OpenResty Proxy¶

New

Introduced in 0.31.0

Dokku can provide integration with the OpenResty proxy service by utilizing the Docker label-based integration implemented by openresty-docker-proxy.

openresty:report [<app>] [<flag>]            # Displays a openresty report for one or more apps
openresty:logs [--num num] [--tail]          # Display openresty log output
openresty:set <app> <property> (<value>)     # Set or clear an openresty property for an app
openresty:show-config <app>                  # Display openresty compose config
openresty:start                              # Starts the openresty server
openresty:stop                               # Stops the openresty server

Requirements¶

Using the openresty plugin integration requires the docker-compose-plugin for Docker. See this document from the Docker documentation for more information on the installation process for the docker-compose-plugin.

Usage¶

Warning

As using multiple proxy plugins on a single Dokku installation can lead to issues routing requests to apps, doing so should be avoided. As the default proxy implementation is nginx, users are encouraged to stop the nginx service before switching to OpenResty.

The OpenResty plugin has specific rules for routing requests:

OpenResty integration is exposed via docker labels attached to containers. Changes in labels require either app deploys or rebuilds.
While OpenResty will respect labels associated with other containers, only web containers have OpenResty labels injected by the plugin.
Only http:80 and https:443 port mappings are supported at this time.
Requests are routed as soon as the container is running and passing healthchecks.

Switching to OpenResty¶

To use the OpenResty plugin, use the proxy:set command for the app in question:

dokku proxy:set node-js-app type openresty

This will enable the docker label-based OpenResty integration. All future deploys will inject the correct labels for OpenResty to read and route requests to containers. Due to the docker label-based integration used by OpenResty, a single deploy or rebuild will be required before requests will route successfully.

dokku ps:rebuild node-js-app

Any changes to domains or port mappings will also require either a deploy or rebuild.

Starting OpenResty container¶

OpenResty can be started via the openresty:start command. This will start a OpenResty container via the docker compose up command.

dokku openresty:start

Stopping the OpenResty container¶

OpenResty may be stopped via the openresty:stop command.

dokku openresty:stop

The OpenResty container will be stopped and removed from the system. If the container is not running, this command will do nothing.

Showing the OpenResty compose config¶

For debugging purposes, it may be useful to show the OpenResty compose config. This can be achieved via the openresty:show-config command.

dokku openresty:show-config

Customizing the OpenResty container image¶

While the default OpenResty image is hardcoded, users may specify an alternative by setting the image property with the --global flag:

dokku openresty:set --global image dokku/openresty-docker-proxy:0.5.6

Checking the OpenResty container's logs¶

It may be necessary to check the OpenResty container's logs to ensure that OpenResty is operating as expected. This can be performed with the openresty:logs command.

dokku openresty:logs

This command also supports the following modifiers:

--num NUM        # the number of lines to display
--tail           # continually stream logs

You can use these modifiers as follows:

dokku openresty:logs --tail --num 10

The above command will show logs continually from the openresty container, with an initial history of 10 log lines

Customizing Openresty Settings for an app¶

OpenResty Properties¶

The OpenResty plugin supports all properties supported by the nginx:set command via openresty:set. At this time, please consult the nginx documentation for more information on what properties are available.

Please note that the oldest running container will be used for OpenResty configuration, and thus newer config may not apply until older app containers are retired during/after a deploy, depending on your zero-downtime settings.

Custom OpenResty Templates¶

At this time, the OpenResty plugin does not allow complete customization of the template used to manage an app's vhost. Apps will use a template provided by the OpenResty container to proxy requests. See the next section for documentation on how to configure portions of the template.

Injecting custom snippets into the OpenResty config¶

The OpenResty plugin allows users to specify templates in their repository for auto-injection into the OpenResty config. Please note that this configuration should be validated prior to deployment or may cause outages in your OpenResty proxy layer.

The following folders within an app repository may have *.conf files that will be automatically injected into the OpenResty config.

openresty/http-includes/: Injected in the server block serving http(s) requests for the app.
openresty/http-location-includes/: Injected in the location block that proxies to the app in the app's respective server block.

Custom snippets filenames may only include alphanumeric, underscore, and dot characters. For security reasons, filenames that contain other characters will be ignored.

Label Management¶

The OpenResty plugin allows you to add custom container labels to apps. These labels are injected into containers during deployment and can be used to configure OpenResty behavior beyond what the plugin provides by default.

Refer to the upstream openresty-docker-proxy documentation for more information on what labels are available.

Adding a label¶

To add a custom container label to an app, use the openresty:labels:add command:

dokku openresty:labels:add node-js-app openresty.directive value

This will add the label openresty.directive=value to the app's containers. After adding a label, you will need to rebuild or redeploy the app for the label to be applied to running containers.

dokku ps:rebuild node-js-app

Removing a label¶

To remove a custom container label from an app, use the openresty:labels:remove command:

dokku openresty:labels:remove node-js-app openresty.directive

This will remove the specified label from the app. After removing a label, you will need to rebuild or redeploy the app for the change to be applied to running containers.

dokku ps:rebuild node-js-app

Showing labels¶

To view all custom container labels for an app, use the openresty:labels:show command:

dokku openresty:labels:show node-js-app

To view a specific label value, provide the label name:

dokku openresty:labels:show node-js-app openresty.directive

SSL Configuration¶

The OpenResty plugin only supports automatic ssl certificates from it's letsencrypt integration. Managed certificates provided by the certs plugin are ignored.

Enabling letsencrypt integration¶

By default, letsencrypt is disabled and https port mappings are ignored. To enable, set the letsencrypt-email property with the --global flag:

dokku openresty:set --global letsencrypt-email automated@dokku.sh

After enabling, the OpenResty container will need to be restarted and apps will need to be rebuilt. All http requests will then be redirected to https.

Customizing the letsencrypt server¶

The letsencrypt integration is set to the production letsencrypt server by default. To change this, set the letsencrypt-server property with the --global flag:

dokku openresty:set --global letsencrypt-server https://acme-staging-v02.api.letsencrypt.org/directory

After enabling, the OpenResty container will need to be restarted and apps will need to be rebuilt to retrieve certificates from the new server.

Limiting letsencrypt to certain domains¶

Warning

Changing this value may cause OpenResty to fail to start if the value is not valid. Caution should be exercised when changing this value from the defaults.

In cases where your server's IP may have invalid domains pointing at it, limiting letsencrypt to certain allowed domains may be desirable to reduce spam requests on the Letsencrypt servers. The default is to allow all domains to have certificates retrieved, but this can be limited by specifying the allowed-letsencrypt-domains-func-base64 global property.

The default internal value for allowed-letsencrypt-domains-func-base64 is the base64 representation of return true, and is meant to be the body of a lua function that return a boolean value.

value="$(echo 'return true' | base64 -w 0)"
dokku openresty:set --global allowed-letsencrypt-domains-func-base64 $value

As this is a global value, once changed, OpenResty should be stopped and started again for the value to take effect:

dokku openresty:stop
dokku openresty:start

A more complex example would be to limit provisioning of certificates to domains in a specific list. The body of the lua function has access to a variable domain, and we can use it like so:

body='allowed_domains = {"domain.com", "extra-domain.com"}

for index, value in ipairs(allowed_domains) do
  if value == domain then
    return true
  end
end

return false
'
value="$(echo "$body" | base64 -w 0)"
dokku openresty:set --global allowed-letsencrypt-domains-func-base64 $value

To reset the value to the default, simply specify a blank value prior to restarting OpenResty:

dokku openresty:set --global allowed-letsencrypt-domains-func-base64

Displaying OpenResty reports for an app¶

You can get a report about the app's OpenResty config using the openresty:report command:

ShellOutput

dokku openresty:report

=====> node-js-app openresty information
       Openresty image:                   dokku/openresty-docker-proxy:0.5.6
       Openresty letsencrypt email:       automated@dokku.sh
=====> python-app openresty information
       Openresty image:                   dokku/openresty-docker-proxy:0.5.6
       Openresty letsencrypt email:       automated@dokku.sh
=====> ruby-app openresty information
       Openresty image:                   dokku/openresty-docker-proxy:0.5.6
       Openresty letsencrypt email:       automated@dokku.sh

You can run the command for a specific app also.

ShellOutput

dokku openresty:report node-js-app

=====> node-js-app openresty information
       Openresty image:                   dokku/openresty-docker-proxy:0.5.6
       Openresty letsencrypt email:       automated@dokku.sh

You can pass flags which will output only the value of the specific information you want. For example:

dokku openresty:report node-js-app --openresty-computed-letsencrypt-email

Properties¶

Settable properties¶

Five properties (image, log-level, letsencrypt-email, letsencrypt-server, allowed-letsencrypt-domains-func-base64) are global only. The rest may be set per-app or globally with --global; a global value applies to any app that has no per-app value, otherwise the built-in default is used.

Global-only properties expose two report flags: --openresty-global-<property> returns the raw stored value (empty when the property has never been set), while --openresty-computed-<property> returns the effective value (the global value if set, otherwise the built-in default).

App-or-global properties expose three report flags: --openresty-<property> returns the raw per-app value (empty when unset), --openresty-global-<property> returns the raw global value (empty when unset), and --openresty-computed-<property> returns the effective value, resolving the per-app value first, then the global value, then the built-in default.

Property	Scope	Default	Report flags	Description
`access-log-format`	app or global	none	`--openresty-access-log-format`, `--openresty-global-access-log-format`, `--openresty-computed-access-log-format`	Custom nginx `log_format` directive used for the access log
`access-log-path`	app or global	`/var/log/nginx/{app}-access.log`	`--openresty-access-log-path`, `--openresty-global-access-log-path`, `--openresty-computed-access-log-path`	Path inside the openresty container where access logs are written
`allowed-letsencrypt-domains-func-base64`	global only	allow-all stub	`--openresty-global-allowed-letsencrypt-domains-func-base64`, `--openresty-computed-allowed-letsencrypt-domains-func-base64`	Base64-encoded Lua function deciding which domains may request a letsencrypt certificate
`bind-address-ipv4`	app or global	none	`--openresty-bind-address-ipv4`, `--openresty-global-bind-address-ipv4`, `--openresty-computed-bind-address-ipv4`	IPv4 address the openresty server block binds to
`bind-address-ipv6`	app or global	`::`	`--openresty-bind-address-ipv6`, `--openresty-global-bind-address-ipv6`, `--openresty-computed-bind-address-ipv6`	IPv6 address the openresty server block binds to
`client-body-timeout`	app or global	`60s`	`--openresty-client-body-timeout`, `--openresty-global-client-body-timeout`, `--openresty-computed-client-body-timeout`	Time allowed to read the request body from the client
`client-header-timeout`	app or global	`60s`	`--openresty-client-header-timeout`, `--openresty-global-client-header-timeout`, `--openresty-computed-client-header-timeout`	Time allowed to read the request header from the client
`client-max-body-size`	app or global	`1m`	`--openresty-client-max-body-size`, `--openresty-global-client-max-body-size`, `--openresty-computed-client-max-body-size`	Maximum allowed request body size
`error-log-path`	app or global	`/var/log/nginx/{app}-error.log`	`--openresty-error-log-path`, `--openresty-global-error-log-path`, `--openresty-computed-error-log-path`	Path inside the openresty container where error logs are written
`hsts`	app or global	`true`	`--openresty-hsts`, `--openresty-global-hsts`, `--openresty-computed-hsts`	When `true`, emits a `Strict-Transport-Security` header on HTTPS responses
`hsts-include-subdomains`	app or global	`true`	`--openresty-hsts-include-subdomains`, `--openresty-global-hsts-include-subdomains`, `--openresty-computed-hsts-include-subdomains`	Adds the `includeSubDomains` directive to the HSTS header
`hsts-max-age`	app or global	`15724800`	`--openresty-hsts-max-age`, `--openresty-global-hsts-max-age`, `--openresty-computed-hsts-max-age`	`max-age` value (seconds) in the HSTS header
`hsts-preload`	app or global	`false`	`--openresty-hsts-preload`, `--openresty-global-hsts-preload`, `--openresty-computed-hsts-preload`	Adds the `preload` directive to the HSTS header
`image`	global only	parsed from `plugins/openresty-vhosts/Dockerfile`	`--openresty-global-image`, `--openresty-computed-image`	Docker image used to run the openresty container
`keepalive-timeout`	app or global	`75s`	`--openresty-keepalive-timeout`, `--openresty-global-keepalive-timeout`, `--openresty-computed-keepalive-timeout`	Time an idle keep-alive connection stays open
`letsencrypt-email`	global only	none	`--openresty-global-letsencrypt-email`, `--openresty-computed-letsencrypt-email`	Contact email enabling letsencrypt; empty disables https issuance
`letsencrypt-server`	global only	`https://acme-v02.api.letsencrypt.org/directory`	`--openresty-global-letsencrypt-server`, `--openresty-computed-letsencrypt-server`	ACME directory used when requesting certificates
`lingering-timeout`	app or global	`5s`	`--openresty-lingering-timeout`, `--openresty-global-lingering-timeout`, `--openresty-computed-lingering-timeout`	Time openresty waits for more client data when closing a connection
`log-level`	global only	`ERROR`	`--openresty-global-log-level`, `--openresty-computed-log-level`	Openresty log level
`proxy-buffer-size`	app or global	system pagesize	`--openresty-proxy-buffer-size`, `--openresty-global-proxy-buffer-size`, `--openresty-computed-proxy-buffer-size`	Buffer size for reading the first part of the upstream response
`proxy-buffering`	app or global	`on`	`--openresty-proxy-buffering`, `--openresty-global-proxy-buffering`, `--openresty-computed-proxy-buffering`	Whether openresty buffers upstream responses (`on` or `off`)
`proxy-buffers`	app or global	`8 {pagesize}`	`--openresty-proxy-buffers`, `--openresty-global-proxy-buffers`, `--openresty-computed-proxy-buffers`	Number and size of buffers used for an upstream response
`proxy-busy-buffers-size`	app or global	`2 pagesize`*	`--openresty-proxy-busy-buffers-size`, `--openresty-global-proxy-busy-buffers-size`, `--openresty-computed-proxy-busy-buffers-size`	Maximum buffer size that can be busy sending a response to the client
`proxy-connect-timeout`	app or global	`60s`	`--openresty-proxy-connect-timeout`, `--openresty-global-proxy-connect-timeout`, `--openresty-computed-proxy-connect-timeout`	Time to establish a connection to the upstream
`proxy-read-timeout`	app or global	`60s`	`--openresty-proxy-read-timeout`, `--openresty-global-proxy-read-timeout`, `--openresty-computed-proxy-read-timeout`	Time to read a response from the upstream
`proxy-send-timeout`	app or global	`60s`	`--openresty-proxy-send-timeout`, `--openresty-global-proxy-send-timeout`, `--openresty-computed-proxy-send-timeout`	Time to transmit a request to the upstream
`send-timeout`	app or global	`60s`	`--openresty-send-timeout`, `--openresty-global-send-timeout`, `--openresty-computed-send-timeout`	Time between two successive write operations to the client
`underscore-in-headers`	app or global	`off`	`--openresty-underscore-in-headers`, `--openresty-global-underscore-in-headers`, `--openresty-computed-underscore-in-headers`	Whether to allow underscores in client request header field names
`x-forwarded-for-value`	app or global	`$remote_addr`	`--openresty-x-forwarded-for-value`, `--openresty-global-x-forwarded-for-value`, `--openresty-computed-x-forwarded-for-value`	Value used for the `X-Forwarded-For` header
`x-forwarded-port-value`	app or global	`$server_port`	`--openresty-x-forwarded-port-value`, `--openresty-global-x-forwarded-port-value`, `--openresty-computed-x-forwarded-port-value`	Value used for the `X-Forwarded-Port` header
`x-forwarded-proto-value`	app or global	`$scheme`	`--openresty-x-forwarded-proto-value`, `--openresty-global-x-forwarded-proto-value`, `--openresty-computed-x-forwarded-proto-value`	Value used for the `X-Forwarded-Proto` header
`x-forwarded-ssl`	app or global	none	`--openresty-x-forwarded-ssl`, `--openresty-global-x-forwarded-ssl`, `--openresty-computed-x-forwarded-ssl`	Value used for the `X-Forwarded-Ssl` header (e.g. `on`/`off`)