Ingress traffic¶

Ingress traffic is traffic that is directed to your application from the internet. This is done by configuring the ingresses block in your NAIS application yaml manifest with the domains you want your application to receive traffic from.

graph LR
  accTitle: Access to application via ingress
  accDescr {
    The sequence diagram shows the following steps:
    1. the user accessing https://myapp.dev.nav.no
    2. The app sends a request to the ingress controller, within the Kubernetes container. http://myapp.mynamespace.svc.cluster.local
    3. The request is sent to another container, the namespace, which contains a service.
    4. The service within the Namespace container can send the request to Pod 1 or Pod 2
  }
  user[User]
  user -->|https://myapp.dev.nav.no| ingresscontroller
  subgraph Kubernetes
    ingresscontroller[Ingress Controller]

    subgraph Namespace
      pod1[Pod 1]
      pod2[Pod 2]
      svc[Service]

      svc-->pod1
      svc-->pod2
    end

    ingresscontroller-->|http://myapp.mynamespace.svc.cluster.local| svc
  end

You can tweak the Ingress configuration by specifying certain Kubernetes annotations in your app spec. A list of supported variables are specified in the Nginx ingress documentation.

As the Nginx ingress documentation states, these parameters are set on the Ingress object. However, Naiserator will copy these parameters from your Application spec.

Custom max body size¶

For nginx, an 413 error will be returned to the client when the size in a request exceeds the maximum allowed size of the client request body. By default, this is set to 1m (1 megabyte).

metadata:
  annotations:
    nginx.ingress.kubernetes.io/proxy-body-size: "8m"

Custom proxy buffer size¶

Sets the size of the buffer proxy_buffer_size used for reading the first part of the response received from the proxied server. By default proxy buffer size is set as 4k

metadata:
  annotations:
    nginx.ingress.kubernetes.io/proxy-buffer-size: "8k"

Custom timeouts¶

In some scenarios is required to have different values for various timeouts. To allow this we provide parameters that allows this customization:

nginx.ingress.kubernetes.io/proxy-connect-timeout
nginx.ingress.kubernetes.io/proxy-send-timeout
nginx.ingress.kubernetes.io/proxy-read-timeout
nginx.ingress.kubernetes.io/proxy-next-upstream
nginx.ingress.kubernetes.io/proxy-next-upstream-timeout
nginx.ingress.kubernetes.io/proxy-next-upstream-tries
nginx.ingress.kubernetes.io/proxy-request-buffering

Note: All timeout values are unitless and in seconds e.g. nginx.ingress.kubernetes.io/proxy-read-timeout: "120" sets a valid 120 seconds proxy read timeout.

WebSockets Support¶

Support for websockets is provided by nginx ingress controller out of the box. No special configuration required.

The only requirement to avoid the close of connections is the increase of the values of proxy-read-timeout and proxy-send-timeout.

The default value of this settings is 60 seconds.

A more adequate value to support websockets is a value higher than one hour (3600).

apiVersion: nais.io/v1alpha1
kind: Application
metadata:
  name: myapplication
  namespace: myteam
  annotations:
    nginx.ingress.kubernetes.io/proxy-read-timeout: "600"
    nginx.ingress.kubernetes.io/proxy-send-timeout: "600"
spec:
  ...

Ingress metrics¶

All requests to your application via ingress will result in metrics being emitted to Prometheus. The metrics are prefixed with nginx_ingress_controller_requests_ and are tagged with the following labels: status, method, host, path, namespace, service.

Ingress metrics label descriptions

Label	Description
`status`	HTTP status code
`method`	HTTP method
`host`	Host header (domain)
`path`	Request path
`namespace`	Namespace of the ingress
`service`	Name of the service (app name)

Example PromQL Queries¶

Number of requests to the myapp application, grouped by status code:

sum by (status) (nginx_ingress_controller_requests{service="myapp", namespace="myteam"})

Number of 5xx errors to the myapp application:

sum(nginx_ingress_controller_requests{service="myapp", namespace="myteam", status=~"5.."})

Percentage of 5xx errors to the myapp application as a ratio of total requests:

100 * (
  sum by (service) (rate(nginx_ingress_controller_requests{status=~"^5\\d\\d", namespace="myteam", service="myapp"}[3m]))
  /
  sum by (service) (rate(nginx_ingress_controller_requests{namespace="myteam", service="myapp"}[3m]))
)

Ingress access logs¶

Request access logs from nginx ingress controller are automatically collected and stored in Kibana.

Here are pre-configured queries for the controller logs in the following clusters:

Log fields description¶

Field	Description
`message`	HTTP request on the following format: "`method` `path` `httpVersion`"
`response_code`	HTTP response code from nginx
`x_upstream_name`	The application receiving the request on the following format "`namespace`-`app-name`-`port`"
`x_upstream_status`	HTTP response code from the application
`x_request_id`	Unique request ID used for correlating further requests from the application to other services

Find your access logs¶

In order to find your team's application access logs, you need to filter on the following fields:

AND x_upstream_name: my-namespace* (replace my-namespace with your namespace)

If you want to filter on a specific application, you can add the following filter:

AND x_upstream_name: my-namespace-my-app* (replace my-namespace with your namespace and my-app with your application name)

If you want to filter out specific HTTP response codes, you can add the following filter:

NOT response_code: 404 (replace 404 with the HTTP response code you want to filter out)

If you want to filter out multiple HTTP response codes, you can add the following filter:

NOT response_code: (404 or 503) (replace 404 and 503 with the HTTP response codes you want to filter out)

If you want to find specific HTTP methods, you can add the following filter:

AND message: GET* (replace GET with the HTTP method you want to filter out)

Some debugging tips¶

If response_code and x_upstream_status are the same it means that the application returned this response code – not nginx. Look in the logs for the corresponding application, this is not a problem with nginx.

Here are some suggestions depending on what http status code you might recieve from nginx:

Code	Suggestion
`400 Bad Request`	If nginx returns `401` error with no further explanation and there is no `x_upstream_name` it means that nginx received an invalid request before it could be sent to the backend. One of the most common problems is duplicate `Authorization` headers.
`413 Request Entity Too Large`	If nginx return `413` error it means that the request body is too large. This can be caused by a large file upload or a large request body. The solution is to add the `proxy-body-size` ingress parameter to an appropriate size.
`502 Bad Gateway`	If nginx return `502` error but the application is returning a `2xx` status code it might be caused by large response headers often cookies. The solution is the add the `proxy-buffer-size` to an appropriate size.

Full ingress example¶

nais.yamlingress.yaml

apiVersion: nais.io/v1alpha1
kind: Application
metadata:
  name: myapplication
  namespace: myteam
  annotations:
    nginx.ingress.kubernetes.io/proxy-body-size: "256M"
    nginx.ingress.kubernetes.io/proxy-buffer-size: "8k"
    nginx.ingress.kubernetes.io/proxy-read-timeout: "300"
spec:
  service:
    protocol: http
  ingresses:
    - https://myapplication.nav.no

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: myapplication-gw-nav-no-abcd1234
  namespace: myteam
  annotations:
    nginx.ingress.kubernetes.io/backend-protocol: "HTTP"    # from ".service.protocol"
    nginx.ingress.kubernetes.io/use-regex: "true"           # this is always on
    nginx.ingress.kubernetes.io/proxy-body-size: "256M"     # copied from annotations
    nginx.ingress.kubernetes.io/proxy-buffer-size: "8k"     # copied from annotations
    nginx.ingress.kubernetes.io/proxy-read-timeout: "300"   # copied from annotations

Last update: 2022-10-21
Created: 2021-05-10