From fbd7b38b0419e21ecd22fe802ede5c0ee3f14a9a Mon Sep 17 00:00:00 2001
From: EduRam <eduardo.ramalho@gmail.com>
Date: Tue, 17 Jul 2018 18:47:23 -0400
Subject: [PATCH] Check user namespaces on Centos7

---
 src/syscall/exec_linux_test.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/syscall/exec_linux_test.go b/src/syscall/exec_linux_test.go
index 17df8f445e..f551e87736 100644
--- a/src/syscall/exec_linux_test.go
+++ b/src/syscall/exec_linux_test.go
@@ -84,6 +84,15 @@ func checkUserNS(t *testing.T) {
 			t.Skip("kernel doesn't support user namespaces")
 		}
 	}
+
+	// On Centos 7.5+, user namespaces are disabled if user.max_user_namespaces = 0
+	if _, err := os.Stat("/proc/sys/user/max_user_namespaces"); err == nil {
+		buf, errRead := ioutil.ReadFile("/proc/sys/user/max_user_namespaces")
+		if errRead == nil && buf[0] == '0' {
+			t.Skip("kernel doesn't support user namespaces")
+		}
+	}
+
 	// When running under the Go continuous build, skip tests for
 	// now when under Kubernetes. (where things are root but not quite)
 	// Both of these are our own environment variables.