fn: docker version check2 (#744)

1) now required docker version is 17.06
2) enable circle ci latest docker install
3) docker driver & agent check minimum version before start

api/agent/drivers/docker/docker.go

@@ -12,6 +12,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/coreos/go-semver/semver"
 	"github.com/fnproject/fn/api/agent/drivers"
 	"github.com/fnproject/fn/api/common"
 	"github.com/fnproject/fn/api/models"
@@ -58,12 +59,45 @@ func NewDocker(conf drivers.Config) *DockerDriver {
 		logrus.WithError(err).Fatal("couldn't resolve hostname")
 	}
 
-	return &DockerDriver{
+	driver := &DockerDriver{
 		conf:     conf,
 		docker:   newClient(),
 		hostname: hostname,
 		auths:    registryFromEnv(),
 	}
+
+	if conf.ServerVersion != "" {
+		err = checkDockerVersion(driver, conf.ServerVersion)
+		if err != nil {
+			logrus.WithError(err).Fatal("docker version error")
+		}
+	}
+
+	return driver
+}
+
+func checkDockerVersion(driver *DockerDriver, expected string) error {
+
+	info, err := driver.docker.Info(context.Background())
+	if err != nil {
+		return err
+	}
+
+	actual, err := semver.NewVersion(info.ServerVersion)
+	if err != nil {
+		return err
+	}
+
+	wanted, err := semver.NewVersion(expected)
+	if err != nil {
+		return err
+	}
+
+	if actual.Compare(*wanted) < 0 {
+		return fmt.Errorf("docker version is too old. Required: %s Found: %s", expected, info.ServerVersion)
+	}
+
+	return nil
 }
 
 func registryFromEnv() map[string]docker.AuthConfiguration {

api/agent/drivers/docker/docker_client.go

@@ -38,6 +38,7 @@ type dockerClient interface {
 	InspectImage(ctx context.Context, name string) (*docker.Image, error)
 	InspectContainerWithContext(container string, ctx context.Context) (*docker.Container, error)
 	Stats(opts docker.StatsOptions) error
+	Info(ctx context.Context) (*docker.DockerInfo, error)
 }
 
 // TODO: switch to github.com/docker/engine-api
@@ -169,6 +170,19 @@ func filterNoSuchContainer(ctx context.Context, err error) error {
 	return err
 }
 
+func (d *dockerWrap) Info(ctx context.Context) (info *docker.DockerInfo, err error) {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "docker_server_version")
+	defer span.Finish()
+
+	ctx, cancel := context.WithTimeout(ctx, retryTimeout)
+	defer cancel()
+	err = d.retry(ctx, func() error {
+		info, err = d.docker.Info()
+		return err
+	})
+	return info, err
+}
+
 func (d *dockerWrap) AttachToContainerNonBlocking(ctx context.Context, opts docker.AttachToContainerOptions) (w docker.CloseWaiter, err error) {
 	span, ctx := opentracing.StartSpanFromContext(ctx, "docker_attach_container")
 	defer span.Finish()

api/agent/drivers/docker/docker_test.go

@@ -63,6 +63,26 @@ func TestRunnerDocker(t *testing.T) {
 	}
 }
 
+func TestRunnerDockerVersion(t *testing.T) {
+
+	dkr := NewDocker(drivers.Config{
+		ServerVersion: "0.0.0",
+	})
+	if dkr == nil {
+		t.Fatal("should not be nil")
+	}
+
+	err := checkDockerVersion(dkr, "1.0.0")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = checkDockerVersion(dkr, "9999.0.0")
+	if err == nil {
+		t.Fatal("should have failed")
+	}
+}
+
 func TestRunnerDockerStdin(t *testing.T) {
 	dkr := NewDocker(drivers.Config{})
 	ctx := context.Background()