7da2cedaf0
* Add weighted-round-robin policy to loadbalance plugin Signed-off-by: Gabor Dozsa <gabor.dozsa@ibm.com>
103 lines
2.5 KiB
Go
103 lines
2.5 KiB
Go
package loadbalance
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import (
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"errors"
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"fmt"
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"path/filepath"
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"time"
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"github.com/coredns/caddy"
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"github.com/coredns/coredns/core/dnsserver"
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"github.com/coredns/coredns/plugin"
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clog "github.com/coredns/coredns/plugin/pkg/log"
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"github.com/miekg/dns"
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)
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var log = clog.NewWithPlugin("loadbalance")
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var errOpen = errors.New("Weight file open error")
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func init() { plugin.Register("loadbalance", setup) }
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type lbFuncs struct {
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shuffleFunc func(*dns.Msg) *dns.Msg
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onStartUpFunc func() error
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onShutdownFunc func() error
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weighted *weightedRR // used in unit tests only
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}
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func setup(c *caddy.Controller) error {
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//shuffleFunc, startUpFunc, shutdownFunc, err := parse(c)
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lb, err := parse(c)
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if err != nil {
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return plugin.Error("loadbalance", err)
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}
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if lb.onStartUpFunc != nil {
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c.OnStartup(lb.onStartUpFunc)
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}
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if lb.onShutdownFunc != nil {
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c.OnShutdown(lb.onShutdownFunc)
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}
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dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
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return LoadBalance{Next: next, shuffle: lb.shuffleFunc}
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})
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return nil
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}
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// func parse(c *caddy.Controller) (string, *weightedRR, error) {
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func parse(c *caddy.Controller) (*lbFuncs, error) {
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config := dnsserver.GetConfig(c)
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for c.Next() {
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args := c.RemainingArgs()
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if len(args) == 0 {
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return &lbFuncs{shuffleFunc: randomShuffle}, nil
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}
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switch args[0] {
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case ramdomShufflePolicy:
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if len(args) > 1 {
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return nil, c.Errf("unknown property for %s", args[0])
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}
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return &lbFuncs{shuffleFunc: randomShuffle}, nil
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case weightedRoundRobinPolicy:
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if len(args) < 2 {
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return nil, c.Err("missing weight file argument")
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}
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if len(args) > 2 {
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return nil, c.Err("unexpected argument(s)")
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}
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weightFileName := args[1]
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if !filepath.IsAbs(weightFileName) && config.Root != "" {
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weightFileName = filepath.Join(config.Root, weightFileName)
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}
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reload := 30 * time.Second // default reload period
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for c.NextBlock() {
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switch c.Val() {
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case "reload":
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t := c.RemainingArgs()
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if len(t) < 1 {
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return nil, c.Err("reload duration value is missing")
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}
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if len(t) > 1 {
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return nil, c.Err("unexpected argument")
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}
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var err error
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reload, err = time.ParseDuration(t[0])
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if err != nil {
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return nil, c.Errf("invalid reload duration '%s'", t[0])
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}
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default:
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return nil, c.Errf("unknown property '%s'", c.Val())
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}
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}
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return createWeightedFuncs(weightFileName, reload), nil
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default:
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return nil, fmt.Errorf("unknown policy: %s", args[0])
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}
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}
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return nil, c.ArgErr()
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}
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