Use default cert dir for oc cluster up client if DOCKER_TLS_VERIFY is set

Author: jimmidyson

pkg/bootstrap/docker/up.go

@@ -9,6 +9,7 @@ import (
 	"runtime"
 
 	"github.com/blang/semver"
+	"github.com/docker/docker/pkg/homedir"
 	dockerclient "github.com/docker/engine-api/client"
 	docker "github.com/fsouza/go-dockerclient"
 	"github.com/golang/glog"
@@ -437,6 +438,14 @@ func getDockerClient(out io.Writer, dockerMachine string, canStartDockerMachine
 		}
 		if len(dockerTLSVerify) > 0 {
 			glog.Infof("DOCKER_TLS_VERIFY=%s", dockerTLSVerify)
+			if len(dockerCertPath) == 0 {
+				home := homedir.Get()
+				if home == "" {
+					return nil, nil, errors.NewError("environment variable HOME must be set if DOCKER_CERT_PATH is not set")
+				}
+				dockerCertPath = filepath.Join(home, ".docker")
+				os.Setenv("DOCKER_CERT_PATH", dockerCertPath)
+			}
 		}
 		if len(dockerCertPath) > 0 {
 			glog.Infof("DOCKER_CERT_PATH=%s", dockerCertPath)