cloudinit/datasource/metadata/ec2/metadata.go
2014-08-05 17:19:43 -07:00

142 lines
3.5 KiB
Go

package ec2
import (
"bufio"
"bytes"
"encoding/json"
"fmt"
"strings"
"github.com/coreos/coreos-cloudinit/pkg"
)
const (
DefaultAddress = "http://169.254.169.254/"
apiVersion = "2009-04-04"
userdataUrl = apiVersion + "/user-data"
metadataUrl = apiVersion + "/meta-data"
)
type metadataService struct {
root string
client pkg.Getter
}
func NewDatasource(root string) *metadataService {
if !strings.HasSuffix(root, "/") {
root += "/"
}
return &metadataService{root, pkg.NewHttpClient()}
}
func (ms metadataService) IsAvailable() bool {
_, err := ms.client.Get(ms.root + apiVersion)
return (err == nil)
}
func (ms metadataService) AvailabilityChanges() bool {
return true
}
func (ms metadataService) ConfigRoot() string {
return ms.root
}
func (ms metadataService) FetchMetadata() ([]byte, error) {
attrs := make(map[string]interface{})
if keynames, err := fetchAttributes(ms.client, fmt.Sprintf("%s/public-keys", ms.metadataUrl())); err == nil {
keyIDs := make(map[string]string)
for _, keyname := range keynames {
tokens := strings.SplitN(keyname, "=", 2)
if len(tokens) != 2 {
return nil, fmt.Errorf("malformed public key: %q", keyname)
}
keyIDs[tokens[1]] = tokens[0]
}
keys := make(map[string]string)
for name, id := range keyIDs {
sshkey, err := fetchAttribute(ms.client, fmt.Sprintf("%s/public-keys/%s/openssh-key", ms.metadataUrl(), id))
if err != nil {
return nil, err
}
keys[name] = sshkey
fmt.Printf("Found SSH key for %q\n", name)
}
attrs["public_keys"] = keys
} else if _, ok := err.(pkg.ErrNotFound); !ok {
return nil, err
}
if hostname, err := fetchAttribute(ms.client, fmt.Sprintf("%s/hostname", ms.metadataUrl())); err == nil {
attrs["hostname"] = hostname
} else if _, ok := err.(pkg.ErrNotFound); !ok {
return nil, err
}
if localAddr, err := fetchAttribute(ms.client, fmt.Sprintf("%s/local-ipv4", ms.metadataUrl())); err == nil {
attrs["local-ipv4"] = localAddr
} else if _, ok := err.(pkg.ErrNotFound); !ok {
return nil, err
}
if publicAddr, err := fetchAttribute(ms.client, fmt.Sprintf("%s/public-ipv4", ms.metadataUrl())); err == nil {
attrs["public-ipv4"] = publicAddr
} else if _, ok := err.(pkg.ErrNotFound); !ok {
return nil, err
}
if content_path, err := fetchAttribute(ms.client, fmt.Sprintf("%s/network_config/content_path", ms.metadataUrl())); err == nil {
attrs["network_config"] = map[string]string{
"content_path": content_path,
}
} else if _, ok := err.(pkg.ErrNotFound); !ok {
return nil, err
}
return json.Marshal(attrs)
}
func (ms metadataService) FetchUserdata() ([]byte, error) {
if data, err := ms.client.GetRetry(ms.userdataUrl()); err == nil {
return data, err
} else if _, ok := err.(pkg.ErrNotFound); ok {
return []byte{}, nil
} else {
return data, err
}
}
func (ms metadataService) Type() string {
return "ec2-metadata-service"
}
func (ms metadataService) metadataUrl() string {
return (ms.root + metadataUrl)
}
func (ms metadataService) userdataUrl() string {
return (ms.root + userdataUrl)
}
func fetchAttributes(client pkg.Getter, url string) ([]string, error) {
resp, err := client.GetRetry(url)
if err != nil {
return nil, err
}
scanner := bufio.NewScanner(bytes.NewBuffer(resp))
data := make([]string, 0)
for scanner.Scan() {
data = append(data, scanner.Text())
}
return data, scanner.Err()
}
func fetchAttribute(client pkg.Getter, url string) (string, error) {
if attrs, err := fetchAttributes(client, url); err == nil && len(attrs) > 0 {
return attrs[0], nil
} else {
return "", err
}
}