open-nomad/client/fingerprint/cgroup.go
Sean Chittenden 710173e9cb
Build the Cgroup fingerprinter on only Linux.
Change the logic from `!linux` to an empty build tag so that *if*
another platform picks up Cgroups support they can add themselves to the
necessary build tags for this fingerprinter and be on their way.
Because this technology isn't inherently Linux-specific and isn't
mutually exclusive of other resource isolation containers, resist the
urge to rename the Cgroup fingerprinter to something generic like the
ResourceContainerFingerprinter.
2016-07-10 13:55:06 -07:00

60 lines
1.5 KiB
Go

// +build linux
package fingerprint
import (
"log"
"time"
"github.com/hashicorp/nomad/nomad/structs"
)
const (
cgroupAvailable = "available"
cgroupUnavailable = "unavailable"
interval = 15
)
type CGroupFingerprint struct {
logger *log.Logger
lastState string
mountPointDetector MountPointDetector
}
// An interface to isolate calls to the cgroup library
// This facilitates testing where we can implement
// fake mount points to test various code paths
type MountPointDetector interface {
MountPoint() (string, error)
}
// Implements the interface detector which calls the cgroups library directly
type DefaultMountPointDetector struct {
}
// Call out to the default cgroup library
func (b *DefaultMountPointDetector) MountPoint() (string, error) {
return FindCgroupMountpointDir()
}
// NewCGroupFingerprint returns a new cgroup fingerprinter
func NewCGroupFingerprint(logger *log.Logger) Fingerprint {
f := &CGroupFingerprint{
logger: logger,
lastState: cgroupUnavailable,
mountPointDetector: &DefaultMountPointDetector{},
}
return f
}
// clearCGroupAttributes clears any node attributes related to cgroups that might
// have been set in a previous fingerprint run.
func (f *CGroupFingerprint) clearCGroupAttributes(n *structs.Node) {
delete(n.Attributes, "unique.cgroup.mountpoint")
}
// Periodic determines the interval at which the periodic fingerprinter will run.
func (f *CGroupFingerprint) Periodic() (bool, time.Duration) {
return true, interval * time.Second
}