Files
Akihiro Suda 06f789cf26 Disable rootless mode except RootlessCgMgr when executed as the root in userns
This PR decomposes `libcontainer/configs.Config.Rootless bool` into `RootlessEUID bool` and
`RootlessCgroups bool`, so as to make "runc-in-userns" to be more compatible with "rootful" runc.

`RootlessEUID` denotes that runc is being executed as a non-root user (euid != 0) in
the current user namespace. `RootlessEUID` is almost identical to the former `Rootless`
except cgroups stuff.

`RootlessCgroups` denotes that runc is unlikely to have the full access to cgroups.
`RootlessCgroups` is set to false if runc is executed as the root (euid == 0) in the initial namespace.
Otherwise `RootlessCgroups` is set to true.
(Hint: if `RootlessEUID` is true, `RootlessCgroups` becomes true as well)

When runc is executed as the root (euid == 0) in an user namespace (e.g. by Docker-in-LXD, Podman, Usernetes),
`RootlessEUID` is set to false but `RootlessCgroups` is set to true.
So, "runc-in-userns" behaves almost same as "rootful" runc except that cgroups errors are ignored.

This PR does not have any impact on CLI flags and `state.json`.

Note about CLI:
* Now `runc --rootless=(auto|true|false)` CLI flag is only used for setting `RootlessCgroups`.
* Now `runc spec --rootless` is only required when `RootlessEUID` is set to true.
  For runc-in-userns, `runc spec`  without `--rootless` should work, when sufficient numbers of
  UID/GID are mapped.

Note about `$XDG_RUNTIME_DIR` (e.g. `/run/user/1000`):
* `$XDG_RUNTIME_DIR` is ignored if runc is being executed as the root (euid == 0) in the initial namespace, for backward compatibility.
  (`/run/runc` is used)
* If runc is executed as the root (euid == 0) in an user namespace, `$XDG_RUNTIME_DIR` is honored if `$USER != "" && $USER != "root"`.
  This allows unprivileged users to allow execute runc as the root in userns, without mounting writable `/run/runc`.

Note about `state.json`:
* `rootless` is set to true when `RootlessEUID == true && RootlessCgroups == true`.

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
2018-09-07 15:05:03 +09:00

156 lines
3.9 KiB
Go

package validate
import (
"testing"
"github.com/opencontainers/runc/libcontainer/configs"
)
func rootlessEUIDConfig() *configs.Config {
return &configs.Config{
Rootfs: "/var",
RootlessEUID: true,
RootlessCgroups: true,
Namespaces: configs.Namespaces(
[]configs.Namespace{
{Type: configs.NEWUSER},
},
),
UidMappings: []configs.IDMap{
{
HostID: 1337,
ContainerID: 0,
Size: 1,
},
},
GidMappings: []configs.IDMap{
{
HostID: 7331,
ContainerID: 0,
Size: 1,
},
},
}
}
func TestValidateRootlessEUID(t *testing.T) {
validator := New()
config := rootlessEUIDConfig()
if err := validator.Validate(config); err != nil {
t.Errorf("Expected error to not occur: %+v", err)
}
}
/* rootlessEUIDMappings */
func TestValidateRootlessEUIDUserns(t *testing.T) {
validator := New()
config := rootlessEUIDConfig()
config.Namespaces = nil
if err := validator.Validate(config); err == nil {
t.Errorf("Expected error to occur if user namespaces not set")
}
}
func TestValidateRootlessEUIDMappingUid(t *testing.T) {
validator := New()
config := rootlessEUIDConfig()
config.UidMappings = nil
if err := validator.Validate(config); err == nil {
t.Errorf("Expected error to occur if no uid mappings provided")
}
}
func TestValidateNonZeroEUIDMappingGid(t *testing.T) {
validator := New()
config := rootlessEUIDConfig()
config.GidMappings = nil
if err := validator.Validate(config); err == nil {
t.Errorf("Expected error to occur if no gid mappings provided")
}
}
/* rootlessEUIDMount() */
func TestValidateRootlessEUIDMountUid(t *testing.T) {
config := rootlessEUIDConfig()
validator := New()
config.Mounts = []*configs.Mount{
{
Source: "devpts",
Destination: "/dev/pts",
Device: "devpts",
},
}
if err := validator.Validate(config); err != nil {
t.Errorf("Expected error to not occur when uid= not set in mount options: %+v", err)
}
config.Mounts[0].Data = "uid=5"
if err := validator.Validate(config); err == nil {
t.Errorf("Expected error to occur when setting uid=5 in mount options")
}
config.Mounts[0].Data = "uid=0"
if err := validator.Validate(config); err != nil {
t.Errorf("Expected error to not occur when setting uid=0 in mount options: %+v", err)
}
config.Mounts[0].Data = "uid=2"
config.UidMappings[0].Size = 10
if err := validator.Validate(config); err != nil {
t.Errorf("Expected error to not occur when setting uid=2 in mount options and UidMapping[0].size is 10")
}
config.Mounts[0].Data = "uid=20"
config.UidMappings[0].Size = 10
if err := validator.Validate(config); err == nil {
t.Errorf("Expected error to occur when setting uid=20 in mount options and UidMapping[0].size is 10")
}
}
func TestValidateRootlessEUIDMountGid(t *testing.T) {
config := rootlessEUIDConfig()
validator := New()
config.Mounts = []*configs.Mount{
{
Source: "devpts",
Destination: "/dev/pts",
Device: "devpts",
},
}
if err := validator.Validate(config); err != nil {
t.Errorf("Expected error to not occur when gid= not set in mount options: %+v", err)
}
config.Mounts[0].Data = "gid=5"
if err := validator.Validate(config); err == nil {
t.Errorf("Expected error to occur when setting gid=5 in mount options")
}
config.Mounts[0].Data = "gid=0"
if err := validator.Validate(config); err != nil {
t.Errorf("Expected error to not occur when setting gid=0 in mount options: %+v", err)
}
config.Mounts[0].Data = "gid=5"
config.GidMappings[0].Size = 10
if err := validator.Validate(config); err != nil {
t.Errorf("Expected error to not occur when setting gid=5 in mount options and GidMapping[0].size is 10")
}
config.Mounts[0].Data = "gid=11"
config.GidMappings[0].Size = 10
if err := validator.Validate(config); err == nil {
t.Errorf("Expected error to occur when setting gid=11 in mount options and GidMapping[0].size is 10")
}
}