debian-mirror-gitlab/workhorse/internal/objectstore/s3_session.go
2021-10-27 15:23:28 +05:30

94 lines
2.9 KiB
Go

package objectstore
import (
"sync"
"time"
"github.com/aws/aws-sdk-go/aws"
"github.com/aws/aws-sdk-go/aws/credentials"
"github.com/aws/aws-sdk-go/aws/session"
"gitlab.com/gitlab-org/gitlab/workhorse/internal/config"
)
type s3Session struct {
session *session.Session
expiry time.Time
}
type s3SessionCache struct {
// An S3 session is cached by its input configuration (e.g. region,
// endpoint, path style, etc.), but the bucket is actually
// determined by the type of object to be uploaded (e.g. CI
// artifact, LFS, etc.) during runtime. In practice, we should only
// need one session per Workhorse process if we only allow one
// configuration for many different buckets. However, using a map
// indexed by the config avoids potential pitfalls in case the
// bucket configuration is supplied at startup or we need to support
// multiple S3 endpoints.
sessions map[config.S3Config]*s3Session
sync.Mutex
}
func (s *s3Session) isExpired() bool {
return time.Now().After(s.expiry)
}
func newS3SessionCache() *s3SessionCache {
return &s3SessionCache{sessions: make(map[config.S3Config]*s3Session)}
}
var (
// By default, it looks like IAM instance profiles may last 6 hours
// (via curl http://169.254.169.254/latest/meta-data/iam/security-credentials/<role_name>),
// but this may be configurable from anywhere for 15 minutes to 12
// hours. To be safe, refresh AWS sessions every 10 minutes.
sessionExpiration = time.Duration(10 * time.Minute)
sessionCache = newS3SessionCache()
)
// SetupS3Session initializes a new AWS S3 session and refreshes one if
// necessary. As recommended in https://docs.aws.amazon.com/sdk-for-go/v1/developer-guide/sessions.html,
// sessions should be cached when possible. Sessions are safe to use
// concurrently as long as the session isn't modified.
func setupS3Session(s3Credentials config.S3Credentials, s3Config config.S3Config) (*session.Session, error) {
sessionCache.Lock()
defer sessionCache.Unlock()
if s, ok := sessionCache.sessions[s3Config]; ok && !s.isExpired() {
return s.session, nil
}
cfg := &aws.Config{
Region: aws.String(s3Config.Region),
S3ForcePathStyle: aws.Bool(s3Config.PathStyle),
}
// In case IAM profiles aren't being used, use the static credentials
if s3Credentials.AwsAccessKeyID != "" && s3Credentials.AwsSecretAccessKey != "" {
cfg.Credentials = credentials.NewStaticCredentials(s3Credentials.AwsAccessKeyID, s3Credentials.AwsSecretAccessKey, "")
}
if s3Config.Endpoint != "" {
cfg.Endpoint = aws.String(s3Config.Endpoint)
}
sess, err := session.NewSession(cfg)
if err != nil {
return nil, err
}
sessionCache.sessions[s3Config] = &s3Session{
expiry: time.Now().Add(sessionExpiration),
session: sess,
}
return sess, nil
}
func ResetS3Session(s3Config config.S3Config) {
sessionCache.Lock()
defer sessionCache.Unlock()
delete(sessionCache.sessions, s3Config)
}