runc/pause.go

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// +build linux
package main
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>
2018-07-05 14:28:21 +08:00
import (
"github.com/sirupsen/logrus"
"github.com/urfave/cli"
)
var pauseCommand = cli.Command{
Name: "pause",
Usage: "pause suspends all processes inside the container",
ArgsUsage: `<container-id>
Where "<container-id>" is the name for the instance of the container to be
paused. `,
Description: `The pause command suspends all processes in the instance of the container.
Use runc list to identify instances of containers and their current status.`,
Action: func(context *cli.Context) error {
if err := checkArgs(context, 1, exactArgs); err != nil {
return err
}
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>
2018-07-05 14:28:21 +08:00
rootlessCg, err := shouldUseRootlessCgroupManager(context)
if err != nil {
return err
}
if rootlessCg {
logrus.Warnf("runc pause may fail if you don't have the full access to cgroups")
}
container, err := getContainer(context)
if err != nil {
return err
}
return container.Pause()
},
}
var resumeCommand = cli.Command{
Name: "resume",
Usage: "resumes all processes that have been previously paused",
ArgsUsage: `<container-id>
Where "<container-id>" is the name for the instance of the container to be
resumed.`,
Description: `The resume command resumes all processes in the instance of the container.
Use runc list to identify instances of containers and their current status.`,
Action: func(context *cli.Context) error {
if err := checkArgs(context, 1, exactArgs); err != nil {
return err
}
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>
2018-07-05 14:28:21 +08:00
rootlessCg, err := shouldUseRootlessCgroupManager(context)
if err != nil {
return err
}
if rootlessCg {
logrus.Warn("runc resume may fail if you don't have the full access to cgroups")
}
container, err := getContainer(context)
if err != nil {
return err
}
return container.Resume()
},
}