actions: Simplify the callback mechanism

This commit makes the callbacks for getting keys easier to understand.
Functions which need keys now take a KeyFunc callback. This callback
contains a ProtectorInfo parameter (basically a read-only version of
metadata.ProtectorData) and a boolean which indicates if the call is
being retried. The documentation is also updated to say which functions
will retry the KeyFunc.

For selecting a protector, there is now an OptionFunc callback which
takes a slice of ProtectorOptions. A ProtectorOption is a ProtectorInfo
along with additional information about a linked filesystem (if
applicable).

This commit also adds in methods for getting the protector options for a
specific filesystem or policy. It also adds a function for getting the
policy descriptor for a specific path.

Change-Id: I41e0d94ffd44e7166b0c5cf1b5d18437960bdf90

1 files changed, 1 insertions, 1 deletions

diff --git a/actions/context_test.go b/actions/context_test.go
index 671b065..74629a3 100644
--- a/actions/context_test.go
+++ b/actions/context_test.go
@@ -31,7 +31,7 @@ var mountpoint = os.Getenv("TEST_FILESYSTEM_ROOT")
 // Makes a context using the testing locations for the filesystem and
 // configuration file.
 func makeContext() (*Context, error) {
-	if err := NewConfigFile(testTime, true); err != nil {
+	if err := CreateConfigFile(testTime, true); err != nil {
 		return nil, err
 	}