generic cred helper

extension/credentialshelper/credentialshelper.go

@@ -0,0 +1,84 @@
+package credentialshelper
+
+import (
+	"errors"
+	"sync"
+
+	"github.com/keel-hq/keel/types"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// CredentialsHelper is a generic interface for implementing cloud vendor specific
+// authorization code
+type CredentialsHelper interface {
+	GetCredentials(registry string) (*types.Credentials, error)
+	IsEnabled() bool
+}
+
+// Common errors
+var (
+	ErrCredentialsNotAvailable = errors.New("no credentials available for this registry")
+)
+
+var (
+	credHelpersM sync.RWMutex
+	credHelpers  = make(map[string]CredentialsHelper)
+)
+
+func RegisterCredentialsHelper(name string, ch CredentialsHelper) {
+	if name == "" {
+		panic("credentialshelper: could not register a Credentials Helper with an empty name")
+	}
+
+	if ch == nil {
+		panic("credentialshelper: could not register a nil Credentials Helper")
+	}
+
+	credHelpersM.Lock()
+	defer credHelpersM.Unlock()
+
+	if _, dup := credHelpers[name]; dup {
+		panic("credentialshelper: RegisterCredentialsHelper called twice for " + name)
+	}
+
+	log.WithFields(log.Fields{
+		"name": name,
+	}).Info("extension.credentialshelper: helper registered")
+
+	credHelpers[name] = ch
+}
+
+// CredentialsHelpers
+type CredentialsHelpers struct {
+}
+
+// New returns a combined list of credential helpers
+func New() *CredentialsHelpers {
+	return &CredentialsHelpers{}
+}
+
+func (ch *CredentialsHelpers) GetCredentials(registry string) (*types.Credentials, error) {
+	credHelpersM.RLock()
+	defer credHelpersM.RUnlock()
+
+	for name, credHelper := range credHelpers {
+		if credHelper.IsEnabled() {
+			creds, err := ch.GetCredentials(registry)
+			if err != nil {
+				if err == ErrCredentialsNotAvailable {
+					continue
+				}
+				log.WithFields(log.Fields{
+					"helper":   name,
+					"error":    err,
+					"registry": registry,
+				}).Error("extension.credentialshelper: credentials not found")
+				continue
+			}
+			return creds, nil
+		}
+	}
+
+	return nil, ErrCredentialsNotAvailable
+}