You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: k3s.go
    path of file: ./repos/testcontainers-go/modules/k3s
    
    the code of the file until where you have to start completion: package k3s

import (
	"context"
	"fmt"
	"io"
	"os"
	"path/filepath"

	"github.com/docker/docker/api/types/container"
	"github.com/docker/docker/api/types/mount"
	"github.com/docker/go-connections/nat"
	"gopkg.in/yaml.v3"

	"github.com/testcontainers/testcontainers-go"
	"github.com/testcontainers/testcontainers-go/wait"
)

var (
	
    
func RunContainer(ctx context.Context, opts ...testcontainers.ContainerCustomizer) (*K3sContainer, error) {
	host, err := getContainerHost(ctx, opts...)
	if err != nil {
		return nil, err
	}

	req := testcontainers.ContainerRequest{
		Image: "docker.io/rancher/k3s:v1.27.1-k3s1",
		ExposedPorts: []string{
			defaultKubeSecurePort,
			defaultRancherWebhookPort,
		},
		Privileged: true,
		HostConfigModifier: func(hc *container.HostConfig) {
			hc.CgroupnsMode = "host"
			hc.Tmpfs = map[string]string{
				"/run":     "",
				"/var/run": "",
			}
			hc.Mounts = []mount.Mount{}
		},
		Cmd: []string{
			"server",
			"--disable=traefik",
			"--tls-san=" + host, // Host which will be used to access the Kubernetes server from tests.
		},
		Env: map[string]string{
			"K3S_KUBECONFIG_MODE": "644",
		},
		WaitingFor: wait.ForLog(".*Node controller sync successful.*").AsRegexp(),
	}

	genericContainerReq := testcontainers.GenericContainerRequest{
		ContainerRequest: req,
		Started:          true,
	}

	for _, opt := range opts {
		opt.Customize(&genericContainerReq)
	}

	container, err := testcontainers.GenericContainer(ctx, genericContainerReq)
	if err != nil {
		return nil, err
	}

	return &K3sContainer{Container: container}, nil
}