Add TokenManager interface and basic implementation

Signed-off-by: Nataliya Issayeva <nissayeva@users.noreply.github.com>

packages/backend-common/src/index.ts

@@ -31,4 +31,5 @@ export * from './paths';
 export * from './reading';
 export * from './scm';
 export * from './service';
+export * from './tokens';
 export * from './util';

packages/backend-common/src/tokens/AuthIdentityTokenManager.ts

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2021 The Backstage Authors
+ *
+ * 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.
+ */
+
+import { TokenManager } from './types';
+
+export class AuthIdentityTokenManager implements TokenManager {
+  private readonly SERVER_TOKEN = 'server-token';
+
+  async getServerToken(): Promise<{ token: string }> {
+    return { token: this.SERVER_TOKEN };
+  }
+
+  async validateToken(token: string): Promise<void> {
+    if (token !== this.SERVER_TOKEN) {
+      throw new Error('Invalid server token');
+    }
+  }
+}

packages/backend-common/src/tokens/index.ts

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2021 The Backstage Authors
+ *
+ * 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.
+ */
+
+export type { TokenManager } from './types';

packages/backend-common/src/tokens/types.ts

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2021 The Backstage Authors
+ *
+ * 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.
+ */
+
+export interface TokenManager {
+  getServerToken: () => Promise<{ token: string }>;
+  validateToken: (token: string) => Promise<void>;
+}