Deploying OpenHTF to a Production Test Station

OpenHTF has no deployment tool of its own; a station is a Python environment, your test package, a config file and something that starts it at boot. This page is the checklist that works.

Project layout

pcb01-eol/
├── pyproject.toml          # or requirements.txt — pinned
├── pcb01_eol/
│   ├── __init__.py
│   ├── main.py             # htf.Test assembly + entry point
│   ├── phases/             # one module per functional area
│   ├── plugs/              # instruments, DUT interfaces
│   └── limits.yaml         # optional: limits per part number
├── config/
│   ├── station-eol-01.yaml
│   └── station-eol-02.yaml
├── scripts/
│   ├── run.sh / run.ps1
│   └── install.sh / install.ps1
└── tests/                  # pytest for plugs and helpers

Keep phases and plugs importable as a package so the same code runs from main.py, from pytest and from a REPL.

Pin everything

openhtf==1.6.1
pyvisa==1.14.1
pyvisa-py==0.7.2
pyserial==3.5
tofupilot==2.*        # if uploading records

Recreate the environment from this file on every station; never pip install interactively on a station. pip freeze > requirements.lock on the reference machine gives you the transitive pins for an audit trail. See Installation.

One config file per station

Everything that differs between stations lives in YAML loaded with --config-file; the code is identical everywhere.

station_id: EOL-01
station_server_port: 4444
dmm_resource: USB0::0x2A8D::0x0101::MY53220001::INSTR
psu_resource: TCPIP0::192.168.10.21::inst0::INSTR
uart_adapter_serial: A50285BI
rf_variant: true
records_dir: /var/lib/pcb01/records

Declare each key with CONF.declare(...) and bind plug constructors with bind_init_args — Configuration, PyVISA guide. python -m pcb01_eol.main --config-help prints every key a station needs.

Entry point

import openhtf as htf
from openhtf.output.callbacks import json_factory
from openhtf.output.servers import station_server
from openhtf.output.web_gui import web_launcher
from openhtf.plugs import user_input
from openhtf.util import configuration

from pcb01_eol.phases import build_phases

CONF = configuration.CONF
RECORDS_DIR = CONF.declare("records_dir", default_value="./records")


def main():
    with station_server.StationServer(history_path=CONF.records_dir) as server:
        web_launcher.launch(f"http://localhost:{CONF.station_server_port}")
        while True:
            test = htf.Test(*build_phases(), test_name="PCB01 EOL")
            test.add_output_callbacks(
                json_factory.OutputToJSON(
                    f"{CONF.records_dir}/{{dut_id}}.{{start_time_millis}}.json", indent=2),
                server.publish_final_state,
            )
            test.execute(test_start=user_input.prompt_for_test_start())


if __name__ == "__main__":
    main()

Reading CONF.station_server_port after the flags are parsed works because execute()/configure() parse them; if you need the value earlier, call test.configure() first or parse with configuration.ARG_PARSER yourself (CLI flags).

Launcher

#!/usr/bin/env bash
set -euo pipefail
cd "$(dirname "$0")/.."
source .venv/bin/activate
exec python -m pcb01_eol.main --config-file "config/station-$(hostname).yaml" -v

Set-Location (Split-Path $PSScriptRoot -Parent)
& .\.venv\Scripts\Activate.ps1
python -m pcb01_eol.main --config-file "config\station-$env:COMPUTERNAME.yaml" -v

Naming config files after the hostname means one launcher for the whole line.

Autostart

[Unit]
Description=PCB01 end-of-line test
After=network-online.target

[Service]
User=operator
WorkingDirectory=/opt/pcb01-eol
ExecStart=/opt/pcb01-eol/scripts/run.sh
Restart=always
RestartSec=3
Environment=TOFUPILOT_API_KEY=%i
StandardOutput=append:/var/log/pcb01-eol.log
StandardError=inherit

[Install]
WantedBy=multi-user.target

sudo systemctl enable --now pcb01-eol

Kiosk browser

web_launcher.launch() opens the default browser; on a station you want a full-screen kiosk pointed at the fixed port instead:

chromium --kiosk --noerrdialogs --disable-infobars http://localhost:4444

Start it from the same launcher (after the server is up) or from the desktop session's autostart, and remove web_launcher.launch() from the code. See Operator UI.

Records

• Write JSON to a local directory first (records_dir); local disk survives network outages.
• Ship them onward with an output callback — a database insert, an S3 sync, or TofuPilot's upload() which queues and retries. Output Callbacks, Manufacturing Test Analytics.
• Rotate or archive the local directory; a busy station produces thousands of files a month.
• Do not inline large attachments (inline_attachments=False) if the records are indexed.

Updates and rollback

• Tag releases of the test package (v2.1.4) and record the tag in metadata: htf.Test(..., test_version="2.1.4"). It lands in every record, so a yield change can be correlated with a test change.
• Deploy with git pull && pip install -r requirements.txt in the launcher's directory, then restart the service. Rollback is git checkout v2.1.3 and restart.
• Never change limits on a station by hand; change limits.yaml in git and redeploy.

Health checks

• --config-help on a fresh station lists every key; a missing one fails loudly at start rather than mid-shift.
• A self_test phase group that talks to every instrument and stops on failure catches unplugged cables before the first unit.
• Log to a file (-v plus StandardOutput=append: or Start-Transcript) so the console is not the only record of a crash.

Related