Validate --cpuset-cpus, --cpuset-mems

Before this patch libcontainer badly errored out with `invalid
argument` or `numerical result out of range` while trying to write
to cpuset.cpus or cpuset.mems with an invalid value provided.
This patch adds validation to --cpuset-cpus and --cpuset-mems flag along with
validation based on system's available cpus/mems before starting a container.

Signed-off-by: Antonio Murdaca <runcom@linux.com>

daemon/daemon_unix.go

@@ -15,6 +15,7 @@ import (
 	"github.com/docker/docker/autogen/dockerversion"
 	"github.com/docker/docker/context"
 	"github.com/docker/docker/daemon/graphdriver"
+	derr "github.com/docker/docker/errors"
 	"github.com/docker/docker/pkg/fileutils"
 	"github.com/docker/docker/pkg/parsers"
 	"github.com/docker/docker/pkg/parsers/kernel"
@@ -197,6 +198,20 @@ func verifyPlatformContainerSettings(ctx context.Context, daemon *Daemon, hostCo
 		hostConfig.CpusetCpus = ""
 		hostConfig.CpusetMems = ""
 	}
+	cpusAvailable, err := sysInfo.IsCpusetCpusAvailable(hostConfig.CpusetCpus)
+	if err != nil {
+		return warnings, derr.ErrorCodeInvalidCpusetCpus.WithArgs(hostConfig.CpusetCpus)
+	}
+	if !cpusAvailable {
+		return warnings, derr.ErrorCodeNotAvailableCpusetCpus.WithArgs(hostConfig.CpusetCpus, sysInfo.Cpus)
+	}
+	memsAvailable, err := sysInfo.IsCpusetMemsAvailable(hostConfig.CpusetMems)
+	if err != nil {
+		return warnings, derr.ErrorCodeInvalidCpusetMems.WithArgs(hostConfig.CpusetMems)
+	}
+	if !memsAvailable {
+		return warnings, derr.ErrorCodeNotAvailableCpusetMems.WithArgs(hostConfig.CpusetMems, sysInfo.Mems)
+	}
 	if hostConfig.BlkioWeight > 0 && !sysInfo.BlkioWeight {
 		warnings = append(warnings, "Your kernel does not support Block I/O weight. Weight discarded.")
 		logrus.Warnf("Your kernel does not support Block I/O weight. Weight discarded.")
@@ -237,10 +252,7 @@ func checkSystem() error {
 	if os.Geteuid() != 0 {
 		return fmt.Errorf("The Docker daemon needs to be run as root")
 	}
-	if err := checkKernel(); err != nil {
-		return err
-	}
-	return nil
+	return checkKernel()
 }
 
 // configureKernelSecuritySupport configures and validate security support for the kernel

errors/daemon.go

@@ -827,4 +827,40 @@ var (
 		Description:    "While trying to delete a container, there was an error trying to delete one of its volumes",
 		HTTPStatusCode: http.StatusInternalServerError,
 	})
+
+	// ErrorCodeInvalidCpusetCpus is generated when user provided cpuset CPUs
+	// are invalid.
+	ErrorCodeInvalidCpusetCpus = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:          "INVALIDCPUSETCPUS",
+		Message:        "Invalid value %s for cpuset cpus.",
+		Description:    "While verifying the container's 'HostConfig', CpusetCpus value was in an incorrect format",
+		HTTPStatusCode: http.StatusInternalServerError,
+	})
+
+	// ErrorCodeInvalidCpusetMems is generated when user provided cpuset mems
+	// are invalid.
+	ErrorCodeInvalidCpusetMems = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:          "INVALIDCPUSETMEMS",
+		Message:        "Invalid value %s for cpuset mems.",
+		Description:    "While verifying the container's 'HostConfig', CpusetMems value was in an incorrect format",
+		HTTPStatusCode: http.StatusInternalServerError,
+	})
+
+	// ErrorCodeNotAvailableCpusetCpus is generated when user provided cpuset
+	// CPUs aren't available in the container's cgroup.
+	ErrorCodeNotAvailableCpusetCpus = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:          "NOTAVAILABLECPUSETCPUS",
+		Message:        "Requested CPUs are not available - requested %s, available: %s.",
+		Description:    "While verifying the container's 'HostConfig', cpuset CPUs provided aren't available in the container's cgroup available set",
+		HTTPStatusCode: http.StatusInternalServerError,
+	})
+
+	// ErrorCodeNotAvailableCpusetMems is generated when user provided cpuset
+	// memory nodes aren't available in the container's cgroup.
+	ErrorCodeNotAvailableCpusetMems = errcode.Register(errGroup, errcode.ErrorDescriptor{
+		Value:          "NOTAVAILABLECPUSETMEMS",
+		Message:        "Requested memory nodes are not available - requested %s, available: %s.",
+		Description:    "While verifying the container's 'HostConfig', cpuset memory nodes provided aren't available in the container's cgroup available set",
+		HTTPStatusCode: http.StatusInternalServerError,
+	})
 )

integration-cli/docker_api_containers_test.go

@@ -1525,3 +1525,29 @@ func (s *DockerSuite) TestContainersApiGetContainersJSONEmpty(c *check.C) {
 		c.Fatalf("Expected empty response to be `[]`, got %q", string(body))
 	}
 }
+
+func (s *DockerSuite) TestPostContainersCreateWithWrongCpusetValues(c *check.C) {
+	testRequires(c, DaemonIsLinux)
+
+	c1 := struct {
+		Image      string
+		CpusetCpus string
+	}{"busybox", "1-42,,"}
+	name := "wrong-cpuset-cpus"
+	status, body, err := sockRequest("POST", "/containers/create?name="+name, c1)
+	c.Assert(err, check.IsNil)
+	c.Assert(status, check.Equals, http.StatusInternalServerError)
+	expected := "Invalid value 1-42,, for cpuset cpus.\n"
+	c.Assert(string(body), check.Equals, expected, check.Commentf("Expected output to contain %q, got %q", expected, string(body)))
+
+	c2 := struct {
+		Image      string
+		CpusetMems string
+	}{"busybox", "42-3,1--"}
+	name = "wrong-cpuset-mems"
+	status, body, err = sockRequest("POST", "/containers/create?name="+name, c2)
+	c.Assert(err, check.IsNil)
+	c.Assert(status, check.Equals, http.StatusInternalServerError)
+	expected = "Invalid value 42-3,1-- for cpuset mems.\n"
+	c.Assert(string(body), check.Equals, expected, check.Commentf("Expected output to contain %q, got %q", expected, string(body)))
+}

integration-cli/docker_cli_run_test.go

@@ -3407,3 +3407,17 @@ func (s *DockerSuite) TestRunStdinBlockedAfterContainerExit(c *check.C) {
 		c.Fatal("timeout waiting for command to exit")
 	}
 }
+
+func (s *DockerSuite) TestRunWrongCpusetCpusFlagValue(c *check.C) {
+	out, _, err := dockerCmdWithError("run", "--cpuset-cpus", "1-10,11--", "busybox", "true")
+	c.Assert(err, check.NotNil)
+	expected := "Error response from daemon: Invalid value 1-10,11-- for cpuset cpus.\n"
+	c.Assert(out, check.Equals, expected, check.Commentf("Expected output to contain %q, got %q", expected, out))
+}
+
+func (s *DockerSuite) TestRunWrongCpusetMemsFlagValue(c *check.C) {
+	out, _, err := dockerCmdWithError("run", "--cpuset-mems", "1-42--", "busybox", "true")
+	c.Assert(err, check.NotNil)
+	expected := "Error response from daemon: Invalid value 1-42-- for cpuset mems.\n"
+	c.Assert(out, check.Equals, expected, check.Commentf("Expected output to contain %q, got %q", expected, out))
+}

integration-cli/docker_cli_run_unix_test.go

@@ -9,11 +9,14 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"strconv"
 	"strings"
 	"time"
 
 	"github.com/docker/docker/pkg/integration/checker"
 	"github.com/docker/docker/pkg/mount"
+	"github.com/docker/docker/pkg/parsers"
+	"github.com/docker/docker/pkg/sysinfo"
 	"github.com/go-check/check"
 	"github.com/kr/pty"
 )
@@ -370,3 +373,41 @@ func (s *DockerSuite) TestRunSwapLessThanMemoryLimit(c *check.C) {
 		c.Fatalf("Expected output to contain %q, not %q", out, expected)
 	}
 }
+
+func (s *DockerSuite) TestRunInvalidCpusetCpusFlagValue(c *check.C) {
+	testRequires(c, cgroupCpuset)
+
+	sysInfo := sysinfo.New(true)
+	cpus, err := parsers.ParseUintList(sysInfo.Cpus)
+	c.Assert(err, check.IsNil)
+	var invalid int
+	for i := 0; i <= len(cpus)+1; i++ {
+		if !cpus[i] {
+			invalid = i
+			break
+		}
+	}
+	out, _, err := dockerCmdWithError("run", "--cpuset-cpus", strconv.Itoa(invalid), "busybox", "true")
+	c.Assert(err, check.NotNil)
+	expected := fmt.Sprintf("Error response from daemon: Requested CPUs are not available - requested %s, available: %s.\n", strconv.Itoa(invalid), sysInfo.Cpus)
+	c.Assert(out, check.Equals, expected, check.Commentf("Expected output to contain %q, got %q", expected, out))
+}
+
+func (s *DockerSuite) TestRunInvalidCpusetMemsFlagValue(c *check.C) {
+	testRequires(c, cgroupCpuset)
+
+	sysInfo := sysinfo.New(true)
+	mems, err := parsers.ParseUintList(sysInfo.Mems)
+	c.Assert(err, check.IsNil)
+	var invalid int
+	for i := 0; i <= len(mems)+1; i++ {
+		if !mems[i] {
+			invalid = i
+			break
+		}
+	}
+	out, _, err := dockerCmdWithError("run", "--cpuset-mems", strconv.Itoa(invalid), "busybox", "true")
+	c.Assert(err, check.NotNil)
+	expected := fmt.Sprintf("Error response from daemon: Requested memory nodes are not available - requested %s, available: %s.\n", strconv.Itoa(invalid), sysInfo.Mems)
+	c.Assert(out, check.Equals, expected, check.Commentf("Expected output to contain %q, got %q", expected, out))
+}

pkg/parsers/parsers.go

@@ -127,7 +127,7 @@ func PartParser(template, data string) (map[string]string, error) {
 		out           = make(map[string]string, len(templateParts))
 	)
 	if len(parts) != len(templateParts) {
-		return nil, fmt.Errorf("Invalid format to parse.  %s should match template %s", data, template)
+		return nil, fmt.Errorf("Invalid format to parse. %s should match template %s", data, template)
 	}
 
 	for i, t := range templateParts {
@@ -196,3 +196,53 @@ func ParseLink(val string) (string, string, error) {
 	}
 	return arr[0], arr[1], nil
 }
+
+// ParseUintList parses and validates the specified string as the value
+// found in some cgroup file (e.g. `cpuset.cpus`, `cpuset.mems`), which could be
+// one of the formats below. Note that duplicates are actually allowed in the
+// input string. It returns a `map[int]bool` with available elements from `val`
+// set to `true`.
+// Supported formats:
+//     7
+//     1-6
+//     0,3-4,7,8-10
+//     0-0,0,1-7
+//     03,1-3      <- this is gonna get parsed as [1,2,3]
+//     3,2,1
+//     0-2,3,1
+func ParseUintList(val string) (map[int]bool, error) {
+	if val == "" {
+		return map[int]bool{}, nil
+	}
+
+	availableInts := make(map[int]bool)
+	split := strings.Split(val, ",")
+	errInvalidFormat := fmt.Errorf("invalid format: %s", val)
+
+	for _, r := range split {
+		if !strings.Contains(r, "-") {
+			v, err := strconv.Atoi(r)
+			if err != nil {
+				return nil, errInvalidFormat
+			}
+			availableInts[v] = true
+		} else {
+			split := strings.SplitN(r, "-", 2)
+			min, err := strconv.Atoi(split[0])
+			if err != nil {
+				return nil, errInvalidFormat
+			}
+			max, err := strconv.Atoi(split[1])
+			if err != nil {
+				return nil, errInvalidFormat
+			}
+			if max < min {
+				return nil, errInvalidFormat
+			}
+			for i := min; i <= max; i++ {
+				availableInts[i] = true
+			}
+		}
+	}
+	return availableInts, nil
+}

pkg/parsers/parsers_test.go

@@ -1,6 +1,7 @@
 package parsers
 
 import (
+	"reflect"
 	"runtime"
 	"strings"
 	"testing"
@@ -238,3 +239,40 @@ func TestParseLink(t *testing.T) {
 		t.Fatalf("Expected error 'bad format for links: link:alias:wrong' but got: %v", err)
 	}
 }
+
+func TestParseUintList(t *testing.T) {
+	valids := map[string]map[int]bool{
+		"":             {},
+		"7":            {7: true},
+		"1-6":          {1: true, 2: true, 3: true, 4: true, 5: true, 6: true},
+		"0-7":          {0: true, 1: true, 2: true, 3: true, 4: true, 5: true, 6: true, 7: true},
+		"0,3-4,7,8-10": {0: true, 3: true, 4: true, 7: true, 8: true, 9: true, 10: true},
+		"0-0,0,1-4":    {0: true, 1: true, 2: true, 3: true, 4: true},
+		"03,1-3":       {1: true, 2: true, 3: true},
+		"3,2,1":        {1: true, 2: true, 3: true},
+		"0-2,3,1":      {0: true, 1: true, 2: true, 3: true},
+	}
+	for k, v := range valids {
+		out, err := ParseUintList(k)
+		if err != nil {
+			t.Fatalf("Expected not to fail, got %v", err)
+		}
+		if !reflect.DeepEqual(out, v) {
+			t.Fatalf("Expected %v, got %v", v, out)
+		}
+	}
+
+	invalids := []string{
+		"this",
+		"1--",
+		"1-10,,10",
+		"10-1",
+		"-1",
+		"-1,0",
+	}
+	for _, v := range invalids {
+		if out, err := ParseUintList(v); err == nil {
+			t.Fatalf("Expected failure with %s but got %v", v, out)
+		}
+	}
+}

pkg/sysinfo/sysinfo.go

@@ -1,5 +1,7 @@
 package sysinfo
 
+import "github.com/docker/docker/pkg/parsers"
+
 // SysInfo stores information about which features a kernel supports.
 // TODO Windows: Factor out platform specific capabilities.
 type SysInfo struct {
@@ -63,4 +65,41 @@ type cgroupBlkioInfo struct {
 type cgroupCpusetInfo struct {
 	// Whether Cpuset is supported or not
 	Cpuset bool
+
+	// Available Cpuset's cpus
+	Cpus string
+
+	// Available Cpuset's memory nodes
+	Mems string
+}
+
+// IsCpusetCpusAvailable returns `true` if the provided string set is contained
+// in cgroup's cpuset.cpus set, `false` otherwise.
+// If error is not nil a parsing error occurred.
+func (c cgroupCpusetInfo) IsCpusetCpusAvailable(provided string) (bool, error) {
+	return isCpusetListAvailable(provided, c.Cpus)
+}
+
+// IsCpusetMemsAvailable returns `true` if the provided string set is contained
+// in cgroup's cpuset.mems set, `false` otherwise.
+// If error is not nil a parsing error occurred.
+func (c cgroupCpusetInfo) IsCpusetMemsAvailable(provided string) (bool, error) {
+	return isCpusetListAvailable(provided, c.Mems)
+}
+
+func isCpusetListAvailable(provided, available string) (bool, error) {
+	parsedProvided, err := parsers.ParseUintList(provided)
+	if err != nil {
+		return false, err
+	}
+	parsedAvailable, err := parsers.ParseUintList(available)
+	if err != nil {
+		return false, err
+	}
+	for k := range parsedProvided {
+		if !parsedAvailable[k] {
+			return false, nil
+		}
+	}
+	return true, nil
 }

pkg/sysinfo/sysinfo_linux.go

@@ -126,7 +126,7 @@ func checkCgroupBlkioInfo(quiet bool) cgroupBlkioInfo {
 
 // checkCgroupCpusetInfo reads the cpuset information from the cpuset cgroup mount point.
 func checkCgroupCpusetInfo(quiet bool) cgroupCpusetInfo {
-	_, err := cgroups.FindCgroupMountpoint("cpuset")
+	mountPoint, err := cgroups.FindCgroupMountpoint("cpuset")
 	if err != nil {
 		if !quiet {
 			logrus.Warn(err)
@@ -134,7 +134,21 @@ func checkCgroupCpusetInfo(quiet bool) cgroupCpusetInfo {
 		return cgroupCpusetInfo{}
 	}
 
-	return cgroupCpusetInfo{Cpuset: true}
+	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)),
+	}
 }
 
 func cgroupEnabled(mountPoint, name string) bool {

pkg/sysinfo/sysinfo_test.go

@@ -0,0 +1,26 @@
+package sysinfo
+
+import "testing"
+
+func TestIsCpusetListAvailable(t *testing.T) {
+	cases := []struct {
+		provided  string
+		available string
+		res       bool
+		err       bool
+	}{
+		{"1", "0-4", true, false},
+		{"01,3", "0-4", true, false},
+		{"", "0-7", true, false},
+		{"1--42", "0-7", false, true},
+		{"1-42", "00-1,8,,9", false, true},
+		{"1,41-42", "43,45", false, false},
+		{"0-3", "", false, false},
+	}
+	for _, c := range cases {
+		r, err := isCpusetListAvailable(c.provided, c.available)
+		if (c.err && err == nil) && r != c.res {
+			t.Fatalf("Expected pair: %v, %v for %s, %s. Got %v, %v instead", c.res, c.err, c.provided, c.available, (c.err && err == nil), r)
+		}
+	}
+}