# O3DE Flatpak

Repackage the official [Open 3D Engine](https://o3de.org/) Linux release as a
**Flatpak** so it can be installed on any distribution — not only Debian/Ubuntu.

A Gitea Actions workflow checks daily for a new O3DE release, builds the Flatpak,
and publishes it as a static [OSTree](https://ostreedev.github.io/ostree/) Flatpak
repository on the `pages` branch of this repo. You add that as a Flatpak remote and
`install` / `update` like any other app.

> **Status:** community / unofficial. O3DE is a large application (~15–18 GB
> installed); building and hosting it is heavy. Treat this as best-effort.

---

## Installing (end users)

```sh
# Flathub provides the runtime O3DE needs
flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

# Add this repo (replace <owner> with the Gitea account that owns the repo)
flatpak remote-add --if-not-exists o3de \
  https://gitea.pc-heini.de/<owner>/o3de-flatpak/raw/branch/pages/o3de.flatpakrepo

flatpak install o3de org.o3de.O3DE
flatpak run org.o3de.O3DE
```

Later updates:

```sh
flatpak update org.o3de.O3DE
```

> The repo is currently **unsigned** (no GPG). Flatpak will add it with GPG
> verification disabled. See *Signing* below to harden this.

---

## How it works

| File | Purpose |
| --- | --- |
| `org.o3de.O3DE.yaml` | `flatpak-builder` manifest. Unpacks the official `o3de_*.deb` into `/app` and wires up a launcher. |
| `o3de-wrapper.sh` | Entry point. Finds the versioned `o3de` Project Manager binary inside the sandbox and sets `LD_LIBRARY_PATH`. |
| `org.o3de.O3DE.desktop` | Desktop entry under the Flatpak app-id. |
| `org.o3de.O3DE.metainfo.xml` | AppStream metadata (version stamped at build time). |
| `scripts/get-latest-version.sh` | Resolves the latest `.deb` URL, version, and SHA-256 from o3debinaries.org. |
| `scripts/build.sh` | Build + test the Flatpak locally. |
| `.gitea/workflows/build-flatpak.yml` | CI: detect new version → build → publish to `pages` → tag `vX.Y.Z`. |

The engine ships as a Debian package at a predictable URL
(`https://o3debinaries.org/main/Latest/Linux/o3de_<ver>.deb`). The build extracts
it (`ar` + `tar`) and copies the payload into the Flatpak's `/app`. The version
directory inside the `.deb` changes every release, so the wrapper discovers the
executable at runtime rather than hard-coding a path.

---

## CI requirements (Gitea Actions)

The workflow targets a **self-hosted `act_runner`**. Because O3DE is large:

- **Disk:** budget **60 GB+** free. The build needs roughly 2–3× the installed
  size (extracted payload in `build-dir` + a copy committed into the OSTree
  `repo/`). The job deletes `build-dir` before publishing to cut peak usage, but
  it can still be tight. If builds fail on space, that's the first thing to check.
- **Privileged container:** Flatpak's sandbox (bubblewrap) needs it. The job sets
  `options: --privileged`; your runner's `config.yaml` must allow privileged
  containers (or run jobs in host mode with `flatpak`/`flatpak-builder` installed
  on the host).
- **Runner label:** the job uses `runs-on: ubuntu-latest`. Change it if your
  runner is registered with a different label.
- **Token:** publishing force-pushes the `pages` branch and creates a `vX.Y.Z`
  tag. The auto-provided `GITHUB_TOKEN` (with `contents: write`) usually suffices.
  If your instance restricts it, create a Personal Access Token with repo write
  access and add it as a secret named **`PUBLISH_TOKEN`** — the workflow prefers
  it automatically.

Trigger it manually from the Gitea Actions UI (`workflow_dispatch`, with an
optional **force** rebuild), or let the daily `cron` run it. It only rebuilds when
the upstream version has no matching `vX.Y.Z` tag yet, so reruns are cheap no-ops.

---

## Building locally

```sh
sudo apt install flatpak flatpak-builder      # or your distro's equivalent
./scripts/build.sh
```

Test without installing:

```sh
flatpak-builder --run build-dir org.o3de.O3DE.yaml o3de-wrapper.sh
```

---

## Signing (recommended hardening)

The first iteration publishes an unsigned repo for simplicity. To sign:

1. Generate a key: `gpg --quick-gen-key "O3DE Flatpak" default default never`
2. Export the public key and add `GPGKey=<base64>` to the generated `.flatpakrepo`.
3. Pass `--gpg-sign=<KEYID>` to both `flatpak-builder` and `build-update-repo`,
   and provide the private key to CI via a secret. Until then, users add the
   remote with GPG verification disabled.

---

## Caveats & things to verify

These were confirmed by inspecting the v26.05 package (`opt/O3DE/26.05/…`):

- **Layout is confirmed for now**: the package installs everything under
  `/opt/O3DE/<ver>/`, with the launcher at `bin/Linux/profile/Default/o3de` and
  ~270 `.so` files beside it (hence the wrapper's `LD_LIBRARY_PATH`). If a future
  release moves things, adjust `o3de-wrapper.sh` and the manifest.
- **Runs against `org.freedesktop.Sdk`, not `Platform`.** O3DE's package
  dependencies are a *build toolchain* (clang/ninja/cmake/pkg-config) because the
  engine compiles project code at runtime. Those live in the SDK. Users therefore
  pull the SDK runtime (larger than Platform) on install — Flatpak does this
  automatically from Flathub.
- **Python is baked in at build time.** O3DE normally downloads its Python runtime
  into its own install tree on first use, but that tree is read-only inside a
  Flatpak. The manifest runs `python/get_python.sh` during the build (with network
  access) so Python is part of the immutable image. **This is the most likely step
  to need tweaking** — verify it on the first real CI build.
- **Runtime writes into the install tree may still fail.** Anything O3DE tries to
  `pip install` or generate *inside* `/opt/O3DE/...` at runtime (e.g. per-gem
  Python deps when building certain projects) will hit the read-only `/app`. Base
  project building should work; exotic gems may not. This is the main open risk.
- **No launcher icon yet.** The `.deb` ships only in-editor asset icons, so the
  desktop entry uses a generic icon. Drop a real O3DE logo into the repo and
  install it in the manifest to fix this.
- **GPU / drivers:** the renderer needs working GPU access. The manifest grants
  `--device=dri`/`--device=all`; on some setups you may also want the matching
  GPU driver extension from Flathub.
- **Sandbox filesystem:** `--filesystem=home` lets the Project Manager create and
  open projects under your home directory. Tighten or widen to taste.
- **Hosting via raw branch URLs** works because Flatpak fetches individual files
  (`summary`, `config`, `objects/…`). Gitea serves these from the `pages` branch.
  If you later put a real static web host in front of it, just change `Url=` in
  the `.flatpakrepo`.

---

*Not affiliated with or endorsed by the Open 3D Foundation. O3DE is licensed under
Apache-2.0 / MIT.*