// requires a path to a platform configuration file in this format:
// <launchablename>:
// cgroup:
// cpus: 4
// memory: 123456
// and the <launchablename> and <cgroupname>
// a cgroup with the name <cgroupname> will be created, using the parameters for
// <launchablename> found in the platform configuration
// then, the current PID will be added to that cgroup
func cgEnter(platconf, launchableName, cgroupName string) error {
platconfBuf, err := ioutil.ReadFile(platconf)
if err != nil {
return err
}
cgMap := make(map[string]map[string]cgroups.Config)
err = yaml.Unmarshal(platconfBuf, cgMap)
if err != nil {
return err
}
if _, ok := cgMap[launchableName]; !ok {
return util.Errorf("Unknown launchable %q in PLATFORM_CONFIG_PATH", launchableName)
}
if _, ok := cgMap[launchableName]["cgroup"]; !ok {
return util.Errorf("Launchable %q has malformed PLATFORM_CONFIG_PATH", launchableName)
}
cgConfig := cgMap[launchableName]["cgroup"]
cgConfig.Name = cgroupName
cg, err := cgroups.Find()
if err != nil {
return util.Errorf("Could not find cgroupfs mount point: %s", err)
}
err = cg.Write(cgConfig)
if _, ok := err.(cgroups.UnsupportedError); ok {
// if a subsystem is not supported, just log
// and carry on
log.Printf("Unsupported subsystem (%s), continuing\n", err)
return nil
} else if err != nil {
return util.Errorf("Could not set cgroup parameters: %s", err)
}
return cg.AddPID(cgConfig.Name, os.Getpid())
}
func main() {
app.Version(version.VERSION)
kingpin.MustParse(app.Parse(os.Args[1:]))
logger := log.New(os.Stderr, "", 0)
// P2 only uses the "memory" and "cpu" resource controllers, and it creates an
// identical hierarchy in either. Just scan "cpu".
sys, err := cgroups.Find()
if err != nil {
logger.Fatalf("error finding cgroups: %v", err)
}
output, err := scanCgroup(sys.CPU)
if err != nil {
logger.Fatalf("error scanning cpu controller: %v", err)
}
data, err := json.Marshal(&output)
if err != nil {
logger.Fatalf("error formatting output: %v", err)
}
_, err = os.Stdout.Write(data)
if err != nil {
logger.Fatalf("error writing output: %v", err)
}
_, _ = os.Stdout.Write([]byte("\n"))
}