PATE Monitor Installation Script

Target platform: Raspberry Pi 3 B+
Target OS: Rasbian 2019-09-26 or newer
Dependencies: Python 3.7.3 or newer, PySerial ver 3.2.1 ...
NOTE: writesd.py can be used with Python 3.5.3+ (Debian Stretch 9), but the Rasbian OS must be Debian 10 based.

Process in Brief

1. Write Rasbian uSD using writesd.py
2. Boot Raspberry Pi and execute /boot/install.py (added by writesd.py)

The main installer (install.py) does some system configuration and installs needed software packages before cloning a number of Github repositories and executing a setup.py script in each of them.

Preparations

• Clone this repository to a Linux PC. One with built-in MMC SD slot is recommended, althought a PC with USB SD adapter will work too.
• If you need to create development instance or utu.fi network, you need DynuDNS account. Create it and set the username and password in the writesd.conf -file.
• Enter the repository directory (pminstall), download and extract Rasbian OS image to this directory.
• Insert SD card. If USB SD adapter is used, specify --device with the appropriate device file. Find out what it is...
• (optional) Review and change Config.py settings for defaults better suited for your system.

Create utu.fi -domain Pate Monitor development instance using a PC with USB-uSD adapter:

# ./writesd.py --device /dev/sdb --mode dev

But, please be absolutely sure your device file points to a uSD, not a harddisk!

Installation Activities (performed by install.py)

• TODO Read boot/install.config for instance mode (dev|uat|prd specifics still unclear... thus todo)
• Sets system timezone as Europe/Helsinki
• Sets keymap to pc105 / fi
• Updates system packages (apt update, apt -y upgrade)
• TODO Configures WiFI AP and dnsmasq DHCP server. Needs to be optional for DevMode installs!
• Creates needed user groups and accounts
• Installs packaged needed by PATE Monitor (apt install ...)
• Configures nginx and uwsgi.
• Clones PATE Monitor related GitHub repositories and executes setup.py from each.

Installation Procedure

A separate script (writesd.py) is provided for creating the Raspbian SD along with additional changes therein. If writesd.py should not work, please refer to manual SD creation instructions.

Using writesd.py

usage: writesd.py [-h] [-m MODE] [--device DEVICE] [--noddns | --ddns]

=============================================================================
University of Turku, Department of Future Technologies
ForeSail-1 / uSD writer for Rasbian based PATE Monitor
Version 0.4.9, 2018-2019 Jani Tammi <jasata@utu.fi>

optional arguments:
  -h, --help            show this help message and exit
  -m MODE, --mode MODE  Instance mode. Default: 'DEV'
  --device DEVICE       Write to specified device.
  --noddns              Do not add DDNS client into the instance.
  --ddns                Add DDNS client into the instance.

Note that writesd.config file can be modified to set the default instance mode. It should also be modified to include DDNS client credentials, if DDNS client is to be used.

Manual Rasbian SD Creation

This is the very minimal that needs to be done. Further details, if interested, should be read from the writeds.py.

1. Write Rasbian image into an SD. (dd if=${rasbian_image} of=/dev/mmcblk0 bs=4M conv=fsync)
2. Mount /dev/mmcblk0p1 (aka. "boot") to /mnt and create file /mnt/ssh (to enable remote SSH connections).
3. Copy the install.py to /mnt/.
4. Create install.config to /mnt/, containing "[Config]\nmode = PRD" (or whatever mode you want).
5. Unmount /mnt/ and remove uSD.

Dev Mode

For a development instances, in utu.fi -domain, you need to enable DDNS client (due to dynamic IP and the unit being headless). Details how to manage that should be read from the writesd.py script source.

Samba (obsoleted by RPi support in VSC Remote - SSH extension)

NOTE: Samba shares are less than ideal for UTU network. One stress reducing approach would be to use Visual Studio Code Inisders edition and Remote-SSH module. As of June 2019, the Remote-SSH has not yet been released for mainstream VSC. NOTE2: November 2019, Raspberry Rasbian support now works! Basic Samba installation steps (using provided smb.conf file):

1. Install Samba: # apt -y install samba.
2. Copy the provided smb.conf into /etc/samba/.
3. Add Samba password for user pi: # smbpasswd -a pi.
4. Restard Samba: # systemctl restart smbd.

Install Pate Monitor

Insert uSD to Raspberry Pi, boot, ssh into the box, assume root identity (sudo su -), run /boot/install.py. Unless errors are reported, the system should now be up and running. Open browser on your Pate Monitor address to check.

DDNS (Dynamic Domain Name Service)

Network environment in UTU provides IP adderesses only to registered MAC addresses (Raspberry Pi's are not registered), and even if they would be, DHCP server leases addresses with the apparent tendency to change every once in awhile (for reasons that I cannot even being to guess). This makes having a headless development unit a nightmare - unless... external DDNS service is used. In this case, Dynu DNS was chosen because of its very simple HTTP API. An account was created and an address of pate.freeddns.org was created. This host name should hereby resolve to the whichever IP the development unit has at the time.

If another account is created/needed, the credentials should be written into writesd.config, from where they will be copied to the DDNS update script, inside the written Rasbian image.

You can control if the DDNS client is included in the written Rasbian image by using --ddns or --noddns commandline options. By default DDNS client is included in development (DEV) and testing (UAT) installations, but this too can be configured in the writesd.config.

Some implementation details

DDNS service is kept up to date by an hourly cron job and by a DH Client hook which executes DDNS client each time dhclient indicates a change in the eth0 interface. The client is also registered as a boot-time system service, which depends on network interface, thus executing once after start-up, once the network interface has been brought up. This should be enough to keep the DDNS record up to date.

For more specific details, writesd.py should be examined.

Change Log

2019.11.04 Updated to Debian 10 based Raspbian Buster Lite 2019-09-26, Python 3.7.3 and PySerial 3.4.