yxnan/l4d2-vpk-trimmer

Trim down the size of VPK files for L4D2 dedicated server hosting

l4d2-vpk-trimmer

Valve Pak (or VPK) files are used in some Source engine games such as Left 4 Dead 2, which usually contain many assets for the custom campaigns. When hosting the custom campaigns on the dedicated server, while we can just drop them into the left4dead2/addons folder, there is a better way we can do.

Consider the servers are usually headless, they don't need to know how a texture looks like, or how the music feels like. By removing those unnecessary files, we can save a lot of space!

1. Typically the output size is 50% of the original (or even smaller on larger campaigns).
2. By removing media files which are hard to compress, we have lowered the compress rate of the vpk files, since the left files (bsp, nav, mdl, etc.) can usually be compressed by a lot. This will save significant amount of time when being transferred over network.

How to use

The usage is simple:

docker run -d --name vpk-trimmer \
    -v /my/upload:/in \
    -v /wherever/addons:/out \
    yxnan/l4d2-vpk-trimmer:latest

You bind mount an input directory (usually your server upload folder) and an output directory (the left4dead2/addons folder), the app will then watch the file actions in the /in directory, once a new vpk file is uploaded, the app will apply the trimming processes on it, and install it to the /out directory.

The accepted input files are either:

1. Plain vpk files.
2. Archives (zip, 7z, rar, ...) that contain vpk files in them. The structure doesn't matter, since the app will find all the vpk files in it and process them.

Any other files will be ignored.

What exactly are trimmed in those vpk files?

1. All directories except maps|modes|missions|models|scripts|scenes|particles.
2. Any file in the root that is not addoninfo.txt.
3. *.vtx and *.vvd files

Check the result

The app will output the campaign name, original size and trimmed size to the stdout, you can check the result using docker logs or any docker management tools:

$ docker logs <container-name>
...
------ Received file: buried-deep_v172.vpk
> Processing buried-deep_v172.vpk
  Campaign installed: burieddeep
  Size: 621M -> 249M
------ done! ------
...
------ Received file: batch_upload.zip
> Processing journey-to-splash-mountain_v10.vpk
  Campaign installed: jtsm
  Size: 909M -> 362M
> Processing suicide-blitz-2_v4.vpk
  Campaign installed: suicideblitz2
  Size: 533M -> 342M
> Processing white-forest_v30.vpk
  Campaign installed: whiteforest_mission
  Size: 250M -> 165M
------ done! ------

Local usage

The app watches the CLOSE_WRITE action, which happens when the file is opened as write mode and has been closed. This usually applies to the situation where a file is uploaded through ftp/sftp, but if you already have that file on the target machine and want it to be processed, you can copy it into /in directory OR move and touch it.