Dokku provides integration with the [Haproxy](http://www.haproxy.org) proxy service by utilizing the Docker label-based integration implemented by [EasyHaproxy](https://github.com/byjg/docker-easy-haproxy).
```
haproxy:report [<app>] [<flag>] # Displays a haproxy report for one or more apps
Using the `haproxy` plugin integration requires the `docker-compose-plugin` for Docker. See [this document](https://docs.docker.com/compose/install/) from the Docker documentation for more information on the installation process for the `docker-compose-plugin`.
> 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 Haproxy.
- Requests are routed as soon as the container is running and passing healthchecks.
### Switching to Haproxy
To use the Haproxy plugin, use the `proxy:set` command for the app in question:
```shell
dokku proxy:set node-js-app haproxy
```
This will enable the docker label-based Haproxy integration. All future deploys will inject the correct labels for Haproxy to read and route requests to containers. Due to the docker label-based integration used by Haproxy, a single deploy or rebuild will be required before requests will route successfully.
```shell
dokku ps:rebuild node-js-app
```
Any changes to domains or port mappings will also require either a deploy or rebuild.
### Starting Haproxy container
Haproxy can be started via the `haproxy:start` command. This will start a Haproxy container via the `docker compose up` command.
```shell
dokku haproxy:start
```
### Stopping the Haproxy container
Haproxy may be stopped via the `haproxy:stop` command.
```shell
dokku haproxy:stop
```
The Haproxy container will be stopped and removed from the system. If the container is not running, this command will do nothing.
### Showing the Haproxy compose config
For debugging purposes, it may be useful to show the Haproxy compose config. This can be achieved via the `haproxy:show-config` command.
```shell
dokku haproxy:show-config
```
### Customizing the Haproxy container image
While the default Haproxy image is hardcoded, users may specify an alternative by setting the `image` property with the `--global` flag:
It may be necessary to check the Haproxy container's logs to ensure that Haproxy is operating as expected. This can be performed with the `haproxy:logs` command.
```shell
dokku haproxy:logs
```
This command also supports the following modifiers:
```shell
--num NUM # the number of lines to display
--tail # continually stream logs
```
You can use these modifiers as follows:
```shell
dokku haproxy:logs --tail --num 10
```
The above command will show logs continually from the vector container, with an initial history of 10 log lines
The haproxy plugin only supports automatic ssl certificates from it's letsencrypt integration. Managed certificates provided by the `certs` plugin are ignored.
After enabling, the Haproxy 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:
