Skip log path tests when they are expected to fail.

The log path test is not expected to pass unless the Docker is using the
JSON logging driver, since that's what the log path is trying to find.
When Docker is using the journald logging driver, there will be no JSON
files in the logging directories for it to find.

Furthermore, when SELinux support is enabled in the Docker daemon,
SELinux will prevent processes running inside Docker containers from
accessing the log files owned by Docker (which is what this test is
trying to accomplish), so let's also skip this test in case SELinux
support is enabled.

Tested:

- With Docker daemon started using --log-driver=journald:

    S [SKIPPING] in Spec Setup (BeforeEach) [8.193 seconds]
    [k8s.io] ContainerLogPath
      Pod with a container
        printed log to stdout
          should print log to correct log path [BeforeEach]
          Jan  3 18:33:44.869: Skipping because Docker daemon is using a logging driver other than "json-file": journald

- With Docker daemon started using --selinux-enabled:

    S [SKIPPING] in Spec Setup (BeforeEach) [8.488 seconds]
    [k8s.io] ContainerLogPath
      Pod with a container
        printed log to stdout
          should print log to correct log path [BeforeEach]
          Jan  3 18:35:58.909: Skipping because Docker daemon is running with SELinux support enabled

- With Docker started using JSON logging driver and with SELinux disabled:

    • [SLOW TEST:16.352 seconds]  (passed)
    [k8s.io] ContainerLogPath
      Pod with a container
        printed log to stdout
          should print log to correct log path
    Ran 1 of 256 Specs in 36.428 seconds
    SUCCESS! -- 1 Passed | 0 Failed | 0 Pending | 255 Skipped

test/e2e_node/docker_util.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/blang/semver"
 	systemdutil "github.com/coreos/go-systemd/util"
+	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/client"
 )
 
@@ -73,20 +74,54 @@ func isDockerLiveRestoreSupported() (bool, error) {
 	return version.GTE(semver.MustParse("1.26.0")), nil
 }
 
+// getDockerInfo returns the Info struct for the running Docker daemon.
+func getDockerInfo() (types.Info, error) {
+	var info types.Info
+	c, err := client.NewClient(defaultDockerEndpoint, "", nil, nil)
+	if err != nil {
+		return info, fmt.Errorf("failed to create docker client: %v", err)
+	}
+	info, err = c.Info(context.Background())
+	if err != nil {
+		return info, fmt.Errorf("failed to get docker info: %v", err)
+	}
+	return info, nil
+}
+
 // isDockerLiveRestoreEnabled returns true if live-restore is enabled in the
 // Docker.
 func isDockerLiveRestoreEnabled() (bool, error) {
-	c, err := client.NewClient(defaultDockerEndpoint, "", nil, nil)
+	info, err := getDockerInfo()
 	if err != nil {
-		return false, fmt.Errorf("failed to create docker client: %v", err)
-	}
-	info, err := c.Info(context.Background())
-	if err != nil {
-		return false, fmt.Errorf("failed to get docker info: %v", err)
+		return false, err
 	}
 	return info.LiveRestoreEnabled, nil
 }
 
+// getDockerLoggingDriver returns the name of the logging driver.
+func getDockerLoggingDriver() (string, error) {
+	info, err := getDockerInfo()
+	if err != nil {
+		return "", err
+	}
+	return info.LoggingDriver, nil
+}
+
+// isDockerSELinuxSupportEnabled checks whether the Docker daemon was started
+// with SELinux support enabled.
+func isDockerSELinuxSupportEnabled() (bool, error) {
+	info, err := getDockerInfo()
+	if err != nil {
+		return false, err
+	}
+	for _, s := range info.SecurityOptions {
+		if s == "selinux" {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
 // startDockerDaemon starts the Docker daemon.
 func startDockerDaemon() error {
 	switch {