Flatpak External Data Checker

This is a tool for checking for outdated or broken links of external data in Flatpak manifests.

Motivation

Flatpak apps are built using external data (git checkouts, tarballs, simple files, etc.). A very specific case of this is the use of extra data, which works as a way to download third party binaries at installation time.

Of course, the links pointing to external data can become obsolete, so it is very important to account for and correct such issues. This is especially critical for the extra data, in which a broken link impedes the installation of the application.

This project offers ways to easily check or monitor the state of such links, as well as the suggestion of new versions.

It works by extracting all the external data of a Flatpak manifest and giving it to a collection of checkers, which will set up the right state and, possibly, new versions of each external data.

Use

The simplest use of this tool is by calling:

flatpak-external-data-checker MANIFEST_FILE

it should display messages about any broken or outdated external data.

Installation

This tool itself is available in flatpak format from Flathub. Install with

flatpak install --from https://dl.flathub.org/repo/appstream/org.flathub.flatpak-external-data-checker.flatpakref

And run with

flatpak run org.flathub.flatpak-external-data-checker MANIFEST_FILE

Running in a container

flatpak-external-data-checker is also avaiable as an OCI image from GitHub Container Registry.

You can use the run-in-container.sh helper script to set up needed CLI options for you and run the image using podman:

~/src/endlessm/flatpak-external-data-checker/run-in-container.sh \
    [ARGS …] \
    ~/src/flathub/com.example.App/com.example.App.json

On Flathub

Flathub runs this tool hourly for all Flatpak repos under github.com/flathub. So, for those repos to receive update PRs, add x-checker-data as needed to sources. Note Flathub's hosted tool only checks the default branch.

To stop Flathub's tool from checking your repo, add "disable-external-data-checker": true to flathub.json in the default branch.

Custom workflow

Alternatively, you can use own workflow. This can be useful if e.g. wanting to update non-default branches.

Put this yaml file under .github/workflows, e.g. put it in .github/workflows/update.yaml. Ensure to put the correct path to the manifest in the last line.

name: Check for updates
on:
  schedule: # for scheduling to work this file must be in the default branch
  - cron: "0 * * * *" # run every hour
  workflow_dispatch: # can be manually dispatched under GitHub's "Actions" tab 

jobs:
  flatpak-external-data-checker:
    runs-on: ubuntu-latest

    strategy:
      matrix:
        branch: [ master ] # list all branches to check
    
    steps:
      - uses: actions/checkout@v3
        with:
          ref: ${{ matrix.branch }}

      - uses: docker://ghcr.io/flathub/flatpak-external-data-checker:latest
        env:
          GIT_AUTHOR_NAME: Flatpak External Data Checker
          GIT_COMMITTER_NAME: Flatpak External Data Checker
          # email sets "github-actions[bot]" as commit author, see https://github.community/t/github-actions-bot-email-address/17204/6
          GIT_AUTHOR_EMAIL: 41898282+github-actions[bot]@users.noreply.github.com
          GIT_COMMITTER_EMAIL: 41898282+github-actions[bot]@users.noreply.github.com
          EMAIL: 41898282+github-actions[bot]@users.noreply.github.com
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          args: --update --never-fork $PATH_TO_MANIFEST # e.g. com.organization.myapp.json

Automatically submitting PRs

When run with the --update flag, this tool can commit any necessary changes to Git and open a GitHub pull request. In order to do this, it requires a GitHub access token, specified in the GITHUB_TOKEN environment variable.

Selectively submitting PRs

The tool will by default open PRs if at least one source is updated. Alternatively, the tool can be configured to only open PRs if at least one "important" source is updated. This can avoid unwanted PRs, e.g. PRs that only update a single library.

To only open PRs when at least one important source is updated, first set require-important-update to true in flathub.json. If using a custom workflow, instead pass --require-important-update to the tool. Then, set property is-important to true in the checker metadata for any important source(s). Sources with is-main-source in their checker metadata are also considered important.

Automatically merging PRs

The tool will also automatically merge previously opened pull request for unavailable (BROKEN) sources if the change has successfully passed CI checks and the token has sufficient privileges.

Automatically merging all submitted PRs, not just unavailable sources, from the tool can be forcefully enabled by setting automerge-flathubbot-prs to true in flathub.json, or it can be completely disabled by setting automerge-flathubbot-prs to false.

Formatting manifests

When writing back JSON files, this tool defaults to four-space indentation, preserving or omitting a trailing newline based on the source file. If you prefer a different formatting, create and commit an .editorconfig file describing your preferred formatting for .json files. At present, this tool respects a subset of EditorConfig settings:

root = true

[*.json]
indent_style = space
# Only integer values are supported; ignored if indent_style=tab
indent_size = 2
insert_final_newline = true

Unfortunately, it is not feasible to preserve JSON-GLib's non-standard /* */ syntax for comments. As an alternative, dictionary keys beginning with // are ignored by flatpak-builder and can be used for comments in many cases.

For YAML files, this tool attempts to preserve existing formatting and comments automatically. .editorconfig is not used. We recommend you follow the Flathub YAML Style Guide.

Changes to Flatpak manifests

For simple checks to see if a URL is broken, no changes are needed. However, you can add additional metadata to the manifest to allow the checker to discover new versions.

Some of the following checkers are able to determine upstream version number, and automatically add it to releases list in metainfo. To specify which source is the app upstream source, set property is-main-source to true in the checker metadata for that source.

Version constraining

The checkers can support version constraining, making it possible to e.g. limit version checking to a certain major version. The property is versions. It should contain key-value pairs where the key is the comparison operator (one of <, >, <=, >=, ==, !=), and the value is the version to compare with So, {"<": "3.38.0", "!=": "3.37.1"} means "any version less than 3.38.0 except 3.37.1". All constraints must match simultaneously, i.e. if one doesn't match -> version is rejected.

URL checker

If the upstream vendor has an URL that redirects to the latest version of the application, you can add something like the following to check and update the URL for the latest version:

"x-checker-data": {
    "type": "rotating-url",
    "url": "http://example.com/last-version",
    "pattern": "http://example.com/foo-v([0-9.]+).tar.gz"
}

The version number for the latest version can be detected in two ways:

If the filename ends with .AppImage, the version number is extracted from the AppImage. (It is run in a bwrap sandbox.)
Otherwise, if "pattern" is specified in "x-checker-data", the given regular expression is matched against the full URL for the latest version, and the first match group is taken to be the version. (This follows the convention used by debian/watch files.)

Some upstream vendors may add unwanted GET query parameters to the download URL, such as identifiers for counting unique downloads. This may result in URL change without change in the actual data. To remove GET query parameters, set strip-query property to true.

HTML checker

Both the version number and the download URL will be gathered from a static HTML page which contains this information:

"x-checker-data": {
    "type": "html",
    "url": "https://www.example.com/download.html",
    "version-pattern": "The latest version is ([\\d\\.-]+)",
    "url-pattern": "(https://www.example.com/pub/foo/v([\\d\\.-]+)/foo.tar.gz)"
}

If the HTML page contains multiple versions with download links, set single pattern containing two nested match groups for both url and version:

"x-checker-data": {
    "type": "html",
    "url": "https://sourceforge.net/projects/qrupdate/rss",
    "pattern": "<link>(https://sourceforge.net/.+/qrupdate-([\\d\\.]+\\d).tar.gz)/download</link>"
}

To disable sorting and get first matched version/url, set sort-matches to false.

The versions property is supported.

URL templates

The HTML checker also supports building the download URL using the retrieved version string, its components according to the Python LooseVersion class and semantic versioning fields:

"x-checker-data": {
    "type": "html",
    "url": "https://www.example.com/download.html",
    "version-pattern": "The latest version is ([\\d\\.-]*)",
    "url-template": "https://www.example.com/$version/v$version.tar.gz"
}

"x-checker-data": {
    "type": "html",
    "url": "https://www.example.com/download.html",
    "version-pattern": "The latest version is ([\\d\\.-]*)",
    "url-template": "https://www.example.com/$major.$minor/v$version.tar.gz"
}

If the placeholder is immediately followed by an underscore, you need to add braces:

"x-checker-data": {
    "type": "html",
    "url": "https://www.example.com/download.html",
    "version-pattern": "The latest version is ([\\d\\.-]*)",
    "url-template": "https://www.example.com/$version0.$version1/v${version0}_${version1}_version2.tar.gz"
}

Git checker

To check for latest git tag in corresponding git source repo, add checker metadata with type git and set tag-pattern to a regular expression with exactly one match group (the pattern will be used to extract version from tag):

"x-checker-data": {
    "type": "git",
    "tag-pattern": "^v([\\d.]+)$"
}

By default tags are sorted based on version number extracted from tag. To disable sorting and keep order from git ls-remote, set sort-tags to false.

If the project follows semver specification, you can set version-scheme property to semantic in order to use semantic version scheme for sorting. In this case, make sure that tag-pattern extracts only valid semver strings.

The versions property is supported.

JSON checker

The JSON checker allows using jq to query JSON data with arbitrary schema to get version and download url.

To use the JSONChecker, specify JSON data URL, version query and url query (you can use $version variable got from the version query in url query):

"x-checker-data": {
    "type": "json",
    "url": "https://api.github.com/repos/stedolan/jq/releases/latest",
    "version-query": ".tag_name | sub(\"^jq-\"; \"\")",
    "url-query": ".assets[] | select(.name==\"jq-\" + $version + \".tar.gz\") | .browser_download_url"
}

for git type sources, specify tag query and, optionaly, commit and version queries:

"x-checker-data": {
    "type": "json",
    "url": "https://api.github.com/repos/stedolan/jq/releases/latest",
    "tag-query": ".tag_name",
    "version-query": "$tag | sub(\"^jq-\"; \"\")",
    "timestamp-query": ".published_at"
}

timestamp-query is optional, but if provided - must return a string with timestamp in ISO format.

See the jq manual for complete information about writing queries.

Inheriting parent source check results

If a parent source is specified, its check results will be accessible in the $parent variable. The $parent object has current and new properties with objects representing current and new parent source data, respectively. The later can be null if parent check didn't get a new version. JSON schema for these objects can be found here.

Debian repo checker

For the DebianRepoChecker, which deals only with deb packages, it can read the following metadata (add it to manifest element it refers to, e.g. where "type": "extra-data" is declared):

"x-checker-data": {
    "type": "debian-repo",
    "package-name": "YOUR_PACKAGE_NAME",
    "root": "ROOT_URL_TO_THE_DEBIAN_REPO",
    "dist": "DEBIAN_DIST",
    "component": "DEBIAN_COMPONENT"
}

Anitya (release-monitoring) checker

Anitya is an upstream release monitoring project by Fedora. It supports multiple backends for retrieving version information from different services, including GitHub, GitLab, Sourceforge, etc. To use the AnityaChecker, specify numeric project ID on release-monitoring.org and add a template for source download URL. Template syntax is the same as for the HTMLChecker:

"x-checker-data": {
    "type": "anitya",
    "project-id": 6377,
    "stable-only": false,
    "versions": {"<": "1.12.0"},
    "url-template": "https://github.com/flatpak/flatpak/releases/download/$version/flatpak-$version.tar.xz"
}

Set stable-only to true to retrieve latest stable version (as recognized by Anitya).

The versions property is supported.

For git type sources, instead of url-template, set tag-template to derive git tag from version.

GNOME checker

Check for latest source tarball for a GNOME project.

"x-checker-data": {
    "type": "gnome",
    "name": "pygobject",
    "versions": {
        "<": "3.38.0"
    },
    "stable-only": true
}

Set stable-only to false to check for pre-releases, too.

The versions property is supported.

PyPI checker

Check for Python package updates on PyPI.

"x-checker-data": {
    "type": "pypi",
    "name": "Pillow"
}

By default it will check for source package (sdist package type). To check for binary package instead, set packagetype to bdist_wheel (only noarch wheels are supported currently).

The versions property is supported.

Electron Auto Update checker

Electron auto update mechanism uses remotely stored metadata files to check for updates. This metadata can be tracked for Flatpak manifest updates.

x-checker-data:
  type: electron-updater
  url: https://example.com/download/latest-linux.yml

The url, if set, must link to a Electron Auto Update metadata file (usually latest-linux.yml).
If url is omitted, the checker will try to guess it based on the current source url.

Make sure to use sha512 checksum for the source, unless it's an extra-data (which supports sha256 only).

JetBrains checker

Special checker that will check for available updates for JetBrains products:

"x-checker-data": {
    "type": "jetbrains",
    "code": "PRODUCT-CODE",
    "release-type": "release or eap (defaults to release)"
}

Snapcraft checker

Special checker that will check for available updates for Snapcraft packages:

"x-checker-data": {
    "type": "snapcraft",
    "name": "PACKAGE-NAME",
    "channel": "stable, beta, or any other tag the project uses"
}

Rust checker

Special checker that will check for available updates for Rust:

"x-checker-data": {
    "type": "rust",
    "package": "package name, for example: rust",
    "channel": "nightly, stable or beta",
    "target": "target triple, for example: x86_64-unknown-linux-gnu"
}

Chromium checker

Special checker that will check for available updates to the Chromium tarballs, as well as the toolchain binaries or sources used to build it.

"x-checker-data": {
    "type": "chromium",
    "component": "chromium, llvm-prebuilt, or llvm-git; defaults to chromium"
}

The following components are supported:

chromium: updates the Chromium tarball itself, used on URL-based sources (e.g. type: archive).
llvm-prebuilt: updates a tarball pointing to the official LLVM prebuilt toolchain archive matching the latest Chromium version. Used on URL-based sources.
llvm-git: updates a type: git source for its commit to point to the LLVM sources for the toolchain used by the latest Chromium version.

License and Copyright

License: GPLv2

vchernin/flatpak-external-data-checker

Flatpak External Data Checker

Motivation

Use

Installation

Running in a container

On Flathub

Custom workflow

Automatically submitting PRs

Selectively submitting PRs

Automatically merging PRs

Formatting manifests

Changes to Flatpak manifests

Version constraining

URL checker

HTML checker

URL templates

Git checker

JSON checker

Inheriting parent source check results

Debian repo checker

Anitya (release-monitoring) checker

GNOME checker

PyPI checker

Electron Auto Update checker

JetBrains checker

Snapcraft checker

Rust checker

Chromium checker

License and Copyright