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|
package traffic
import (
"crypto/tls"
"fmt"
"math/rand"
"strings"
"time"
"github.com/coredns/coredns/core/dnsserver"
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/plugin/metrics"
clog "github.com/coredns/coredns/plugin/pkg/log"
"github.com/coredns/coredns/plugin/pkg/parse"
pkgtls "github.com/coredns/coredns/plugin/pkg/tls"
"github.com/coredns/coredns/plugin/pkg/transport"
"github.com/coredns/coredns/plugin/traffic/xds"
"github.com/caddyserver/caddy"
"google.golang.org/grpc"
"google.golang.org/grpc/credentials"
)
var log = clog.NewWithPlugin("traffic")
func init() { plugin.Register("traffic", setup) }
func setup(c *caddy.Controller) error {
rand.Seed(int64(time.Now().Nanosecond()))
t, err := parseTraffic(c)
if err != nil {
return plugin.Error("traffic", err)
}
dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
t.Next = next
return t
})
c.OnStartup(func() error {
go func() {
for {
opts := []grpc.DialOption{grpc.WithInsecure()}
if t.tlsConfig != nil {
opts = []grpc.DialOption{grpc.WithTransportCredentials(credentials.NewTLS(t.tlsConfig))}
}
i := 0
redo:
i = i % len(t.hosts)
if t.c, err = xds.New(t.hosts[i], t.node, opts...); err != nil {
log.Warning(err)
time.Sleep(2 * time.Second) // back off foo
i++
goto redo
}
if err := t.c.Run(); err != nil {
log.Warning(err)
time.Sleep(2 * time.Second) // back off foo
i++
goto redo
}
}
}()
metrics.MustRegister(c, xds.ClusterGauge)
return nil
})
c.OnShutdown(func() error { return t.c.Stop() })
return nil
}
func parseTraffic(c *caddy.Controller) (*Traffic, error) {
toHosts := []string{}
t := &Traffic{node: "coredns", mgmt: "xds"}
var (
err error
tlsConfig *tls.Config
tlsServerName string
)
t.origins = make([]string, len(c.ServerBlockKeys))
for i := range c.ServerBlockKeys {
t.origins[i] = plugin.Host(c.ServerBlockKeys[i]).Normalize()
}
for c.Next() {
args := c.RemainingArgs()
if len(args) < 1 {
return nil, c.ArgErr()
}
toHosts, err = parse.HostPortOrFile(args...)
if err != nil {
return nil, err
}
for i := range toHosts {
if !strings.HasPrefix(toHosts[i], transport.GRPC+"://") {
return nil, fmt.Errorf("not a %s scheme: %s", transport.GRPC, toHosts[i])
}
// now cut the prefix off again, because the dialler needs to see normal address strings. All this
// grpc:// stuff is to enforce uniform across plugins and future proofing for other protocols.
toHosts[i] = toHosts[i][len(transport.GRPC+"://"):]
}
for c.NextBlock() {
switch c.Val() {
case "cluster":
args := c.RemainingArgs()
if len(args) != 1 {
return nil, c.ArgErr()
}
t.mgmt = args[0]
case "id":
args := c.RemainingArgs()
if len(args) != 1 {
return nil, c.ArgErr()
}
t.node = args[0]
case "tls":
args := c.RemainingArgs()
if len(args) > 3 {
return nil, c.ArgErr()
}
tlsConfig, err = pkgtls.NewTLSConfigFromArgs(args...)
if err != nil {
return nil, err
}
case "tls_servername":
if !c.NextArg() {
return nil, c.ArgErr()
}
tlsServerName = c.Val()
default:
return nil, c.Errf("unknown property '%s'", c.Val())
}
}
}
if tlsConfig != nil {
t.tlsConfig = tlsConfig
if tlsServerName != "" {
t.tlsConfig.ServerName = tlsServerName
}
}
t.hosts = toHosts
return t, nil
}
|
