-
Notifications
You must be signed in to change notification settings - Fork 1
/
service.go
176 lines (160 loc) · 4.36 KB
/
service.go
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
169
170
171
172
173
174
175
176
package aws
import (
"errors"
"os"
"log"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/service/ec2"
"github.com/aws/aws-sdk-go/aws/credentials"
"github.com/aws/aws-sdk-go/aws/session"
"time"
)
type Service struct {
Config *Config
logger *log.Logger
awsConfig *aws.Config
updateTicker *time.Ticker
ec2Instances []*EC2Instance
}
type EC2Instance struct {
Address string
PublicIP string
PrivateIP string
PubicDNS string
PrivateDNS string
Name string
UpdateTime time.Time
}
var (
notFoundError = errors.New("no matching resource found")
)
func NewService(c Config) *Service {
awsConfig := aws.NewConfig().WithCredentials(
credentials.NewStaticCredentials(c.AccessKeyID, c.SecretAccessKey, "")).WithRegion(c.Region)
s := &Service{
Config: &c,
logger: log.New(os.Stderr, "[aws] ", log.LstdFlags),
awsConfig: awsConfig,
}
return s
}
func (s *Service) Open() error {
err := s.UpdateCache()
s.updateTicker = time.NewTicker(30 * time.Second)
go func() {
for range s.updateTicker.C {
s.UpdateCache()
}
}()
return err;
}
func (s *Service) Close() error {
s.updateTicker.Stop()
s.updateTicker = nil
return nil;
}
func (s *Service) GetAllEC2Names() []string {
names := make([]string, 0, len(s.ec2Instances));
s.eachEC2Instance(func(idx int, instance *EC2Instance) bool {
names = append(names, instance.Name)
return true
})
return names
}
func (s *Service) GetEC2FromName(name string) (instances []EC2Instance) {
s.eachEC2Instance(func(idx int, inst *EC2Instance) bool {
if inst.Name == name {
instances = append(instances, *inst)
}
return true
})
return instances
}
func (s *Service) GetEC2NameFromIP(ip string) (error, string) {
instance := s.findEC2Instance(func(ec2 *EC2Instance) bool {
return ip != "" && (ec2.PrivateIP == ip || ec2.PublicIP == ip)
})
if instance == nil {
return notFoundError, ""
} else {
return nil, instance.Name
}
}
func (s *Service) UpdateCache() error {
ec2 := ec2.New(session.New(s.awsConfig))
resp, err := ec2.DescribeInstances(nil)
if err != nil {
return err;
}
instances := make([]*EC2Instance, 0, 10)
for _, rev := range resp.Reservations {
for _, inst := range rev.Instances {
ec2 := newEC2(inst)
instances = append(instances, ec2)
}
}
s.ec2Instances = instances
s.logger.Printf("got %d ec2 instances", len(instances))
return nil
}
func newEC2(inst *ec2.Instance) *EC2Instance {
ec2 := &EC2Instance{}
for _, tag := range inst.Tags {
if tag.Key != nil && *tag.Key == "Name" {
ec2.Name = *tag.Value
break
}
}
if inst.PublicDnsName != nil {
ec2.PubicDNS = *inst.PublicDnsName
ec2.Address = ec2.PubicDNS
}
if inst.PublicIpAddress != nil {
ec2.PublicIP = *inst.PublicIpAddress
}
if inst.PrivateDnsName != nil {
ec2.PrivateDNS = *inst.PrivateDnsName
if ec2.Address == "" {
ec2.Address = ec2.PrivateDNS
}
}
if inst.PrivateIpAddress != nil {
ec2.PrivateIP = *inst.PrivateIpAddress
}
ec2.UpdateTime = time.Now()
return ec2
}
func (s *Service) findEC2Instances(filterFunc func(*EC2Instance) bool, limit int) []*EC2Instance {
instances := s.ec2Instances
filtered := make([]*EC2Instance, 0, limit)
for _, inst := range instances {
if filterFunc(inst) {
filtered = append(filtered, inst)
}
if limit > 0 && len(filtered) == limit {
break
}
}
return filtered
}
func (s *Service) findEC2Instance(filterFunc func(*EC2Instance) bool) *EC2Instance {
instances := s.findEC2Instances(filterFunc, 1)
if len(instances) == 0 {
return nil
} else {
return instances[0]
}
}
func (s *Service) eachEC2Instance(iterFunc func(index int, instance *EC2Instance) bool) int {
loopCount := 0
for idx, inst := range s.ec2Instances {
loopCount += 1
if !iterFunc(idx, inst) {
break
}
}
return loopCount
}
func (ec2 *EC2Instance) Age() uint32 {
return uint32(time.Now().Sub(ec2.UpdateTime).Seconds())
}