"HTTP Trigger Trigger" is an HTTP server application that take requests and for every request it either triggers an HTTP request to some other upstream destination, or it executes a shell command. The configuration is stored in a simple INI file.

The difference between HTTP Trigger Trigger and many other HTTP proxies (such as nginx and Apache) is that its backend requests are fully independent of their equivalent frontend request (except timing, obviously). This means, among other things, that all GET and POST parameters are stripped off.

HTTP Trigger Trigger also supports rate limitting. This makes it very useful to make sure that your backend infrastructure will not be DDoS:ed/overloaded in case of a DDoS attack against HTTP Trigger Trigger.

The initial usecase was to securely expose to the web a build tool trigger so that Github could trigger builds when new pushes arrives.

In general, this tool is useful when you'd like to expose a certain internal API endpoint to an insecure network, and you'd like to do this in a very secure fashion.

Installing/developing ----------The easiest way to install is to download a precompiled release. You can also build the software yourself using a $GOPATH/Go workspace:

$ mkdir -p ~/src/http-trigger-trigger
$ export GOPATH=~/src/http-trigger-trigger
$ cd $GOPATH
$ mkdir -p src/github.com/JensRantil
$ cd src/github.com/JensRantil
$ git clone git@github.com:JensRantil/http-trigger-trigger.git
$ cd http-trigger-trigger
$ go get
$ go build

The binary built is http-trigger-trigger.

See setup.ini.example for an example configuration file containing all possible key/values. The file uses standard INI format. Here's a stripped down example:

listen=:8080

[/trigger/backend/http]
url = http://upstream.server.example.com/other-trigger

[/trigger/script]
command = echo Hello World

[/rate/limited/trigger]
url = http://upstream2.server.example.com/another-trigger
queue_size=2
hit_delay=1s

For every request all endpoints will be matched sequentially against the INI section. The first match will trigger a request to its corresponding url. If listen is not defined, it will use port 8080 and listen on all interfaces.

Create your configuration file, and start using:

TRIGGER_TRIGGER_CONFIG=./config.ini ./http-trigger-trigger

• Allow certain GET or POST parameters to pass through (and be renamed).
• Do input matching based on other things than path:
  • HTTP method
  • Host header.
• Modify the default response content.