fix: trigger nginx proxy rebuild early to avoid downtime if deploying large numbers of processes

Due to how the nginx proxy implementation works, if an app has either many process types or many containers for a process type other than web, it is possible to see downtime on the web process due to the old web containers rotating out _before_ we reload the nginx config.

The correct fix would be to use some sort of dns-based resolution for the nginx config, but pending that change, we reload nginx twice now - ugh - to avoid this.

plugins/nginx-vhosts/scheduler-post-deploy-process

@@ -0,0 +1,24 @@
+#!/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-scheduler-post-deploy-process() {
+  declare desc="nginx-vhosts scheduler-post-deploy-process plugin trigger"
+  declare trigger="scheduler-post-deploy-process"
+  declare APP="$1" PROCESS_TYPE="$2"
+
+  if [[ "$PROCESS_TYPE" != "web" ]]; then
+    return
+  fi
+
+  if [[ "$(plugn trigger proxy-type "$APP")" != "nginx" ]]; then
+    return
+  fi
+
+  dokku_log_info1 "Triggering early nginx proxy rebuild"
+  plugn trigger proxy-build-config "$APP"
+}
+
+trigger-nginx-vhosts-scheduler-post-deploy-process "$@"

plugins/scheduler-docker-local/bin/scheduler-deploy-process

@@ -51,6 +51,8 @@ main() {
   PARALLEL_DEPLOY_COUNT="$(plugn trigger "app-json-process-deploy-parallelism" "$APP" "$PROC_TYPE")"
   DOKKU_CHECKS_DISABLED="$DOKKU_CHECKS_DISABLED" INJECT_INIT_FLAG="$INJECT_INIT_FLAG" parallel --will-cite --halt soon,fail=1 --jobs "$PARALLEL_DEPLOY_COUNT" --ungroup <"$PROCESS_TMP_FILE"
 
+  plugn trigger scheduler-post-deploy-process "$APP" "$PROC_TYPE"
+
   # cleanup when we scale down
   if [[ "$PROC_COUNT" == 0 ]]; then
     local CONTAINER_IDX_OFFSET=0