Consul Load-Balancing made simple

fabiolb/fabio https://fabiolb.net
starsStars 6517
forksForks 575
watchersWatchers 6517
current-versionCurrent version v1.5.15
total-releasesTotal releases 55
open_issues_countOpen issues 230
dateFirst release 2015-11-30
dateLatest release 2020-12-01
updateLast update 2020-12-22


  1. From release 1.5.15 onward, fabio changes the default GOGC from 800 back to the golang default of 100. Apparently this made some sense back in the golang 1.5 days, but with changes introduced with golang 1.12 and others, this is probably no longer a very good default. This is still configurable, as always, but the new default should make the most sense for most users.

  2. From release 1.5.14, release hashes are signed with a new PGP key. See details here.

  3. From release 1.5.14 onward, fabio binary releases are compiled with golang 1.15+.
    This means that the fabio will no longer validate upstream https certificates that do not have SAN extensions matching the server name. This may be a concern if fabio is communicating with https backends with misconfigured certificates. If this is a problem, you can specify tlsskipverify=true on the route.

fabio is a fast, modern, zero-conf load balancing HTTP(S) and TCP router for deploying applications managed by consul.

Register your services in consul, provide a health check and fabio will start routing traffic to them. No configuration required. Deployment, upgrading and refactoring has never been easier.

fabio is developed and maintained by The Fabio Authors.

It powers some of the largest websites in The Netherlands (marktplaats.nl), Australia (gumtree.com.au) and Italy (www.kijiji.it). It delivers 23.000 req/sec every day since Sep 2015 without problems.

It integrates with Consul, Vault, Amazon ELB, Amazon API Gateway and more.

It supports (Full feature list)

Watch Kelsey Hightower demo Consul, Nomad, Vault and fabio at HashiConf EU 2016.

The full documentation is on fabiolb.net

Getting started

  1. Install from source, binary, Homebrew.

    # go 1.15 or higher is required
    go get github.com/fabiolb/fabio                     (>= go1.15)
    brew install fabio                                  (OSX/macOS stable)
    brew install --devel fabio                          (OSX/macOS devel)
    docker pull fabiolb/fabio                           (Docker)
    https://github.com/fabiolb/fabio/releases           (pre-built binaries)
  2. Register your service in consul.

    Make sure that each instance registers with a unique ServiceID and a service name without spaces.

  3. Register a health check in consul as described here.

    By default fabio only watches services which have a passing health check, unless overridden with registry.consul.service.status.

  4. Register one urlprefix- tag per host/path prefix it serves, e.g.:

# HTTP/S examples
urlprefix-/css                                     # path route
urlprefix-i.com/static                             # host specific path route
urlprefix-mysite.com/                              # host specific catch all route
urlprefix-/foo/bar strip=/foo                      # path stripping (forward '/bar' to upstream)
urlprefix-/foo/bar proto=https                     # HTTPS upstream
urlprefix-/foo/bar proto=https tlsskipverify=true  # HTTPS upstream and self-signed cert

# TCP examples
urlprefix-:3306 proto=tcp                          # route external port 3306

Make sure the prefix for HTTP routes contains at least one slash (/).

See the full list of options in the Documentation.

  1. Start fabio without a config file (assuming a running consul agent on localhost:8500) Watch the log output how fabio picks up the route to your service. Try starting/stopping your service to see how the routing table changes instantly.

  2. Send all your HTTP traffic to fabio on port 9999. For TCP proxying see TCP proxy.

  3. Done

Author and Founder



This project exists thanks to all the people who contribute. [Contribute].


  • Contributions up to 14 Apr 2017 before 38f73da

    MIT Licensed Copyright (c) 2017 eBay Software Foundation. All rights reserved.

  • Contributions after 14 Apr 2017 starting with 38f73da

    MIT Licensed Copyright (c) 2017-2019 Frank Schroeder. All rights reserved.

  • Contributions after 22 Jan 2020 starting with 9da7b1b

    MIT Licensed Copyright (c) 2020 Education Networks of America. All rights reserved.

See LICENSE for details.

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