k3s

90-k8s.conf

# /etc/sysctl.d/90-k8s.conf

### FILE SYSTEM SETTINGS ###
fs.file-max = 2097152

### VIRTUAL MEMORY SETTINGS ###
# Decrease SWAP
vm.dirty_ratio = 15
vm.dirty_background_ratio = 8

# Panic and OOM Behavior
vm.panic_on_oom = 0
vm.overcommit_memory = 1

### CPU SCHEDULING SETTINGS ###
# Sets the time before the kernel considers migrating a process to another core
kernel.sched_migration_cost_ns = 2000000

# Group tasks by TTY
# kernel.sched_autogroup_enabled = 0

### NETWORKING SETTINGS ###

# General Networking
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
net.core.optmem_max = 25165824
net.core.netdev_max_backlog = 65536
net.core.somaxconn = 65535

# TCP Settings
net.ipv4.tcp_synack_retries = 2
net.ipv4.tcp_fin_timeout = 15
net.ipv4.tcp_keepalive_time = 300
net.ipv4.tcp_keepalive_probes = 5
net.ipv4.tcp_keepalive_intvl = 15
net.ipv4.tcp_rfc1337 = 1
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_max_tw_buckets = 1440000
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_mem = 786432 1048576 26777216
net.ipv4.tcp_rmem = 8192 87380 33554432
net.ipv4.tcp_wmem = 8192 65536 33554432

# UDP Settings
net.ipv4.udp_mem = 65536 131072 262144
net.ipv4.udp_rmem_min = 16384
net.ipv4.udp_wmem_min = 16384

# # Local Port Range
# net.ipv4.ip_local_port_range = 2000 65535

# IPv4 Buffer Sizes
net.core.rmem_default = 31457280
net.core.rmem_max = 33554432
net.core.wmem_default = 31457280
net.core.wmem_max = 33554432

# Disable IPv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

# Adjusting Maximum Backlog and SYN Backlog
net.core.netdev_max_backlog = 5000
net.ipv4.tcp_max_syn_backlog = 2048

### KERNEL HARDENING ###
kernel.panic = 10
kernel.panic_on_oops = 1
kernel.keys.root_maxbytes = 25000000

/etc/rancher/k3s/kubelet-config.yaml - agent

apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration

featureGates:
NodeSwap: true

serializeImagePulls: true

memorySwap:
swapBehavior: "LimitedSwap"

kubeReserved:
cpu: "200m"
memory: "384Mi"
ephemeral-storage: "1Gi"

systemReserved:
cpu: "100m"
memory: "512Mi"
ephemeral-storage: "4Gi"

evictionHard:
memory.available: "128Mi"
nodefs.available: "10%"
nodefs.inodesFree: "5%"

imageMinimumGCAge: "2h"
imageGCHighThresholdPercent: 85
imageGCLowThresholdPercent: 80
imageMaximumGCAge: "48h"