packer-cn/builder/amazon/common/access_config.go

118 lines
3.0 KiB
Go

package common
import (
"fmt"
"io/ioutil"
"net/http"
"strings"
"unicode"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/credentials"
"github.com/aws/aws-sdk-go/aws/credentials/ec2rolecreds"
"github.com/aws/aws-sdk-go/aws/ec2metadata"
"github.com/aws/aws-sdk-go/aws/session"
"github.com/mitchellh/packer/template/interpolate"
)
// AccessConfig is for common configuration related to AWS access
type AccessConfig struct {
AccessKey string `mapstructure:"access_key"`
SecretKey string `mapstructure:"secret_key"`
RawRegion string `mapstructure:"region"`
Token string `mapstructure:"token"`
ProfileName string `mapstructure:"profile"`
}
// Config returns a valid aws.Config object for access to AWS services, or
// an error if the authentication and region couldn't be resolved
func (c *AccessConfig) Config() (*aws.Config, error) {
var creds *credentials.Credentials
region, err := c.Region()
if err != nil {
return nil, err
}
config := aws.NewConfig().WithRegion(region).WithMaxRetries(11)
if c.ProfileName != "" {
profile, err := NewFromProfile(c.ProfileName)
if err != nil {
return nil, err
}
creds, err = profile.CredentialsFromProfile(config)
if err != nil {
return nil, err
}
} else {
sess := session.New(config)
creds = credentials.NewChainCredentials([]credentials.Provider{
&credentials.StaticProvider{Value: credentials.Value{
AccessKeyID: c.AccessKey,
SecretAccessKey: c.SecretKey,
SessionToken: c.Token,
}},
&credentials.EnvProvider{},
&credentials.SharedCredentialsProvider{Filename: "", Profile: ""},
&ec2rolecreds.EC2RoleProvider{
Client: ec2metadata.New(sess),
},
})
}
return config.WithCredentials(creds), nil
}
// Region returns the aws.Region object for access to AWS services, requesting
// the region from the instance metadata if possible.
func (c *AccessConfig) Region() (string, error) {
if c.RawRegion != "" {
if valid := ValidateRegion(c.RawRegion); valid == false {
return "", fmt.Errorf("Not a valid region: %s", c.RawRegion)
}
return c.RawRegion, nil
}
md, err := GetInstanceMetaData("placement/availability-zone")
if err != nil {
return "", err
}
region := strings.TrimRightFunc(string(md), unicode.IsLetter)
return region, nil
}
func (c *AccessConfig) Prepare(ctx *interpolate.Context) []error {
var errs []error
if c.RawRegion != "" {
if valid := ValidateRegion(c.RawRegion); valid == false {
errs = append(errs, fmt.Errorf("Unknown region: %s", c.RawRegion))
}
}
if len(errs) > 0 {
return errs
}
return nil
}
func GetInstanceMetaData(path string) (contents []byte, err error) {
url := "http://169.254.169.254/latest/meta-data/" + path
resp, err := http.Get(url)
if err != nil {
return
}
defer resp.Body.Close()
if resp.StatusCode != 200 {
err = fmt.Errorf("Code %d returned for url %s", resp.StatusCode, url)
return
}
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return
}
return []byte(body), err
}