1 files changed, 254 insertions, 0 deletions
diff --git a/pkg/sysinfo/sysinfo_linux.go b/pkg/sysinfo/sysinfo_linux.go
new file mode 100644
index 000000000..f4047b63c
--- /dev/null
+++ b/pkg/sysinfo/sysinfo_linux.go
@@ -0,0 +1,254 @@
+package sysinfo
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path"
+	"strings"
+
+	"github.com/opencontainers/runc/libcontainer/cgroups"
+	"github.com/sirupsen/logrus"
+	"golang.org/x/sys/unix"
+)
+
+func findCgroupMountpoints() (map[string]string, error) {
+	cgMounts, err := cgroups.GetCgroupMounts(false)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to parse cgroup information: %v", err)
+	}
+	mps := make(map[string]string)
+	for _, m := range cgMounts {
+		for _, ss := range m.Subsystems {
+			mps[ss] = m.Mountpoint
+		}
+	}
+	return mps, nil
+}
+
+// New returns a new SysInfo, using the filesystem to detect which features
+// the kernel supports. If `quiet` is `false` warnings are printed in logs
+// whenever an error occurs or misconfigurations are present.
+func New(quiet bool) *SysInfo {
+	sysInfo := &SysInfo{}
+	cgMounts, err := findCgroupMountpoints()
+	if err != nil {
+		logrus.Warnf("Failed to parse cgroup information: %v", err)
+	} else {
+		sysInfo.cgroupMemInfo = checkCgroupMem(cgMounts, quiet)
+		sysInfo.cgroupCPUInfo = checkCgroupCPU(cgMounts, quiet)
+		sysInfo.cgroupBlkioInfo = checkCgroupBlkioInfo(cgMounts, quiet)
+		sysInfo.cgroupCpusetInfo = checkCgroupCpusetInfo(cgMounts, quiet)
+		sysInfo.cgroupPids = checkCgroupPids(quiet)
+	}
+
+	_, ok := cgMounts["devices"]
+	sysInfo.CgroupDevicesEnabled = ok
+
+	sysInfo.IPv4ForwardingDisabled = !readProcBool("/proc/sys/net/ipv4/ip_forward")
+	sysInfo.BridgeNFCallIPTablesDisabled = !readProcBool("/proc/sys/net/bridge/bridge-nf-call-iptables")
+	sysInfo.BridgeNFCallIP6TablesDisabled = !readProcBool("/proc/sys/net/bridge/bridge-nf-call-ip6tables")
+
+	// Check if AppArmor is supported.
+	if _, err := os.Stat("/sys/kernel/security/apparmor"); !os.IsNotExist(err) {
+		sysInfo.AppArmor = true
+	}
+
+	// Check if Seccomp is supported, via CONFIG_SECCOMP.
+	if err := unix.Prctl(unix.PR_GET_SECCOMP, 0, 0, 0, 0); err != unix.EINVAL {
+		// Make sure the kernel has CONFIG_SECCOMP_FILTER.
+		if err := unix.Prctl(unix.PR_SET_SECCOMP, unix.SECCOMP_MODE_FILTER, 0, 0, 0); err != unix.EINVAL {
+			sysInfo.Seccomp = true
+		}
+	}
+
+	return sysInfo
+}
+
+// checkCgroupMem reads the memory information from the memory cgroup mount point.
+func checkCgroupMem(cgMounts map[string]string, quiet bool) cgroupMemInfo {
+	mountPoint, ok := cgMounts["memory"]
+	if !ok {
+		if !quiet {
+			logrus.Warn("Your kernel does not support cgroup memory limit")
+		}
+		return cgroupMemInfo{}
+	}
+
+	swapLimit := cgroupEnabled(mountPoint, "memory.memsw.limit_in_bytes")
+	if !quiet && !swapLimit {
+		logrus.Warn("Your kernel does not support swap memory limit")
+	}
+	memoryReservation := cgroupEnabled(mountPoint, "memory.soft_limit_in_bytes")
+	if !quiet && !memoryReservation {
+		logrus.Warn("Your kernel does not support memory reservation")
+	}
+	oomKillDisable := cgroupEnabled(mountPoint, "memory.oom_control")
+	if !quiet && !oomKillDisable {
+		logrus.Warn("Your kernel does not support oom control")
+	}
+	memorySwappiness := cgroupEnabled(mountPoint, "memory.swappiness")
+	if !quiet && !memorySwappiness {
+		logrus.Warn("Your kernel does not support memory swappiness")
+	}
+	kernelMemory := cgroupEnabled(mountPoint, "memory.kmem.limit_in_bytes")
+	if !quiet && !kernelMemory {
+		logrus.Warn("Your kernel does not support kernel memory limit")
+	}
+
+	return cgroupMemInfo{
+		MemoryLimit:       true,
+		SwapLimit:         swapLimit,
+		MemoryReservation: memoryReservation,
+		OomKillDisable:    oomKillDisable,
+		MemorySwappiness:  memorySwappiness,
+		KernelMemory:      kernelMemory,
+	}
+}
+
+// checkCgroupCPU reads the cpu information from the cpu cgroup mount point.
+func checkCgroupCPU(cgMounts map[string]string, quiet bool) cgroupCPUInfo {
+	mountPoint, ok := cgMounts["cpu"]
+	if !ok {
+		if !quiet {
+			logrus.Warn("Unable to find cpu cgroup in mounts")
+		}
+		return cgroupCPUInfo{}
+	}
+
+	cpuShares := cgroupEnabled(mountPoint, "cpu.shares")
+	if !quiet && !cpuShares {
+		logrus.Warn("Your kernel does not support cgroup cpu shares")
+	}
+
+	cpuCfsPeriod := cgroupEnabled(mountPoint, "cpu.cfs_period_us")
+	if !quiet && !cpuCfsPeriod {
+		logrus.Warn("Your kernel does not support cgroup cfs period")
+	}
+
+	cpuCfsQuota := cgroupEnabled(mountPoint, "cpu.cfs_quota_us")
+	if !quiet && !cpuCfsQuota {
+		logrus.Warn("Your kernel does not support cgroup cfs quotas")
+	}
+
+	cpuRealtimePeriod := cgroupEnabled(mountPoint, "cpu.rt_period_us")
+	if !quiet && !cpuRealtimePeriod {
+		logrus.Warn("Your kernel does not support cgroup rt period")
+	}
+
+	cpuRealtimeRuntime := cgroupEnabled(mountPoint, "cpu.rt_runtime_us")
+	if !quiet && !cpuRealtimeRuntime {
+		logrus.Warn("Your kernel does not support cgroup rt runtime")
+	}
+
+	return cgroupCPUInfo{
+		CPUShares:          cpuShares,
+		CPUCfsPeriod:       cpuCfsPeriod,
+		CPUCfsQuota:        cpuCfsQuota,
+		CPURealtimePeriod:  cpuRealtimePeriod,
+		CPURealtimeRuntime: cpuRealtimeRuntime,
+	}
+}
+
+// checkCgroupBlkioInfo reads the blkio information from the blkio cgroup mount point.
+func checkCgroupBlkioInfo(cgMounts map[string]string, quiet bool) cgroupBlkioInfo {
+	mountPoint, ok := cgMounts["blkio"]
+	if !ok {
+		if !quiet {
+			logrus.Warn("Unable to find blkio cgroup in mounts")
+		}
+		return cgroupBlkioInfo{}
+	}
+
+	weight := cgroupEnabled(mountPoint, "blkio.weight")
+	if !quiet && !weight {
+		logrus.Warn("Your kernel does not support cgroup blkio weight")
+	}
+
+	weightDevice := cgroupEnabled(mountPoint, "blkio.weight_device")
+	if !quiet && !weightDevice {
+		logrus.Warn("Your kernel does not support cgroup blkio weight_device")
+	}
+
+	readBpsDevice := cgroupEnabled(mountPoint, "blkio.throttle.read_bps_device")
+	if !quiet && !readBpsDevice {
+		logrus.Warn("Your kernel does not support cgroup blkio throttle.read_bps_device")
+	}
+
+	writeBpsDevice := cgroupEnabled(mountPoint, "blkio.throttle.write_bps_device")
+	if !quiet && !writeBpsDevice {
+		logrus.Warn("Your kernel does not support cgroup blkio throttle.write_bps_device")
+	}
+	readIOpsDevice := cgroupEnabled(mountPoint, "blkio.throttle.read_iops_device")
+	if !quiet && !readIOpsDevice {
+		logrus.Warn("Your kernel does not support cgroup blkio throttle.read_iops_device")
+	}
+
+	writeIOpsDevice := cgroupEnabled(mountPoint, "blkio.throttle.write_iops_device")
+	if !quiet && !writeIOpsDevice {
+		logrus.Warn("Your kernel does not support cgroup blkio throttle.write_iops_device")
+	}
+	return cgroupBlkioInfo{
+		BlkioWeight:          weight,
+		BlkioWeightDevice:    weightDevice,
+		BlkioReadBpsDevice:   readBpsDevice,
+		BlkioWriteBpsDevice:  writeBpsDevice,
+		BlkioReadIOpsDevice:  readIOpsDevice,
+		BlkioWriteIOpsDevice: writeIOpsDevice,
+	}
+}
+
+// checkCgroupCpusetInfo reads the cpuset information from the cpuset cgroup mount point.
+func checkCgroupCpusetInfo(cgMounts map[string]string, quiet bool) cgroupCpusetInfo {
+	mountPoint, ok := cgMounts["cpuset"]
+	if !ok {
+		if !quiet {
+			logrus.Warn("Unable to find cpuset cgroup in mounts")
+		}
+		return cgroupCpusetInfo{}
+	}
+
+	cpus, err := ioutil.ReadFile(path.Join(mountPoint, "cpuset.cpus"))
+	if err != nil {
+		return cgroupCpusetInfo{}
+	}
+
+	mems, err := ioutil.ReadFile(path.Join(mountPoint, "cpuset.mems"))
+	if err != nil {
+		return cgroupCpusetInfo{}
+	}
+
+	return cgroupCpusetInfo{
+		Cpuset: true,
+		Cpus:   strings.TrimSpace(string(cpus)),
+		Mems:   strings.TrimSpace(string(mems)),
+	}
+}
+
+// checkCgroupPids reads the pids information from the pids cgroup mount point.
+func checkCgroupPids(quiet bool) cgroupPids {
+	_, err := cgroups.FindCgroupMountpoint("", "pids")
+	if err != nil {
+		if !quiet {
+			logrus.Warn(err)
+		}
+		return cgroupPids{}
+	}
+
+	return cgroupPids{
+		PidsLimit: true,
+	}
+}
+
+func cgroupEnabled(mountPoint, name string) bool {
+	_, err := os.Stat(path.Join(mountPoint, name))
+	return err == nil
+}
+
+func readProcBool(path string) bool {
+	val, err := ioutil.ReadFile(path)
+	if err != nil {
+		return false
+	}
+	return strings.TrimSpace(string(val)) == "1"
+}