1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
|
/*
* Copyright 2019 Intel Corporation, 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 namegenerator
import (
"encoding/json"
"log"
"strings"
"sync"
"github.com/onap/multicloud-k8s/src/k8splugin/internal/db"
"github.com/docker/engine/pkg/namesgenerator"
pkgerrors "github.com/pkg/errors"
)
const (
storeName = "instanceNames"
tag = "names"
)
var (
nameCache = &cache{}
cacheKeyGlobal = cacheKey{"k8sPluginCacheKey"}
)
type cache struct {
cache map[string]bool
mux sync.Mutex
}
type cacheKey struct {
Key string `json:"key"`
}
func (c cacheKey) String() string {
out, err := json.Marshal(c)
if err != nil {
return ""
}
return string(out)
}
func (c *cache) init() {
// We have either restarted or this is the first time
// that a name is being requested since the service came
// up.
if c.cache == nil {
c.cache = make(map[string]bool)
err := c.readCacheFromDB()
if err != nil {
log.Println("Error Reading from DB: ", err.Error())
return
}
}
}
func (c *cache) isAlreadyUsed(name string) bool {
if _, ok := c.cache[name]; ok {
return true
}
return false
}
func (c *cache) readCacheFromDB() error {
// Read the latest from cache
data, err := db.DBconn.Read(storeName, cacheKeyGlobal, tag)
if err != nil {
log.Println("Error reading name cache from Database: ", err)
return pkgerrors.Wrap(err, "Reading cache from DB")
}
err = db.DBconn.Unmarshal(data, &c.cache)
if err != nil {
log.Println("Error unmarshaling data into cache: ", err)
return pkgerrors.Wrap(err, "Unmarshaling cache from DB")
}
return nil
}
// writeCacheToDB will update the DB with the updated cache
func (c *cache) writeCacheToDB() {
//Update the database as well
err := db.DBconn.Update(storeName, cacheKeyGlobal, tag, c.cache)
if err != nil {
// TODO: Replace with DBconn variable
if strings.Contains(err.Error(), "Error finding master table") {
err = db.DBconn.Create(storeName, cacheKeyGlobal, tag, c.cache)
if err != nil {
log.Println("Error creating the entry in DB. Will try later...")
return
}
} else {
log.Println("Error updating DB: ", err.Error())
return
}
}
}
func (c *cache) generateName() string {
c.mux.Lock()
defer c.mux.Unlock()
c.init()
for {
//Call moby package here to generate name
name := namesgenerator.GetRandomName(0)
if c.isAlreadyUsed(name) {
// Generate another name
log.Printf("Name %s already used", name)
continue
}
c.cache[name] = true
// Update the cache and db
c.writeCacheToDB()
return name
}
}
func (c *cache) releaseName(name string) {
c.mux.Lock()
defer c.mux.Unlock()
c.init()
if c.isAlreadyUsed(name) {
c.cache[name] = false
// Update the cache and db
c.writeCacheToDB()
}
}
// Generate returns an autogenerated name
func Generate() string {
return nameCache.generateName()
}
// Release name from cache
func Release(name string) {
nameCache.releaseName(name)
}
|
