Annotations ¶

You can add these Kubernetes annotations to specific Ingress objects to customize their behavior.

Canary ¶

In some cases, you may want to "canary" a new set of changes by sending a small number of requests to a different service than the production service. The canary annotation enables the Ingress spec to act as an alternative service for requests to route to depending on the rules applied. The following annotations to configure canary can be enabled after nginx.ingress.kubernetes.io/canary: "true" is set:

• nginx.ingress.kubernetes.io/canary-by-header: The header to use for notifying the Ingress to route the request to the service specified in the Canary Ingress. When the request header is set to always, it will be routed to the canary. When the header is set to never, it will never be routed to the canary. For any other value, the header will be ignored and the request compared against the other canary rules by precedence.

• nginx.ingress.kubernetes.io/canary-by-header-value: The header value to match for notifying the Ingress to route the request to the service specified in the Canary Ingress. When the request header is set to this value, it will be routed to the canary. For any other header value, the header will be ignored and the request compared against the other canary rules by precedence. This annotation has to be used together with nginx.ingress.kubernetes.io/canary-by-header. The annotation is an extension of the nginx.ingress.kubernetes.io/canary-by-header to allow customizing the header value instead of using hardcoded values. It doesn't have any effect if the nginx.ingress.kubernetes.io/canary-by-header annotation is not defined.

• nginx.ingress.kubernetes.io/canary-by-header-pattern: This works the same way as canary-by-header-value except it does PCRE Regex matching. Note that when canary-by-header-value is set this annotation will be ignored. When the given Regex causes error during request processing, the request will be considered as not matching.

• nginx.ingress.kubernetes.io/canary-by-cookie: The cookie to use for notifying the Ingress to route the request to the service specified in the Canary Ingress. When the cookie value is set to always, it will be routed to the canary. When the cookie is set to never, it will never be routed to the canary. For any other value, the cookie will be ignored and the request compared against the other canary rules by precedence.

• nginx.ingress.kubernetes.io/canary-weight: The integer based (0 - ) percent of random requests that should be routed to the service specified in the canary Ingress. A weight of 0 implies that no requests will be sent to the service in the Canary ingress by this canary rule. A weight of <weight-total> means implies all requests will be sent to the alternative service specified in the Ingress. <weight-total> defaults to 100, and can be increased via nginx.ingress.kubernetes.io/canary-weight-total.

• nginx.ingress.kubernetes.io/canary-weight-total: The total weight of traffic. If unspecified, it defaults to 100.

Canary rules are evaluated in order of precedence. Precedence is as follows: canary-by-header -> canary-by-cookie -> canary-weight

Note that when you mark an ingress as canary, then all the other non-canary annotations will be ignored (inherited from the corresponding main ingress) except nginx.ingress.kubernetes.io/load-balance, nginx.ingress.kubernetes.io/upstream-hash-by, and annotations related to session affinity. If you want to restore the original behavior of canaries when session affinity was ignored, set nginx.ingress.kubernetes.io/affinity-canary-behavior annotation with value legacy on the canary ingress definition.

Known Limitations

Currently a maximum of one canary ingress can be applied per Ingress rule.

Rewrite ¶

In some scenarios the exposed URL in the backend service differs from the specified path in the Ingress rule. Without a rewrite any request will return 404. Set the annotation nginx.ingress.kubernetes.io/rewrite-target to the path expected by the service.

If the Application Root is exposed in a different path and needs to be redirected, set the annotation nginx.ingress.kubernetes.io/app-root to redirect requests for /.

Session Affinity ¶

The annotation nginx.ingress.kubernetes.io/affinity enables and sets the affinity type in all Upstreams of an Ingress. This way, a request will always be directed to the same upstream server. The only affinity type available for NGINX is cookie.

The annotation nginx.ingress.kubernetes.io/affinity-mode defines the stickiness of a session. Setting this to balanced (default) will redistribute some sessions if a deployment gets scaled up, therefore rebalancing the load on the servers. Setting this to persistent will not rebalance sessions to new servers, therefore providing maximum stickiness.

The annotation nginx.ingress.kubernetes.io/affinity-canary-behavior defines the behavior of canaries when session affinity is enabled. Setting this to sticky (default) will ensure that users that were served by canaries, will continue to be served by canaries. Setting this to legacy will restore original canary behavior, when session affinity was ignored.

Cookie affinity ¶

If you use the cookie affinity type you can also specify the name of the cookie that will be used to route the requests with the annotation nginx.ingress.kubernetes.io/session-cookie-name. The default is to create a cookie named 'INGRESSCOOKIE'.

The NGINX annotation nginx.ingress.kubernetes.io/session-cookie-path defines the path that will be set on the cookie. This is optional unless the annotation nginx.ingress.kubernetes.io/use-regex is set to true; Session cookie paths do not support regex.

Use nginx.ingress.kubernetes.io/session-cookie-domain to set the Domain attribute of the sticky cookie.

Use nginx.ingress.kubernetes.io/session-cookie-samesite to apply a SameSite attribute to the sticky cookie. Browser accepted values are None, Lax, and Strict. Some browsers reject cookies with SameSite=None, including those created before the SameSite=None specification (e.g. Chrome 5X). Other browsers mistakenly treat SameSite=None cookies as SameSite=Strict (e.g. Safari running on OSX 14). To omit SameSite=None from browsers with these incompatibilities, add the annotation nginx.ingress.kubernetes.io/session-cookie-conditional-samesite-none: "true".

Use nginx.ingress.kubernetes.io/session-cookie-expires to control the cookie expires, its value is a number of seconds until the cookie expires.

Use nginx.ingress.kubernetes.io/session-cookie-path to control the cookie path when use-regex is set to true.

Use nginx.ingress.kubernetes.io/session-cookie-change-on-failure to control the cookie change after request failure.

Authentication ¶

It is possible to add authentication by adding additional annotations in the Ingress rule. The source of the authentication is a secret that contains usernames and passwords.

The annotations are:

nginx.ingress.kubernetes.io/auth-type: [basic|digest]

Indicates the HTTP Authentication Type: Basic or Digest Access Authentication.

nginx.ingress.kubernetes.io/auth-secret: secretName

The name of the Secret that contains the usernames and passwords which are granted access to the paths defined in the Ingress rules. This annotation also accepts the alternative form "namespace/secretName", in which case the Secret lookup is performed in the referenced namespace instead of the Ingress namespace.

nginx.ingress.kubernetes.io/auth-secret-type: [auth-file|auth-map]

The auth-secret can have two forms:

• auth-file - default, an htpasswd file in the key auth within the secret
• auth-map - the keys of the secret are the usernames, and the values are the hashed passwords

nginx.ingress.kubernetes.io/auth-realm: "realm string"

Custom NGINX upstream hashing ¶

NGINX supports load balancing by client-server mapping based on consistent hashing for a given key. The key can contain text, variables or any combination thereof. This feature allows for request stickiness other than client IP or cookies. The ketama consistent hashing method will be used which ensures only a few keys would be remapped to different servers on upstream group changes.

There is a special mode of upstream hashing called subset. In this mode, upstream servers are grouped into subsets, and stickiness works by mapping keys to a subset instead of individual upstream servers. Specific server is chosen uniformly at random from the selected sticky subset. It provides a balance between stickiness and load distribution.

To enable consistent hashing for a backend:

nginx.ingress.kubernetes.io/upstream-hash-by: the nginx variable, text value or any combination thereof to use for consistent hashing. For example: nginx.ingress.kubernetes.io/upstream-hash-by: "$request_uri" or nginx.ingress.kubernetes.io/upstream-hash-by: "$request_uri$host" or nginx.ingress.kubernetes.io/upstream-hash-by: "${request_uri}-text-value" to consistently hash upstream requests by the current request URI.

"subset" hashing can be enabled setting nginx.ingress.kubernetes.io/upstream-hash-by-subset: "true". This maps requests to subset of nodes instead of a single one. nginx.ingress.kubernetes.io/upstream-hash-by-subset-size determines the size of each subset (default 3).

Please check the chashsubset example.

Custom NGINX load balancing ¶

This is similar to load-balance in ConfigMap, but configures load balancing algorithm per ingress.

Note that nginx.ingress.kubernetes.io/upstream-hash-by takes preference over this. If this and nginx.ingress.kubernetes.io/upstream-hash-by are not set then we fallback to using globally configured load balancing algorithm.

Custom NGINX upstream vhost ¶

This configuration setting allows you to control the value for host in the following statement: proxy_set_header Host $host, which forms part of the location block. This is useful if you need to call the upstream server by something other than $host.

Client Certificate Authentication ¶

It is possible to enable Client Certificate Authentication using additional annotations in Ingress Rule.

Client Certificate Authentication is applied per host and it is not possible to specify rules that differ for individual paths.

To enable, add the annotation nginx.ingress.kubernetes.io/auth-tls-secret: namespace/secretName. This secret must have a file named ca.crt containing the full Certificate Authority chain ca.crt that is enabled to authenticate against this Ingress.

You can further customize client certificate authentication and behavior with these annotations:

• nginx.ingress.kubernetes.io/auth-tls-verify-depth: The validation depth between the provided client certificate and the Certification Authority chain. (default: 1)
• nginx.ingress.kubernetes.io/auth-tls-verify-client: Enables verification of client certificates. Possible values are:
  • on: Request a client certificate that must be signed by a certificate that is included in the secret key ca.crt of the secret specified by nginx.ingress.kubernetes.io/auth-tls-secret: namespace/secretName. Failed certificate verification will result in a status code 400 (Bad Request) (default)
  • off: Don't request client certificates and don't do client certificate verification.
  • optional: Do optional client certificate validation against the CAs from auth-tls-secret. The request fails with status code 400 (Bad Request) when a certificate is provided that is not signed by the CA. When no or an otherwise invalid certificate is provided, the request does not fail, but instead the verification result is sent to the upstream service.
  • optional_no_ca: Do optional client certificate validation, but do not fail the request when the client certificate is not signed by the CAs from auth-tls-secret. Certificate verification result is sent to the upstream service.
• nginx.ingress.kubernetes.io/auth-tls-error-page: The URL/Page that user should be redirected in case of a Certificate Authentication Error
• nginx.ingress.kubernetes.io/auth-tls-pass-certificate-to-upstream: Indicates if the received certificates should be passed or not to the upstream server in the header ssl-client-cert. Possible values are "true" or "false" (default).
• nginx.ingress.kubernetes.io/auth-tls-match-cn: Adds a sanity check for the CN of the client certificate that is sent over using a string / regex starting with "CN=", example: "CN=myvalidclient". If the certificate CN sent during mTLS does not match your string / regex it will fail with status code 403. Another way of using this is by adding multiple options in your regex, example: "CN=(option1|option2|myvalidclient)". In this case, as long as one of the options in the brackets matches the certificate CN then you will receive a 200 status code.

The following headers are sent to the upstream service according to the auth-tls-* annotations:

• ssl-client-issuer-dn: The issuer information of the client certificate. Example: "CN=My CA"
• ssl-client-subject-dn: The subject information of the client certificate. Example: "CN=My Client"
• ssl-client-verify: The result of the client verification. Possible values: "SUCCESS", "FAILED: "
• ssl-client-cert: The full client certificate in PEM format. Will only be sent when nginx.ingress.kubernetes.io/auth-tls-pass-certificate-to-upstream is set to "true". Example: -----BEGIN%20CERTIFICATE-----%0A...---END%20CERTIFICATE-----%0A

Backend Certificate Authentication ¶

It is possible to authenticate to a proxied HTTPS backend with certificate using additional annotations in Ingress Rule.

• nginx.ingress.kubernetes.io/proxy-ssl-secret: secretName: Specifies a Secret with the certificate tls.crt, key tls.key in PEM format used for authentication to a proxied HTTPS server. It should also contain trusted CA certificates ca.crt in PEM format used to verify the certificate of the proxied HTTPS server. This annotation expects the Secret name in the form "namespace/secretName".
• nginx.ingress.kubernetes.io/proxy-ssl-verify: Enables or disables verification of the proxied HTTPS server certificate. (default: off)
• nginx.ingress.kubernetes.io/proxy-ssl-verify-depth: Sets the verification depth in the proxied HTTPS server certificates chain. (default: 1)
• nginx.ingress.kubernetes.io/proxy-ssl-ciphers: Specifies the enabled ciphers for requests to a proxied HTTPS server. The ciphers are specified in the format understood by the OpenSSL library.
• nginx.ingress.kubernetes.io/proxy-ssl-name: Allows to set proxy_ssl_name. This allows overriding the server name used to verify the certificate of the proxied HTTPS server. This value is also passed through SNI when a connection is established to the proxied HTTPS server.
• nginx.ingress.kubernetes.io/proxy-ssl-protocols: Enables the specified protocols for requests to a proxied HTTPS server.
• nginx.ingress.kubernetes.io/proxy-ssl-server-name: Enables passing of the server name through TLS Server Name Indication extension (SNI, RFC 6066) when establishing a connection with the proxied HTTPS server.

Configuration snippet ¶

Using this annotation you can add additional configuration to the NGINX location. For example:

nginx.ingress.kubernetes.io/configuration-snippet: |
  more_set_headers "Request-Id: $req_id";

Be aware this can be dangerous in multi-tenant clusters, as it can lead to people with otherwise limited permissions being able to retrieve all secrets on the cluster. The recommended mitigation for this threat is to disable this feature, so it may not work for you. See CVE-2021-25742 and the related issue on github for more information.

Custom HTTP Errors ¶

Like the custom-http-errors value in the ConfigMap, this annotation will set NGINX proxy-intercept-errors, but only for the NGINX location associated with this ingress. If a default backend annotation is specified on the ingress, the errors will be routed to that annotation's default backend service (instead of the global default backend). Different ingresses can specify different sets of error codes. Even if multiple ingress objects share the same hostname, this annotation can be used to intercept different error codes for each ingress (for example, different error codes to be intercepted for different paths on the same hostname, if each path is on a different ingress). If custom-http-errors is also specified globally, the error values specified in this annotation will override the global value for the given ingress' hostname and path.

Example usage:

nginx.ingress.kubernetes.io/custom-http-errors: "404,415"

Default Backend ¶

This annotation is of the form nginx.ingress.kubernetes.io/default-backend: <svc name> to specify a custom default backend. This <svc name> is a reference to a service inside of the same namespace in which you are applying this annotation. This annotation overrides the global default backend. In case the service has multiple ports, the first one is the one which will receive the backend traffic.

This service will be used to handle the response when the configured service in the Ingress rule does not have any active endpoints. It will also be used to handle the error responses if both this annotation and the custom-http-errors annotation are set.

Enable CORS ¶

To enable Cross-Origin Resource Sharing (CORS) in an Ingress rule, add the annotation nginx.ingress.kubernetes.io/enable-cors: "true". This will add a section in the server location enabling this functionality.

CORS can be controlled with the following annotations:

• nginx.ingress.kubernetes.io/cors-allow-methods: Controls which methods are accepted.

  This is a multi-valued field, separated by ',' and accepts only letters (upper and lower case).

  • Default: GET, PUT, POST, DELETE, PATCH, OPTIONS
  • Example: nginx.ingress.kubernetes.io/cors-allow-methods: "PUT, GET, POST, OPTIONS"

• nginx.ingress.kubernetes.io/cors-allow-headers: Controls which headers are accepted.

  This is a multi-valued field, separated by ',' and accepts letters, numbers, _ and -.

  • Default: DNT,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Range,Authorization
  • Example: nginx.ingress.kubernetes.io/cors-allow-headers: "X-Forwarded-For, X-app123-XPTO"

• nginx.ingress.kubernetes.io/cors-expose-headers: Controls which headers are exposed to response.

  This is a multi-valued field, separated by ',' and accepts letters, numbers, _, - and *.

  • Default: empty
  • Example: nginx.ingress.kubernetes.io/cors-expose-headers: "*, X-CustomResponseHeader"

• nginx.ingress.kubernetes.io/cors-allow-origin: Controls what's the accepted Origin for CORS.

  This is a multi-valued field, separated by ','. It must follow this format: http(s)://origin-site.com or http(s)://origin-site.com:port

  • Default: *
  • Example: nginx.ingress.kubernetes.io/cors-allow-origin: "https://origin-site.com:4443, http://origin-site.com, https://example.org:1199"

  It also supports single level wildcard subdomains and follows this format: http(s)://*.foo.bar, http(s)://*.bar.foo:8080 or http(s)://*.abc.bar.foo:9000 - Example: nginx.ingress.kubernetes.io/cors-allow-origin: "https://*.origin-site.com:4443, http://*.origin-site.com, https://example.org:1199"

• nginx.ingress.kubernetes.io/cors-allow-credentials: Controls if credentials can be passed during CORS operations.

  • Default: true
  • Example: nginx.ingress.kubernetes.io/cors-allow-credentials: "false"

• nginx.ingress.kubernetes.io/cors-max-age: Controls how long preflight requests can be cached.

  • Default: 1728000
  • Example: nginx.ingress.kubernetes.io/cors-max-age: 600

HTTP2 Push Preload. ¶

Enables automatic conversion of preload links specified in the “Link” response header fields into push requests.

Server Alias ¶

Allows the definition of one or more aliases in the server definition of the NGINX configuration using the annotation nginx.ingress.kubernetes.io/server-alias: "<alias 1>,<alias 2>". This will create a server with the same configuration, but adding new values to the server_name directive.

For more information please see the server_name documentation.

Server snippet ¶

Using the annotation nginx.ingress.kubernetes.io/server-snippet it is possible to add custom configuration in the server configuration block.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/server-snippet: |
        set $agentflag 0;

        if ($http_user_agent ~* "(Mobile)" ){
          set $agentflag 1;
        }

        if ( $agentflag = 1 ) {
          return 301 https://m.example.com;
        }

Client Body Buffer Size ¶

Sets buffer size for reading client request body per location. In case the request body is larger than the buffer, the whole body or only its part is written to a temporary file. By default, buffer size is equal to two memory pages. This is 8K on x86, other 32-bit platforms, and x86-64. It is usually 16K on other 64-bit platforms. This annotation is applied to each location provided in the ingress rule.

For more information please see https://nginx.org

External Authentication ¶

To use an existing service that provides authentication the Ingress rule can be annotated with nginx.ingress.kubernetes.io/auth-url to indicate the URL where the HTTP request should be sent.

nginx.ingress.kubernetes.io/auth-url: "URL to the authentication service"

Additionally it is possible to set:

• nginx.ingress.kubernetes.io/auth-keepalive: <Connections> to specify the maximum number of keepalive connections to auth-url. Only takes effect when no variables are used in the host part of the URL. Defaults to 0 (keepalive disabled).

Note: does not work with HTTP/2 listener because of a limitation in Lua subrequests. UseHTTP2 configuration should be disabled!

• nginx.ingress.kubernetes.io/auth-keepalive-share-vars: Whether to share Nginx variables among the current request and the auth request. Example use case is to track requests: when set to "true" X-Request-ID HTTP header will be the same for the backend and the auth request. Defaults to "false".
• nginx.ingress.kubernetes.io/auth-keepalive-requests: <Requests> to specify the maximum number of requests that can be served through one keepalive connection. Defaults to 1000 and only applied if auth-keepalive is set to higher than 0.
• nginx.ingress.kubernetes.io/auth-keepalive-timeout: <Timeout> to specify a duration in seconds which an idle keepalive connection to an upstream server will stay open. Defaults to 60 and only applied if auth-keepalive is set to higher than 0.
• nginx.ingress.kubernetes.io/auth-method: <Method> to specify the HTTP method to use.
• nginx.ingress.kubernetes.io/auth-signin: <SignIn_URL> to specify the location of the error page.
• nginx.ingress.kubernetes.io/auth-signin-redirect-param: <SignIn_URL> to specify the URL parameter in the error page which should contain the original URL for a failed signin request.
• nginx.ingress.kubernetes.io/auth-response-headers: <Response_Header_1, ..., Response_Header_n> to specify headers to pass to backend once authentication request completes.
• nginx.ingress.kubernetes.io/auth-proxy-set-headers: <ConfigMap> the name of a ConfigMap that specifies headers to pass to the authentication service
• nginx.ingress.kubernetes.io/auth-request-redirect: <Request_Redirect_URL> to specify the X-Auth-Request-Redirect header value.
• nginx.ingress.kubernetes.io/auth-cache-key: <Cache_Key> this enables caching for auth requests. specify a lookup key for auth responses. e.g. $remote_user$http_authorization. Each server and location has it's own keyspace. Hence a cached response is only valid on a per-server and per-location basis.
• nginx.ingress.kubernetes.io/auth-cache-duration: <Cache_duration> to specify a caching time for auth responses based on their response codes, e.g. 200 202 30m. See proxy_cache_valid for details. You may specify multiple, comma-separated values: 200 202 10m, 401 5m. defaults to 200 202 401 5m.
• nginx.ingress.kubernetes.io/auth-always-set-cookie: <Boolean_Flag> to set a cookie returned by auth request. By default, the cookie will be set only if an upstream reports with the code 200, 201, 204, 206, 301, 302, 303, 304, 307, or 308.
• nginx.ingress.kubernetes.io/auth-snippet: <Auth_Snippet> to specify a custom snippet to use with external authentication, e.g.

nginx.ingress.kubernetes.io/auth-url: http://foo.com/external-auth
nginx.ingress.kubernetes.io/auth-snippet: |
    proxy_set_header Foo-Header 42;

Note: nginx.ingress.kubernetes.io/auth-snippet is an optional annotation. However, it may only be used in conjunction with nginx.ingress.kubernetes.io/auth-url and will be ignored if nginx.ingress.kubernetes.io/auth-url is not set

Global External Authentication ¶

By default the controller redirects all requests to an existing service that provides authentication if global-auth-url is set in the NGINX ConfigMap. If you want to disable this behavior for that ingress, you can use enable-global-auth: "false" in the NGINX ConfigMap. nginx.ingress.kubernetes.io/enable-global-auth: indicates if GlobalExternalAuth configuration should be applied or not to this Ingress rule. Default values is set to "true".

Rate Limiting ¶

These annotations define limits on connections and transmission rates. These can be used to mitigate DDoS Attacks.

• nginx.ingress.kubernetes.io/limit-connections: number of concurrent connections allowed from a single IP address. A 503 error is returned when exceeding this limit.
• nginx.ingress.kubernetes.io/limit-rps: number of requests accepted from a given IP each second. The burst limit is set to this limit multiplied by the burst multiplier, the default multiplier is 5. When clients exceed this limit, limit-req-status-code default: 503 is returned.
• nginx.ingress.kubernetes.io/limit-rpm: number of requests accepted from a given IP each minute. The burst limit is set to this limit multiplied by the burst multiplier, the default multiplier is 5. When clients exceed this limit, limit-req-status-code default: 503 is returned.
• nginx.ingress.kubernetes.io/limit-burst-multiplier: multiplier of the limit rate for burst size. The default burst multiplier is 5, this annotation override the default multiplier. When clients exceed this limit, limit-req-status-code default: 503 is returned.
• nginx.ingress.kubernetes.io/limit-rate-after: initial number of kilobytes after which the further transmission of a response to a given connection will be rate limited. This feature must be used with proxy-buffering enabled.
• nginx.ingress.kubernetes.io/limit-rate: number of kilobytes per second allowed to send to a given connection. The zero value disables rate limiting. This feature must be used with proxy-buffering enabled.
• nginx.ingress.kubernetes.io/limit-whitelist: client IP source ranges to be excluded from rate-limiting. The value is a comma separated list of CIDRs.

If you specify multiple annotations in a single Ingress rule, limits are applied in the order limit-connections, limit-rpm, limit-rps.

To configure settings globally for all Ingress rules, the limit-rate-after and limit-rate values may be set in the NGINX ConfigMap. The value set in an Ingress annotation will override the global setting.

The client IP address will be set based on the use of PROXY protocol or from the X-Forwarded-For header value when use-forwarded-headers is enabled.

Global Rate Limiting ¶

Note: Be careful when configuring both (Local) Rate Limiting and Global Rate Limiting at the same time. They are two completely different rate limiting implementations. Whichever limit exceeds first will reject the requests. It might be a good idea to configure both of them to ease load on Global Rate Limiting backend in cases of spike in traffic.

The stock NGINX rate limiting does not share its counters among different NGINX instances. Given that most ingress-nginx deployments are elastic and number of replicas can change any day it is impossible to configure a proper rate limit using stock NGINX functionalities. Global Rate Limiting overcome this by using lua-resty-global-throttle. lua-resty-global-throttle shares its counters via a central store such as memcached. The obvious shortcoming of this is users have to deploy and operate a memcached instance in order to benefit from this functionality. Configure the memcached using these configmap settings.

Here are a few remarks for ingress-nginx integration of lua-resty-global-throttle:

1. We minimize memcached access by caching exceeding limit decisions. The expiry of cache entry is the desired delay lua-resty-global-throttle calculates for us. The Lua Shared Dictionary used for that is global_throttle_cache. Currently its size defaults to 10M. Customize it as per your needs using lua-shared-dicts. When we fail to cache the exceeding limit decision then we log an NGINX error. You can monitor for that error to decide if you need to bump the cache size. Without cache the cost of processing a request is two memcached commands: GET, and INCR. With the cache it is only INCR.
2. Log NGINX variable $global_rate_limit_exceeding's value to have some visibility into what portion of requests are rejected (value y), whether they are rejected using cached decision (value c), or if they are not rejected (default value n). You can use log-format-upstream to include that in access logs.
3. In case of an error it will log the error message and fail open.

4. The annotations below creates Global Rate Limiting instance per ingress. That means if there are multiple paths configured under the same ingress, the Global Rate Limiting will count requests to all the paths under the same counter. Extract a path out into its own ingress if you need to isolate a certain path.

5. nginx.ingress.kubernetes.io/global-rate-limit: Configures maximum allowed number of requests per window. Required.

6. nginx.ingress.kubernetes.io/global-rate-limit-window: Configures a time window (i.e 1m) that the limit is applied. Required.
7. nginx.ingress.kubernetes.io/global-rate-limit-key: Configures a key for counting the samples. Defaults to $remote_addr. You can also combine multiple NGINX variables here, like ${remote_addr}-${http_x_api_client} which would mean the limit will be applied to requests coming from the same API client (indicated by X-API-Client HTTP request header) with the same source IP address.
8. nginx.ingress.kubernetes.io/global-rate-limit-ignored-cidrs: comma separated list of IPs and CIDRs to match client IP against. When there's a match request is not considered for rate limiting.

Permanent Redirect ¶

This annotation allows to return a permanent redirect (Return Code 301) instead of sending data to the upstream. For example nginx.ingress.kubernetes.io/permanent-redirect: https://www.google.com would redirect everything to Google.

Permanent Redirect Code ¶

This annotation allows you to modify the status code used for permanent redirects. For example nginx.ingress.kubernetes.io/permanent-redirect-code: '308' would return your permanent-redirect with a 308.

Temporal Redirect ¶

This annotation allows you to return a temporal redirect (Return Code 302) instead of sending data to the upstream. For example nginx.ingress.kubernetes.io/temporal-redirect: https://www.google.com would redirect everything to Google with a Return Code of 302 (Moved Temporarily)

SSL Passthrough ¶

The annotation nginx.ingress.kubernetes.io/ssl-passthrough instructs the controller to send TLS connections directly to the backend instead of letting NGINX decrypt the communication. See also TLS/HTTPS in the User guide.

Service Upstream ¶

By default the Ingress-Nginx Controller uses a list of all endpoints (Pod IP/port) in the NGINX upstream configuration.

The nginx.ingress.kubernetes.io/service-upstream annotation disables that behavior and instead uses a single upstream in NGINX, the service's Cluster IP and port.

This can be desirable for things like zero-downtime deployments . See issue #257.

Known Issues ¶

If the service-upstream annotation is specified the following things should be taken into consideration:

• Sticky Sessions will not work as only round-robin load balancing is supported.
• The proxy_next_upstream directive will not have any effect meaning on error the request will not be dispatched to another upstream.

Server-side HTTPS enforcement through redirect ¶

By default the controller redirects (308) to HTTPS if TLS is enabled for that ingress. If you want to disable this behavior globally, you can use ssl-redirect: "false" in the NGINX ConfigMap.

To configure this feature for specific ingress resources, you can use the nginx.ingress.kubernetes.io/ssl-redirect: "false" annotation in the particular resource.

When using SSL offloading outside of cluster (e.g. AWS ELB) it may be useful to enforce a redirect to HTTPS even when there is no TLS certificate available. This can be achieved by using the nginx.ingress.kubernetes.io/force-ssl-redirect: "true" annotation in the particular resource.

To preserve the trailing slash in the URI with ssl-redirect, set nginx.ingress.kubernetes.io/preserve-trailing-slash: "true" annotation for that particular resource.

Redirect from/to www ¶

In some scenarios is required to redirect from www.domain.com to domain.com or vice versa. To enable this feature use the annotation nginx.ingress.kubernetes.io/from-to-www-redirect: "true"

Denylist source range ¶

You can specify blocked client IP source ranges through the nginx.ingress.kubernetes.io/denylist-source-range annotation. The value is a comma separated list of CIDRs, e.g. 10.0.0.0/24,172.10.0.1.

To configure this setting globally for all Ingress rules, the denylist-source-range value may be set in the NGINX ConfigMap.

Whitelist source range ¶

You can specify allowed client IP source ranges through the nginx.ingress.kubernetes.io/whitelist-source-range annotation. The value is a comma separated list of CIDRs, e.g. 10.0.0.0/24,172.10.0.1.

To configure this setting globally for all Ingress rules, the whitelist-source-range value may be set in the NGINX ConfigMap.

Custom timeouts ¶

Using the configuration configmap it is possible to set the default global timeout for connections to the upstream servers. In some scenarios is required to have different values. To allow this we provide annotations 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.

Proxy redirect ¶

The annotations nginx.ingress.kubernetes.io/proxy-redirect-from and nginx.ingress.kubernetes.io/proxy-redirect-to will set the first and second parameters of NGINX's proxy_redirect directive respectively. It is possible to set the text that should be changed in the Location and Refresh header fields of a proxied server response

Setting "off" or "default" in the annotation nginx.ingress.kubernetes.io/proxy-redirect-from disables nginx.ingress.kubernetes.io/proxy-redirect-to, otherwise, both annotations must be used in unison. Note that each annotation must be a string without spaces.

By default the value of each annotation is "off".

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. This size can be configured by the parameter client_max_body_size.

To configure this setting globally for all Ingress rules, the proxy-body-size value may be set in the NGINX ConfigMap. To use custom values in an Ingress rule define these annotation:

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

Proxy cookie domain ¶

Sets a text that should be changed in the domain attribute of the "Set-Cookie" header fields of a proxied server response.

To configure this setting globally for all Ingress rules, the proxy-cookie-domain value may be set in the NGINX ConfigMap.

Proxy cookie path ¶

Sets a text that should be changed in the path attribute of the "Set-Cookie" header fields of a proxied server response.

To configure this setting globally for all Ingress rules, the proxy-cookie-path value may be set in the NGINX ConfigMap.

Proxy buffering ¶

Enable or disable proxy buffering proxy_buffering. By default proxy buffering is disabled in the NGINX config.

To configure this setting globally for all Ingress rules, the proxy-buffering value may be set in the NGINX ConfigMap. To use custom values in an Ingress rule define these annotation:

nginx.ingress.kubernetes.io/proxy-buffering: "on"

Proxy buffers Number ¶

Sets the number of the buffers in proxy_buffers used for reading the first part of the response received from the proxied server. By default proxy buffers number is set as 4

To configure this setting globally, set proxy-buffers-number in NGINX ConfigMap. To use custom values in an Ingress rule, define this annotation:

nginx.ingress.kubernetes.io/proxy-buffers-number: "4"

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"

To configure this setting globally, set proxy-buffer-size in NGINX ConfigMap. To use custom values in an Ingress rule, define this annotation:

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

Proxy max temp file size ¶

When buffering of responses from the proxied server is enabled, and the whole response does not fit into the buffers set by the proxy_buffer_size and proxy_buffers directives, a part of the response can be saved to a temporary file. This directive sets the maximum size of the temporary file setting the proxy_max_temp_file_size. The size of data written to the temporary file at a time is set by the proxy_temp_file_write_size directive.

The zero value disables buffering of responses to temporary files.

To use custom values in an Ingress rule, define this annotation:

nginx.ingress.kubernetes.io/proxy-max-temp-file-size: "1024m"

Proxy HTTP version ¶

Using this annotation sets the proxy_http_version that the Nginx reverse proxy will use to communicate with the backend. By default this is set to "1.1".

nginx.ingress.kubernetes.io/proxy-http-version: "1.0"

SSL ciphers ¶

Specifies the enabled ciphers.

Using this annotation will set the ssl_ciphers directive at the server level. This configuration is active for all the paths in the host.

nginx.ingress.kubernetes.io/ssl-ciphers: "ALL:!aNULL:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP"

The following annotation will set the ssl_prefer_server_ciphers directive at the server level. This configuration specifies that server ciphers should be preferred over client ciphers when using the SSLv3 and TLS protocols.

nginx.ingress.kubernetes.io/ssl-prefer-server-ciphers: "true"

Connection proxy header ¶

Using this annotation will override the default connection header set by NGINX. To use custom values in an Ingress rule, define the annotation:

nginx.ingress.kubernetes.io/connection-proxy-header: "keep-alive"

Enable Access Log ¶

Access logs are enabled by default, but in some scenarios access logs might be required to be disabled for a given ingress. To do this, use the annotation:

nginx.ingress.kubernetes.io/enable-access-log: "false"

Enable Rewrite Log ¶

Rewrite logs are not enabled by default. In some scenarios it could be required to enable NGINX rewrite logs. Note that rewrite logs are sent to the error_log file at the notice level. To enable this feature use the annotation:

nginx.ingress.kubernetes.io/enable-rewrite-log: "true"

Enable Opentracing ¶

Opentracing can be enabled or disabled globally through the ConfigMap but this will sometimes need to be overridden to enable it or disable it for a specific ingress (e.g. to turn off tracing of external health check endpoints)

nginx.ingress.kubernetes.io/enable-opentracing: "true"

Opentracing Trust Incoming Span ¶

The option to trust incoming trace spans can be enabled or disabled globally through the ConfigMap but this will sometimes need to be overridden to enable it or disable it for a specific ingress (e.g. only enable on a private endpoint)

nginx.ingress.kubernetes.io/opentracing-trust-incoming-span: "true"

Enable Opentelemetry ¶

Opentelemetry can be enabled or disabled globally through the ConfigMap but this will sometimes need to be overridden to enable it or disable it for a specific ingress (e.g. to turn off telemetry of external health check endpoints)

nginx.ingress.kubernetes.io/enable-opentelemetry: "true"

Opentelemetry Trust Incoming Span ¶

The option to trust incoming trace spans can be enabled or disabled globally through the ConfigMap but this will sometimes need to be overridden to enable it or disable it for a specific ingress (e.g. only enable on a private endpoint)

nginx.ingress.kubernetes.io/opentelemetry-trust-incoming-spans: "true"

X-Forwarded-Prefix Header ¶

To add the non-standard X-Forwarded-Prefix header to the upstream request with a string value, the following annotation can be used:

nginx.ingress.kubernetes.io/x-forwarded-prefix: "/path"

ModSecurity ¶

ModSecurity is an OpenSource Web Application firewall. It can be enabled for a particular set of ingress locations. The ModSecurity module must first be enabled by enabling ModSecurity in the ConfigMap. Note this will enable ModSecurity for all paths, and each path must be disabled manually.

It can be enabled using the following annotation:

nginx.ingress.kubernetes.io/enable-modsecurity: "true"

You can enable the OWASP Core Rule Set by setting the following annotation:

nginx.ingress.kubernetes.io/enable-owasp-core-rules: "true"

You can pass transactionIDs from nginx by setting up the following:

nginx.ingress.kubernetes.io/modsecurity-transaction-id: "$request_id"

You can also add your own set of modsecurity rules via a snippet:

nginx.ingress.kubernetes.io/modsecurity-snippet: |
SecRuleEngine On
SecDebugLog /tmp/modsec_debug.log

Note: If you use both enable-owasp-core-rules and modsecurity-snippet annotations together, only the modsecurity-snippet will take effect. If you wish to include the OWASP Core Rule Set or recommended configuration simply use the include statement:

nginx 0.24.1 and below

nginx.ingress.kubernetes.io/modsecurity-snippet: |
Include /etc/nginx/owasp-modsecurity-crs/nginx-modsecurity.conf
Include /etc/nginx/modsecurity/modsecurity.conf

nginx.ingress.kubernetes.io/modsecurity-snippet: |
Include /etc/nginx/owasp-modsecurity-crs/nginx-modsecurity.conf

Backend Protocol ¶

Using backend-protocol annotations is possible to indicate how NGINX should communicate with the backend service. (Replaces secure-backends in older versions) Valid Values: HTTP, HTTPS, GRPC, GRPCS and FCGI

By default NGINX uses HTTP.

Example:

nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"

Use Regex ¶

Using the nginx.ingress.kubernetes.io/use-regex annotation will indicate whether or not the paths defined on an Ingress use regular expressions. The default value is false.

The following will indicate that regular expression paths are being used:

nginx.ingress.kubernetes.io/use-regex: "true"

The following will indicate that regular expression paths are not being used:

nginx.ingress.kubernetes.io/use-regex: "false"

When this annotation is set to true, the case insensitive regular expression location modifier will be enforced on ALL paths for a given host regardless of what Ingress they are defined on.

Additionally, if the rewrite-target annotation is used on any Ingress for a given host, then the case insensitive regular expression location modifier will be enforced on ALL paths for a given host regardless of what Ingress they are defined on.

Please read about ingress path matching before using this modifier.

Satisfy ¶

By default, a request would need to satisfy all authentication requirements in order to be allowed. By using this annotation, requests that satisfy either any or all authentication requirements are allowed, based on the configuration value.

nginx.ingress.kubernetes.io/satisfy: "any"

Mirror ¶

Enables a request to be mirrored to a mirror backend. Responses by mirror backends are ignored. This feature is useful, to see how requests will react in "test" backends.

The mirror backend can be set by applying:

nginx.ingress.kubernetes.io/mirror-target: https://test.env.com/$request_uri

By default the request-body is sent to the mirror backend, but can be turned off by applying:

nginx.ingress.kubernetes.io/mirror-request-body: "off"

Also by default header Host for mirrored requests will be set the same as a host part of uri in the "mirror-target" annotation. You can override it by "mirror-host" annotation:

nginx.ingress.kubernetes.io/mirror-target: https://1.2.3.4/$request_uri
nginx.ingress.kubernetes.io/mirror-host: "test.env.com"

Note: The mirror directive will be applied to all paths within the ingress resource.

The request sent to the mirror is linked to the original request. If you have a slow mirror backend, then the original request will throttle.

For more information on the mirror module see ngx_http_mirror_module

Stream snippet ¶

Using the annotation nginx.ingress.kubernetes.io/stream-snippet it is possible to add custom stream configuration.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/stream-snippet: |
      server {
        listen 8000;
        proxy_pass 127.0.0.1:80;
      }