Fedora Coreos Installing K3s With Ignition
Thomas Büttner
So i wanted to experiment a bit with K3s, IPv6 and Cilium for that i want to try it with a clean environment each time, that was my excuse to try fiddling with Ignition again.
Also i don’t want to just curl the install script into bash as a oneshot service, instead i downloaded the script ran it with bash -x and came up with this (shortened) Butane config:
1variant: fcos
2version: 1.5.0
3systemd:
4 units:
5 - name: rpm-ostree-install-k3s-selinux.service
6 enabled: true
7 contents: |
8 [Unit]
9 Description=Layer k3s-selinux with rpm-ostree
10 Wants=network-online.target
11 After=network-online.target
12 Before=zincati.service
13 ConditionPathExists=!/var/lib/misc/%N.stamp
14
15 [Service]
16 Type=oneshot
17 RemainAfterExit=yes
18 ExecStart=/usr/bin/rpm-ostree --idempotent install --apply-live --allow-inactive --assumeyes k3s-selinux
19 ExecStart=/bin/touch /var/lib/misc/%N.stamp
20 ExecStartPost=/usr/sbin/restorecon -Rv /usr/local/bin
21
22 [Install]
23 WantedBy=multi-user.target
24 - name: k3s.service
25 enabled: true
26 contents: |
27 [Unit]
28 Description=Lightweight Kubernetes
29 Documentation=https://k3s.io
30 ConditionPathExists=/usr/share/selinux/packages/k3s.pp
31 Wants=network-online.target
32 After=network-online.target
33
34 [Install]
35 WantedBy=multi-user.target
36
37 [Service]
38 Type=notify
39 EnvironmentFile=-/etc/default/%N
40 EnvironmentFile=-/etc/sysconfig/%N
41 EnvironmentFile=-/etc/systemd/system/k3s.service.env
42 KillMode=process
43 Delegate=yes
44 # Having non-zero Limit*s causes performance problems due to accounting overhead
45 # in the kernel. We recommend using cgroups to do container-local accounting.
46 LimitNOFILE=1048576
47 LimitNPROC=infinity
48 LimitCORE=infinity
49 TasksMax=infinity
50 TimeoutStartSec=0
51 Restart=always
52 RestartSec=5s
53 ExecStartPre=/bin/sh -xc '! /usr/bin/systemctl is-enabled --quiet nm-cloud-setup.service'
54 ExecStartPre=-/sbin/modprobe br_netfilter
55 ExecStartPre=-/sbin/modprobe overlay
56 ExecStart=/usr/local/bin/k3s \
57 server \
58 '--selinux'
59storage:
60 files:
61 - path: /usr/local/bin/k3s
62 mode: 0755
63 contents:
64 source: https://github.com/k3s-io/k3s/releases/download/v1.27.5+k3s1/k3s
65 verification:
66 hash: sha256-aa3387f1e01e21478d8042d6ab0cb25c299fe0920e2e30fc760ab36fb7a3d459
67 - path: /usr/local/bin/k3s-killall.sh
68 mode: 0755
69 contents:
70 local: k3s-killall.sh
71 - path: /usr/local/bin/k3s-uninstall.sh
72 mode: 0755
73 contents:
74 local: k3s-uninstall.sh
75 - path: /etc/systemd/system/k3s.service.env
76 mode: 0600
77 contents:
78 inline: ""
79 - path: /etc/yum.repos.d/rancher-k3s-common.repo
80 contents:
81 inline: |
82 [rancher-k3s-common-stable]
83 name=Rancher K3s Common (stable)
84 baseurl=https://rpm.rancher.io/k3s/stable/common/coreos/noarch
85 enabled=1
86 gpgcheck=1
87 repo_gpgcheck=0
88 gpgkey=https://rpm.rancher.io/public.key
89 links:
90 - path: /usr/local/bin/kubectl
91 target: /usr/local/bin/k3s
92 - path: /usr/local/bin/crictl
93 target: /usr/local/bin/k3s
The referenced k3s-uninstall.sh and k3s-killall.sh scripts are straight out of the normal install generated from the script.