secretsource: move all external developers relevant parts in one file

Author: mstoykov

secretsource/extension.go

@@ -14,6 +14,16 @@ import (
 // the secret.
 type Constructor func(Params) (Source, error)
 
+// Source is the interface a secret source needs to implement
+type Source interface {
+	// Human readable description to be printed on the cli
+	Description() string
+	// Get retrives the value for a given key and returns it.
+	// Logging the value before it is returned is going to lead to it being leaked.
+	// The error might lead to an exception visible to users.
+	Get(key string) (value string, err error)
+}
+
 // Params contains all possible constructor parameters an output may need.
 type Params struct {
 	ConfigArgument string // the string on the cli