# opc-plc Docker fixture

[Microsoft Industrial IoT's opc-plc](https://github.com/Azure-Samples/iot-edge-opc-plc)
— pinned Docker image that stands up an OPC UA server at
`opc.tcp://localhost:50000` with step-up counters, random nodes, alarm
simulation, and other canonical simulated shapes. Replaces the PowerShell
launcher pattern used by the Modbus / S7 fixtures — Docker is the launcher
here since opc-plc ships pre-containerized.

| File | Purpose |
|---|---|
| [`docker-compose.yml`](docker-compose.yml) | Service definition for `otopcua-opc-plc` — image pin, port map, command flags. |
| (this file) | How to run it. |

## Install

Docker Desktop (Windows) or the docker CLI + daemon (Linux/macOS). Per
`CLAUDE.md` Phase 1 decision #134 the dev box already has Docker Desktop
configured with the WSL 2 backend — nothing new to install.

## Run

From the repo root:

```powershell
docker compose -f tests\Drivers\ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests\Docker\docker-compose.yml up
```

Or from this folder:

```powershell
docker compose up
```

First run pulls the image (~250 MB). Startup takes ~5-10 seconds; the
healthcheck in the compose file surfaces ready state in `docker ps`.

To run detached (CI pattern):

```powershell
docker compose up -d
```

Stop with `docker compose down` (removes the container) or `docker compose stop`
(keeps it for fast restart).

## Endpoint

- Default: `opc.tcp://localhost:50000`
- Override by setting `OPCUA_SIM_ENDPOINT` before `dotnet test` — e.g. point
  at a real OPC UA server in the lab, or at a different Docker host.

## What opc-plc advertises

Command flags in `docker-compose.yml` enable:

- `--pn=50000` — OPC UA endpoint on port 50000
- `--ut` — unsecured transport endpoint advertised (SecurityPolicy=None).
  Secured policies are still on the endpoint list; `--ut` just adds an
  unsecured option.
- `--aa` — auto-accept client certs (opc-plc's cert trust store lives
  inside the container + resets each spin-up, so without this the driver's
  first contact would be rejected).
- `--alm` — alarm simulation enabled; opc-plc publishes
  `TripAlarmType`, `ExclusiveDeviationAlarmType`,
  `NonExclusiveLevelAlarmType`, and `DialogConditionType` events.

Not turned on (but available via compose-file tweaks):

- `--daa` — disable anonymous auth; forces username or cert tokens. Flip
  on when username-auth / cert-auth smoke tests land.
- `--fn` / `--fr` / `--ft` — fast-node variants (100 / 1 000 / 10 000 Hz
  update rates) for subscription-stress coverage. Not needed for smoke.
- `--sn` / `--sr` — slow-node / special-shape coverage.

## Run the integration tests

In a separate shell, with the simulator running:

```powershell
cd C:\Users\dohertj2\Desktop\lmxopcua
dotnet test tests\Drivers\ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.IntegrationTests
```

Tests auto-skip with a clear `SkipReason` when `localhost:50000` isn't
reachable within 2 seconds (`OpcPlcFixture`).

## Known limitations

opc-plc uses the OPCFoundation.NetStandard stack internally — same as
our driver. That means bugs common to the stack itself are **not** caught
by this fixture; the follow-up to add `open62541/open62541` as a second
independent-stack image (task tracked in #215's follow-ups) would close
that.

See [`docs/drivers/OpcUaClient-Test-Fixture.md`](../../../docs/drivers/OpcUaClient-Test-Fixture.md)
for the full coverage map + what's still trusted from field deployments.

## References

- [opc-plc GitHub](https://github.com/Azure-Samples/iot-edge-opc-plc)
- [mcr.microsoft.com/iotedge/opc-plc tags](https://mcr.microsoft.com/v2/iotedge/opc-plc/tags/list)
- [`docs/drivers/OpcUaClient-Test-Fixture.md`](../../../docs/drivers/OpcUaClient-Test-Fixture.md)
