boulder/grpc/client.go

51 lines
1.7 KiB
Go

package grpc
import (
"crypto/tls"
"fmt"
"github.com/grpc-ecosystem/go-grpc-prometheus"
"github.com/jmhodges/clock"
"github.com/prometheus/client_golang/prometheus"
"google.golang.org/grpc"
"github.com/letsencrypt/boulder/cmd"
bcreds "github.com/letsencrypt/boulder/grpc/creds"
)
// ClientSetup creates a gRPC TransportCredentials that presents
// a client certificate and validates the the server certificate based
// on the provided *tls.Config.
// It dials the remote service and returns a grpc.ClientConn if successful.
func ClientSetup(c *cmd.GRPCClientConfig, tls *tls.Config, clientMetrics *grpc_prometheus.ClientMetrics, clk clock.Clock) (*grpc.ClientConn, error) {
if len(c.ServerAddresses) == 0 {
return nil, fmt.Errorf("boulder/grpc: ServerAddresses is empty")
}
if tls == nil {
return nil, errNilTLS
}
ci := clientInterceptor{c.Timeout.Duration, clientMetrics, clk}
creds := bcreds.NewClientCredentials(tls.RootCAs, tls.Certificates)
return grpc.Dial(
"", // Since our staticResolver provides addresses we don't need to pass an address here
grpc.WithTransportCredentials(creds),
grpc.WithBalancer(grpc.RoundRobin(newStaticResolver(c.ServerAddresses))),
grpc.WithUnaryInterceptor(ci.intercept),
)
}
type registry interface {
MustRegister(...prometheus.Collector)
}
// NewClientMetrics constructs a *grpc_prometheus.ClientMetrics, registered with
// the given registry, with timing histogram enabled. It must be called a
// maximum of once per registry, or there will be conflicting names.
func NewClientMetrics(stats registry) *grpc_prometheus.ClientMetrics {
metrics := grpc_prometheus.NewClientMetrics()
metrics.EnableClientHandlingTimeHistogram()
stats.MustRegister(metrics)
return metrics
}