forked from aws/aws-sdk-go-v2
/
shared_config.go
430 lines (364 loc) · 11.8 KB
/
shared_config.go
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package external
import (
"fmt"
"io/ioutil"
"os"
"path/filepath"
"runtime"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/go-ini/ini"
)
const (
// Static Credentials group
accessKeyIDKey = `aws_access_key_id` // group required
secretAccessKey = `aws_secret_access_key` // group required
sessionTokenKey = `aws_session_token` // optional
// Assume Role Credentials group
roleArnKey = `role_arn` // group required
sourceProfileKey = `source_profile` // group required
externalIDKey = `external_id` // optional
mfaSerialKey = `mfa_serial` // optional
roleSessionNameKey = `role_session_name` // optional
// Additional Config fields
regionKey = `region`
)
// DefaultSharedConfigProfile is the default profile to be used when
// loading configuration from the config files if another profile name
// is not provided.
var DefaultSharedConfigProfile = `default`
// DefaultSharedCredentialsFilename returns the SDK's default file path
// for the shared credentials file.
//
// Builds the shared config file path based on the OS's platform.
//
// - Linux/Unix: $HOME/.aws/credentials
// - Windows: %USERPROFILE%\.aws\credentials
func DefaultSharedCredentialsFilename() string {
return filepath.Join(userHomeDir(), ".aws", "credentials")
}
// DefaultSharedConfigFilename returns the SDK's default file path for
// the shared config file.
//
// Builds the shared config file path based on the OS's platform.
//
// - Linux/Unix: $HOME/.aws/config
// - Windows: %USERPROFILE%\.aws\config
func DefaultSharedConfigFilename() string {
return filepath.Join(userHomeDir(), ".aws", "config")
}
// DefaultSharedConfigFiles is a slice of the default shared config files that
// the will be used in order to load the SharedConfig.
var DefaultSharedConfigFiles = []string{
DefaultSharedCredentialsFilename(),
DefaultSharedConfigFilename(),
}
// AssumeRoleConfig provides the values defining the configuration for an IAM
// assume role.
type AssumeRoleConfig struct {
RoleARN string
ExternalID string
MFASerial string
RoleSessionName string
sourceProfile string
Source *SharedConfig
}
// SharedConfig represents the configuration fields of the SDK config files.
type SharedConfig struct {
Profile string
// Credentials values from the config file. Both aws_access_key_id
// and aws_secret_access_key must be provided together in the same file
// to be considered valid. The values will be ignored if not a complete group.
// aws_session_token is an optional field that can be provided if both of the
// other two fields are also provided.
//
// aws_access_key_id
// aws_secret_access_key
// aws_session_token
Credentials aws.Credentials
AssumeRole AssumeRoleConfig
// Region is the region the SDK should use for looking up AWS service endpoints
// and signing requests.
//
// region
Region string
}
// GetRegion returns the region for the profile if a region is set.
func (c SharedConfig) GetRegion() (string, error) {
return c.Region, nil
}
// GetCredentialsValue returns the credentials for a profile if they were set.
func (c SharedConfig) GetCredentialsValue() (aws.Credentials, error) {
return c.Credentials, nil
}
// GetAssumeRoleConfig returns the assume role config for a profile. Will be
// a zero value if not set.
func (c SharedConfig) GetAssumeRoleConfig() (AssumeRoleConfig, error) {
return c.AssumeRole, nil
}
// LoadSharedConfigIgnoreNotExist is an alias for LoadSharedConfig with the
// addition of ignoring when none of the files exist or when the profile
// is not found in any of the files.
func LoadSharedConfigIgnoreNotExist(configs Configs) (Config, error) {
cfg, err := LoadSharedConfig(configs)
if err != nil {
if _, ok := err.(SharedConfigNotExistErrors); ok {
return SharedConfig{}, nil
}
return nil, err
}
return cfg, nil
}
// LoadSharedConfig uses the Configs passed in to load the SharedConfig from file
// The file names and profile name are sourced from the Configs.
//
// If profile name is not provided DefaultSharedConfigProfile (default) will
// be used.
//
// If shared config filenames are not provided DefaultSharedConfigFiles will
// be used.
//
// Config providers used:
// * SharedConfigProfileProvider
// * SharedConfigFilesProvider
func LoadSharedConfig(configs Configs) (Config, error) {
var profile string
var files []string
var ok bool
var err error
profile, ok, err = GetSharedConfigProfile(configs)
if err != nil {
return nil, err
}
if !ok {
profile = DefaultSharedConfigProfile
}
files, ok, err = GetSharedConfigFiles(configs)
if err != nil {
return nil, err
}
if !ok {
files = DefaultSharedConfigFiles
}
return NewSharedConfig(profile, files)
}
// NewSharedConfig retrieves the configuration from the list of files
// using the profile provided. The order the files are listed will determine
// precedence. Values in subsequent files will overwrite values defined in
// earlier files.
//
// For example, given two files A and B. Both define credentials. If the order
// of the files are A then B, B's credential values will be used instead of A's.
func NewSharedConfig(profile string, filenames []string) (SharedConfig, error) {
if len(filenames) == 0 {
return SharedConfig{}, fmt.Errorf("no shared config files provided")
}
files, err := loadSharedConfigIniFiles(filenames)
if err != nil {
return SharedConfig{}, err
}
cfg := SharedConfig{}
if err = cfg.setFromIniFiles(profile, files); err != nil {
return SharedConfig{}, err
}
if len(cfg.AssumeRole.sourceProfile) > 0 {
if err := cfg.setAssumeRoleSource(profile, files); err != nil {
return SharedConfig{}, err
}
}
return cfg, nil
}
type sharedConfigFile struct {
Filename string
IniData *ini.File
}
func loadSharedConfigIniFiles(filenames []string) ([]sharedConfigFile, error) {
files := make([]sharedConfigFile, 0, len(filenames))
errs := SharedConfigNotExistErrors{}
for _, filename := range filenames {
b, err := ioutil.ReadFile(filename)
if err != nil {
if os.IsNotExist(err) {
errs = append(errs,
SharedConfigFileNotExistError{Filename: filename, Err: err},
)
continue
}
return nil, SharedConfigLoadError{Filename: filename, Err: err}
}
f, err := ini.Load(b)
if err != nil {
return nil, SharedConfigLoadError{Filename: filename, Err: err}
}
files = append(files, sharedConfigFile{
Filename: filename, IniData: f,
})
}
if len(files) == 0 {
return nil, errs
}
return files, nil
}
func (c *SharedConfig) setAssumeRoleSource(origProfile string, files []sharedConfigFile) error {
var assumeRoleSrc SharedConfig
// Multiple level assume role chains are not support
if c.AssumeRole.sourceProfile == origProfile {
assumeRoleSrc = *c
assumeRoleSrc.AssumeRole = AssumeRoleConfig{}
} else {
err := assumeRoleSrc.setFromIniFiles(c.AssumeRole.sourceProfile, files)
if err != nil {
return SharedConfigAssumeRoleError{
Profile: c.Profile,
RoleARN: c.AssumeRole.RoleARN,
Err: err,
}
}
}
if len(assumeRoleSrc.Credentials.AccessKeyID) == 0 {
return SharedConfigAssumeRoleError{
Profile: c.Profile,
RoleARN: c.AssumeRole.RoleARN,
Err: fmt.Errorf("source profile has no shared credentials"),
}
}
c.AssumeRole.Source = &assumeRoleSrc
return nil
}
// Returns an error if all of the files fail to load. If at least one file is
// successfully loaded and contains the profile, no error will be returned.
func (c *SharedConfig) setFromIniFiles(profile string, files []sharedConfigFile) error {
c.Profile = profile
existErrs := SharedConfigNotExistErrors{}
for _, f := range files {
if err := c.setFromIniFile(profile, f); err != nil {
if _, ok := err.(SharedConfigProfileNotExistError); ok {
existErrs = append(existErrs, err)
continue
}
return err
}
}
if len(existErrs) == len(files) {
return existErrs
}
return nil
}
// setFromFile loads the configuration from the file using
// the profile provided. A SharedConfig pointer type value is used so that
// multiple config file loadings can be chained.
//
// Only loads complete logically grouped values, and will not set fields in cfg
// for incomplete grouped values in the config. Such as credentials. For example
// if a config file only includes aws_access_key_id but no aws_secret_access_key
// the aws_access_key_id will be ignored.
func (c *SharedConfig) setFromIniFile(profile string, file sharedConfigFile) error {
section, err := file.IniData.GetSection(profile)
if err != nil {
// Fallback to to alternate profile name: profile <name>
section, err = file.IniData.GetSection(fmt.Sprintf("profile %s", profile))
if err != nil {
return SharedConfigProfileNotExistError{
Filename: file.Filename,
Profile: profile,
Err: err,
}
}
}
// Shared Credentials
akid := section.Key(accessKeyIDKey).String()
secret := section.Key(secretAccessKey).String()
if len(akid) > 0 && len(secret) > 0 {
c.Credentials = aws.Credentials{
AccessKeyID: akid,
SecretAccessKey: secret,
SessionToken: section.Key(sessionTokenKey).String(),
Source: fmt.Sprintf("SharedConfigCredentials: %s", file.Filename),
}
}
// Assume Role
roleArn := section.Key(roleArnKey).String()
srcProfile := section.Key(sourceProfileKey).String()
if len(roleArn) > 0 && len(srcProfile) > 0 {
c.AssumeRole = AssumeRoleConfig{
RoleARN: roleArn,
ExternalID: section.Key(externalIDKey).String(),
MFASerial: section.Key(mfaSerialKey).String(),
RoleSessionName: section.Key(roleSessionNameKey).String(),
sourceProfile: srcProfile,
}
}
// Region
if v := section.Key(regionKey).String(); len(v) > 0 {
c.Region = v
}
return nil
}
// SharedConfigNotExistErrors provides an error type for failure to load shared
// config because resources do not exist.
type SharedConfigNotExistErrors []error
func (es SharedConfigNotExistErrors) Error() string {
msg := "failed to load shared config\n"
for _, e := range es {
msg += "\t" + e.Error()
}
return msg
}
// SharedConfigLoadError is an error for the shared config file failed to load.
type SharedConfigLoadError struct {
Filename string
Err error
}
// Cause is the underlying error that caused the failure.
func (e SharedConfigLoadError) Cause() error {
return e.Err
}
func (e SharedConfigLoadError) Error() string {
return fmt.Sprintf("failed to load shared config file, %s, %v", e.Filename, e.Err)
}
// SharedConfigFileNotExistError is an error for the shared config when
// the filename does not exist.
type SharedConfigFileNotExistError struct {
Filename string
Profile string
Err error
}
// Cause is the underlying error that caused the failure.
func (e SharedConfigFileNotExistError) Cause() error {
return e.Err
}
func (e SharedConfigFileNotExistError) Error() string {
return fmt.Sprintf("failed to open shared config file, %s, %v", e.Filename, e.Err)
}
// SharedConfigProfileNotExistError is an error for the shared config when
// the profile was not find in the config file.
type SharedConfigProfileNotExistError struct {
Filename string
Profile string
Err error
}
// Cause is the underlying error that caused the failure.
func (e SharedConfigProfileNotExistError) Cause() error {
return e.Err
}
func (e SharedConfigProfileNotExistError) Error() string {
return fmt.Sprintf("failed to get shared config profile, %s, in %s, %v", e.Profile, e.Filename, e.Err)
}
// SharedConfigAssumeRoleError is an error for the shared config when the
// profile contains assume role information, but that information is invalid
// or not complete.
type SharedConfigAssumeRoleError struct {
Profile string
RoleARN string
Err error
}
func (e SharedConfigAssumeRoleError) Error() string {
return fmt.Sprintf("failed to load assume role %s, of profile %s, %v",
e.RoleARN, e.Profile, e.Err)
}
func userHomeDir() string {
if runtime.GOOS == "windows" { // Windows
return os.Getenv("USERPROFILE")
}
// *nix
return os.Getenv("HOME")
}