A simple cache middleware for Laravel 5, which won't cache authenticated pages.

Cache.php

<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\Request;
use Illuminate\Contracts\Auth\Guard;
use Illuminate\Contracts\Cache\Repository;

class Cache
{
    /**
     * The Guard implementation.
     *
     * @var \Illuminate\Contracts\Auth\Guard
     */
    protected $auth;

    /**
     * The cache implementation.
     *
     * @var \Illuminate\Contracts\Cache\Repository
     */
    protected $cache;

    /**
     * The number of minutes to cache the response.
     *
     * @var int
     */
    protected $minutes = 60;

    /**
     * Create a new filter instance.
     *
     * @param  \Illuminate\Contracts\Auth\Guard        $auth
     * @param  \Illuminate\Contracts\Cache\Repository  $cache
     * @return void
     */
    public function __construct(Guard $auth, Repository $cache)
    {
        $this->auth = $auth;
        $this->cache = $cache;
    }

    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  Closure                   $next
     * @return mixed
     */
    public function handle($request, Closure $next)
    {
        $cacheKey = $this->getCacheKey($request);

        if ($this->isCacheEligible($cacheKey)  && $this->cacheExists($cacheKey)) {
            return $this->cache->get($cacheKey);
        }

        return $next($request);
    }

    /**
     * Determine whether a cached item already exists.
     *
     * @param  string
     * @return bool
     */
    protected function cacheExists($cacheKey)
    {
        return $this->cache->has($cacheKey);
    }

    /**
     * Determine whether the cache is eligible to be used.
     *
     * @param  string  $cacheKey
     * @return bool
     */
    protected function isCacheEligible($cacheKey)
    {
        return $this->auth->guest();
    }

    /**
     * Get the cache key for the request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return string
     */
    protected function getCacheKey(Request $request)
    {
        return str_slug("route-{$request->url()}");
    }

    /**
     * Perform any final actions for the request lifecycle.
     *
     * @param  \Illuminate\Http\Request    $request
     * @param  \Illuminate\Http\Response  $response
     * @return void
     */
    public function terminate($request, $response)
    {
        $cacheKey = $this->getCacheKey($request);

        if ($this->isCacheEligible($cacheKey)) {
            $this->cache->put($cacheKey, $response->getContent(), $this->minutes);
        }
    }
}