Admiral Patrick

I’m surprisingly level-headed for being a walking knot of anxiety.

Ask me anything.

Special skills include: Knowing all the “na na na nah nah nah na” parts of the Three’s Company theme.

I also develop Tesseract UI for Lemmy/Sublinks

Avatar by @SatyrSack@feddit.org

  • 139 Posts
  • 2.21K Comments
Joined 3 years ago
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Cake day: June 6th, 2023

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  • I’ve got bot detection setup in Nginx on my VPS which used to return 444 (Nginx for "close the connection and waste no more resources processing it), but I recently started piping that traffic to Nepenthes to return gibberish data for them to train on.

    I documented a rough guide in the comment here. Of relevance to you are the two .conf files at the bottom. In the deny-disallowed.conf, change the line for return 301 ... to return 444

    I also utilize firewall and fail2ban in the VPS to block bad actors, overly-aggressive scrapers, password brute forces, etc and the link between the VPS and my homelab equipment never sees that traffic.

    In the case of a DDoS, I’ve done the following:

    • Enable aggressive rate limits in Nginx (it may be slow for everyone but it’s still up)
    • Just stop either Wireguard or Nginx on the VPS until the storm blows over. (Crude but useful to avoid any bandwidth overages if you’re charged for inbound traffic).

    Granted, I’m not running anything mission-critical, just some services for friends and family, so I can deal with a little downtime.



  • I have never used it, so take this with a grain of salt, but last I read, with the free tier, you could not secure traffic between yourself and Cloudflare with your own certs which implies they can decrypt and read that traffic. What, if anything, they do with that capability I do not know. I just do not trust my hosted assets to be secured with certs/keys I do not control.

    There are other things CF can do (bot detection, DDoS protection, etc), but if you just want to avoid exposing your home IP, a cheap VPS running Nginx can work the same way as a CF tunnel. Setup Wireguard on the VPS and have your backend servers in Nginx connect to your home assets via that. If the VPS is the “server” side of the WG tunnel, you don’t have to open any local ports in your router at all. I’ve been doing that, originally with OpenVPN, since before CF tunnels were ever offered as a service.

    Edit: You don’t even need WG, really. If you setup a persistent SSH tunnel and forward / bind a port to your VPS, you can tunnel the traffic over that.













  • So, I set this up recently and agree with all of your points about the actual integration being glossed over.

    I already had bot detection setup in my Nginx config, so adding Nepenthes was just changing the behavior of that. Previously, I had just returned either 404 or 444 to those requests but now it redirects them to Nepenthes.

    Rather than trying to do rewrites and pretend the Nepenthes content is under my app’s URL namespace, I just do a redirect which the bot crawlers tend to follow just fine.

    There’s several parts to this to keep my config sane. Each of those are in include files.

    • An include file that looks at the user agent, compares it to a list of bot UA regexes, and sets a variable to either 0 or 1. By itself, that include file doesn’t do anything more than set that variable. This allows me to have it as a global config without having it apply to every virtual host.

    • An include file that performs the action if a variable is set to true. This has to be included in the server portion of each virtual host where I want the bot traffic to go to Nepenthes. If this isn’t included in a virtual host’s server block, then bot traffic is allowed.

    • A virtual host where the Nepenthes content is presented. I run a subdomain (content.mydomain.xyz). You could also do this as a path off of your protected domain, but this works for me and keeps my already complex config from getting any worse. Plus, it was easier to integrate into my existing bot config. Had I not already had that, I would have run it off of a path (and may go back and do that when I have time to mess with it again).

    The map-bot-user-agents.conf is included in the http section of Nginx and applies to all virtual hosts. You can either include this in the main nginx.conf or at the top (above the server section) in your individual virtual host config file(s).

    The deny-disallowed.conf is included individually in each virtual hosts’s server section. Even though the bot detection is global, if the virtual host’s server section does not include the action file, then nothing is done.

    Files

    map-bot-user-agents.conf

    Note that I’m treating Google’s crawler the same as an AI bot because…well, it is. They’re abusing their search position by double-dipping on the crawler so you can’t opt out of being crawled for AI training without also preventing it from crawling you for search engine indexing. Depending on your needs, you may need to comment that out. I’ve also commented out the Python requests user agent. And forgive the mess at the bottom of the file. I inherited the seed list of user agents and haven’t cleaned up that massive regex one-liner.

    # Map bot user agents
    ## Sets the $ua_disallowed variable to 0 or 1 depending on the user agent. Non-bot UAs are 0, bots are 1
    
    map $http_user_agent $ua_disallowed {
        default 		0;
        "~PerplexityBot"	1;
        "~PetalBot"		1;
        "~applebot"		1;
        "~compatible; zot"	1;
        "~Meta"		1;
        "~SurdotlyBot"	1;
        "~zgrab"		1;
        "~OAI-SearchBot"	1;
        "~Protopage"	1;
        "~Google-Test"	1;
        "~BacklinksExtendedBot" 1;
        "~microsoft-for-startups" 1;
        "~CCBot"		1;
        "~ClaudeBot"	1;
        "~VelenPublicWebCrawler"	1;
        "~WellKnownBot"	1;
        #"~python-requests"	1;
        "~bitdiscovery"	1;
        "~bingbot"		1;
        "~SemrushBot" 	1;
        "~Bytespider" 	1;
        "~AhrefsBot" 	1;
        "~AwarioBot"	1;
    #    "~Poduptime" 	1;
        "~GPTBot" 		1;
        "~DotBot"	 	1;
        "~ImagesiftBot"	1;
        "~Amazonbot"	1;
        "~GuzzleHttp" 	1;
        "~DataForSeoBot" 	1;
        "~StractBot"	1;
        "~Googlebot"	1;
        "~Barkrowler"	1;
        "~SeznamBot"	1;
        "~FriendlyCrawler"	1;
        "~facebookexternalhit" 1;
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    ^likse|^LinkextractorPro|^LinkScan|^LNSpiderguy|^LinkWalker|msnbot|MSIECrawler|MJ12bot|MegaIndex|^Magnet|^Mag-Net|^MarkWatch|Mass.Downloader|masscan|^Mata.Hari|^Memo|^MIIxpc|^NAMEPROTECT|^Navroad|^NearSite|^NetAnts|^Netcraft|^NetMechanic|^NetSpider|^NetZIP|^NextGenSearchBot|^NICErs
    PRO|^niki-bot|^NimbleCrawler|^Nimbostratus-Bot|^Ninja|^Nmap|nmap|^NPbot|Offline.Explorer|Offline.Navigator|OpenLinkProfiler|^Octopus|^Openfind|^OutfoxBot|Pixray|probethenet|proximic|^PageGrabber|^pavuk|^pcBrowser|^Pockey|^ProPowerBot|^ProWebWalker|^psbot|^Pump|python-requests\/|^Qu
    eryN.Metasearch|^RealDownload|Reaper|^Reaper|^Ripper|Ripper|Recorder|^ReGet|^RepoMonkey|^RMA|scanbot|SEOkicks-Robot|seoscanners|^Stripper|^Sucker|Siphon|Siteimprove|^SiteSnagger|SiteSucker|^SlySearch|^SmartDownload|^Snake|^Snapbot|^Snoopy|Sosospider|^sogou|spbot|^SpaceBison|^spanne
    r|^SpankBot|Spinn4r|^Sqworm|Sqworm|Stripper|Sucker|^SuperBot|SuperHTTP|^SuperHTTP|^Surfbot|^suzuran|^Szukacz|^tAkeOut|^Teleport|^Telesoft|^TurnitinBot|^The.Intraformant|^TheNomad|^TightTwatBot|^Titan|^True_Robot|^turingos|^TurnitinBot|^URLy.Warning|^Vacuum|^VCI|VidibleScraper|^Void
    EYE|^WebAuto|^WebBandit|^WebCopier|^WebEnhancer|^WebFetch|^Web.Image.Collector|^WebLeacher|^WebmasterWorldForumBot|WebPix|^WebReaper|^WebSauger|Website.eXtractor|^Webster|WebShag|^WebStripper|WebSucker|^WebWhacker|^WebZIP|Whack|Whacker|^Widow|Widow|WinHTTrack|^WISENutbot|WWWOFFLE|^
    WWWOFFLE|^WWW-Collector-E|^Xaldon|^Xenu|^Zade|^Zeus|ZmEu|^Zyborg|SemrushBot|^WebFuck|^MJ12bot|^majestic12|^WallpapersHD)" 1;
    
    }
    
    
    deny-disallowed.conf
    # Deny disallowed user agents
    if ($ua_disallowed) { 
        # This redirects them to the Nepenthes domain. So far, pretty much all the bot crawlers have been happy to accept the redirect and crawl the tarpit continuously 
    	return 301 https://content.mydomain.xyz/;
    }