fix: instantiate settings lazily to avoid requiring environment variables during import and testing

Author: a-klos

libs/admin-api-lib/src/admin_api_lib/dependency_container.py

@@ -91,12 +91,15 @@ class DependencyContainer(DeclarativeContainer):
     stackit_chunker_embedder_settings = StackitEmbedderSettings()
     ollama_chunker_embedder_settings = OllamaEmbedderSettings()
     ollama_settings = OllamaSettings()
-    langfuse_settings = LangfuseSettings()
-    stackit_vllm_settings = StackitVllmSettings()
+    # Instantiate lazily: env vars are required and should not be needed during import/test collection.
+    langfuse_settings = Singleton(LangfuseSettings)
+    # Instantiate lazily: STACKIT_VLLM_API_KEY may not be set for unit tests.
+    stackit_vllm_settings = Singleton(StackitVllmSettings)
     document_extractor_settings = DocumentExtractorSettings()
     rag_class_type_settings = RAGClassTypeSettings()
     rag_api_settings = RAGAPISettings()
-    key_value_store_settings = KeyValueSettings()
+    # Instantiate lazily: USECASE_KEYVALUE_HOST / USECASE_KEYVALUE_PORT are required.
+    key_value_store_settings = Singleton(KeyValueSettings)
     summarizer_settings = SummarizerSettings()
     source_uploader_settings = SourceUploaderSettings()
     retry_decorator_settings = RetryDecoratorSettings()
@@ -168,9 +171,9 @@ class DependencyContainer(DeclarativeContainer):
 
     langfuse = Singleton(
         Langfuse,
-        public_key=langfuse_settings.public_key,
-        secret_key=langfuse_settings.secret_key,
-        host=langfuse_settings.host,
+        public_key=langfuse_settings.provided.public_key,
+        secret_key=langfuse_settings.provided.secret_key,
+        host=langfuse_settings.provided.host,
     )
     summarizer_prompt = SUMMARIZE_PROMPT