Flatpak packaging for Delta Chat Desktop

Building

If you'd like to locally build this flapak, you'll need both flatpak and flatpak-builder installed. E.g. on Debian you can run apt install flatpak flatpak-builder to install these tools. See https://flatpak.org/setup/ for more information on this for your platform.

flatpak dependencies

If you haven't done so yet, you need to have flathub set up as a remote repository:

flatpak remote-add --if-not-exists \
    flathub https://flathub.org/repo/flathub.flatpakrepo

You also need to install the required flatpak runtime, SDK and electron BaseApp. At the time of this writing they are the 20.08 versions, but check the chat.delta.desktop.yml's runtime-version and base-version properties for the current version numbers.

flatpak install flathub \
    org.freedesktop.Platform//20.08 \
    org.freedesktop.Sdk//20.08 \
    org.electronjs.Electron2.BaseApp//20.08 \
    org.freedesktop.Sdk.Extension.node10//20.08

Building the application

To simply build the application in a build-directory invoke flatpak-builder pointing to the manifest:

flatpak-builder build-dir chat.delta.desktop.yml

To install the local build you can add the --install flag. To upload the built application to a repository, which can just be a local directory, add the --repo=repo flag.

Uploading to flathub

Each commit to the https://github.com/flathub/chat.delta.desktop master branch will result in a new release being published to flathub. So once a pull request is merged no more work needs to be done to publish the release.

Upgrading to a new release

Get hold of a newer version of the desktop app and the Rust binding, e.g. git fetch --tags. Check the newest tags out, so that their dependencies can be seen.

cd delta-chat-desktop
git fetch --tags
git checkout v1.13.0  # or whatever the latest tag is

cd delta-chat-rust
git fetch --tags
git checkout 1.46.0

Re-generating rust sources

Since flatpak does not allow the build to download things while building we have to resolve all the cargo dependencies statically beforehand. This is done by processing the Cargo.lock file into the generated-source-rust.json file:

python3 ../flatpak-builder-tools/cargo/flatpak-cargo-generator.py \
    -o generated-sources-rust.json \
    ../deltachat-core-rust/Cargo.lock

Make sure you generate it from the correct downloaded release.

Re-generating npm sources

Since flatpak does not allow the build to download things while building we have to resolve all the npm dependencies beforehand. This is done by converting the package-lock.json, which should contain all the dependencies, into a manifest snipped suitabled for building flatpaks.

Upstream ships the package-lock.json file so it should not be necessary to generate it. However, sometimes the file is not updated in lockstep with package.json and then dependencies will be missing during build time. In that case, it's best to wait for upstream to provide the lock file, but it should be possible to run npm install to get the lockfile updated.

To create the generated-sources.json file you need a copy of the https://github.com/flatpak/flatpak-builder-tools.git repository and invoke the node/flatpak-node-generator.py script, e.g.:

python3 ../flatpak-builder-tools/node/flatpak-node-generator.py \
    npm ../deltachat-desktop/package-lock.json \
    --recursive --split \
    --output generated-sources-npm.json

This will produce the generated-sources-npm-?.json files which is referenced in the chat.delta.desktop.yml manifest. Because that file is quite big and Github seems to not like big files all too much, the generator offers a --split option, cf. https://github.com/flatpak/flatpak-builder-tools/blob/204309e0066a66a6f3c9ad7c5edb870513a7504c/node/README.md#splitting-mode.