Background

Background run + logging (lcpd-grpcd)

This doc describes practical ways to:

• run lcpd-grpcd in the background
• keep logs on disk (with basic rotation)

Note: logs are sensitive. lcpd-grpcd is designed to avoid logging raw prompts/outputs, but logs still contain metadata (peer ids, job ids, prices, timings). See Logging & privacy.

For long-running infrastructure, use a service manager (systemd/launchd). For “keep running after I close my terminal”, the repo script is usually enough.

Option A (recommended for quick use): repo script + log file

The repo ships a small runner script:

cd go-lcpd
./scripts/lcpd-grpcd --help

0) Build the daemon binary (one-time)

cd go-lcpd
mkdir -p bin
GOBIN="$PWD/bin" go install ./tools/lcpd-grpcd

1) Configure environment

You can keep startup parameters and secrets out of your shell history by using direnv (.envrc, recommended). If you don’t use direnv, export LCPD_* env vars in your shell or service manager configuration.

Option A: direnv (.envrc)

cd go-lcpd
cp .envrc.sample .envrc
direnv allow

Then edit .envrc to add your LCPD_* settings.

Requester-only (no Provider execution) tip:

• If you run from a directory containing config.yaml, lcpd-grpcd will use it by default.
• This repo’s go-lcpd/config.yaml keeps the Provider disabled by default.
• If you have a different config.yaml that enables the Provider (or you’re running from another working directory), you can force Provider disabled by setting LCPD_PROVIDER_CONFIG_PATH=/dev/null (empty YAML).

2) Start / stop

Start (background):

cd go-lcpd
./scripts/lcpd-grpcd up

Status:

cd go-lcpd
./scripts/lcpd-grpcd status

Tail logs:

cd go-lcpd
./scripts/lcpd-grpcd logs

Stop (graceful SIGINT):

cd go-lcpd
./scripts/lcpd-grpcd down

Sanity checks

Quick status checks:

cd go-lcpd
./scripts/lcpd-grpcd status
tail -n 50 ./.data/lcpd-grpcd/logs/lcpd-grpcd.log

Port-level checks (pick one):

nc -vz 127.0.0.1 50051

lsof -nP -iTCP:50051 -sTCP:LISTEN

If you override the listen address (e.g. LCPD_GRPCD_GRPC_ADDR=127.0.0.1:15051), adjust the port accordingly.

Logs + rotation behavior

• Log link path default: ./.data/lcpd-grpcd/logs/lcpd-grpcd.log (gitignored)
• PID file: ./.data/lcpd-grpcd/pids/lcpd-grpcd.pid
• At each startup, a new dated log file is created (e.g. lcpd-grpcd.YYYYmmdd-HHMMSS.<pid>.<rand>.log).
• lcpd-grpcd.log is a symlink pointing at the current run’s log file.
• Only the newest LCPD_GRPCD_LOG_KEEP_ROTATED run logs are kept (default 10).

Option B: systemd (Linux)

systemd gives you:

• auto-restart on crashes
• boot-time startup
• robust log retention via journald

Minimal user service example (recommended when lnd certs/macaroons live under your home directory):

1. Write ~/.config/systemd/user/lcpd-grpcd.service:

[Unit]
Description=lcpd-grpcd (Lightning Compute Protocol daemon)
After=network-online.target

[Service]
Type=simple
WorkingDirectory=/ABS/PATH/TO/go-lcpd
ExecStart=/usr/bin/env direnv exec /ABS/PATH/TO/go-lcpd /ABS/PATH/TO/go-lcpd/bin/lcpd-grpcd -grpc_addr=127.0.0.1:50051
Restart=on-failure
RestartSec=2s
KillSignal=SIGINT

[Install]
WantedBy=default.target

2. Start + enable:

systemctl --user daemon-reload
systemctl --user enable --now lcpd-grpcd

3. Logs:

journalctl --user -u lcpd-grpcd -f

To keep user services running across reboots without an active login session, you may need:

loginctl enable-linger "$USER"

Option C: launchd (macOS)

launchd is the macOS service manager. For background + auto-restart, use a LaunchAgent (runs as your user).

1. Create ~/Library/LaunchAgents/com.bruwbird.lcpd-grpcd.plist (adjust absolute paths):

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
  <dict>
    <key>Label</key>
    <string>com.bruwbird.lcpd-grpcd</string>

    <key>ProgramArguments</key>
    <array>
      <string>/bin/bash</string>
      <string>-lc</string>
      <string>cd /ABS/PATH/TO/go-lcpd && exec direnv exec . ./bin/lcpd-grpcd -grpc_addr=127.0.0.1:50051</string>
    </array>

    <key>RunAtLoad</key>
    <true/>
    <key>KeepAlive</key>
    <true/>

    <key>StandardOutPath</key>
    <string>/ABS/PATH/TO/go-lcpd/.data/lcpd-grpcd/logs/lcpd-grpcd.launchd.out.log</string>
    <key>StandardErrorPath</key>
    <string>/ABS/PATH/TO/go-lcpd/.data/lcpd-grpcd/logs/lcpd-grpcd.launchd.err.log</string>
  </dict>
</plist>

2. Load it:

launchctl bootstrap "gui/$UID" ~/Library/LaunchAgents/com.bruwbird.lcpd-grpcd.plist
launchctl enable "gui/$UID/com.bruwbird.lcpd-grpcd"
launchctl kickstart -k "gui/$UID/com.bruwbird.lcpd-grpcd"

3. Inspect status:

launchctl print "gui/$UID/com.bruwbird.lcpd-grpcd"

Notes:

• The plist uses direnv exec so you can keep credentials out of the plist itself (store secrets in .envrc).
• macOS does not rotate these log files automatically; use newsyslog or periodically archive/delete old logs.