deploy: persistent systemd unit running a pinned release binary with Restart=on-failure + boot enable, plus a liveness timer that restarts the daemon if a register round-trip stops answering

deploy/echoircd-dev.service

@@ -0,0 +1,19 @@
+[Unit]
+Description=echoIRCd (production) — native Rust ircd
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+User=debian
+WorkingDirectory=/home/debian/irc/ircd/echoIRCd
+LimitNOFILE=200000
+# runs a PINNED release binary (bin/echoircd), not target/debug — so a stray
+# `cargo build` never changes what a restart would launch. Deploy = copy a fresh
+# `cargo build --release` binary over bin/echoircd, then `systemctl restart`.
+ExecStart=/home/debian/irc/ircd/echoIRCd/bin/echoircd /home/debian/irc/ircd/echoIRCd/echoircd.conf
+Restart=on-failure
+RestartSec=2
+
+[Install]
+WantedBy=multi-user.target

deploy/echoircd-liveness.service

@@ -0,0 +1,8 @@
+[Unit]
+Description=echoIRCd liveness probe — restart the daemon if it stops responding
+
+[Service]
+Type=oneshot
+# a hung (but not exited) daemon isn't caught by Restart=on-failure; this probe
+# does a real register round-trip and restarts the service if it doesn't answer.
+ExecStart=/home/debian/irc/ircd/echoIRCd/scripts/liveness.sh 6767

deploy/echoircd-liveness.timer

@@ -0,0 +1,10 @@
+[Unit]
+Description=Run the echoIRCd liveness probe periodically
+
+[Timer]
+OnBootSec=2min
+OnUnitActiveSec=2min
+AccuracySec=15s
+
+[Install]
+WantedBy=timers.target

scripts/liveness.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+# echoIRCd liveness probe: do a real NICK/USER register round-trip on the plaintext
+# port and, if the daemon doesn't answer with a 001 welcome, restart it. Catches a
+# hung core (process alive but not serving), which Restart=on-failure alone can't.
+# Run by echoircd-liveness.timer.
+set -u
+PORT="${1:-6767}"
+
+if python3 - "$PORT" <<'PY'
+import socket, sys, time
+port = int(sys.argv[1])
+try:
+    s = socket.create_connection(("127.0.0.1", port), timeout=5)
+    s.settimeout(5)
+    s.sendall(b"NICK livecheck\r\nUSER lc 0 * :liveness\r\n")
+    data = b""
+    end = time.time() + 6
+    while time.time() < end:
+        d = s.recv(4096)
+        if not d:
+            break
+        data += d
+        if b" 001 " in data:
+            break
+    try:
+        s.sendall(b"QUIT :liveness\r\n")
+    except OSError:
+        pass
+    s.close()
+    sys.exit(0 if b" 001 " in data else 1)
+except OSError:
+    sys.exit(1)
+PY
+then
+    exit 0
+fi
+
+echo "echoircd liveness: no 001 from 127.0.0.1:${PORT} within timeout — restarting echoircd-dev.service"
+systemctl restart echoircd-dev.service