K3s: Extra args with "<" are problematic for shell (kubelet eviction rules)

[digger18]

Describe the bug
When trying to start k3s server with extra arguments that contains the "<" char, the shell interprets it as an stdin redirection which breaks the k3s startup.

To Reproduce
Run the following command:

curl -sfL https://get.k3s.io | INSTALL_K3S_VERSION='v0.5.0' sh -s - --docker --no-deploy traefik --kubelet-arg='eviction-soft=memory.available<500Mi' --kubelet-arg='eviction-soft-grace-period=memory.available=1m' --kubelet-arg='eviction-hard=memory.available<100Mi' --kubelet-arg='eviction-soft=nodefs.available<15%' --kubelet-arg='eviction-soft-grace-period=nodefs.available=60m' --kubelet-arg='eviction-hard=nodefs.available<10%' --kubelet-arg='eviction-soft=nodefs.inodesFree<10%' --kubelet-arg='eviction-soft-grace-period=nodefs.inodesFree=120m' --kubelet-arg='eviction-hard=nodefs.inodesFree<5%'

Which will result in the following systemd file:

[Unit]
Description=Lightweight Kubernetes
Documentation=https://k3s.io
After=network-online.target

[Service]
Type=notify
EnvironmentFile=/etc/systemd/system/k3s.service.env
ExecStartPre=-/sbin/modprobe br_netfilter
ExecStartPre=-/sbin/modprobe overlay
ExecStart=/usr/local/bin/k3s server --docker --no-deploy traefik --kubelet-arg=eviction-soft=memory.available<500Mi --kubelet-arg=eviction-soft-grace-period=memory.available=1m --kubelet-arg=eviction-hard=memory.available<100Mi --kubelet-arg=eviction-soft=nodefs.available<15% --kubelet-arg=eviction-soft-grace-period=nodefs.available=60m --kubelet-arg=eviction-hard=nodefs.available<10% --kubelet-arg=eviction-soft=nodefs.inodesFree<10% --kubelet-arg=eviction-soft-grace-period=nodefs.inodesFree=120m --kubelet-arg=eviction-hard=nodefs.inodesFree<5%
KillMode=process
Delegate=yes
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TasksMax=infinity
TimeoutStartSec=0
Restart=always

[Install]
WantedBy=multi-user.target

Running this command in shell will provide the following error:

# /usr/local/bin/k3s server --docker --no-deploy traefik --kubelet-arg=eviction-soft=memory.available<500Mi --kubelet-arg=eviction-soft-grace-period=memory.available=1m --kubelet-arg=eviction-hard=memory.available<100Mi --kubelet-arg=eviction-soft=nodefs.available<15% --kubelet-arg=eviction-soft-grace-period=nodefs.available=60m --kubelet-arg=eviction-hard=nodefs.available<10% --kubelet-arg=eviction-soft=nodefs.inodesFree<10% --kubelet-arg=eviction-soft-grace-period=nodefs.inodesFree=120m --kubelet-arg=eviction-hard=nodefs.inodesFree<5%
-su: 500Mi: No such file or directory

Expected behavior
The args should be encapsulated with quotes so the shell will not break if args uses special shell characters or operators.

[erikwilson]

@digger18 a fix has been merged for this, please feel free to re-open if it does not solve the issue.

[Jintree]

The problem is also still.

[brandond]

We fixed it in the install script. If you're running k3s server from the command-line you are responsible for appropriately quoting the arguments yourself. Just put the flags with < or > in quotes.

[Jintree]

@brandond thanks～.-kubelet-arg=eviction-hard=imagefs.available<1%,nodefs.available<1% --kubelet-arg=eviction-minimum-reclaim=imagefs.available=1%,nodefs.available=1% can be used in the install script.