## Contents * [Customizing NGINX](#customizing-nginx) * [Custom NGINX configuration](#custom-nginx-configuration) * [Custom NGINX template](#custom-nginx-template) * [Annotations](#annotations) * [Custom NGINX upstream checks](#custom-nginx-upstream-checks) * [Authentication](#authentication) * [Rewrite](#rewrite) * [Rate limiting](#rate-limiting) * [Secure backends](#secure-backends) * [Server-side HTTPS enforcement through redirect](#server-side-https-enforcement-through-redirect) * [Whitelist source range](#whitelist-source-range) * [Allowed parameters in configuration ConfigMap](#allowed-parameters-in-configuration-configmap) * [Default configuration options](#default-configuration-options) * [Websockets](#websockets) * [Optimizing TLS Time To First Byte (TTTFB)](#optimizing-tls-time-to-first-byte-tttfb) * [Retries in non-idempotent methods](#retries-in-non-idempotent-methods) ### Customizing NGINX There are 3 ways to customize NGINX: 1. [ConfigMap](#allowed-parameters-in-configuration-configmap): create a stand alone ConfigMap, use this if you want a different global configuration 2. [annotations](#annotations): use this if you want a specific configuration for the site defined in the Ingress rule 3. custom template: when more specific settings are required, like [open_file_cache](http://nginx.org/en/docs/http/ngx_http_core_module.html#open_file_cache), custom [log_format](http://nginx.org/en/docs/http/ngx_http_log_module.html#log_format), adjust [listen](http://nginx.org/en/docs/http/ngx_http_core_module.html#listen) options as `rcvbuf` or when is not possible to change an through the ConfigMap. #### Custom NGINX configuration It is possible to customize the defaults in NGINX using a ConfigMap. Please check the [custom configuration](examples/custom-configuration/README.md) example. #### Annotations The following annotations are supported: |Name |type| |---------------------------|------| |[ingress.kubernetes.io/add-base-url](#rewrite)|true or false| |[ingress.kubernetes.io/auth-realm](#authentication)|string| |[ingress.kubernetes.io/auth-secret](#authentication)|string| |[ingress.kubernetes.io/auth-type](#authentication)|basic or digest| |[ingress.kubernetes.io/auth-url](#external-authentication)|string| |[ingress.kubernetes.io/limit-connections](#rate-limiting)|number| |[ingress.kubernetes.io/limit-rps](#rate-limiting)|number| |[ingress.kubernetes.io/rewrite-target](#rewrite)|URI| |[ingress.kubernetes.io/secure-backends](#secure-backends)|true or false| |[ingress.kubernetes.io/ssl-redirect](#server-side-https-enforcement-through-redirect)|true or false| |[ingress.kubernetes.io/upstream-max-fails](#custom-nginx-upstream-checks)|number| |[ingress.kubernetes.io/upstream-fail-timeout](#custom-nginx-upstream-checks)|number| |[ingress.kubernetes.io/whitelist-source-range](#whitelist-source-range)|CIDR| #### Custom NGINX template The NGINX template is located in the file `/etc/nginx/template/nginx.tmpl`. Mounting a volume is possible to use a custom version. Use the [custom-template](examples/custom-template/README.md) example as a guide. **Please note the template is tied to the Go code. Do not change names in the variable `$cfg`.** For more information about the template syntax please check the [Go template package](https://golang.org/pkg/text/template/). In addition to the built-in functions provided by the Go package the following functions are also available: - empty: returns true if the specified parameter (string) is empty - contains: [strings.Contains](https://golang.org/pkg/strings/#Contains) - hasPrefix: [strings.HasPrefix](https://golang.org/pkg/strings/#Contains) - hasSuffix: [strings.HasSuffix](https://golang.org/pkg/strings/#HasSuffix) - toUpper: [strings.ToUpper](https://golang.org/pkg/strings/#ToUpper) - toLower: [strings.ToLower](https://golang.org/pkg/strings/#ToLower) - buildLocation: helper to build the NGINX Location section in each server - buildProxyPass: builds the reverse proxy configuration - buildRateLimitZones: helper to build all the required rate limit zones - buildRateLimit: helper to build a limit zone inside a location if contains a rate limit annotation ### Custom NGINX upstream checks NGINX exposes some flags in the [upstream configuration](http://nginx.org/en/docs/http/ngx_http_upstream_module.html#upstream) that enable the configuration of each server in the upstream. The Ingress controller allows custom `max_fails` and `fail_timeout` parameters in a global context using `upstream-max-fails` and `upstream-fail-timeout` in the NGINX ConfigMap or in a particular Ingress rule. `upstream-max-fails` defaults to 0. This means NGINX will respect the container's `readinessProbe` if it is defined. If there is no probe and no values for `upstream-max-fails` NGINX will continue to send traffic to the container. **With the default configuration NGINX will not health check your backends. Whenever the endpoints controller notices a readiness probe failure, that pod's IP will be removed from the list of endpoints. This will trigger the NGINX controller to also remove it from the upstreams.** To use custom values in an Ingress rule define these annotations: `ingress.kubernetes.io/upstream-max-fails`: number of unsuccessful attempts to communicate with the server that should occur in the duration set by the `upstream-fail-timeout` parameter to consider the server unavailable. `ingress.kubernetes.io/upstream-fail-timeout`: time in seconds during which the specified number of unsuccessful attempts to communicate with the server should occur to consider the server unavailable. This is also the period of time the server will be considered unavailable. In NGINX, backend server pools are called "[upstreams](http://nginx.org/en/docs/http/ngx_http_upstream_module.html)". Each upstream contains the endpoints for a service. An upstream is created for each service that has Ingress rules defined. **Important:** All Ingress rules using the same service will use the same upstream. Only one of the Ingress rules should define annotations to configure the upstream servers. Please check the [custom upstream check](examples/custom-upstream-check/README.md) example. ### 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 inside the the key `auth` The annotations are: ``` ingress.kubernetes.io/auth-type: [basic|digest] ``` Indicates the [HTTP Authentication Type: Basic or Digest Access Authentication](https://tools.ietf.org/html/rfc2617). ``` ingress.kubernetes.io/auth-secret: secretName ``` The name of the secret that contains the usernames and passwords with access to the `path`s defined in the Ingress Rule. The secret must be created in the same namespace as the Ingress rule. ``` ingress.kubernetes.io/auth-realm: "realm string" ``` Please check the [auth](examples/auth/README.md) example. ### External Authentication To use an existing service that provides authentication the Ingress rule can be annotated with `ingress.kubernetes.io/auth-url` to indicate the URL where the HTTP request should be sent. Additionally it is possible to set `ingress.kubernetes.io/auth-method` to specify the HTTP method to use (GET or POST) and `ingress.kubernetes.io/auth-send-body` to true or false (default). ``` ingress.kubernetes.io/auth-url: "URL to the authentication service" ``` Please check the [external-auth](examples/external-auth/README.md) example. ### 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 `ingress.kubernetes.io/rewrite-target` to the path expected by the service. If the application contains relative links it is possible to add an additional annotation `ingress.kubernetes.io/add-base-url` that will prepend a [`base` tag](https://developer.mozilla.org/en/docs/Web/HTML/Element/base) in the header of the returned HTML from the backend. Please check the [rewrite](examples/rewrite/README.md) example. ### Rate limiting The annotations `ingress.kubernetes.io/limit-connections` and `ingress.kubernetes.io/limit-rps` define a limit on the connections that can be opened by a single client IP address. This can be used to mitigate [DDoS Attacks](https://www.nginx.com/blog/mitigating-ddos-attacks-with-nginx-and-nginx-plus). `ingress.kubernetes.io/limit-connections`: number of concurrent connections allowed from a single IP address. `ingress.kubernetes.io/limit-rps`: number of connections that may be accepted from a given IP each second. If you specify both annotations in a single Ingress rule, `limit-rps` takes precedence. ### Secure backends By default NGINX uses `http` to reach the services. Adding the annotation `ingress.kubernetes.io/secure-backends: "true"` in the Ingress rule changes the protocol to `https`. ### Server-side HTTPS enforcement through redirect By default the controller redirects (301) to `HTTPS` if TLS is enabled for that ingress. If you want to disable that behaviour globally, you can use `ssl-redirect: "false"` in the NGINX config map To configure this feature for specific ingress resources, you can use the `ingress.kubernetes.io/ssl-redirect: "false"` annotation in the particular resource ### Whitelist source range You can specify the allowed client IP source ranges through the `ingress.kubernetes.io/whitelist-source-range` annotation. The value is a comma separated list of [CIDRs](https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing), 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. Please check the [whitelist](examples/whitelist/README.md) example. ### **Allowed parameters in configuration ConfigMap:** **body-size:** Sets the maximum allowed size of the client request body. See NGINX [client_max_body_size](http://nginx.org/en/docs/http/ngx_http_core_module.html#client_max_body_size). **custom-http-errors:** Enables which HTTP codes should be passed for processing with the [error_page directive](http://nginx.org/en/docs/http/ngx_http_core_module.html#error_page). Setting at least one code also enables [proxy_intercept_errors](http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_intercept_errors) which are required to process error_page. Example usage: `custom-http-errors: 404,415` **enable-sticky-sessions:** Enables sticky sessions using cookies. This is provided by [nginx-sticky-module-ng](https://bitbucket.org/nginx-goodies/nginx-sticky-module-ng) module. **enable-vts-status:** Allows the replacement of the default status page with a third party module named [nginx-module-vts](https://github.com/vozlt/nginx-module-vts). **error-log-level:** Configures the logging level of errors. Log levels above are listed in the order of increasing severity. http://nginx.org/en/docs/ngx_core_module.html#error_log **gzip-types:** Sets the MIME types in addition to "text/html" to compress. The special value "\*" matches any MIME type. Responses with the "text/html" type are always compressed if `use-gzip` is enabled. **hsts:** Enables or disables the header HSTS in servers running SSL. HTTP Strict Transport Security (often abbreviated as HSTS) is a security feature (HTTP header) that tell browsers that it should only be communicated with using HTTPS, instead of using HTTP. It provides protection against protocol downgrade attacks and cookie theft. https://developer.mozilla.org/en-US/docs/Web/Security/HTTP_strict_transport_security https://blog.qualys.com/securitylabs/2016/03/28/the-importance-of-a-proper-http-strict-transport-security-implementation-on-your-web-server **hsts-include-subdomains:** Enables or disables the use of HSTS in all the subdomains of the servername. **hsts-max-age:** Sets the time, in seconds, that the browser should remember that this site is only to be accessed using HTTPS. **keep-alive:** Sets the time during which a keep-alive client connection will stay open on the server side. The zero value disables keep-alive client connections. http://nginx.org/en/docs/http/ngx_http_core_module.html#keepalive_timeout **max-worker-connections:** Sets the maximum number of simultaneous connections that can be opened by each [worker process](http://nginx.org/en/docs/ngx_core_module.html#worker_connections). **proxy-buffer-size:** Sets the size of the buffer used for [reading the first part of the response](http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_buffer_size) received from the proxied server. This part usually contains a small response header.` **proxy-connect-timeout:** Sets the timeout for [establishing a connection with a proxied server](http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_connect_timeout). It should be noted that this timeout cannot usually exceed 75 seconds. **proxy-read-timeout:** Sets the timeout in seconds for [reading a response from the proxied server](http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_read_timeout). The timeout is set only between two successive read operations, not for the transmission of the whole response. **proxy-send-timeout:** Sets the timeout in seconds for [transmitting a request to the proxied server](http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_send_timeout). The timeout is set only between two successive write operations, not for the transmission of the whole request. **retry-non-idempotent:** Since 1.9.13 NGINX will not retry non-idempotent requests (POST, LOCK, PATCH) in case of an error in the upstream server. The previous behavior can be restored using the value "true". **server-name-hash-bucket-size:** Sets the size of the bucket for the server names hash tables. http://nginx.org/en/docs/hash.html http://nginx.org/en/docs/http/ngx_http_core_module.html#server_names_hash_bucket_size **server-name-hash-max-size:** Sets the maximum size of the [server names hash tables](http://nginx.org/en/docs/http/ngx_http_core_module.html#server_names_hash_max_size) used in server names, map directive’s values, MIME types, names of request header strings, etc. http://nginx.org/en/docs/hash.html **map-hash-bucket-size:** Sets the bucket size for the [map variables hash tables](http://nginx.org/en/docs/http/ngx_http_map_module.html#map_hash_bucket_size). The details of setting up hash tables are provided in a separate [document](http://nginx.org/en/docs/hash.html) **ssl-buffer-size:** Sets the size of the [SSL buffer](http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_buffer_size) used for sending data. The default of 4k helps NGINX to improve TLS Time To First Byte (TTTFB). https://www.igvita.com/2013/12/16/optimizing-nginx-tls-time-to-first-byte/ **ssl-ciphers:** Sets the [ciphers](http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_ciphers) list to enable. The ciphers are specified in the format understood by the OpenSSL library. The default cipher list is: `ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA`. The ordering of a ciphersuite is very important because it decides which algorithms are going to be selected in priority. The recommendation above prioritizes algorithms that provide perfect [forward secrecy](https://wiki.mozilla.org/Security/Server_Side_TLS#Forward_Secrecy). Please check the [Mozilla SSL Configuration Generator](https://mozilla.github.io/server-side-tls/ssl-config-generator/). **ssl-dh-param:** sets the Base64 string that contains Diffie-Hellman key to help with "Perfect Forward Secrecy." https://www.openssl.org/docs/manmaster/apps/dhparam.html https://wiki.mozilla.org/Security/Server_Side_TLS#DHE_handshake_and_dhparam http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_dhparam **ssl-protocols:** Sets the [SSL protocols](http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_protocols) to use. The default is: `TLSv1 TLSv1.1 TLSv1.2`. TLSv1 is enabled to allow old clients like: - [IE 8-10 / Win 7](https://www.ssllabs.com/ssltest/viewClient.html?name=IE&version=8-10&platform=Win%207&key=113) - [Java 7u25](https://www.ssllabs.com/ssltest/viewClient.html?name=Java&version=7u25&key=26) If you don't need to support these clients please remove `TLSv1` to improve security. Please check the result of the configuration using `https://ssllabs.com/ssltest/analyze.html` or `https://testssl.sh`. **ssl-redirect:** Sets the global value of redirects (301) to HTTPS if the server has a TLS certificate (defined in an Ingress rule) Default is "true". **ssl-session-cache:** Enables or disables the use of shared [SSL cache](http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_cache) among worker processes. **ssl-session-cache-size:** Sets the size of the [SSL shared session cache](http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_cache) between all worker processes. **ssl-session-tickets:** Enables or disables session resumption through [TLS session tickets](http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_tickets). **ssl-session-timeout:** Sets the time during which a client may [reuse the session](http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_session_timeout) parameters stored in a cache. **upstream-max-fails:** Sets the number of unsuccessful attempts to communicate with the [server](http://nginx.org/en/docs/http/ngx_http_upstream_module.html#upstream) that should happen in the duration set by the `fail_timeout` parameter to consider the server unavailable. **upstream-fail-timeout:** Sets the time during which the specified number of unsuccessful attempts to communicate with the [server](http://nginx.org/en/docs/http/ngx_http_upstream_module.html#upstream) should happen to consider the server unavailable. **use-gzip:** Enables or disables compression of HTTP responses using the ["gzip" module](http://nginx.org/en/docs/http/ngx_http_gzip_module.html) The default mime type list to compress is: `application/atom+xml application/javascript aplication/x-javascript application/json application/rss+xml application/vnd.ms-fontobject application/x-font-ttf application/x-web-app-manifest+json application/xhtml+xml application/xml font/opentype image/svg+xml image/x-icon text/css text/plain text/x-component`. **use-http2:** Enables or disables [HTTP/2](http://nginx.org/en/docs/http/ngx_http_v2_module.html) support in secure connections. **use-proxy-protocol:** Enables or disables the [PROXY protocol](https://www.nginx.com/resources/admin-guide/proxy-protocol/) to receive client connection (real IP address) information passed through proxy servers and load balancers such as HAProxy and Amazon Elastic Load Balancer (ELB). **worker-processes:** Sets the number of [worker processes](http://nginx.org/en/docs/ngx_core_module.html#worker_processes). The default of "auto" means number of available CPU cores. ### Default configuration options The following table shows the options, the default value and a description. |name |default| |---------------------------|------| |body-size|1m| |custom-http-errors|" "| |enable-sticky-sessions|"false"| |enable-vts-status|"false"| |error-log-level|notice| |gzip-types|| |hsts|"true"| |hsts-include-subdomains|"true"| |hsts-max-age|"15724800"| |keep-alive|"75"| |max-worker-connections|"16384"| |proxy-connect-timeout|"5"| |proxy-read-timeout|"60"| |proxy-real-ip-cidr|0.0.0.0/0| |proxy-send-timeout|"60"| |retry-non-idempotent|"false"| |server-name-hash-bucket-size|"64"| |server-name-hash-max-size|"512"| |ssl-buffer-size|4k| |ssl-ciphers|| |ssl-protocols|TLSv1 TLSv1.1 TLSv1.2| |ssl-session-cache|"true"| |ssl-session-cache-size|10m| |ssl-session-tickets|"true"| |ssl-session-timeout|10m| |use-gzip|"true"| |use-http2|"true"| |vts-status-zone-size|10m| |worker-processes|number of CPUs| ### Websockets Support for websockets is provided by NGINX 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 `30 seconds`. A more adequate value to support websockets is a value higher than one hour (`3600`). ### Optimizing TLS Time To First Byte (TTTFB) NGINX provides the configuration option [ssl_buffer_size](http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_buffer_size) to allow the optimization of the TLS record size. This improves the [Time To First Byte](https://www.igvita.com/2013/12/16/optimizing-nginx-tls-time-to-first-byte/) (TTTFB). The default value in the Ingress controller is `4k` (NGINX default is `16k`). ### Retries in non-idempotent methods Since 1.9.13 NGINX will not retry non-idempotent requests (POST, LOCK, PATCH) in case of an error. The previous behavior can be restored using `retry-non-idempotent=true` in the configuration ConfigMap.