Package python3-module-ephemeral-port-reserve: Information

Sometimes you need a networked program to bind to a port that can't be
hard-coded. Generally this is when you want to run several of them
in parallel; if they all bind to port 8080, only one of them can succeed.

The usual solution is the "port 0 trick". If you bind to port 0, your
kernel will find some arbitrary high-numbered port that's unused and
bind to that. Afterward you can query the actual port that was bound
to if you need to use the port number elsewhere. However, there are
cases where the port 0 trick won't work. For example, mysqld takes
port 0 to mean "the port configured in my.cnf". Docker can bind your
containers to port 0, but uses its own implementation to find a free
port which races and fails in the face of parallelism.

Package python3-module-ephemeral-port-reserve: Information

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