--- a/pkg/auth/store.go	Mon Nov 26 11:01:11 2018 +0100
+++ b/pkg/auth/store.go	Mon Nov 26 11:15:52 2018 +0100
@@ -22,11 +22,14 @@
 	bolt "github.com/etcd-io/bbolt"
 )
 
+// ErrNoSuchToken is returned if a given token does not
+// exists th the session store.
 var ErrNoSuchToken = errors.New("No such token")
 
 // Sessions is the global connection pool.
 var Sessions *SessionStore
 
+// SessionStore encapsulates a set of currently active sessions.
 type SessionStore struct {
 	storage  *bolt.DB
 	sessions map[string]*Session
@@ -35,6 +38,11 @@
 
 var sessionsBucket = []byte("sessions")
 
+// NewSessionStore creates a new session store.
+// If the filename is empty the session are only hold in memory.
+// If the filename is not empty the sessions are mirrored to
+// a file with this name. Use the later option if you want
+// a persistent session store.
 func NewSessionStore(filename string) (*SessionStore, error) {
 
 	ss := &SessionStore{
@@ -125,6 +133,8 @@
 	}
 }
 
+// Delete removes a session identified by its token from the
+// session store. Returns true if there was such s session.
 func (ss *SessionStore) Delete(token string) bool {
 	res := make(chan bool)
 	ss.cmds <- func() {
@@ -156,6 +166,9 @@
 	}
 }
 
+// Add puts a session into the session store identified by
+// a given token. An old session with the same key will
+// be replaced.
 func (ss *SessionStore) Add(token string, session *Session) {
 	res := make(chan struct{})
 
@@ -173,6 +186,9 @@
 	<-res
 }
 
+// Renew refreshes a session. It takes an old token to
+// identify a session and returns a new token with the
+// freshed up one.
 func (ss *SessionStore) Renew(token string) (string, error) {
 
 	type result struct {
@@ -202,6 +218,8 @@
 	return r.newToken, r.err
 }
 
+// Session returns the session associated with given token.
+// Returns nil if no matching session was found.
 func (ss *SessionStore) Session(token string) *Session {
 	res := make(chan *Session)
 	ss.cmds <- func() {
@@ -217,6 +235,7 @@
 	return <-res
 }
 
+// Logout removes all sessions of a given user from the session store.
 func (ss *SessionStore) Logout(user string) {
 	ss.cmds <- func() {
 		for token, session := range ss.sessions {
@@ -228,6 +247,8 @@
 	}
 }
 
+// Shutdown closes the session store.
+// If using the persistent mode the backing session database is closed.
 func (ss *SessionStore) Shutdown() error {
 	if db := ss.storage; db != nil {
 		log.Println("info: shutdown persistent session store.")