baggage-filter

Introduction

A Rust-based Istio WASM filter that generates a W3C Trace Context-compliant baggage header, containing key-value pairs specified by the configuration.

Features

• Adds the headers specified in the config as items in the baggage header. If the header does not exist, create it. If it already exists, overwrite the value of keys with the same name while retaining the other items. Refer to ./resources/wasmplugin.yaml.

Getting started

# Install Rust. Note: Installing via brew on macOS may not compile correctly. Follow the official Rust installation path instead.
> curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# Install cargo-make (build tool; refer to Makefile.toml).
> cargo install cargo-make

# Install wasm-opt (binaryen) (for macOS; other OSes require a different method. If installation fails, skip this step by removing the optimize-wasm task from Makefile.toml).
> brew install binaryen

# Create a .env file at the root and set DOCKER_IMAGE_PATH. Example below:
DOCKER_IMAGE_PATH=anyflow/baggage-filter

# Run tests -> Rust build -> Image optimization -> Docker build -> Docker push
> cargo make deploy

How to Test at Runtime in Istio

# Change the WASM log level of the target pod to debug.
> istioctl pc log -n <namespace name> <pod name> --level wasm:debug

# Filter logs to show only baggage-filter
> k logs -n <namespace name> <pod name> -f | grep -F '[bf]'

# Apply resources/telemetry.yaml: To add baggage header in the trace tag.
> kubectl apply -f telemetry.yaml

# Apply resources/wasmplugin.yaml: Check logs to confirm successful loading, e.g., "[bf] Configuration successful, configured headers:".
> kubectl apply -f wasmplugin.yaml

# Make a curl request and verify if the matching success log appears, e.g., "[bf] Set new baggage: x-message-id=0123456789".

License

baggage-filter is released under version 2.0 of the Apache License.