Utku Ozdemir f55f5df739
feat: move dashboard package & run it in tty2
Move dashboard package into a common location where both Talos and talosctl can use it.

Add support for overriding stdin, stdout, stderr and ctt in process runner.

Create a dashboard service which runs the dashboard on /dev/tty2.

Redirect kernel messages to tty1 and switch to tty2 after starting the dashboard on it.

Related to siderolabs/talos#6841, siderolabs/talos#4791.

Signed-off-by: Utku Ozdemir <utku.ozdemir@siderolabs.com>
2023-02-28 12:00:25 +01:00

114 lines
3.2 KiB
Go

// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
// Package wrapperd provides a wrapper for running services.
package wrapperd
import (
"flag"
"log"
"os"
"strings"
"github.com/containerd/cgroups"
cgroupsv2 "github.com/containerd/cgroups/v2"
"github.com/containerd/containerd/sys"
"github.com/siderolabs/gen/slices"
"golang.org/x/sys/unix"
"kernel.org/pub/linux/libs/security/libcap/cap"
krnl "github.com/siderolabs/talos/pkg/kernel"
"github.com/siderolabs/talos/pkg/machinery/constants"
"github.com/siderolabs/talos/pkg/machinery/kernel"
)
var (
name string
droppedCaps string
cgroupPath string
oomScore int
uid int
)
// Main is the entrypoint into /sbin/wrapperd.
//
//nolint:gocyclo
func Main() {
flag.StringVar(&name, "name", "", "process name")
flag.StringVar(&droppedCaps, "dropped-caps", "", "comma-separated list of capabilities to drop")
flag.StringVar(&cgroupPath, "cgroup-path", "", "cgroup path to use")
flag.IntVar(&oomScore, "oom-score", 0, "oom score to set")
flag.IntVar(&uid, "uid", 0, "uid to set for the process")
flag.Parse()
currentPid := os.Getpid()
if oomScore != 0 {
if err := sys.AdjustOOMScore(currentPid, oomScore); err != nil {
log.Fatalf("Failed to change OOMScoreAdj of process %s to %d", name, oomScore)
}
}
// load the cgroup and put the process into the cgroup
if cgroupPath != "" {
if cgroups.Mode() == cgroups.Unified {
cgv2, err := cgroupsv2.LoadManager(constants.CgroupMountPath, cgroupPath)
if err != nil {
log.Fatalf("failed to load cgroup %s: %v", cgroupPath, err)
}
if err := cgv2.AddProc(uint64(currentPid)); err != nil {
log.Fatalf("Failed to move process %s to cgroup: %v", name, err)
}
} else {
cgv1, err := cgroups.Load(cgroups.V1, cgroups.StaticPath(cgroupPath))
if err != nil {
log.Fatalf("failed to load cgroup %s: %v", cgroupPath, err)
}
if err := cgv1.Add(cgroups.Process{
Pid: currentPid,
}); err != nil {
log.Fatalf("Failed to move process %s to cgroup: %v", name, err)
}
}
}
prop, err := krnl.ReadParam(&kernel.Param{Key: "proc.sys.kernel.kexec_load_disabled"})
if v := strings.TrimSpace(string(prop)); err == nil && v != "0" {
log.Printf("kernel.kexec_load_disabled is %v, skipping dropping capabilities", v)
} else if droppedCaps != "" {
caps := strings.Split(droppedCaps, ",")
dropCaps := slices.Map(caps, func(c string) cap.Value {
capability, capErr := cap.FromName(c)
if capErr != nil {
log.Fatalf("failed to parse capability: %v", capErr)
}
return capability
})
// drop capabilities
iab := cap.IABGetProc()
if err = iab.SetVector(cap.Bound, true, dropCaps...); err != nil {
log.Fatalf("failed to set capabilities: %v", err)
}
if err = iab.SetProc(); err != nil {
log.Fatalf("failed to apply capabilities: %v", err)
}
}
if uid > 0 {
err = unix.Setuid(uid)
if err != nil {
log.Fatalf("failed to setuid: %v", err)
}
}
if err := unix.Exec(flag.Args()[0], flag.Args()[0:], os.Environ()); err != nil {
log.Fatalf("failed to exec: %v", err)
}
}