26d1432ae6
* Update all plugins to use plugin/pkg/log I wish this could have been done with sed. Alas manually changed all callers to use the new plugin/pkg/log package. * Error -> Info * Add docs to debug plugin as well
100 lines
2.6 KiB
Go
100 lines
2.6 KiB
Go
package proxy
|
|
|
|
import (
|
|
"crypto/tls"
|
|
"fmt"
|
|
|
|
"github.com/coredns/coredns/pb"
|
|
"github.com/coredns/coredns/plugin/pkg/log"
|
|
"github.com/coredns/coredns/plugin/pkg/trace"
|
|
"github.com/coredns/coredns/request"
|
|
|
|
"github.com/grpc-ecosystem/grpc-opentracing/go/otgrpc"
|
|
"github.com/miekg/dns"
|
|
opentracing "github.com/opentracing/opentracing-go"
|
|
"golang.org/x/net/context"
|
|
"google.golang.org/grpc"
|
|
"google.golang.org/grpc/credentials"
|
|
)
|
|
|
|
type grpcClient struct {
|
|
dialOpts []grpc.DialOption
|
|
clients map[string]pb.DnsServiceClient
|
|
conns []*grpc.ClientConn
|
|
upstream *staticUpstream
|
|
}
|
|
|
|
func newGrpcClient(tls *tls.Config, u *staticUpstream) *grpcClient {
|
|
g := &grpcClient{upstream: u}
|
|
|
|
if tls == nil {
|
|
g.dialOpts = append(g.dialOpts, grpc.WithInsecure())
|
|
} else {
|
|
g.dialOpts = append(g.dialOpts, grpc.WithTransportCredentials(credentials.NewTLS(tls)))
|
|
}
|
|
g.clients = map[string]pb.DnsServiceClient{}
|
|
|
|
return g
|
|
}
|
|
|
|
func (g *grpcClient) Exchange(ctx context.Context, addr string, state request.Request) (*dns.Msg, error) {
|
|
msg, err := state.Req.Pack()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if cl, ok := g.clients[addr]; ok {
|
|
reply, err := cl.Query(ctx, &pb.DnsPacket{Msg: msg})
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
d := new(dns.Msg)
|
|
err = d.Unpack(reply.Msg)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return d, nil
|
|
}
|
|
return nil, fmt.Errorf("grpc exchange - no connection available for host: %s ", addr)
|
|
}
|
|
|
|
func (g *grpcClient) Transport() string { return "tcp" }
|
|
|
|
func (g *grpcClient) Protocol() string { return "grpc" }
|
|
|
|
func (g *grpcClient) OnShutdown(p *Proxy) error {
|
|
g.clients = map[string]pb.DnsServiceClient{}
|
|
for i, conn := range g.conns {
|
|
err := conn.Close()
|
|
if err != nil {
|
|
log.Warningf("Error closing connection %d: %s\n", i, err)
|
|
}
|
|
}
|
|
g.conns = []*grpc.ClientConn{}
|
|
return nil
|
|
}
|
|
|
|
func (g *grpcClient) OnStartup(p *Proxy) error {
|
|
dialOpts := g.dialOpts
|
|
if p.Trace != nil {
|
|
if t, ok := p.Trace.(trace.Trace); ok {
|
|
onlyIfParent := func(parentSpanCtx opentracing.SpanContext, method string, req, resp interface{}) bool {
|
|
return parentSpanCtx != nil
|
|
}
|
|
intercept := otgrpc.OpenTracingClientInterceptor(t.Tracer(), otgrpc.IncludingSpans(onlyIfParent))
|
|
dialOpts = append(dialOpts, grpc.WithUnaryInterceptor(intercept))
|
|
} else {
|
|
log.Warningf("Wrong type for trace plugin reference: %s", p.Trace)
|
|
}
|
|
}
|
|
for _, host := range g.upstream.Hosts {
|
|
conn, err := grpc.Dial(host.Name, dialOpts...)
|
|
if err != nil {
|
|
log.Warningf("Skipping gRPC host '%s' due to Dial error: %s\n", host.Name, err)
|
|
} else {
|
|
g.clients[host.Name] = pb.NewDnsServiceClient(conn)
|
|
g.conns = append(g.conns, conn)
|
|
}
|
|
}
|
|
return nil
|
|
}
|