Add a WithPrivileged OCI constructor and the options needed to build it

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

oci/spec_opts.go

@@ -27,6 +27,18 @@ import (
 // SpecOpts sets spec specific information to a newly generated OCI spec
 type SpecOpts func(context.Context, Client, *containers.Container, *specs.Spec) error
 
+// Compose converts a sequence of spec operations into a single operation
+func Compose(opts ...SpecOpts) SpecOpts {
+	return func(ctx context.Context, client Client, c *containers.Container, s *specs.Spec) error {
+		for _, o := range opts {
+			if err := o(ctx, client, c, s); err != nil {
+				return err
+			}
+		}
+		return nil
+	}
+}
+
 // setProcess sets Process to empty if unset
 func setProcess(s *specs.Spec) {
 	if s.Process == nil {

oci/spec_opts_unix.go

@@ -443,20 +443,23 @@ func WithUsername(username string) SpecOpts {
 	}
 }
 
-// WithAllCapabilities set all linux capabilities for the process
-func WithAllCapabilities(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
+// WithCapabilities sets Linux capabilities on the process
+func WithCapabilities(caps []string) SpecOpts {
+	return func(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
 		setCapabilities(s)
 
-	caps := getAllCapabilities()
-
 		s.Process.Capabilities.Bounding = caps
 		s.Process.Capabilities.Effective = caps
 		s.Process.Capabilities.Permitted = caps
 		s.Process.Capabilities.Inheritable = caps
 
 		return nil
+	}
 }
 
+// WithAllCapabilities sets all linux capabilities for the process
+var WithAllCapabilities = WithCapabilities(getAllCapabilities())
+
 func getAllCapabilities() []string {
 	last := capability.CAP_LAST_CAP
 	// hack for RHEL6 which has no /proc/sys/kernel/cap_last_cap
@@ -512,3 +515,93 @@ func getGIDFromPath(root string, filter func(user.Group) bool) (gid uint32, err
 func isRootfsAbs(root string) bool {
 	return filepath.IsAbs(root)
 }
+
+// WithMaskedPaths sets the masked paths option
+func WithMaskedPaths(paths []string) SpecOpts {
+	return func(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
+		setLinux(s)
+		s.Linux.MaskedPaths = paths
+		return nil
+	}
+}
+
+// WithReadonlyPaths sets the read only paths option
+func WithReadonlyPaths(paths []string) SpecOpts {
+	return func(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
+		setLinux(s)
+		s.Linux.ReadonlyPaths = paths
+		return nil
+	}
+}
+
+// WithWriteableSysfs makes any sysfs mounts writeable
+func WithWriteableSysfs(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
+	for i, m := range s.Mounts {
+		if m.Type == "sysfs" {
+			var options []string
+			for _, o := range m.Options {
+				if o == "ro" {
+					o = "rw"
+				}
+				options = append(options, o)
+			}
+			s.Mounts[i].Options = options
+		}
+	}
+	return nil
+}
+
+// WithWriteableCgroupfs makes any cgroup mounts writeable
+func WithWriteableCgroupfs(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
+	for i, m := range s.Mounts {
+		if m.Type == "cgroup" {
+			var options []string
+			for _, o := range m.Options {
+				if o == "ro" {
+					o = "rw"
+				}
+				options = append(options, o)
+			}
+			s.Mounts[i].Options = options
+		}
+	}
+	return nil
+}
+
+// WithSelinuxLabel sets the process SELinux label
+func WithSelinuxLabel(label string) SpecOpts {
+	return func(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
+		setProcess(s)
+		s.Process.SelinuxLabel = label
+		return nil
+	}
+}
+
+// WithApparmorProfile sets the Apparmor profile for the process
+func WithApparmorProfile(profile string) SpecOpts {
+	return func(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
+		setProcess(s)
+		s.Process.ApparmorProfile = profile
+		return nil
+	}
+}
+
+// WithSeccompUnconfined clears the seccomp profile
+func WithSeccompUnconfined(_ context.Context, _ Client, _ *containers.Container, s *specs.Spec) error {
+	setLinux(s)
+	s.Linux.Seccomp = nil
+	return nil
+}
+
+// WithPrivileged sets up options for a privileged container
+// TODO(justincormack) device handling
+var WithPrivileged = Compose(
+	WithAllCapabilities,
+	WithMaskedPaths(nil),
+	WithReadonlyPaths(nil),
+	WithWriteableSysfs,
+	WithWriteableCgroupfs,
+	WithSelinuxLabel(""),
+	WithApparmorProfile(""),
+	WithSeccompUnconfined,
+)

oci/spec_unix_test.go

@@ -108,3 +108,116 @@ func TestWithLinuxNamespace(t *testing.T) {
 		}
 	}
 }
+
+func TestWithCapabilities(t *testing.T) {
+	t.Parallel()
+
+	ctx := namespaces.WithNamespace(context.Background(), "testing")
+
+	s, err := GenerateSpec(ctx, nil, &containers.Container{ID: t.Name()},
+		WithCapabilities([]string{"CAP_SYS_ADMIN"}),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(s.Process.Capabilities.Bounding) != 1 || s.Process.Capabilities.Bounding[0] != "CAP_SYS_ADMIN" {
+		t.Error("Unexpected capabilities set")
+	}
+	if len(s.Process.Capabilities.Effective) != 1 || s.Process.Capabilities.Effective[0] != "CAP_SYS_ADMIN" {
+		t.Error("Unexpected capabilities set")
+	}
+	if len(s.Process.Capabilities.Permitted) != 1 || s.Process.Capabilities.Permitted[0] != "CAP_SYS_ADMIN" {
+		t.Error("Unexpected capabilities set")
+	}
+	if len(s.Process.Capabilities.Inheritable) != 1 || s.Process.Capabilities.Inheritable[0] != "CAP_SYS_ADMIN" {
+		t.Error("Unexpected capabilities set")
+	}
+}
+
+func TestWithCapabilitiesNil(t *testing.T) {
+	t.Parallel()
+
+	ctx := namespaces.WithNamespace(context.Background(), "testing")
+
+	s, err := GenerateSpec(ctx, nil, &containers.Container{ID: t.Name()},
+		WithCapabilities(nil),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(s.Process.Capabilities.Bounding) != 0 {
+		t.Errorf("Unexpected capabilities set: length is non zero (%d)", len(s.Process.Capabilities.Bounding))
+	}
+	if len(s.Process.Capabilities.Effective) != 0 {
+		t.Errorf("Unexpected capabilities set: length is non zero (%d)", len(s.Process.Capabilities.Effective))
+	}
+	if len(s.Process.Capabilities.Permitted) != 0 {
+		t.Errorf("Unexpected capabilities set: length is non zero (%d)", len(s.Process.Capabilities.Permitted))
+	}
+	if len(s.Process.Capabilities.Inheritable) != 0 {
+		t.Errorf("Unexpected capabilities set: length is non zero (%d)", len(s.Process.Capabilities.Inheritable))
+	}
+}
+
+func TestWithPrivileged(t *testing.T) {
+	t.Parallel()
+
+	ctx := namespaces.WithNamespace(context.Background(), "testing")
+
+	s, err := GenerateSpec(ctx, nil, &containers.Container{ID: t.Name()},
+		WithCapabilities(nil),
+		WithMounts([]specs.Mount{
+			{Type: "cgroup", Destination: "/sys/fs/cgroup", Options: []string{"ro"}},
+		}),
+		WithPrivileged,
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if len(s.Process.Capabilities.Bounding) == 0 {
+		t.Error("Expected capabilities to be set with privileged")
+	}
+
+	var foundSys, foundCgroup bool
+	for _, m := range s.Mounts {
+		switch m.Type {
+		case "sysfs":
+			foundSys = true
+			var found bool
+			for _, o := range m.Options {
+				switch o {
+				case "ro":
+					t.Errorf("Found unexpected read only %s mount", m.Type)
+				case "rw":
+					found = true
+				}
+			}
+			if !found {
+				t.Errorf("Did not find rw mount option for %s", m.Type)
+			}
+		case "cgroup":
+			foundCgroup = true
+			var found bool
+			for _, o := range m.Options {
+				switch o {
+				case "ro":
+					t.Errorf("Found unexpected read only %s mount", m.Type)
+				case "rw":
+					found = true
+				}
+			}
+			if !found {
+				t.Errorf("Did not find rw mount option for %s", m.Type)
+			}
+		}
+	}
+	if !foundSys {
+		t.Error("Did not find mount for sysfs")
+	}
+	if !foundCgroup {
+		t.Error("Did not find mount for cgroupfs")
+	}
+}