refactor: move the proxy port map from config to property

Also remove all direct references to DOKKU_PROXY_PORT_MAP from outside of ports.

docs/appendices/0.31.0-migration-guide.md

@@ -7,6 +7,7 @@
 - The `traefik` integration now mounts config to `/data` instead of the path `/acme.json`, fixing permissions issues under certain architectures. To take advantage of the new functionality, the traefik container should be stopped (via `dokku traefik:stop`) and then started (via `dokku traefik:start`).
 - Users no longer need to clear the `source-image` git property when transitioning from image-based deploys (`git:from-image` and `git:load-image`) to other deployment methods (git push, `git:from-archive`, `git:sync`).
 - For deploys via the `git:from-image` and `git:load-image` commands, the `CHECKS` file is now extracted from the configured `WORKDIR` property of the image. For all other deploys - git push, `git:from-archive`, `git:sync` - will have the `CHECKS` extracted directly from the source code. The filename in both cases is `CHECKS` and cannot be modified.
+- The environment variable `DOKKU_PROXY_PORT_MAP` has been migrated to the properties system. Direct changes to the value will be ignored, and users should interact with port maps via the `ports` plugin.
 
 ## Deprecations
 

docs/configuration/environment-variables.md

@@ -116,7 +116,6 @@ The following config variables have special meanings and can be set in a variety
 | `DOKKU_PARALLEL_ARGUMENTS`.    | none                            | `dokku config:set`                                                                                                                               | Allows passing custom arguments to parallel for `ps:*all` commands |
 | `DOKKU_PROXY_PORT`             | automatically assigned          | `/etc/environment` <br /> `~dokku/.dokkurc` <br /> `~dokku/.dokkurc/*` <br /> `dokku config:set`                                                 | |
 | `DOKKU_PROXY_SSL_PORT`         | automatically assigned          | `/etc/environment` <br /> `~dokku/.dokkurc` <br /> `~dokku/.dokkurc/*` <br /> `dokku config:set`                                                 | |
-| `DOKKU_PROXY_PORT_MAP`         | automatically assigned          | `dokku ports:add` <br /> `dokku ports:remove`, `dokku ports:clear`                                                             | |
 | `DOKKU_SKIP_ALL_CHECKS`        | none                            | `dokku config:set`                                                                                                                               | |
 | `DOKKU_SKIP_CLEANUP`           |                                 | `/etc/environment` <br /> `~dokku/.dokkurc` <br /> `~dokku/.dokkurc/*`                                                                           | When a deploy is triggered, if this is set to a non-empty value, then old docker containers and images will not be removed. |
 | `DOKKU_SKIP_DEFAULT_CHECKS`    |                                 | `dokku config:set`                                                                                                                               | |

docs/networking/port-management.md

@@ -84,8 +84,6 @@ dokku ports:add node-js-app http:8080:5000
 ```
 
 ```
------> Setting config vars
-       DOKKU_PROXY_PORT_MAP: http:80:5000 http:8080:5000
 -----> Configuring node-js-app.dokku.me...(using built-in template)
 -----> Creating http nginx.conf
        Reloading nginx
@@ -120,8 +118,6 @@ dokku ports:set node-js-app http:8080:5000
 ```
 
 ```
------> Setting config vars
-       DOKKU_PROXY_PORT_MAP: http:80:5000 http:8080:5000
 -----> Configuring node-js-app.dokku.me...(using built-in template)
 -----> Creating http nginx.conf
        Reloading nginx

docs/networking/proxies/nginx.md

@@ -376,8 +376,8 @@ Unsetting this value is the same as enabling custom nginx config usage.
 {{ .PROXY_PORT }}                   Non-SSL nginx listener port (same as `DOKKU_PROXY_PORT` config var)
 {{ .PROXY_SSL_PORT }}               SSL nginx listener port (same as `DOKKU_PROXY_SSL_PORT` config var)
 {{ .NOSSL_SERVER_NAME }}            List of non-SSL VHOSTS
-{{ .PROXY_PORT_MAP }}               List of port mappings (same as `DOKKU_PROXY_PORT_MAP` config var)
-{{ .PROXY_UPSTREAM_PORTS }}         List of configured upstream ports (derived from `DOKKU_PROXY_PORT_MAP` config var)
+{{ .PROXY_PORT_MAP }}               List of port mappings (same as the `port-map` ports property)
+{{ .PROXY_UPSTREAM_PORTS }}         List of configured upstream ports (derived from the `port-map` ports property)
 {{ .RAW_TCP_PORTS }}                List of exposed tcp ports as defined by Dockerfile `EXPOSE` directive (**Dockerfile apps only**)
 {{ .SSL_INUSE }}                    Boolean set when an app is SSL-enabled
 {{ .SSL_SERVER_NAME }}              List of SSL VHOSTS