> **FastCGI** is a [binary protocol](https://en.wikipedia.org/wiki/Binary_protocol "Binary protocol") for interfacing interactive programs with a [web server](https://en.wikipedia.org/wiki/Web_server "Web server"). [...] (It's) aim is to reduce the overhead related to interfacing between web server and CGI programs, allowing a server to handle more web page requests per unit of time.
The _ingress-nginx_ ingress controller can be used to directly expose [FastCGI](https://en.wikipedia.org/wiki/FastCGI) servers. Enabling FastCGI in your Ingress only requires setting the _backend-protocol_ annotation to `FCGI`, and with a couple more annotations you can customize the way _ingress-nginx_ handles the communication with your FastCGI _server_.
The _Pod_ example object below exposes port `9000`, which is the conventional FastCGI port.
```yaml
apiVersion: v1
kind: Pod
metadata:
name: example-app
labels:
app: example-app
spec:
containers:
- name: example-app
image: example-app:1.0
ports:
- containerPort: 9000
name: fastcgi
```
The _Service_ object example below matches port `9000` from the _Pod_ object above.
```yaml
apiVersion: v1
kind: Service
metadata:
name: example-service
spec:
selector:
app: example-app
ports:
- port: 9000
targetPort: 9000
name: fastcgi
```
And the _Ingress_ and _ConfigMap_ objects below demonstrates the supported _FastCGI_ specific annotations (NGINX actually has 50 FastCGI directives, all of which have not been exposed in the ingress yet), and matches the service `example-service`, and the port named `fastcgi` from above. The _ConfigMap_**must** be created first for the _Ingress Controller_ to be able to find it when the _Ingress_ object is created, otherwise you will need to restart the _Ingress Controller_ pods.
```yaml
# The ConfigMap MUST be created first for the ingress controller to be able to
**This enables the _FastCGI_ mode for all paths defined in the _Ingress_ object**
### The `nginx.ingress.kubernetes.io/fastcgi-index` Annotation
To specify an index file, the `fastcgi-index` annotation value can optionally be set. In the example below, the value is set to `index.php`. This annotation corresponds to [the _NGINX_ `fastcgi_index` directive](https://nginx.org/en/docs/http/ngx_http_fastcgi_module.html#fastcgi_index).
### The `nginx.ingress.kubernetes.io/fastcgi-params-configmap` Annotation
To specify [_NGINX_ `fastcgi_param` directives](https://nginx.org/en/docs/http/ngx_http_fastcgi_module.html#fastcgi_param), the `fastcgi-params-configmap` annotation is used, which in turn must lead to a _ConfigMap_ object containing the _NGINX_`fastcgi_param` directives as key/values.
