tests/docker.userns: Set SELinux to permissive mode

A docker bug causes the docker daemon to fail in creating a container
when the '--userns-remap' option is used and SELinux is enforcing.
Set SELinux to permisive mode so this test can run.
See: opencontainers/runc#1562 (nsenter:
improve namespace creation and SELinux IPC handling).

Fixes runtime errors like these:

  OCI runtime create failed: running exec setns process for init caused exit

Signed-off-by: Geoff Levand <[email protected]>

kola/tests/docker/docker.go

@@ -381,7 +381,13 @@ func dockerUserns(c cluster.TestCluster) {
 
 	genDockerContainer(c, m, "userns-test", []string{"echo", "sleep"})
 
-	c.MustSSH(m, `sudo setenforce 1`)
+	// A docker bug causes the docker daemon to fail in creating a container
+	// when the '--userns-remap' option is used and SELinux is enforcing.
+	// Set SELinux to permisive mode so this test can run.
+	// See: https://github.com/opencontainers/runc/pull/1562 (nsenter:
+	// improve namespace creation and SELinux IPC handling).
+	c.MustSSH(m, "sudo setenforce 0")
+
 	output := c.MustSSH(m, `docker run userns-test echo fj.fj`)
 	if !bytes.Equal(output, []byte("fj.fj")) {
 		c.Fatalf("expected fj.fj, got %s", string(output))