NOTE: You should read the Caveats section first, before proceeding with the rest document

This is a simple library, written in Go, for interacting with the HAProxy UNIX Socket commands interface.

The common way of interacting with the HAProxy stats socket interface is via a common UNIX socket. However, even thought it is never done by default, it is also possible to define multiple stats socket instance in HAProxy configuration, and make them listen to a TCP port instead of a UNIX socket. The go-haproxy library allows using all the supported ways for connecting to HAProxy, i.e., a TCP port (either via IPv4 or IPv6), or via a UNIX socket.

The current library uses the non-interactive mode to connect to HAProxy stats socket interface. This means you only send a single line per time. HAProxy will process this line, send its response back to the client, and finally it will close the connection immediately after the end of the response. In case you want to send multiple commands in a single line, you need to delimit them with a semi-colon (';').

To facilitate a user, we ship a custom Makefile for managing the go-haproxy library, i.e., build the library, run the tests, etc.

There are no special Requirements for the current library, just a working Go environment. The go-haproxy library is currently developed with the following Stable release:

$ go version
go version go1.10.3 linux/amd64

• Initialize a HAProxy connection object using a common UNIX socket:

haproxy := haproxy.HAProxyClient{
        AfNet:   "unix",
        Address: "/run/haproxy.sock",
        Timeout: time.Second * 2,
}

• Initialize a HAProxy connection object using a TCP port:

// via IPv4
haproxy := haproxy.HAProxyClient{
        AfNet:   "tcp4",
        Address: "10.0.0.1:8000",
        Timeout: time.Second * 2,
}

// via IPv6
haproxy := haproxy.HAProxyClient{
        AfNet:   "tcp6",
        Address: "[fc00::]:8000",
        Timeout: time.Second * 2,
}

• Run a HAProxy command and retrieve the response:

response, err := haproxy.SendCommand("show acl")
if err != nil {
        log.Fatal(err)
}
log.Println(response)

For more information on using the current library, you can address the example files under the samples/ directory.

As already said, you simply need a working Go environment and you'll have a fully functioning development environment for the go-haproxy library.

• To properly format the source code, build the project and its dependencies, or run the tests, you are advised to use the Makefile:

$ make build
$ make fmt
$ make tests
$ make          // run everything

---

NOTE: The test suite of the go-haproxy client is located under the $(TEST_DIR) directory on the contrary to the official Go lang way of defining tests. The reason behind this approach is that I simply don't like maintaining my test files along with the main source code.

However, this approach causes an obvious issue, i.e., you can not import and subsequently test the client's non-exported functions. A temporary workaround in order to be able testing all client's functions and also continue maintaining the test suite in a separate folder, is to symlink the complete test suite to its proper location prior to running it, and unlink it as soon as the test run completes, either successfully or not.

• This is still a work-in-progress library. More functionality in terms of improved error handling, handy HAProxy command wrappers, better unit tests, docs additions, etc, will be added in the future.
• Note that this library is more a mean to experiment with the Go language, its packaging system, the testing framework, and so on, rather than a tool tested in production environments.