Gogeta

Gogeta is a dynamic reverse proxy which configuration is based on etcd. It provides real time dynamic reconfiguration of routes without having to restart the process.

It is part of the nuxeo.io infrastructure.

How it works

It is basically an HTTP cluster router that holds its configuration in etcd. Default behavior is to use the IoEtcdResolver. For instance, when running gogeta like this :

    gogeta -etcdAddress="http://172.17.42.1:4001" \
           -domainDir="/domains" \
           -serviceDir="/services" \
           -templateDir="/usr/local/go/src/github.com/nuxeo/gogeta/templates"

Here is the workflow of the request

• client asks for mycustomdomain.com

• proxy looks at /domains/mycustomdomain.com/[type,value]

• if type is service we look for /services/{value}/1/location which value is in the form

  {"host":"172.13.4.3","port":42567}
  

• the request is proxied to http://{host}:{port}/

• if type is uri

• the request is proxied to the value of /domains/mycustomdomain.com/value

It is possible to have several instances of a service by differenciating them with the serviceIndex key part :

/services/myService/1/location
/services/myService/2/location

Gogeta will loadbalance the requests on those two instances using a round robin implementation.

Sample configuration

To summarize, here are the keys needed to proxy customdomain.com to 172.41.4.5:42654

/services/myService/1/location = {"host":"172.41.4.5", "port": 42654}
/domains/mycustomdomain.com/type = service
/domains/mycustomdomain.com/value = myService

Service Status

Optionally, services may have a status. This is a directory that is held at /services/{serviceName}/{serviceIndex}/status. It holds three values:

• current: The current status of the service in [stopped|starting|started|stopping|passivated]
• expected: The expected status of the service [stopped|started|passivated]
• alive: a heartbeat that the service must update.

Based on those values, Gogeta will serve wait pages with the according HTTP status code.

Configuration

Several parameters allow to configure the way the proxy behave :

• domainDir allows to select the prefix of the key where it watches for domain
• serviceDir allows to select the prefix of the key where it watches for environments
• etcdAddress specify the address of the etcd server
• port port to listen
• templateDir a template directory for error status page
• resolverType: choose the resolver to use
  • Env: EnvResolver
  • Dummy: DummyResolver
  • by default : IoEtcd

Debug

You can log all goroutines callstack by sending a SIGUSR1 signal to the process.

kill -SIGUSR1 `pidof gogeta`

Build and Test

Gogeta uses GOM to build. Simply install GOM then :

gom build
gom install

To run the test :

gom test

There are integration tests that may be run. To do so you need to start an etcd server listening on port 4001. You may use the Philip Southam etcd server docker image that is very small for instance. After that run

IT_Test=true gom test

If you want a more interactive test session, we use GoConvey that gives you a web interface to show the tests execution. Each time a file is saved, the tests are reevaluated. To run it :

goconvey
IT_Test=true goconvey

Run with Docker

You can run Gogeta thru Docker, since its image is build in the central Docker repository.

/usr/bin/docker run --rm --name gogeta -p 7777:7777 arken/gogeta

Report & Contribute

We are glad to welcome new developers on this initiative, and even simple usage feedback is great.

• Ask your questions on Nuxeo Answers
• Report issues on this github repository (see issues link on the right)
• Contribute: Send pull requests!

About Nuxeo

Nuxeo provides a modular, extensible Java-based open source software platform for enterprise content management, and packaged applications for document management, digital asset management and case management.

Designed by developers for developers, the Nuxeo platform offers a modern architecture, a powerful plug-in model and extensive packaging capabilities for building content applications.

More information on: http://www.nuxeo.com/