cdzombak/feedfilter repository overview

feedfilter allows filtering an RSS feed based on a CEL⁠ expression that decides which items to include.

⁠Usage

feedfilter [options]

⁠Options

• -config <path>: Path to config file (default: ./config.json)
• -from <source>: Feed source (URL, file path, or '-' for stdin). Overrides config file.
• -to <destination>: Output destination (file path or '-' for stdout). Overrides config file.
• -version: Print version and exit

⁠Configuration

feedfilter uses a JSON configuration file to specify the feed source, output destination, filtering rules, and output format. The configuration file should contain:

{
  "from": "https://example.com/feed.xml",
  "to": "/path/to/output.xml",
  "to_fmt": "rss",
  "include_if": "title.contains('keyword') || categories.exists(c, c == 'tech')",
  "meta": {
    "title": "Filtered Feed",
    "description": "A filtered version of the original feed",
    "link": "https://example.com"
  }
}

⁠Configuration Fields

• from: URL, file path, or '-' for stdin. Required unless -from flag is used.
• to: File path or '-' for stdout. Required unless -to flag is used.
• to_fmt (required): Output format - "rss", "atom", or "json"
• include_if (optional): CEL expression to determine which items to include. If empty, all items are included.
• meta (optional): Metadata for the output feed
  • title: Feed title (use "$$ORIG$$" to use original feed's title)
  • description: Feed description (use "$$ORIG$$" to use original feed's description)
  • link: Feed link URL

⁠CEL Expression Variables

The include_if CEL expression has access to these variables for each feed item:

• title (string): Item title
• description (string): Item description
• link (string): Item link
• categories (list of strings): Item categories

⁠Installation

⁠macOS via Homebrew

brew install cdzombak/oss/feedfilter

⁠Debian via apt repository

Install my Debian repository⁠ if you haven't already:

sudo mkdir -p /etc/apt/keyrings
curl -fsSL https://dist.cdzombak.net/keys/dist-cdzombak-net.gpg -o /etc/apt/keyrings/dist-cdzombak-net.gpg
sudo chmod 644 /etc/apt/keyrings/dist-cdzombak-net.gpg
sudo mkdir -p /etc/apt/sources.list.d
sudo curl -fsSL https://dist.cdzombak.net/cdzombak-oss.sources -o /etc/apt/sources.list.d/cdzombak-oss.sources
sudo chmod 644 /etc/apt/sources.list.d/cdzombak-oss.sources
sudo apt update

Then install feedfilter via apt-get:

sudo apt-get install feedfilter

⁠Manual installation from build artifacts

Pre-built binaries for Linux and macOS on various architectures are downloadable from each GitHub Release⁠. Debian packages for each release are available as well.

⁠Build and install locally

git clone https://github.com/cdzombak/feedfilter.git
cd feedfilter
make build
cp out/feedfilter $INSTALL_DIR

⁠Docker images

Docker images are available for a variety of Linux architectures from Docker Hub⁠ and GHCR⁠. Images are based on the scratch image and are as small as possible.

Run them via, for example:

docker run -v ./config.json:/config.json --rm cdzombak/feedfilter:1 -config /config.json
docker run -v ./config.json:/config.json --rm ghcr.io/cdzombak/feedfilter:1 -config /config.json
# Or use flags to override config:
echo '<rss>...</rss>' | docker run -i --rm cdzombak/feedfilter:1 -from - -to - -config /config.json

⁠License

GNU General Public License v3.0; see LICENSE⁠ in this repository.

⁠Author

This project is maintained by Chris Dzombak (dzombak.com⁠ / github.com/cdzombak⁠).