Packwiz support

[sugoidogo]

I manage several modpacks using Packwiz, and I've written a few automations to make my life with it easier. I'm looking for a way to test the client-side and server-side of a packwiz modpack before pushing updates, and it looks like this is the tool I need, but I'm a little lost on how to get the modpack working with headlessmc. I can use packwiz-installer to set up the mods, but I don't see any documentation on how I would use the resulting folders with the headlessmc jar file or docker container. It would be nice if headlessmc had support for packwiz packs built in, if I could point headlessmc at the pack.toml file and have it prepare the modloader and java version from that metadata, but I could also parse and pass the metadta in my own tools, then use packwiz-installer to prepare the mods, then test that the client can successfully join the server (or at least that the client and server both successfully load). If that's something that can be done with headlessmc right now, I'd love to know how, and if not I'd like to make this a feature request to add whatever options are needed for headlessmc to be used this way.

[okafke]

I actually do not have that much experience with mod packs. Is it just a mods folder filled with mods?
In that case you just need use the config.properties/system properties to point hmc.gamedir=<your dir> to the directory that the game is going to be launched in, so the one with the mods folder and use hmc launch fabric:1.21.10 or similar.

See the mc-runtime-test and mc-server-test for Github Actions that do this.

As for support of packwiz toml files inside HeadlessMc I'll note that down. HeadlessMc already needs to use a toml parser for Forge mod files so we might as well support packwiz. But this is a feature for the v3 of HeadlessMc which might take a while.

[sugoidogo]

I actually do not have that much experience with mod packs. Is it just a mods folder filled with mods?

Modpacks can include mods, resource packs, shader packs, configs, etc. Basically the entire minecraft folder, except for the launcher/loader files. Typically the launcher will read the pack metadata and set up the installation of minecraft/forge/fabric/etc and then download/copy all the modpack files into the resulting minecraft folder and launch. hmc already does the first half, and packwiz-installer already does the second half, so I figure it should be a simple addition to get the loader info from the packwiz metadata and then run the packwiz-installer to acheive automated testing of packwiz modpacks.

In that case you just need use the config.properties/system properties to point hmc.gamedir= to the directory that the game is going to be launched in, so the one with the mods folder and use hmc launch fabric:1.21.10 or similar. See the mc-runtime-test and mc-server-test for Github Actions that do this.

Sorry, I'm not seeing any documentation on those pages that describe how to do that? It does seem from the examples like I can just put my files in the run folder for github actions and it would pick them up from there, but is that the same for the docker container? I also don't see any documentation on using the docker container or jar file non-interactively, does hmc support command line arguments?

As for support of packwiz toml files inside HeadlessMc I'll note that down. HeadlessMc already needs to use a toml parser for Forge mod files so we might as well support packwiz. But this is a feature for the v3 of HeadlessMc which might take a while.

That's great news, thank you for your replies.

[okafke]

I think the documentation is pretty alright: https://headlesshq.github.io/headlessmc/configuration/

Besides the commands and their flags and options, HeadlessMc creates a config.properties file in the HeadlessMC folder. This file can be used to configure HeadlessMc further. All properties that can be put in the config file can also be specified as system properties on the command line:

java -Dhmc.some.property=value -jar headlessmc-launcher.jar

mc-runtime-test configures the launched Minecraft instance to run inside the run folder, this is done by putting

hmc.gamedir=./run

Into HeadlessMC/config.properties.
https://github.com/headlesshq/mc-runtime-test/blob/f170c7a7c8aa1d7118cddc75d1d1426b3e09b5a6/action.yml#L57
So what you wanna do is dump your modpack into the run folder, mods go into run/mods, resourcepacks into run/resources etc.

like I can just put my files in the run folder for github actions and it would pick them up from there

Yes

but is that the same for the docker container?

No, the default configuration of the docker container is here:

headlessmc/headlessmc-scripts/HeadlessMC/config.properties

Line 3 in c99630e

hmc.gamedir=/headlessmc/HeadlessMC/run

You would mount your files into the docker container: https://docs.docker.com/reference/cli/docker/container/run/#volume

For your automation I am not 100% sure why you would need HeadlessMc to read the modpack metadata. I mean you know which pack is associated with which java/mc version? I will definitely add modpack support at some point but I am trying to understand what you need.

[sugoidogo]

Gave the documentation another read, I don't know how I missed that section before. I also noticed this section that answers my other question:

By default, HeadlessMc will run in interactive mode. It will continuously listen for commands, until you end the process with quit. You can also execute singular commands by specifying them at start with --command

I think I must have missed that because that section is named "interactive mode", and I was looking for a "non-interactive" mode, I might suggest renaming that bit, given that interactive mode is the default.

As far as this feature request goes, what I would like is for there to be a packwiz command and/or an optional argument to the launch/server launch commands, that selects the minecraft and modloader versions from the pack.toml and additionally calls the packwiz-installer to prepare the run folder before launch, so that automated testing could be done simply by calling for example java -jar headlessmc.jar --command launch packwiz-pack=./pack.toml

Of course I could string together an automation with the existing capabilities of hmc, but I would like to be able to use the docker container in my development environment to have the entire run folder constructed and discarded with each test, whereas right now I would need to run packwiz-installer in a new folder, call the docker container with the appropriate launch options for my pack's loader versions and that folder mounted to the run folder, and then remove the folder afterwards.

[okafke]

Ok, as packwiz support might take a while, I would like to look for a solution first that does not require it:

I am not sure I 100% understand your docker process, couldn't you use create the run folder inside the container with packwiz-installer as well?

[sugoidogo]

I certainly could, although it would be much more verbose of a command since I wouldn't have access to my aliases inside the container, but that's not necessarily a blocker either. Regardless, it's not an urgent issue, there's no need to worry about another solution. I can still use hmc as is, the purpose of this feature request is just to allow firing off a test with a single command, instead of having to manually set up the test environment every time.