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

262 lines
8.6 KiB
Go

package common
import (
"crypto/tls"
"fmt"
"log"
"net/http"
"strings"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/awserr"
"github.com/aws/aws-sdk-go/aws/credentials"
"github.com/aws/aws-sdk-go/aws/session"
"github.com/aws/aws-sdk-go/service/ec2"
"github.com/aws/aws-sdk-go/service/ec2/ec2iface"
cleanhttp "github.com/hashicorp/go-cleanhttp"
"github.com/hashicorp/packer/template/interpolate"
vaultapi "github.com/hashicorp/vault/api"
)
type VaultAWSEngineOptions struct {
Name string `mapstructure:"name"`
RoleARN string `mapstructure:"role_arn"`
// Specifies the TTL for the use of the STS token. This
// is specified as a string with a duration suffix. Valid only when
// credential_type is assumed_role or federation_token. When not
// specified, the default_sts_ttl set for the role will be used. If that
// is also not set, then the default value of 3600s will be used. AWS
// places limits on the maximum TTL allowed. See the AWS documentation on
// the DurationSeconds parameter for AssumeRole (for assumed_role
// credential types) and GetFederationToken (for federation_token
// credential types) for more details.
TTL string `mapstructure:"ttl" required:"false"`
EngineName string `mapstructure:"engine_name"`
}
func (v *VaultAWSEngineOptions) Empty() bool {
return len(v.Name) == 0 && len(v.RoleARN) == 0 &&
len(v.EngineName) == 0 && len(v.TTL) == 0
}
// AccessConfig is for common configuration related to AWS access
type AccessConfig struct {
// The access key used to communicate with AWS. Learn
// how to set this
AccessKey string `mapstructure:"access_key" required:"true"`
// This option is useful if you use a cloud
// provider whose API is compatible with aws EC2. Specify another endpoint
// like this https://ec2.custom.endpoint.com.
CustomEndpointEc2 string `mapstructure:"custom_endpoint_ec2" required:"false"`
// Enable automatic decoding of
// any encoded authorization (error) messages using the
// sts:DecodeAuthorizationMessage API. Note: requires that the effective
// user/role have permissions to sts:DecodeAuthorizationMessage on resource
// *. Default false.
DecodeAuthZMessages bool `mapstructure:"decode_authorization_messages" required:"false"`
// This allows skipping TLS
// verification of the AWS EC2 endpoint. The default is false.
InsecureSkipTLSVerify bool `mapstructure:"insecure_skip_tls_verify" required:"false"`
// The MFA
// TOTP
// code. This should probably be a user variable since it changes all the
// time.
MFACode string `mapstructure:"mfa_code" required:"false"`
// The profile to use in the shared credentials file for
// AWS. See Amazon's documentation on specifying
// profiles
// for more details.
ProfileName string `mapstructure:"profile" required:"false"`
// The name of the region, such as us-east-1, in which
// to launch the EC2 instance to create the AMI.
RawRegion string `mapstructure:"region" required:"true"`
// The secret key used to communicate with AWS. Learn
// how to set this
SecretKey string `mapstructure:"secret_key" required:"true"`
// Set to true if you want to skip
// validation of the ami_regions configuration option. Default false.
SkipValidation bool `mapstructure:"skip_region_validation" required:"false"`
SkipMetadataApiCheck bool `mapstructure:"skip_metadata_api_check"`
// The access token to use. This is different from the
// access key and secret key. If you're not sure what this is, then you
// probably don't need it. This will also be read from the AWS_SESSION_TOKEN
// environmental variable.
Token string `mapstructure:"token" required:"false"`
session *session.Session
// Get credentials from Hashicorp Vault's aws
// secrets engine. You must already have created a role to use. For more
// information about generating credentials via the Vault engine, see the
// Vault
// docs.
// If you set this flag, you must also set the below options:
VaultAWSEngine VaultAWSEngineOptions `mapstructure:"vault_aws_engine" required:"false"`
getEC2Connection func() ec2iface.EC2API
}
// 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) Session() (*session.Session, error) {
if c.session != nil {
return c.session, nil
}
config := aws.NewConfig().WithCredentialsChainVerboseErrors(true)
staticCreds := credentials.NewStaticCredentials(c.AccessKey, c.SecretKey, c.Token)
if _, err := staticCreds.Get(); err != credentials.ErrStaticCredentialsEmpty {
config.WithCredentials(staticCreds)
}
if c.RawRegion != "" {
config = config.WithRegion(c.RawRegion)
}
if c.CustomEndpointEc2 != "" {
config = config.WithEndpoint(c.CustomEndpointEc2)
}
config = config.WithHTTPClient(cleanhttp.DefaultClient())
transport := config.HTTPClient.Transport.(*http.Transport)
if c.InsecureSkipTLSVerify {
transport.TLSClientConfig = &tls.Config{
InsecureSkipVerify: true,
}
}
transport.Proxy = http.ProxyFromEnvironment
opts := session.Options{
SharedConfigState: session.SharedConfigEnable,
Config: *config,
}
if c.ProfileName != "" {
opts.Profile = c.ProfileName
}
if c.MFACode != "" {
opts.AssumeRoleTokenProvider = func() (string, error) {
return c.MFACode, nil
}
}
sess, err := session.NewSessionWithOptions(opts)
if err != nil {
return nil, err
}
log.Printf("Found region %s", *sess.Config.Region)
c.session = sess
cp, err := c.session.Config.Credentials.Get()
if err != nil {
if awsErr, ok := err.(awserr.Error); ok && awsErr.Code() == "NoCredentialProviders" {
return nil, fmt.Errorf("No valid credential sources found for AWS Builder. " +
"Please see https://www.packer.io/docs/builders/amazon.html#specifying-amazon-credentials " +
"for more information on providing credentials for the AWS Builder.")
} else {
return nil, fmt.Errorf("Error loading credentials for AWS Provider: %s", err)
}
}
log.Printf("[INFO] AWS Auth provider used: %q", cp.ProviderName)
if c.DecodeAuthZMessages {
DecodeAuthZMessages(c.session)
}
LogEnvOverrideWarnings()
return c.session, nil
}
func (c *AccessConfig) SessionRegion() string {
if c.session == nil {
panic("access config session should be set.")
}
return aws.StringValue(c.session.Config.Region)
}
func (c *AccessConfig) IsGovCloud() bool {
return strings.HasPrefix(c.SessionRegion(), "us-gov-")
}
func (c *AccessConfig) IsChinaCloud() bool {
return strings.HasPrefix(c.SessionRegion(), "cn-")
}
func (c *AccessConfig) GetCredsFromVault() error {
// const EnvVaultAddress = "VAULT_ADDR"
// const EnvVaultToken = "VAULT_TOKEN"
vaultConfig := vaultapi.DefaultConfig()
cli, err := vaultapi.NewClient(vaultConfig)
if err != nil {
return fmt.Errorf("Error getting Vault client: %s", err)
}
if c.VaultAWSEngine.EngineName == "" {
c.VaultAWSEngine.EngineName = "aws"
}
path := fmt.Sprintf("/%s/creds/%s", c.VaultAWSEngine.EngineName,
c.VaultAWSEngine.Name)
secret, err := cli.Logical().Read(path)
if err != nil {
return fmt.Errorf("Error reading vault secret: %s", err)
}
if secret == nil {
return fmt.Errorf("Vault Secret does not exist at the given path.")
}
c.AccessKey = secret.Data["access_key"].(string)
c.SecretKey = secret.Data["secret_key"].(string)
token := secret.Data["security_token"]
if token != nil {
c.Token = token.(string)
} else {
c.Token = ""
}
return nil
}
func (c *AccessConfig) Prepare(ctx *interpolate.Context) []error {
var errs []error
if c.SkipMetadataApiCheck {
log.Println("(WARN) skip_metadata_api_check ignored.")
}
// Make sure it's obvious from the config how we're getting credentials:
// Vault, Packer config, or environemnt.
if !c.VaultAWSEngine.Empty() {
if len(c.AccessKey) > 0 {
errs = append(errs,
fmt.Errorf("If you have set vault_aws_engine, you must not set"+
" the access_key or secret_key."))
}
// Go ahead and grab those credentials from Vault now, so we can set
// the keys and token now.
err := c.GetCredsFromVault()
if err != nil {
errs = append(errs, err)
}
}
if (len(c.AccessKey) > 0) != (len(c.SecretKey) > 0) {
errs = append(errs,
fmt.Errorf("`access_key` and `secret_key` must both be either set or not set."))
}
return errs
}
func (c *AccessConfig) NewEC2Connection() (ec2iface.EC2API, error) {
if c.getEC2Connection != nil {
return c.getEC2Connection(), nil
}
sess, err := c.Session()
if err != nil {
return nil, err
}
ec2conn := ec2.New(sess)
return ec2conn, nil
}