Get DepotDownloader to use lancache

[nutterthanos]

Hi i was wondering how you can get depotdownloader to use lancache?
if this already isn't implemented can this be added as a feature?
thanks

[nutterthanos]

ok so this get moved here and pretty much pushed aside from being answered?

[voided]

@nutterthanos Sorry for the lack of replies, we're a small team of volunteers. We generally move issues to discussions when they're not bug related.

However, I am interested in understanding your use case for lancache support if you're still looking for this functionality.

[GoTeamScotch]

DepotDownloader uses steam's servers to download game files, similar to the actual Steam client app. I would assume if your PC running DepotDownloader is setup to route through LanCache, then LanCache would serve back files same as usual. LanCache just detects if you're requesting files from a given domain (steam.com, etc) before it kicks in and serves files it has already downloaded. Does it seem to not work?

[crkinard]

Does not work. Watching DepotDownloader download Cyberpunk 2077. Resource Monitor is saying it's pulling from 151.205.4.161 (which obviously is not my local LanCache IP).

[nutterthanos]

It never worked for me hence why I asked this originally.

[LordRalex]

Steam doesn't just use the override of a DNS server to handle it. It does a lot more logic to decide if Lancaches are in use, and how to handle them. This is not logic that DepotDownloader does, and so it's only assuming it's the very large DNS overrides, which are not used.

lancachenet/monolithic#85 has good information on this process.

In short:

As of today's Steam Client update, there is now full support in Steam for a lancache. The way it works is by setting a DNS override for lancache.steamcontent.com pointing to the IP address of your cache server.
The Steam client will then use that cache server for all downloads. It will still make requests to the cache server using the hostname of the Valve content server to download from, but it will connect to your cache.
In addition, it will increase the maximum number of connections per IP from 4 to 32. This should solve the issue people have been seeing with slow initial downloads through lancache. It will also prevent the Steam Client from using Open Caching, which caused some downloads to not be cached correctly.

So, because DepotDownloader is not doing that same logic, it's not using the caches. These are the only DNS entries (the last one being the local CDNs to actually get said files)

media.steampowered.com
api.steampowered.com
cache6-dfw1.steamcontent.com

[Dimensional]

Looking through code a bit, I found that in CDNClientPool.cs, line 95 has an argument where the server type has to either be SteamCache or CDN. Perhaps this needs to be updated, since the SteamKit2 has this and Lancache listed in it's library?

[LordRalex]

One thing that I've noticed while also looking at it, is that HTTPS is also being used. This means that while the traffic can go through the lancache (even if you redirect all domains like before), because it's under HTTPS, it is still not able to cache the requests.

So, knowing that, the checks also would be "downgrading" the connection to the content server to HTTP if it's a cache server.

I don't even see a way to tell DepotDownloader to not use HTTPS, so there is no way to make it work as-is to use a cache server.

[nutterthanos]

currently there is not since there is no config file that you can mess with to get it to do that.
steamctl does but login system is old so i end up with http 429 or whatever on logins.
also steamctl is so broken it can't download any apps/games now
as i understand the list comes from https://api.steampowered.com/IContentServerDirectoryService/GetServersForSteamPipe/v1/?cell_id=
cell_id being After you log on, the CM sends you a "cell ID". Steam divides the world into regions, called "cells". There's a list here. The official client saves this ID, and sends it back in subsequent login requests.

Edit: CellMap.vdf is gone
don't know how its determined anymore

[nutterthanos]

i got an working workaround
it involves using a proxy server like charles proxy and using like the rewrite function/map remote function to get it to run through the trigger domain lancache.steamcontent.com

This is temporary solution and not official but unofficially works