herolib/lib/installers/virt/kubernetes_installer/instructions.md

need to install following

#!/bin/bash

set -euo pipefail

EXTRA_ARGS=""

log_info() { echo '[INFO] ' "$@" }

log_fatal() { echo '[ERROR] ' "$@" >&2 exit 1 }

source_env_file() { local env_file="${1:-}"

if [ ! -f "$env_file" ]; then
    log_fatal "Environment file not found: $env_file"
fi
    
set -a
source "$env_file"
set +a

}

check_root() { if [ "$EUID" -ne 0 ]; then log_fatal "This script must be run as root" fi }

install_deps() { log_info "Updating package lists..." if ! apt-get update -qq > /dev/null 2>&1; then log_fatal "Failed to update package lists" fi

if ! command -v curl &> /dev/null; then
    log_info "Installing curl..."
    apt-get install -y -qq curl > /dev/null 2>&1 || log_fatal "Failed to install curl"
fi

if ! command -v ip &> /dev/null; then
    log_info "Installing iproute2 for ip command..."
    apt-get install -y -qq iproute2 > /dev/null 2>&1 || log_fatal "Failed to install iproute2"
fi

if ! command -v k3s &> /dev/null; then
    log_info "Installing k3s..."
    if ! curl -fsSL -o /usr/local/bin/k3s https://github.com/k3s-io/k3s/releases/download/v1.33.1+k3s1/k3s 2>/dev/null; then
        log_fatal "Failed to download k3s"
    fi
    chmod +x /usr/local/bin/k3s
fi

if ! command -v kubectl &> /dev/null; then
    log_info "Installing kubectl..."
    if ! curl -fsSL -o /usr/local/bin/kubectl https://dl.k8s.io/release/v1.33.1/bin/linux/amd64/kubectl 2>/dev/null; then
        log_fatal "Failed to download kubectl"
    fi
    chmod +x /usr/local/bin/kubectl
fi

}

get_iface_ipv6() { local iface="$1"

# Step 1: Find the next-hop for 400::/7
local route_line
route_line=$(ip -6 route | grep "^400::/7.*dev ${iface}" || true)
if [ -z "$route_line" ]; then
    log_fatal "No 400::/7 route found via interface ${iface}"
fi

# Extract next-hop IPv6
local nexthop
nexthop=$(echo "$route_line" | awk '{for(i=1;i<=NF;i++) if ($i=="via") print $(i+1)}')
local prefix
prefix=$(echo "$nexthop" | cut -d':' -f1-4)

# Step 3: Get global IPv6 addresses and match subnet
local ipv6_list
ipv6_list=$(ip -6 addr show dev "$iface" scope global | awk '/inet6/ {print $2}' | cut -d'/' -f1)

local ip ip_prefix
for ip in $ipv6_list; do
    ip_prefix=$(echo "$ip" | cut -d':' -f1-4)
    if [ "$ip_prefix" = "$prefix" ]; then
        echo "$ip"
        return 0
    fi
done

log_fatal "No global IPv6 address found on ${iface} matching prefix ${prefix}"

}

prepare_args() { log_info "Preparing k3s arguments..."

if [ -z "${K3S_FLANNEL_IFACE:-}" ]; then
    log_fatal "K3S_FLANNEL_IFACE not set, it should be your mycelium interface"
else 
    local ipv6
    ipv6=$(get_iface_ipv6 "$K3S_FLANNEL_IFACE")
    EXTRA_ARGS="$EXTRA_ARGS --node-ip=$ipv6"
fi

if [ -n "${K3S_DATA_DIR:-}" ]; then
    log_info "k3s data-dir set to: $K3S_DATA_DIR"
    if [ -d "/var/lib/rancher/k3s" ] && [ -n "$(ls -A /var/lib/rancher/k3s 2>/dev/null)" ]; then
        cp -r /var/lib/rancher/k3s/* $K3S_DATA_DIR && rm -rf /var/lib/rancher/k3s
    fi
    EXTRA_ARGS="$EXTRA_ARGS --data-dir $K3S_DATA_DIR --kubelet-arg=root-dir=$K3S_DATA_DIR/kubelet"
fi

if [[ "${MASTER:-}" = "true" ]]; then
    EXTRA_ARGS="$EXTRA_ARGS --cluster-cidr=2001:cafe:42::/56"
    EXTRA_ARGS="$EXTRA_ARGS --service-cidr=2001:cafe:43::/112"
    EXTRA_ARGS="$EXTRA_ARGS --flannel-ipv6-masq"
fi

if [ -z "${K3S_URL:-}" ]; then
    # Add additional SANs for planetary network IP, public IPv4, and public IPv6  
    # https://github.com/threefoldtech/tf-images/issues/98
    local ifaces=( "tun0" "eth1" "eth2" )

    for iface in "${ifaces[@]}"
    do
        # Check if interface exists before querying
        if ! ip addr show "$iface" &>/dev/null; then
            continue
        fi
        
        local addrs
        addrs=$(ip addr show "$iface" 2>/dev/null | grep -E "inet |inet6 " | grep "global" | cut -d '/' -f1 | awk '{print $2}' || true)
        
        local addr
        for addr in $addrs
        do
            # Validate the IP address by trying to route to it
            if ip route get "$addr" &>/dev/null; then
                EXTRA_ARGS="$EXTRA_ARGS --tls-san $addr"
            fi
        done
    done
    
    if [ "${HA:-}" = "true" ]; then
        EXTRA_ARGS="$EXTRA_ARGS --cluster-init"
    fi
else
    if [ -z "${K3S_TOKEN:-}" ]; then
        log_fatal "K3S_TOKEN must be set when K3S_URL is specified (joining a cluster)"
    fi
fi

}

patch_manifests() { log_info "Patching manifests..."

dir="${K3S_DATA_DIR:-/var/lib/rancher/k3s}"
manifest="$dir/server/manifests/tfgw-crd.yaml"

# If K3S_URL found, remove manifest and exit. it is an agent node
if [[ -n "${K3S_URL:-}" ]]; then
    rm -f "$manifest"
    log_info "Agent node detected, removed manifest: $manifest"
    exit 0
fi

# If K3S_URL not found, patch the manifest. it is a server node
[[ ! -f "$manifest" ]] && echo "Manifest not found: $manifest" >&2 && exit 1

sed -i \
    -e "s|\${MNEMONIC}|${MNEMONIC:-}|g" \
    -e "s|\${NETWORK}|${NETWORK:-}|g" \
    -e "s|\${TOKEN}|${TOKEN:-}|g" \
    "$manifest"

}

run_node() { if [ -z "${K3S_URL:-}" ]; then log_info "Starting k3s server (initializing new cluster)..." log_info "Command: k3s server --flannel-iface $K3S_FLANNEL_IFACE $EXTRA_ARGS" exec k3s server --flannel-iface "$K3S_FLANNEL_IFACE" $EXTRA_ARGS 2>&1 elif [ "${MASTER:-}" = "true" ]; then log_info "Starting k3s server (joining existing cluster as master)..." log_info "Command: k3s server --server $K3S_URL --flannel-iface $K3S_FLANNEL_IFACE $EXTRA_ARGS" exec k3s server --server "$K3S_URL" --flannel-iface "$K3S_FLANNEL_IFACE" $EXTRA_ARGS 2>&1 else log_info "Starting k3s agent (joining existing cluster as worker)..." log_info "Command: k3s agent --server $K3S_URL --flannel-iface $K3S_FLANNEL_IFACE $EXTRA_ARGS" exec k3s agent --server "$K3S_URL" --flannel-iface "$K3S_FLANNEL_IFACE" $EXTRA_ARGS 2>&1 fi }

main() { source_env_file "${1:-}" check_root install_deps prepare_args patch_manifests run_node }

main "$@"

INSTRUCTIONS: USE HEROLIB AS MUCH AS POSSIBLE e.g. SAL