Add user list

users/user.go

@@ -1,6 +1,10 @@
 package users
 
-import "golang.org/x/crypto/bcrypt"
+import (
+	"fmt"
+
+	"golang.org/x/crypto/bcrypt"
+)
 
 type Role string
 
@@ -16,10 +20,13 @@ type User struct {
 	Role           Role   `json:"role"`
 }
 
+var ErrNoSuchUser = fmt.Errorf("no such user")
+
 type UserStore interface {
 	Get(username string) (*User, error)
 	Store(user *User) error
 	Delete(username string) error
+	List() ([]string, error)
 }
 
 func (u *User) ValidatePassword(password string) error {

users/userstore_bolt.go

@@ -6,6 +6,8 @@ import (
 	"go.etcd.io/bbolt"
 )
 
+var _ UserStore = &BoltUserStore{}
+
 var keyUsers = []byte("users")
 
 type BoltUserStore struct {
@@ -67,3 +69,22 @@ func (s *BoltUserStore) Delete(username string) error {
 		return bkt.Delete([]byte(username))
 	})
 }
+func (s *BoltUserStore) List() ([]string, error) {
+	var ids []string
+
+	err := s.db.View(func(tx *bbolt.Tx) error {
+		bkt := tx.Bucket(keyUsers)
+
+		c := bkt.Cursor()
+
+		for k, _ := c.First(); k != nil; k, _ = c.Next() {
+			ids = append(ids, string(k))
+		}
+
+		return nil
+	})
+	if err != nil {
+		return nil, err
+	}
+	return ids, nil
+}

users/userstore_memory.go

@@ -5,6 +5,8 @@ import (
 	"sync"
 )
 
+var _ UserStore = &MemoryUserStore{}
+
 type MemoryUserStore struct {
 	users map[string]*User
 	lock  sync.Mutex
@@ -37,3 +39,14 @@ func (s *MemoryUserStore) Delete(username string) error {
 	delete(s.users, username)
 	return nil
 }
+func (s *MemoryUserStore) List() ([]string, error) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	var ids []string
+	for k := range s.users {
+		ids = append(ids, k)
+	}
+
+	return ids, nil
+}

users/userstore_test.go

@@ -47,5 +47,27 @@ func RunUserStoreTest(newFunc func() (func(), users.UserStore), t *testing.T) {
 				t.Errorf("User mismatch: %s", cmp.Diff(user, userMap[k]))
 			}
 		}
+
+		l, err := s.List()
+		if err != nil {
+			t.Fatalf("Error listing users: %s", err)
+		}
+		if len(l) != len(userMap) {
+			t.Errorf("List wrong amount of users.")
+		}
+
+		for _, username := range l {
+			if err := s.Delete(username); err != nil {
+				t.Fatalf("Error deleting user: %s", err)
+			}
+		}
+
+		l, err = s.List()
+		if err != nil {
+			t.Fatalf("Error listing after delete: %s", err)
+		}
+		if len(l) != 0 {
+			t.Fatalf("List is not empty after deleting all")
+		}
 	})
 }