Initial commit: stateful OpenStack API laboratory simulator.

Ship Keystone auth, multi-service handlers (Yoga→Dalmatian), Compose/Helm
packaging, API contract packs, and pytest/Pulumi coverage labs.

app/config.py

@@ -0,0 +1,61 @@
+"""Typed application configuration."""
+
+from __future__ import annotations
+
+from functools import lru_cache
+from pathlib import Path
+from typing import Literal
+
+from pydantic import Field, SecretStr
+from pydantic_settings import BaseSettings, SettingsConfigDict
+
+
+class Settings(BaseSettings):
+    """Runtime settings loaded from environment variables and an optional `.env`."""
+
+    model_config = SettingsConfigDict(
+        env_file=".env",
+        env_file_encoding="utf-8",
+        extra="ignore",
+        frozen=True,
+    )
+
+    app_name: str = "openstack-api-simulator"
+    app_host: str = "0.0.0.0"  # noqa: S104 - the container must accept external traffic
+    # Internal listen port. Public OpenStack service ports are published by api-gateway.
+    app_port: int = Field(default=8080, ge=1, le=65535)
+    database_url: SecretStr = SecretStr(
+        "postgresql://openstack:openstack@localhost:5432/openstack_simulator"
+    )
+    db_pool_min_size: int = Field(default=1, ge=1, le=100)
+    db_pool_max_size: int = Field(default=10, ge=1, le=100)
+    db_connect_timeout_seconds: float = Field(default=10.0, gt=0, le=60)
+    db_command_timeout_seconds: float = Field(default=30.0, gt=0, le=300)
+    log_level: str = "INFO"
+    request_id_header: str = "X-Request-ID"
+    contract_snapshot: Path | None = None
+    compatibility_evidence: Path | None = None
+    contract_fallback: Literal["error", "schema-default", "fixture"] = "error"
+    catalog_artifact_url_6: str = "stub://openstack/yoga/api-contract"
+    catalog_artifact_url_7: str = "stub://openstack/antelope/api-contract"
+    catalog_artifact_url_8: str = "stub://openstack/caracal/api-contract"
+    catalog_artifact_url_9: str = "stub://openstack/dalmatian/api-contract"
+    ticket_signing_key: SecretStr = SecretStr("development-only-signing-key-change-me")
+    task_worker_concurrency: int = Field(default=2, ge=1, le=32)
+    task_lease_seconds: float = Field(default=30.0, gt=1, le=300)
+    simulation_time_scale: float = Field(default=10.0, gt=0, le=10000)
+
+    def catalog_artifact_urls(self) -> dict[int, str]:
+        return {
+            6: self.catalog_artifact_url_6,
+            7: self.catalog_artifact_url_7,
+            8: self.catalog_artifact_url_8,
+            9: self.catalog_artifact_url_9,
+        }
+
+
+@lru_cache(maxsize=1)
+def get_settings() -> Settings:
+    """Return the immutable process configuration."""
+
+    return Settings()