# Using WSGI with Nova

Changed in version 33.0.0: Removed support for the eventlet server scripts, `nova-api`, `nova-api-metadata` and `nova-api-os-compute`. Only WSGI-based deployments are supported going forward and it is no longer possible to run the compute API and metadata APIs in the same process, as it was with the eventlet scripts.

Changed in version 33.0.0: Removed the `nova-api-wsgi` and `nova-metadata-wsgi` WSGI scripts previously provided by Nova. Deployment tooling should instead reference the Python module paths for these services, `nova.wsgi.osapi_compute` and `nova.wsgi.metadata`, if their chosen WSGI server supports this (gunicorn, uWSGI) or implement a `.wsgi` script themselves if not (mod_wsgi).

Nova provides two APIs: a compute API (a.k.a. the REST API) and a metadata API. Both of these APIs are implemented as generic Python HTTP servers that implement WSGI and are expected to be deployed using a server with WSGI support.

To facilitate this, Nova provides a WSGI module for each API that provide the `application` object that most WSGI servers require. These can be found at `nova.wsgi.osapi_compute` and `nova.wsgi.metadata` for the compute API and the metadata API, respectively. The `application` objects are automatically configured with configuration from `nova.conf` and `api-paste.ini` by default, and the the config files and config directory can be overridden via the `OS_NOVA_CONFIG_FILES` and `OS_NOVA_CONFIG_DIR` environment variables.

Note

File paths listed in `OS_NOVA_CONFIG_FILES` are relative to `OS_NOVA_CONFIG_DIR` and delimited by `;`.

DevStack deploys the compute and metadata APIs behind Apache using uwsgi via mod_proxy_uwsgi. Inspecting the configuration created there can provide some guidance on one option for managing the WSGI scripts. It is important to remember, however, that one of the major features of using WSGI is that there are many different ways to host a WSGI application. Different servers make different choices about performance and configurability. It is up to you, as a deployer, to choose an appropriate server for your deployment.

this page last updated: 2026-06-08 08:40:45

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