Do not touch grpc logger from within the packages

Libraries should not make process wide changes unless requested to.

Signed-off-by: Kenfe-Mickael Laventure <mickael.laventure@gmail.com>

client_test.go

@@ -5,6 +5,8 @@ import (
 	"context"
 	"flag"
 	"fmt"
+	"io/ioutil"
+	golog "log"
 	"os"
 	"os/exec"
 	"runtime"
@@ -12,6 +14,8 @@ import (
 	"testing"
 	"time"
 
+	"google.golang.org/grpc/grpclog"
+
 	"github.com/containerd/containerd/log"
 	"github.com/containerd/containerd/namespaces"
 	"github.com/containerd/containerd/testutil"
@@ -26,6 +30,9 @@ var (
 )
 
 func init() {
+	// Discard grpc logs so that they don't mess with our stdio
+	grpclog.SetLogger(golog.New(ioutil.Discard, "", golog.LstdFlags))
+
 	flag.StringVar(&address, "address", defaultAddress, "The address to the containerd socket for use in the tests")
 	flag.BoolVar(&noDaemon, "no-daemon", false, "Do not start a dedicated daemon for the tests")
 	flag.BoolVar(&noCriu, "no-criu", false, "Do not run the checkpoint tests")