Rename serverkeyapi to signingkeyserver (#1492)

* Rename serverkeyapi to signingkeyserver

We use "api" for public facing stuff and "server" for internal stuff.
As the server key API is internal only, we call it 'signing key server',
which also clarifies the type of key (as opposed to TLS keys, E2E keys, etc)

* Convert docker/scripts to use signing-key-server

* Rename missed bits

signingkeyserver/storage/keydb.go

@@ -0,0 +1,45 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !wasm
+
+package storage
+
+import (
+	"fmt"
+
+	"golang.org/x/crypto/ed25519"
+
+	"github.com/matrix-org/dendrite/internal/config"
+	"github.com/matrix-org/dendrite/signingkeyserver/storage/postgres"
+	"github.com/matrix-org/dendrite/signingkeyserver/storage/sqlite3"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+// NewDatabase opens a database connection.
+func NewDatabase(
+	dbProperties *config.DatabaseOptions,
+	serverName gomatrixserverlib.ServerName,
+	serverKey ed25519.PublicKey,
+	serverKeyID gomatrixserverlib.KeyID,
+) (Database, error) {
+	switch {
+	case dbProperties.ConnectionString.IsSQLite():
+		return sqlite3.NewDatabase(dbProperties, serverName, serverKey, serverKeyID)
+	case dbProperties.ConnectionString.IsPostgres():
+		return postgres.NewDatabase(dbProperties, serverName, serverKey, serverKeyID)
+	default:
+		return nil, fmt.Errorf("unexpected database type")
+	}
+}