Test a raw TCP or UDP service

For a service that speaks its own protocol, use the tcp or udp driver. Each iteration opens a connection, sends the body, optionally checks the reply, and closes. Driver settings go in repeatable -opt key=value flags.

# Does the service answer PING with PONG? Read until the reply contains PONG.
vegaload run -target tcp://127.0.0.1:6379 -protocol tcp \
  -body 'PING\r\n' -opt expect=PONG -vus 10 -duration 20s

# Read exactly 8 bytes back, or read until a delimiter, or only connect.
vegaload run -target tcp://127.0.0.1:7000 -protocol tcp -body 'hello\n' -opt read=8
vegaload run -target tcp://127.0.0.1:25 -protocol tcp -opt until='\r\n' -opt expect=220
vegaload run -target tcp://127.0.0.1:7000 -protocol tcp

# Send one UDP datagram. Add -opt reply=true or -opt expect=... to wait for an answer.
vegaload run -target udp://127.0.0.1:514 -protocol udp -body '<13>test message\n'

The tcp options are read, until, expect, max, tls and escape. The udp options are reply, expect and escape. In -body, expect and until, the text may use \n, \r, \t, \0, \\ and \xNN. Pass -opt escape=false to send backslashes as they are. Use -opt tls=true for a TLS service, with -insecure if its certificate is not trusted. tls=true takes the four options under "TLS with your own CA". UDP has no TLS, so those options are an error. A misspelled option is an error, not ignored. The same host allowlist and caps apply as for HTTP targets. Each iteration opens a new connection, so a very high rate on one machine can run out of local ports. Keep the rate moderate, or spread the load over more machines.