serf-hosts-updater

serf-hosts-updater is a Serf event handler for automatic updating /etc/hosts file to represent Serf networking. This is especially useful when used in combination with Docker, because docker containers are normally assigned a random IP address.

Compared to a similar software, this handler has several benefits.

• It can use with setuid, so no need to execute serf as root user.
• It can send SIGHUP to dnsmasq in order to enable new entries.

This software developed using Go.

Installation

To build serf-hosts-updater, you must install Go. Please refer to Go's official documentation.

Then, you can install this handler by:

$ go get github.com/yosisa/serf-hosts-updater

A single binary file is installed to $GOPATH/bin/serf-hosts-updater.

If you plan to execute serf as a non-root user, you must set proper permissions to this program. It is recommended to copy this program from $GOPATH/bin to /usr/local/bin.

$ sudo cp $GOPATH/bin/serf-hosts-updater /usr/local/bin
$ sudo chmod u+s,g+s /usr/local/bin/serf-hosts-updater

Usage

You can use this program as a serf event handler. When you configure serf by a json file, append path to the program to the list of event_handlers:

{
    "event_handlers": [
        "/usr/local/bin/serf-hosts-updater"
    ]
}

Or, enable dnsmasq reloader if dnsmasq is running in your host:

{
    "event_handlers": [
        "/usr/local/bin/serf-hosts-updater -dnsmasq"
    ]
}

License

This software is distributed under the MIT license.