1// Copyright 2015 The etcd Authors
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package api
16
17import (
18	"sync"
19
20	"go.etcd.io/etcd/version"
21	"go.uber.org/zap"
22
23	"github.com/coreos/go-semver/semver"
24	"github.com/coreos/pkg/capnslog"
25)
26
27type Capability string
28
29const (
30	AuthCapability  Capability = "auth"
31	V3rpcCapability Capability = "v3rpc"
32)
33
34var (
35	plog = capnslog.NewPackageLogger("go.etcd.io/etcd", "etcdserver/api")
36
37	// capabilityMaps is a static map of version to capability map.
38	capabilityMaps = map[string]map[Capability]bool{
39		"3.0.0": {AuthCapability: true, V3rpcCapability: true},
40		"3.1.0": {AuthCapability: true, V3rpcCapability: true},
41		"3.2.0": {AuthCapability: true, V3rpcCapability: true},
42		"3.3.0": {AuthCapability: true, V3rpcCapability: true},
43		"3.4.0": {AuthCapability: true, V3rpcCapability: true},
44	}
45
46	enableMapMu sync.RWMutex
47	// enabledMap points to a map in capabilityMaps
48	enabledMap map[Capability]bool
49
50	curVersion *semver.Version
51)
52
53func init() {
54	enabledMap = map[Capability]bool{
55		AuthCapability:  true,
56		V3rpcCapability: true,
57	}
58}
59
60// UpdateCapability updates the enabledMap when the cluster version increases.
61func UpdateCapability(lg *zap.Logger, v *semver.Version) {
62	if v == nil {
63		// if recovered but version was never set by cluster
64		return
65	}
66	enableMapMu.Lock()
67	if curVersion != nil && !curVersion.LessThan(*v) {
68		enableMapMu.Unlock()
69		return
70	}
71	curVersion = v
72	enabledMap = capabilityMaps[curVersion.String()]
73	enableMapMu.Unlock()
74
75	if lg != nil {
76		lg.Info(
77			"enabled capabilities for version",
78			zap.String("cluster-version", version.Cluster(v.String())),
79		)
80	} else {
81		plog.Infof("enabled capabilities for version %s", version.Cluster(v.String()))
82	}
83}
84
85func IsCapabilityEnabled(c Capability) bool {
86	enableMapMu.RLock()
87	defer enableMapMu.RUnlock()
88	if enabledMap == nil {
89		return false
90	}
91	return enabledMap[c]
92}
93
94func EnableCapability(c Capability) {
95	enableMapMu.Lock()
96	defer enableMapMu.Unlock()
97	enabledMap[c] = true
98}
99