Configure Ingress Controller x509 Client Authentication

Used to configure for Smart Card (HSPD-12 and Common Access Cards (CAC))

Annotations

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

Tip Annotation keys and values can only be strings. Other types, such as boolean or numeric values must be quoted, i.e. "true", "false", "100".

Note The annotation prefix can be changed using the --annotations-prefix command line argument, but the default is nginx.ingress.kubernetes.io, as described in the table below.

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 . 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-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 - 100) 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 100 means implies all requests will be sent to the alternative service specified in the Ingress.

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 and nginx.ingress.kubernetes.io/upstream-hash-by.

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 /.

!!! example Please check the rewrite example.

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 stickyness 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 stickyness.

!!! attention If more than one Ingress is defined for a host and at least one Ingress uses nginx.ingress.kubernetes.io/affinity: cookie, then only paths on the Ingress using nginx.ingress.kubernetes.io/affinity will use session cookie affinity. All paths defined on other Ingresses for the host will be load balanced through the random selection of a backend server.

!!! example Please check the affinity example.

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.

Authentication

Is possible to add authentication 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"

!!! example Please check the auth example.

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" 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. 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.

The annotations are:

• nginx.ingress.kubernetes.io/auth-tls-secret: secretName: The name of the Secret that contains the full Certificate Authority chain ca.crt that is enabled to authenticate against this Ingress. 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-tls-verify-depth: The validation depth between the provided client certificate and the Certification Authority chain.
• nginx.ingress.kubernetes.io/auth-tls-verify-client: Enables verification of client certificates.
• 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. By default this is disabled.

!!! example Please check the client-certs example.

!!! attention TLS with Client Authentication is not possible in Cloudflare and might result in unexpected behavior.

Cloudflare only allows Authenticated Origin Pulls and is required to use their own certificate: [https://blog.cloudflare.com/protecting-the-origin-with-tls-authenticated-origin-pulls/](https://blog.cloudflare.com/protecting-the-origin-with-tls-authenticated-origin-pulls/)

Only Authenticated Origin Pulls are allowed and can be configured by following their tutorial: [https://support.cloudflare.com/hc/en-us/articles/204494148-Setting-up-NGINX-to-use-TLS-Authenticated-Origin-Pulls](https://support.cloudflare.com/hc/en-us/articles/204494148-Setting-up-NGINX-to-use-TLS-Authenticated-Origin-Pulls)

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 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/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-protocols: Enables the specified protocols for requests to a 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";

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.

This service will be handle the response when the service in the Ingress rule does not have active endpoints. It will also handle the error responses if both this annotation and the custom-http-errors annotation is 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,X-CustomHeader,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type,Authorization
  • Example: nginx.ingress.kubernetes.io/cors-allow-headers: "X-Forwarded-For, X-app123-XPTO"
• nginx.ingress.kubernetes.io/cors-allow-origin controls what’s the accepted Origin for CORS. This is a single field value, with the following 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"
• 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

!!! note For more information please see https://enable-cors.org

HTTP2 Push Preload.

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

!!! example

* `nginx.ingress.kubernetes.io/http2-push-preload: "true"`

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.

!!! Note A server-alias name cannot conflict with the hostname of an existing server. If it does, the server-alias annotation will be ignored. If a server-alias is created and later a new server with the same hostname is created, the new server configuration will take place over the alias configuration.

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: extensions/v1beta1
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;
        }

!!! attention This annotation can be used only once per host.

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.

!!! note The annotation value must be given in a format understood by Nginx.

!!! example

* `nginx.ingress.kubernetes.io/client-body-buffer-size: "1000"` # 1000 bytes
* `nginx.ingress.kubernetes.io/client-body-buffer-size: 1k` # 1 kilobyte
* `nginx.ingress.kubernetes.io/client-body-buffer-size: 1K` # 1 kilobyte
* `nginx.ingress.kubernetes.io/client-body-buffer-size: 1m` # 1 megabyte
* `nginx.ingress.kubernetes.io/client-body-buffer-size: 1M` # 1 megabyte

For more information please see http://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-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-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-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

!!! example Please check the external-auth example.

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".

!!! note For more information please see global-auth-url.

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 5 times the limit. 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 5 times the limit. 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.

Permanent Redirect

This annotation allows to return a permanent redirect 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.

!!! note SSL Passthrough is disabled by default and requires starting the controller with the --enable-ssl-passthrough flag.

!!! attention Because SSL Passthrough works on layer 4 of the OSI model (TCP) and not on the layer 7 (HTTP), using SSL Passthrough invalidates all the other annotations set on an Ingress object.

Service Upstream

By default the NGINX ingress 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 as it reduces the need to reload NGINX configuration when Pods come up and down. 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.

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"

!!! attention If at some point a new Ingress is created with a host equal to one of the options (like domain.com) the annotation will be omitted.

!!! attention For HTTPS to HTTPS redirects is mandatory the SSL Certificate defined in the Secret, located in the TLS section of Ingress, contains both FQDN in the common name of the certificate.

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.

!!! note Adding an annotation to an Ingress rule overrides any global restriction.

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

Proxy redirect

With the annotations nginx.ingress.kubernetes.io/proxy-redirect-from and nginx.ingress.kubernetes.io/proxy-redirect-to 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"

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"

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"

Lua Resty WAF

Using lua-resty-waf-* annotations we can enable and control the lua-resty-waf Web Application Firewall per location.

Following configuration will enable the WAF for the paths defined in the corresponding ingress:

nginx.ingress.kubernetes.io/lua-resty-waf: "active"

In order to run it in debugging mode you can set nginx.ingress.kubernetes.io/lua-resty-waf-debug to "true" in addition to the above configuration. The other possible values for nginx.ingress.kubernetes.io/lua-resty-waf are inactive and simulate. In inactive mode WAF won’t do anything, whereas in simulate mode it will log a warning message if there’s a matching WAF rule for given request. This is useful to debug a rule and eliminate possible false positives before fully deploying it.

lua-resty-waf comes with predefined set of rules https://github.com/p0pr0ck5/lua-resty-waf/tree/84b4f40362500dd0cb98b9e71b5875cb1a40f1ad/rules that covers ModSecurity CRS. You can use nginx.ingress.kubernetes.io/lua-resty-waf-ignore-rulesets to ignore a subset of those rulesets. For an example:

nginx.ingress.kubernetes.io/lua-resty-waf-ignore-rulesets: "41000_sqli, 42000_xss"

will ignore the two mentioned rulesets.

It is also possible to configure custom WAF rules per ingress using the nginx.ingress.kubernetes.io/lua-resty-waf-extra-rules annotation. For an example the following snippet will configure a WAF rule to deny requests with query string value that contains word foo:

nginx.ingress.kubernetes.io/lua-resty-waf-extra-rules: '[=[ { "access": [ { "actions": { "disrupt" : "DENY" }, "id": 10001, "msg": "my custom rule", "operator": "STR_CONTAINS", "pattern": "foo", "vars": [ { "parse": [ "values", 1 ], "type": "REQUEST_ARGS" } ] } ], "body_filter": [], "header_filter":[] } ]=]'

Since the default allowed contents were "text/html", "text/json", "application/json" We can enable the following annotation for allow all contents type:

nginx.ingress.kubernetes.io/lua-resty-waf-allow-unknown-content-types: "true"

The default score of lua-resty-waf is 5, which usually triggered if hitting 2 default rules, you can modify the score threshold with following annotation:

nginx.ingress.kubernetes.io/lua-resty-waf-score-threshold: "10"

When you enabled HTTPS in the endpoint and since resty-lua will return 500 error when processing “multipart” contents Reference for this issue

By default, it will be “true”

You may enable the following annotation for work around:

nginx.ingress.kubernetes.io/lua-resty-waf-process-multipart-body: "false"

For details on how to write WAF rules, please refer to https://github.com/p0pr0ck5/lua-resty-waf.

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"

ModSecurity will run in “Detection-Only” mode using the recommended configuration.

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

InfluxDB

Using influxdb-* annotations we can monitor requests passing through a Location by sending them to an InfluxDB backend exposing the UDP socket using the nginx-influxdb-module.

nginx.ingress.kubernetes.io/enable-influxdb: "true"
nginx.ingress.kubernetes.io/influxdb-measurement: "nginx-reqs"
nginx.ingress.kubernetes.io/influxdb-port: "8089"
nginx.ingress.kubernetes.io/influxdb-host: "127.0.0.1"
nginx.ingress.kubernetes.io/influxdb-server-name: "nginx-ingress"

For the influxdb-host parameter you have two options:

• Use an InfluxDB server configured with the UDP protocol enabled.
• Deploy Telegraf as a sidecar proxy to the Ingress controller configured to listen UDP with the socket listener input and to write using anyone of the outputs plugins like InfluxDB, Apache Kafka, Prometheus, etc.. (recommended)

It’s important to remember that there’s no DNS resolver at this stage so you will have to configure an ip address to nginx.ingress.kubernetes.io/influxdb-host. If you deploy Influx or Telegraf as sidecar (another container in the same pod) this becomes straightforward since you can directly use 127.0.0.1.

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 AJP

By default NGINX uses HTTP.

Example:

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

Use Regex

!!! attention When using this annotation with the NGINX annotation nginx.ingress.kubernetes.io/affinity of type cookie, nginx.ingress.kubernetes.io/session-cookie-path must be also set; Session cookie paths do not support 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.

You can mirror a request to the /mirror path on your ingress, by applying the below:

nginx.ingress.kubernetes.io/mirror-uri: "/mirror"

The mirror path can be defined as a separate ingress resource:

location = /mirror {
    internal;
    proxy_pass http://test_backend;
}

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"

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

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

For more information on the mirror module see https://nginx.org/en/docs/http/ngx_http_mirror_module.html