Add rest-api example (#889)

examples/rest-api/utils.py

@@ -0,0 +1,21 @@
+def generate_error_message_for_api_keys(error: ValueError) -> str:
+    env_mapping = {
+        "OPENAI_API_KEY": "OPENAI_API_KEY",
+        "OPENAI_API_TYPE": "OPENAI_API_TYPE",
+        "OPENAI_API_BASE": "OPENAI_API_BASE",
+        "OPENAI_API_VERSION": "OPENAI_API_VERSION",
+        "COHERE_API_KEY": "COHERE_API_KEY",
+        "ANTHROPIC_API_KEY": "ANTHROPIC_API_KEY",
+        "JINACHAT_API_KEY": "JINACHAT_API_KEY",
+        "HUGGINGFACE_ACCESS_TOKEN": "HUGGINGFACE_ACCESS_TOKEN",
+        "REPLICATE_API_TOKEN": "REPLICATE_API_TOKEN",
+    }
+
+    missing_keys = [env_mapping[key] for key in env_mapping if key in str(error)]
+    if missing_keys:
+        missing_keys_str = ", ".join(missing_keys)
+        return f"""Please set the {missing_keys_str} environment variable(s) when running the Docker container.
+Example: `docker run -e {missing_keys[0]}=xxx embedchain/app:rest-api-latest`
+"""
+    else:
+        return "Unknown error occurred."