feat: Pull invalid nginx configuration when the nginx configs fail to validate

- expose an nginx:validate command that can be used to show validation information
- properly reference the invalid nginx config, rather than tell the user that another app's nginx config is invalid when deploying their own app
- allow a user to cleanup bad nginx config files out of band when they are blocking a deploy _without_ requiring knowing where that nginx config is

Note that this may have issues with generated nginx.conf files that depend on other apps or other parts of the nginx config. For now, this is acceptable, though it is something that needs to be field tested.

Closes #3162

plugins/nginx-vhosts/functions

@@ -6,6 +6,7 @@ source "$PLUGIN_AVAILABLE_PATH/config/functions"
 source "$PLUGIN_AVAILABLE_PATH/domains/functions"
 source "$PLUGIN_AVAILABLE_PATH/proxy/functions"
 source "$PLUGIN_AVAILABLE_PATH/ps/functions"
+source "$PLUGIN_AVAILABLE_PATH/nginx-vhosts/internal-functions"
 
 get_nginx_location() {
   declare desc="check that nginx is at the expected location and return it"
@@ -25,26 +26,45 @@ get_nginx_location() {
 
 validate_nginx() {
   declare desc="validate entire nginx config"
-  local NGINX_LOCATION
+  declare APP="${1:-}" FLAG="${2:-}"
+  local NGINX_LOCATION EXIT_CODE
   NGINX_LOCATION=$(get_nginx_location)
   if [[ -z "$NGINX_LOCATION" ]]; then
     exit 1;
   fi
 
+  if [[ "$APP" == "--clean" ]]; then
+    APP=""
+    FLAG="--clean"
+  fi
+
   set +e
   sudo "$NGINX_LOCATION" -t > /dev/null 2>&1
-  local exit_code=$?
+  EXIT_CODE=$?
   set -e
-  if [[ "$exit_code" -ne "0" ]]; then
-    sudo "$NGINX_LOCATION" -t
-    shopt -s nullglob
-    local conf_file
-    for conf_file in $DOKKU_ROOT/*/nginx.conf; do
-      dokku_log_verbose "validate_nginx failed. contents of $conf_file below..."
-      cat "$conf_file"
-    done
-    exit "$exit_code"
+  if [[ "$EXIT_CODE" -eq "0" ]]; then
+    return
   fi
+
+  if [[ -n "$APP" ]]; then
+    nginx_vhosts_validate_single_func "$APP" "$FLAG"
+  else
+    for app in $(dokku_apps); do
+      nginx_vhosts_validate_single_func "$app" "$FLAG"
+    done
+  fi
+
+  set +e
+  sudo "$NGINX_LOCATION" -t > /dev/null 2>&1
+  EXIT_CODE=$?
+  set -e
+  if [[ "$EXIT_CODE" -eq "0" ]]; then
+    return
+  fi
+
+
+  sudo "$NGINX_LOCATION" -t
+  exit $?
 }
 
 restart_nginx() {
@@ -320,7 +340,7 @@ nginx_build_config() {
     PROXY_PORT_MAP=$(echo "$PROXY_PORT_MAP" | xargs) # trailing spaces mess up default template
 
     eval "$(config_export app "$APP")"
-    local SIGIL_PARAMS=(-f $NGINX_TEMPLATE APP="$APP" DOKKU_ROOT="$DOKKU_ROOT"
+    local SIGIL_PARAMS=(-f "$NGINX_TEMPLATE" APP="$APP" DOKKU_ROOT="$DOKKU_ROOT"
           NOSSL_SERVER_NAME="$NOSSL_SERVER_NAME"
           DOKKU_APP_LISTENERS="$DOKKU_APP_LISTENERS"
           DOKKU_LIB_ROOT="$DOKKU_LIB_ROOT"