Serf Template

Template rendering with Serf.

Installation

$ git clone https://github.com/phamhongviet/serf-template.git
$ cd serf-template
$ go build

Usage

$ serf-template config-file

Instead of reading anything from stdin or environment variables, Serf Template get members' information from the RPC interface. Serf Temlate subscribe to member related events from RPC stream (member-join, member-failed, member-update, member-leave and member-reap).

Configuration

Example:

{
  "serf": "path/to/serf"
  "name": "regexp",
  "role": "regexp",
  "status": "regexp",
  "tags": {
    "key1": "value1",
    "key2": "value2",
    "key3": "value3"
  },
  "rpc-addr": "127.0.0.1:7373",
  "rpc-auth": "rpcauthtoken",
  "rpc-timeout": 1000,
  "templates": [
    {
    "src": "/path/to/template.tpl",
    "dest": "/path/to/result.file",
    "cmd": "service dummy restart"
    },
    {
    "src": "/path/to/src.file",
    "dest": "/path/to/dest.file",
    "cmd": "service dummier restart",
    }
  ]
}

Template File

Serf Template consumes template files in Go Template format. Template files are rendered with a list of members with Name, Addr, Port, Tags and Status.

Member structure example:

{
  "name": "web-1",
  "addr": "172.16.0.21",
  "port": 7946,
  "tags": {
    "webport": "8080",
    "app": "nginx",
    "role": "web"
  },
  "status": "failed",
}

Template file example:

{{ range . }}{{ if eq .Status "alive" }}
server {{.Name}} at {{.Addr}} with serf at {{.Port}} and {{.Tags.app}} at {{.Tags.webport}}
{{ end }}{{ end }}

The above template file would produce a file like this:

server web-1 at 172.16.0.21 with serf at 7946 and nginx at 8080
server web-2 at 172.16.0.22 with serf at 7946 and nginx at 8080
server web-3 at 172.16.0.23 with serf at 7946 and httpd at 80