open-nomad/client/fingerprint/cgroup_linux.go

58 lines
1.5 KiB
Go

// +build linux
package fingerprint
import (
"fmt"
client "github.com/hashicorp/nomad/client/config"
"github.com/hashicorp/nomad/nomad/structs"
"github.com/opencontainers/runc/libcontainer/cgroups"
)
// FindCgroupMountpointDir is used to find the cgroup mount point on a Linux
// system.
func FindCgroupMountpointDir() (string, error) {
mount, err := cgroups.FindCgroupMountpointDir()
if err != nil {
switch e := err.(type) {
case *cgroups.NotFoundError:
// It's okay if the mount point is not discovered
return "", nil
default:
// All other errors are passed back as is
return "", e
}
}
return mount, nil
}
// Fingerprint tries to find a valid cgroup moint point
func (f *CGroupFingerprint) Fingerprint(cfg *client.Config, node *structs.Node) (bool, error) {
mount, err := f.mountPointDetector.MountPoint()
if err != nil {
f.clearCGroupAttributes(node)
return false, fmt.Errorf("Failed to discover cgroup mount point: %s", err)
}
// Check if a cgroup mount point was found
if mount == "" {
// Clear any attributes from the previous fingerprint.
f.clearCGroupAttributes(node)
if f.lastState == cgroupAvailable {
f.logger.Printf("[INFO] fingerprint.cgroups: cgroups are unavailable")
}
f.lastState = cgroupUnavailable
return true, nil
}
node.Attributes["unique.cgroup.mountpoint"] = mount
if f.lastState == cgroupUnavailable {
f.logger.Printf("[INFO] fingerprint.cgroups: cgroups are available")
}
f.lastState = cgroupAvailable
return true, nil
}