gobetween

gobetween - modern & minimalistic load balancer and reverse-proxy for the Cloud era.

Current status: Maintenance mode, accepting PRs. Currently in use in several highly loaded production environments.

Features

  • Fast L4 Load Balancing
  • Clear & Flexible Configuration with TOML or JSON
    • File - read configuration from the file
    • URL - query URL by HTTP and get configuration from the response body
    • Consul - query Consul key-value storage API for configuration
  • Management REST API
    • System Information - general server info
    • Configuration - dump current config
    • Servers - list, create & delete
    • Stats & Metrics - for servers and backends including rx/tx, status, active connections & etc.
  • Discovery
    • Static - hardcode backends list in the config file
    • Docker - query backends from Docker / Swarm API filtered by label
    • Exec - execute an arbitrary program and get backends from its stdout
    • JSON - query arbitrary http url and pick backends from response json (of any structure)
    • Plaintext - query arbitrary http and parse backends from response text with customized regexp
    • SRV - query DNS server and get backends from SRV records
    • Consul - query Consul Services API for backends
    • LXD - query backends from LXD
  • Healthchecks
    • Ping - simple TCP ping healthcheck
    • Exec - execute arbitrary program passing host & port as options, and read healthcheck status from the stdout
    • Probe - send specific bytes to backend (udp, tcp or tls) and expect a correct answer (bytes or regexp)
  • Balancing Strategies (with SNI support)
    • Weight - select backend from pool based relative weights of backends
    • Roundrobin - simple elect backend from pool in circular order
    • Iphash - route client to the same backend based on client ip hash
    • Iphash1 - same as iphash but backend removal consistent (clients remain connecting to the same backend, even if some other backends down)
    • Leastconn - select backend with least active connections
    • Leastbandwidth - backends with least bandwidth
  • Integrates seamlessly with Docker and with any custom system (thanks to Exec discovery and healthchecks)
  • Single binary distribution

Architecture

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Usage

Hacking

Debug and Test

Run several web servers for tests in different terminals:

  • $ python -m SimpleHTTPServer 8000
  • $ python -m SimpleHTTPServer 8001

Instead of Python's internal HTTP module, you can also use a single binary (Go based) webserver like: https://github.com/udhos/gowebhello

gowebhello has support for SSL sertificates as well (HTTPS mode), in case you want to do quick demos of the TLS+SNI capabilities of gobetween.

Put localhost:8000 and localhost:8001 to static_list of static discovery in config file, then try it:

  • $ gobetween -c gobetween.toml
  • $ curl http://localhost:3000

Enable profiler and debug issues you encounter

[profiler]
enabled = true     # false | true
bind    = ":6060"  # "host:port"

Performance

It's Fast! See Performance Testing

The Name

It's a play on words: gobetween ("go between").

Also, it's written in Go, and it's a proxy so it's something that stays between 2 parties

GitHub

https://github.com/yyyar/gobetween