# PiDP 10 Services

## Overview

This repository combines a set of useful scripts and services, to run on the
PiDP-10 in order to make it easier to work with it and develop for it. These
services can be installed on the PiDP-10 and automate tasks such as copying
files onto the ITS operating system. These tools help automate processes, that
would require interaction with the Linux part of the PiDP-10 when developing on
another system.

## git-monitor

The git-monitor is a system service that monitors a target directory on the
PiDP-10. It contains a file with a list of git repositories to monitor, one at a
time. The service will check if any of the repositories changed, and pull them.
After a successful pull a script will be called, if it exists, that allows the
newly updated repository to interact with a running PDP-10 simulation.

The monitor consists of a script, that needs to be installed to `/usr/local/bin`
and a systemd unit-file to run it as a service.

### Installation

To install the git-monitor, clone this repository to the target computer, and
run the install script:

```bash
git clone https://gitea.orca-central.de/jali/PiDP10Services.git
sudo ./install.sh
```

This will install the service on your system and start it. If you want the
service to be enabled on system boot, enable the service:

```bash
sudo systemctl enable git-monitor.service
```

### Configuration

The service is usable immediately after installation. The service is configured
through a series of environment variables, that can be set to change the default
behaviour. There are five different environment variables to configure the
service with:

<table>
  <tr>
    <th>Environment Variable</th>
    <th>Description</th>
    <th>Default Value</th>
  </tr>
  <tr>
    <td>GITMONITOR_URLS</td>
    <td>A file that contains the list of observed repositories in a directory by name and URL.</td>
    <td>/opt/src/repository.list</td>
  </tr>
  <tr>
    <td>GITMONITOR_LOCAL_PATH</td>
    <td>The path in which the clone repositories will be stored.</td>
    <td>/opt/src</td>
  </tr>
  <tr>
    <td>GITMONITOR_BRANCH_NAME</td>
    <td>The name of the branch to observe.</td>
    <td>develop</td>
  </tr>
  <tr>
    <td>GITMONITOR_POLL_INTERVALL</td>
    <td>The number of seconds to wait until the next poll.</td>
    <td>30</td>
  </tr>
  <tr>
    <td>GITMONITOR_LOCK_FILE</td>
    <td>The lock file that is used to monitor the service. </td>
    <td>/run/lock/git-monitor.lock</td>
  </tr>
</table>

You can override these settings by creating an override file for the service
unit. Create a new file
`/etc/serviced/service/git-monitor.service.d/override.conf` by typing
`sudo systemctl edit git-monitor.service`. You can then uncomment the
`Environment` statements, and change the value of the variables accordingly.