caddy-frontend: Add port-redirection config file generation

software/caddy-frontend/instance-apache-frontend.cfg

@@ -14,6 +14,7 @@ parts =
   frontend-caddy-graceful
   frontend-nginx-graceful
   not-found-html
+  port-redirection
   promise-frontend-caddy-configuration
   promise-caddy-frontend-v4-https
   promise-caddy-frontend-v4-http
@@ -768,3 +769,13 @@ port = $${instance-parameter:configuration.plain_nginx_port}
 recipe = slapos.cookbook:wrapper
 command-line = ${buildout:bin-directory}/is-process-older-than-dependency-set $${nginx-configuration:pid-file} 
 wrapper-path = $${directory:promise}/promise-nginx-is-process-older-than-dependency-set
+
+[port-redirection]
+<= jinja2-template-base
+template = inline:
+  [{"srcPort": 80, "destPort": {{ http_port }}}, {"srcPort": 443, "destPort": {{ https_port }}}]
+rendered = $${buildout:directory}/.slapos-port-redirect
+mode = 0644
+extra-context =
+    key http_port instance-parameter:configuration.plain_http_port
+    key https_port instance-parameter:configuration.port