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|
package loadbalance
import (
"errors"
"fmt"
"path/filepath"
"time"
"github.com/coredns/caddy"
"github.com/coredns/coredns/core/dnsserver"
"github.com/coredns/coredns/plugin"
clog "github.com/coredns/coredns/plugin/pkg/log"
"github.com/miekg/dns"
)
var log = clog.NewWithPlugin("loadbalance")
var errOpen = errors.New("Weight file open error")
func init() { plugin.Register("loadbalance", setup) }
type lbFuncs struct {
shuffleFunc func(*dns.Msg) *dns.Msg
onStartUpFunc func() error
onShutdownFunc func() error
weighted *weightedRR // used in unit tests only
}
func setup(c *caddy.Controller) error {
//shuffleFunc, startUpFunc, shutdownFunc, err := parse(c)
lb, err := parse(c)
if err != nil {
return plugin.Error("loadbalance", err)
}
if lb.onStartUpFunc != nil {
c.OnStartup(lb.onStartUpFunc)
}
if lb.onShutdownFunc != nil {
c.OnShutdown(lb.onShutdownFunc)
}
dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
return LoadBalance{Next: next, shuffle: lb.shuffleFunc}
})
return nil
}
// func parse(c *caddy.Controller) (string, *weightedRR, error) {
func parse(c *caddy.Controller) (*lbFuncs, error) {
config := dnsserver.GetConfig(c)
for c.Next() {
args := c.RemainingArgs()
if len(args) == 0 {
return &lbFuncs{shuffleFunc: randomShuffle}, nil
}
switch args[0] {
case ramdomShufflePolicy:
if len(args) > 1 {
return nil, c.Errf("unknown property for %s", args[0])
}
return &lbFuncs{shuffleFunc: randomShuffle}, nil
case weightedRoundRobinPolicy:
if len(args) < 2 {
return nil, c.Err("missing weight file argument")
}
if len(args) > 2 {
return nil, c.Err("unexpected argument(s)")
}
weightFileName := args[1]
if !filepath.IsAbs(weightFileName) && config.Root != "" {
weightFileName = filepath.Join(config.Root, weightFileName)
}
reload := 30 * time.Second // default reload period
for c.NextBlock() {
switch c.Val() {
case "reload":
t := c.RemainingArgs()
if len(t) < 1 {
return nil, c.Err("reload duration value is missing")
}
if len(t) > 1 {
return nil, c.Err("unexpected argument")
}
var err error
reload, err = time.ParseDuration(t[0])
if err != nil {
return nil, c.Errf("invalid reload duration '%s'", t[0])
}
default:
return nil, c.Errf("unknown property '%s'", c.Val())
}
}
return createWeightedFuncs(weightFileName, reload), nil
default:
return nil, fmt.Errorf("unknown policy: %s", args[0])
}
}
return nil, c.ArgErr()
}
|
