varnishtest "Bug fix: master CLI connection slots freed on client disconnect"

# Regression test for a master CLI socket connection leak in master-worker mode.
#
# mworker_proxy has a fixed maxconn of 10.  When clients connect to the master
# socket, send a command that is forwarded to a busy worker, and then close
# the connection due to a client-side receive timeout, haproxy must free each
# slot as the client disconnects.
#
# Without the fix: slots remain occupied after the client disconnects, so the
# master CLI becomes unreachable once all 10 slots are filled.
# With the fix: slots are freed on client disconnect and the master CLI keeps
# accepting new connections.
#
# The worker is made unresponsive using "debug dev delay" (expert-mode) with
# nbthread 1 so a single delay blocks the entire worker CLI.  This avoids
# using SIGSTOP/SIGCONT which can be unreliable in CI environments.

#REGTEST_TYPE=bug

feature cmd "command -v socat"
feature cmd "command -v timeout"
feature ignore_unknown_macro

server s1 {
} -start

haproxy h1 -W -S -conf {
    global
        nbthread 1

    defaults
        mode http
        timeout connect "${HAPROXY_TEST_TIMEOUT-5s}"
        timeout client  "${HAPROXY_TEST_TIMEOUT-5s}"
        timeout server  "${HAPROXY_TEST_TIMEOUT-5s}"

    frontend fe
        bind "fd@${fe}"
        default_backend be

    backend be
        server s1 ${s1_addr}:${s1_port}
} -start

# Fill all 10 master CLI slots (mworker_proxy->maxconn is hardcoded to 10).
# Each socat sends "expert-mode on" followed by "@1 debug dev delay 10000"
# which blocks the single worker thread for 10 s.  After 2 s the timeout(1)
# wrapper kills socat, simulating a client-side receive timeout.  "wait"
# ensures all background processes have exited before proceeding.
shell {
    for i in $(seq 1 10); do
        (printf "expert-mode on\n@1 debug dev delay 10000\n" \
         | timeout 2 socat TCP:${h1_mcli_addr}:${h1_mcli_port} - 2>/dev/null) &
    done
    wait
}

# This is the key assertion: after all 10 clients have disconnected, a new
# connection to the master CLI must succeed.  With the bug all 10 slots are
# still marked occupied and this connect is refused or times out.
haproxy h1 -mcli {
    send "show version"
    expect ~ "3."
}