command-flow.md

flow — creates isolated flows of messages

flow {<subcommands>}

You can think of flow as namespaces or visibility scopes.

Subcommands: all commands are allowed.

flow should be used to create separate processing chains:

# WRONG
from udp 1001;
to tcp 1.2.3.4:1002;
from udp 1003;
to tcp 1.2.3.4:1004; # Receives messages from both ports 1001 AND 1003!

# separate flows
flow {from udp 1001; to tcp 1.2.3.4:1002}
flow {from udp 1003; to tcp 1.2.3.4:1004}

Message routing for flow:

from udp 1001;
flow {
    # Incoming messages are only emitted out of `flow`,
    # subcommands do not receive them.
    from udp 1002;
    to file some.log; # receives messages only from port 1002
    # After last subcommand messages are dropped
}
to stdout; # Receives messages only from port 1001