Capture

The Capture filter’s job is to find a series of bytes within a packet, and capture it into Filter Dynamic Metadata, so that it can be utilised by filters further down the chain.

This is often used as a way of retrieving authentication tokens from a packet, and used in combination with Concatenate and TokenRouter filter to provide common packet routing utilities.

Capture strategies

There are multiple strategies for capturing bytes from the packet.

Suffix

Captures bytes from the end of the packet.

Prefix

Captures bytes from the start of the packet.

Regex

Captures bytes using a regular expression. Unlike other capture strategies, the regular expression can return one or many values if there are multiple matches.

Filter name

quilkin.filters.capture.v1alpha1.Capture

Configuration Examples

#![allow(unused)]
fn main() {
let yaml = "
version: v1alpha1
filters:
  - name: quilkin.filters.capture.v1alpha1.Capture
    config:
      metadataKey: myapp.com/myownkey
      prefix:
        size: 3
        remove: false
clusters:
  - endpoints:
      - address: 127.0.0.1:7001
";
let config = quilkin::config::Config::from_reader(yaml.as_bytes()).unwrap();
assert_eq!(config.filters.load().len(), 1);
}

Configuration Options (Rust Doc)

{{#include ../../../target/quilkin.filters.capture.v1alpha1.yaml}}