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/
main.go
104 lines (85 loc) · 2.02 KB
/
main.go
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package main
import (
"flag"
"log"
"net/http"
"os"
"strings"
"time"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/ec2metadata"
"github.com/aws/aws-sdk-go/service/ec2"
)
var (
outputFile string
)
func init() {
flag.StringVar(&outputFile, "o", "", "output file")
}
func main() {
flag.Parse()
output := []string{}
instanceId, region := getInstanceIdAndRegion()
output = append(output, "instance-id="+*instanceId)
output = append(output, "region="+*region)
tags := getTags(region, instanceId)
for _, tag := range tags {
output = append(output, tag)
}
if outputFile != "" {
file, err := os.Create(outputFile)
if err != nil {
log.Fatal(err)
}
file.WriteString("FLEET_METADATA=" + strings.Join(output, ","))
} else {
os.Stdout.WriteString("FLEET_METADATA=" + strings.Join(output, ","))
}
}
func getInstanceIdAndRegion() (*string, *string) {
metadata := ec2metadata.New(&ec2metadata.Config{
HTTPClient: &http.Client{
Timeout: time.Duration(1 * time.Second),
},
})
if !metadata.Available() {
log.Fatal("AWS Metadata Service is not reachable.")
}
instanceId, err := metadata.GetMetadata("instance-id")
if err != nil {
log.Fatal(err)
}
region, err := metadata.Region()
if err != nil {
log.Fatal(err)
}
return &instanceId, ®ion
}
func getTags(region *string, instanceId *string) []string {
output := []string{}
service := ec2.New(&aws.Config{
Region: region,
})
instances, err := service.DescribeInstances(&ec2.DescribeInstancesInput{
InstanceIds: []*string{instanceId},
})
if err != nil {
log.Fatal(err)
}
if len(instances.Reservations) > 1 {
// more than one reservation isn't expected
log.Fatal("Not Expected: Reservations > 1")
}
for _, res := range instances.Reservations {
if len(res.Instances) > 1 {
// more than one instance isn't expected
log.Fatal("Not Expected: Instances > 1")
}
for _, instance := range res.Instances {
for _, tag := range instance.Tags {
output = append(output, *tag.Key+"="+*tag.Value)
}
}
}
return output
}