machine.go

/*
   Copyright 2014 CoreOS, Inc.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package registry

import (
	"path"
	"strings"
	"time"

	"github.com/coreos/fleet/etcd"
	"github.com/coreos/fleet/machine"
)

const (
	machinePrefix = "machines"
)

func (r *EtcdRegistry) Machines() (machines []machine.MachineState, err error) {
	req := etcd.Get{
		Key:       path.Join(r.keyPrefix, machinePrefix),
		Sorted:    true,
		Recursive: true,
	}

	resp, err := r.etcd.Do(&req)
	if err != nil {
		if isKeyNotFound(err) {
			err = nil
		}
		return
	}

	for _, node := range resp.Node.Nodes {
		for _, obj := range node.Nodes {
			if !strings.HasSuffix(obj.Key, "/object") {
				continue
			}

			var mach machine.MachineState
			err = unmarshal(obj.Value, &mach)
			if err != nil {
				return
			}

			machines = append(machines, mach)
		}
	}

	return
}

func (r *EtcdRegistry) SetMachineState(ms machine.MachineState, ttl time.Duration) (uint64, error) {
	json, err := marshal(ms)
	if err != nil {
		return uint64(0), err
	}

	update := etcd.Update{
		Key:   path.Join(r.keyPrefix, machinePrefix, ms.ID, "object"),
		Value: json,
		TTL:   ttl,
	}

	resp, err := r.etcd.Do(&update)
	if err == nil {
		return resp.Node.ModifiedIndex, nil
	}

	// If state was not present, explicitly create it so the other members
	// in the cluster know this is a new member
	create := etcd.Create{
		Key:   path.Join(r.keyPrefix, machinePrefix, ms.ID, "object"),
		Value: json,
		TTL:   ttl,
	}

	resp, err = r.etcd.Do(&create)
	if err != nil {
		return uint64(0), err
	}

	return resp.Node.ModifiedIndex, nil
}

func (r *EtcdRegistry) RemoveMachineState(machID string) error {
	req := etcd.Delete{
		Key: path.Join(r.keyPrefix, machinePrefix, machID, "object"),
	}
	_, err := r.etcd.Do(&req)
	if isKeyNotFound(err) {
		err = nil
	}
	return err
}