oci: abstract out cgroup calls per platform

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

oci: abstract out syscall for platforms

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

oci: abstract out the unix pipe per platform

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

oci: change the unix calls to be platform independent

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

oci/oci_linux.go

@@ -0,0 +1,47 @@
+// +build linux
+
+package oci
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"syscall"
+
+	"github.com/containerd/cgroups"
+	rspec "github.com/opencontainers/runtime-spec/specs-go"
+	"golang.org/x/sys/unix"
+)
+
+func createContainerPlatform(c *Container, cgroupParent string, pid int) error {
+	control, err := cgroups.New(cgroups.V1, cgroups.StaticPath(filepath.Join(cgroupParent, "/crio-conmon-"+c.id)), &rspec.LinuxResources{})
+	if err != nil {
+		return fmt.Errorf("Failed to add conmon to cgroupfs sandbox cgroup: %v", err)
+	} else {
+		// Here we should defer a crio-connmon- cgroup hierarchy deletion, but it will
+		// always fail as conmon's pid is still there.
+		// Fortunately, kubelet takes care of deleting this for us, so the leak will
+		// only happens in corner case where one does a manual deletion of the container
+		// through e.g. runc. This should be handled by implementing a conmon monitoring
+		// routine that does the cgroup cleanup once conmon is terminated.
+		if err := control.Add(cgroups.Process{Pid: pid}); err != nil {
+			fmt.Errorf("Failed to add conmon to cgroupfs sandbox cgroup: %v", err)
+		}
+	}
+	return nil
+}
+
+func sysProcAttrPlatform() *syscall.SysProcAttr {
+	return &syscall.SysProcAttr{
+		Setpgid: true,
+	}
+}
+
+// newPipe creates a unix socket pair for communication
+func newPipe() (parent *os.File, child *os.File, err error) {
+	fds, err := unix.Socketpair(unix.AF_LOCAL, unix.SOCK_STREAM|unix.SOCK_CLOEXEC, 0)
+	if err != nil {
+		return nil, nil, err
+	}
+	return os.NewFile(uintptr(fds[1]), "parent"), os.NewFile(uintptr(fds[0]), "child"), nil
+}