Added AWS provider to metadata package

Signed-off-by: Ken Cochrane <kencochrane@gmail.com>

pkg/metadata/main.go

@@ -47,7 +47,7 @@ var netProviders []Provider
 var cdromProviders []Provider
 
 func init() {
-	netProviders = []Provider{NewGCP()}
+	netProviders = []Provider{NewGCP(), NewAWS()}
 	cdromProviders = []Provider{NewCDROM()}
 }
 

pkg/metadata/provider_aws.go

@@ -0,0 +1,105 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"path"
+	"time"
+)
+
+const (
+	userDataURL = "http://169.254.169.254/latest/user-data"
+	metaDataURL = "http://169.254.169.254/latest/meta-data/"
+)
+
+// ProviderAWS is the type implementing the Provider interface for AWS
+type ProviderAWS struct {
+}
+
+// NewAWS returns a new ProviderAWS
+func NewAWS() *ProviderAWS {
+	return &ProviderAWS{}
+}
+
+func (p *ProviderAWS) String() string {
+	return "AWS"
+}
+
+// Probe checks if we are running on AWS
+func (p *ProviderAWS) Probe() bool {
+	// Getting the hostname should always work...
+	_, err := awsGet(metaDataURL + "hostname")
+	return (err == nil)
+}
+
+// Extract gets both the AWS specific and generic userdata
+func (p *ProviderAWS) Extract() ([]byte, error) {
+	// Get host name. This must not fail
+	hostname, err := awsGet(metaDataURL + "hostname")
+	if err != nil {
+		return nil, err
+	}
+	err = ioutil.WriteFile(path.Join(ConfigPath, Hostname), hostname, 0644)
+	if err != nil {
+		return nil, fmt.Errorf("AWS: Failed to write hostname: %s", err)
+	}
+
+	if err := p.handleSSH(); err != nil {
+		log.Printf("AWS: Failed to get ssh data: %s", err)
+	}
+
+	// Generic userdata
+	userData, err := awsGet(userDataURL)
+	if err != nil {
+		log.Printf("AWS: Failed to get user-data: %s", err)
+		// This is not an error
+		return nil, nil
+	}
+	return userData, nil
+}
+
+// awsGet requests and extracts the requested URL
+func awsGet(url string) ([]byte, error) {
+	var client = &http.Client{
+		Timeout: time.Second * 2,
+	}
+
+	req, err := http.NewRequest("", url, nil)
+	if err != nil {
+		return nil, fmt.Errorf("AWS: http.NewRequest failed: %s", err)
+	}
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("AWS: Could not contact metadata service: %s", err)
+	}
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("AWS: Status not ok: %d", resp.StatusCode)
+	}
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("AWS: Failed to read http response: %s", err)
+	}
+	return body, nil
+}
+
+// SSH keys:
+func (p *ProviderAWS) handleSSH() error {
+	sshKeys, err := awsGet(metaDataURL + "public-keys/0/openssh-key")
+	if err != nil {
+		return fmt.Errorf("Failed to get sshKeys: %s", err)
+	}
+
+	if err := os.Mkdir(path.Join(ConfigPath, SSH), 0755); err != nil {
+		return fmt.Errorf("Failed to create %s: %s", SSH, err)
+	}
+
+	err = ioutil.WriteFile(path.Join(ConfigPath, SSH, "authorized_keys"), sshKeys, 0600)
+	if err != nil {
+		return fmt.Errorf("Failed to write ssh keys: %s", err)
+	}
+	return nil
+}