.accept_redirects = 0
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net.bridge.bridge-nf-call-iptables = 1
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net.ipv4.ip_forward = 1
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net.bridge.bridge-nf-call-ip6tables = 1
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EOF
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sysctl --system
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# Disable Ubuntu caching DNS resolver
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systemctl disable systemd-resolved.service
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systemctl stop systemd-resolved
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rm -fv /etc/resolv.conf
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cat > /etc/resolv.conf << EOF
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nameserver 1.1.1.1
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nameserver 8.8.8.8
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EOF
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# Disable multipathd as Longhorn handles that itself
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systemctl mask multipathd
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systemctl disable multipathd
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systemctl stop multipathd
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# Disable Snapcraft
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systemctl mask snapd
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systemctl disable snapd
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systemctl stop snapd
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# Permit root login
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sed -i -e 's/PermitRootLogin no/PermitRootLogin without-password/' /etc/ssh/sshd_config
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systemctl reload ssh
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cat << EOF > /root/.ssh/authorized_keys
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sk-ecdsa-sha2-nistp256@openssh.com AAAAInNrLWVjZHNhLXNoYTItbmlzdHAyNTZAb3BlbnNzaC5jb20AAAAIbmlzdHAyNTYAAABBBD4/e9SWYWYoNZMkkF+NirhbmHuUgjoCap42kAq0pLIXFwIqgVTCre03VPoChIwBClc8RspLKqr5W3j0fG8QwnQAAAAEc3NoOg== lauri@lauri-x13
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EOF
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userdel -f ubuntu
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apt-get remove -yq cloud-init
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```
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Install packages, for Raspbian set `OS=Debian_11`
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```bash
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OS=xUbuntu_20.04
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VERSION=1.23
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cat <<EOF | sudo tee /etc/apt/sources.list.d/devel:kubic:libcontainers:stable.list
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deb https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable/$OS/ /
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EOF
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cat <<EOF | sudo tee /etc/apt/sources.list.d/devel:kubic:libcontainers:stable:cri-o:$VERSION.list
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deb http://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable:/cri-o:/$VERSION/$OS/ /
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EOF
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curl -L https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/stable/$OS/Release.key | sudo apt-key --keyring /etc/apt/trusted.gpg.d/libcontainers.gpg add -
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curl -L https://download.opensuse.org/repositories/devel:kubic:libcontainers:stable:cri-o:$VERSION/$OS/Release.key | sudo apt-key --keyring /etc/apt/trusted.gpg.d/libcontainers-cri-o.gpg add -
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curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
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echo "deb https://apt.kubernetes.io/ kubernetes-xenial main" > /etc/apt/sources.list.d/kubernetes.list
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apt-get update
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apt-get install -yqq apt-transport-https curl cri-o cri-o-runc kubelet=1.23.5-00 kubectl=1.23.5-00 kubeadm=1.23.5-00
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sudo systemctl daemon-reload
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sudo systemctl enable crio --now
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apt-mark hold kubelet kubeadm kubectl
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sed -i -e 's/unqualified-search-registries = .*/unqualified-search-registries = ["docker.io"]/' /etc/containers/registries.conf
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```
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On master:
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```
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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
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```
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For the `kubeadm join` command specify FQDN via `--node-name $(hostname -f)`.
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After forming the cluster add taints:
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```bash
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for j in $(seq 1 9); do
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kubectl label nodes worker${j}.kube.k-space.ee node-role.kubernetes.io/worker=''
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done
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for j in $(seq 1 3); do
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kubectl taint nodes mon${j}.kube.k-space.ee dedicated=monitoring:NoSchedule
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kubectl label nodes mon${j}.kube.k-space.ee dedicated=monitoring
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done
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for j in $(seq 1 4); do
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kubectl taint nodes storage${j}.kube.k-space.ee dedicated=storage:NoSchedule
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kubectl label nodes storage${j}.kube.k-space.ee dedicated=storage
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done
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```
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On Raspberry Pi you need to take additonal steps:
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* Manually enable cgroups by appending
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`cgroup_memory=1 cgroup_enable=memory` to `/boot/cmdline.txt`,
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* Disable swap with `swapoff -a; apt-get purge -y dphys-swapfile`
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* For mounting Longhorn volumes on Rasbian install `open-iscsi`
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For `arm64` nodes add suitable taint to prevent scheduling non-multiarch images on them:
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```bash
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kubectl taint nodes worker9.kube.k-space.ee arch=arm64:NoSchedule
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```
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