feat: inject docker labels when nginx proxy implementation is in use

This will allow users to switch to a docker label-based nginx proxy server transparently without rebuilds (after the first one), which would mimic how the caddy, haproxy, and traefik proxy implementations work.

See https://github.com/dokku/nginx-docker-proxy for an example server implementation.

plugins/nginx-vhosts/docker-args-process-deploy

@@ -0,0 +1,58 @@
+#!/usr/bin/env bash
+set -eo pipefail
+[[ $DOKKU_TRACE ]] && set -x
+source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
+source "$PLUGIN_AVAILABLE_PATH/nginx-vhosts/functions"
+
+trigger-nginx-vhosts-docker-args-process-deploy() {
+  declare desc="nginx-vhosts docker-args-process-deploy plugin trigger"
+  declare trigger="docker-args-process-deploy"
+  declare APP="$1" IMAGE_SOURCE_TYPE="$2" IMAGE_TAG="$3" PROC_TYPE="$4" CONTAINER_INDEX="$5"
+  local output
+  local STDIN=$(cat)
+
+  if [[ "$PROC_TYPE" != "web" ]]; then
+    return
+  fi
+
+  if [[ "$(plugn trigger proxy-type "$APP")" != "nginx" ]]; then
+    return
+  fi
+
+  if [[ "$(plugn trigger proxy-is-enabled "$APP")" != "true" ]]; then
+    return
+  fi
+
+  if ! plugn trigger domains-vhost-enabled "$APP" 2>/dev/null; then
+    return
+  fi
+
+  # ensure we have a port mapping
+  plugn trigger ports-configure "$APP"
+
+  output="$output '--label=nginx.access-log-format=$(fn-nginx-access-log-format "$APP")'"
+  output="$output '--label=nginx.bind-address-ipv4=$(fn-nginx-bind-address-ipv4 "$APP")'"
+  output="$output '--label=nginx.bind-address-ipv6=$(fn-nginx-bind-address-ipv6 "$APP")'"
+  output="$output '--label=nginx.client-max-body-size=$(fn-nginx-client-max-body-size "$APP")'"
+  output="$output '--label=nginx.hsts-include-subdomains=$(fn-nginx-hsts-include-subdomains "$APP")'"
+  output="$output '--label=nginx.hsts-max-age=$(fn-nginx-hsts-max-age "$APP")'"
+  output="$output '--label=nginx.hsts-preload=$(fn-nginx-hsts-preload "$APP")'"
+  output="$output '--label=nginx.hsts=$(fn-nginx-hsts-is-enabled "$APP")'"
+  output="$output '--label=nginx.https-port=443'"
+  output="$output '--label=nginx.domains=$(plugn trigger domains-list "$APP" | xargs)'"
+  output="$output '--label=nginx.initial-network=$(plugn trigger network-get-property "$APP" initial-network)'"
+  output="$output '--label=nginx.port-mapping=$(plugn trigger ports-get "$APP" | xargs)'"
+  output="$output '--label=nginx.proxy-buffer-size=$(fn-nginx-proxy-buffer-size "$APP")'"
+  output="$output '--label=nginx.proxy-buffering=$(fn-nginx-proxy-buffering "$APP")'"
+  output="$output '--label=nginx.proxy-buffers=$(fn-nginx-proxy-buffers "$APP")'"
+  output="$output '--label=nginx.proxy-busy-buffer-size=$(fn-nginx-proxy-busy-buffers-size "$APP")'"
+  output="$output '--label=nginx.proxy-read-timeout=$(fn-nginx-proxy-read-timeout "$APP")'"
+  output="$output '--label=nginx.x-forwarded-for-value=$(fn-nginx-x-forwarded-for-value "$APP")'"
+  output="$output '--label=nginx.x-forwarded-port-value=$(fn-nginx-x-forwarded-port-value "$APP")'"
+  output="$output '--label=nginx.x-forwarded-proto-value=$(fn-nginx-x-forwarded-proto-value "$APP")'"
+  output="$output '--label=nginx.x-forwarded-ssl=$(fn-nginx-x-forwarded-ssl "$APP")'"
+
+  echo -n "$STDIN$output"
+}
+
+trigger-nginx-vhosts-docker-args-process-deploy "$@"