envoy

Start with configuration file

$ envoy -c [/path/to/config.yaml]

$ envoy -c [config.yaml] --mode validate

$ envoy -c [config.yaml] --service-cluster [my-cluster]

$ envoy -c [config.yaml] --service-node [node-1]

$ envoy -c [config.yaml] --base-id [1]

$ envoy --config-yaml "[yaml-string]"

$ envoy -c [config.yaml] -l debug

envoy [options]

envoy is a high-performance L4/L7 proxy and communication bus designed for large modern service-oriented architectures. It handles load balancing, service discovery, observability, and provides advanced traffic management features.
Configuration is provided via YAML, JSON, or protobuf files specified with -c. The configuration defines listeners (ports), clusters (upstreams), routes, and filters. Dynamic configuration can be fetched from xDS APIs.
Hot restart allows upgrading Envoy without dropping connections. The --base-id identifies shared memory regions between parent and child processes. Use --restart-epoch to coordinate restarts.
The validate mode checks configuration syntax and semantics without starting the proxy, useful for CI/CD pipelines.
Envoy is commonly deployed as a sidecar proxy in service meshes (Istio, Consul Connect) or as an edge/ingress proxy. It supports HTTP/1.1, HTTP/2, gRPC, TCP, and UDP protocols.

-c, --config-path path

Path to bootstrap configuration file (.json, .yaml, .pb, .pb_text).

Inline YAML configuration string. Merges with --config-path.

Run mode: serve (default) or validate.

Local service cluster name.

Local service node identifier.

Local service zone for locality.

IP version for local address: v4 or v6.

Log level: trace, debug, info, warning, error, critical, off.

Path to log file.

Log message format string.

Per-component log levels.

Base ID for shared memory (hot restart).

Automatically select unused base ID.

Hot restart epoch number.

Number of worker threads.

File buffer flush interval in milliseconds.

Time to drain connections during hot restart.

Time before parent shuts down during hot restart.

Show version information.

Show help message.

/etc/envoy/envoy.yaml

Common location for Envoy bootstrap configuration file.

Bootstrap configuration defining listeners, clusters, routes, and filters.

Configuration complexity can be high for advanced use cases. Hot restart requires proper base-id coordination. Memory usage scales with number of connections and clusters. Some features require specific filter configurations.

Envoy was created at Lyft by Matt Klein and open-sourced in September 2016. It was designed to handle Lyft's microservices traffic with focus on observability and debuggability. Envoy joined the CNCF in 2017 and graduated in 2018. It became the foundation for service meshes like Istio and is widely used as a data plane proxy.

nginx(1), haproxy(1), istioctl(1), traefik(1)