Skip to main content Link Search Menu Expand Document (external link)
NethServer 8

Port allocation

Many web application modules need a TCP port to run a backend exposed by Traefik. Such modules can set the org.nethserver.tcp-ports-demand which takes an integer number as value. Example:

org.nethserver.tcp-ports-demand=1

The randomly-allocated TCP port number will be available inside the TCP_PORT environment variable and it will be available to all step scripts and inside systemd units. The available environment variables will be:

  • TCP_PORT: it is always present and it contains always the first port, i.e. 1000
  • TCP_PORTS_RANGE: only if value is greater than 1, it contains the list of ports in range format, i.e 1000-1002
  • TCP_PORTS: only if value is greater than 1 and less or equal than 8, it contains a comma separated list of ports like, i.e. 1000,10001,10002

Currently last allocated port is saved inside Redis at node/<node_id>/tcp_ports_sequence.