Moudi Oracle

The Moudi oracle offers invaluable automated support for Moudi organizers.

Run

Install node.js
Run npm install in this directory
Run node src/js/oracle.js <configfile.json> [--force] to run the moudi-oracle

The provided configuration file must be in the format documented below, you can find an example file with empty history (fill in proper organizers and mailer passwords) in the config folder.

Note that the script can only be run once per month. It will exit, if it detects, that it has already been run for the current mont. You can use --force as 2nd argument to force finding of next month's moudi.

Run as Cron Job

Note that cron sends a mail if there's a problem during execution. This is no good on systems that have no mail infrastructure set up.

It's better to log the cron output by redirecting sterr to stout and using the standard unix logging facilities, as described in this post:

0 0 1 * * node oracle.js config.json 2>&1 | /usr/bin/logger -t moudi-oracle

Output will be in /var/log/messages (can be filtered by tag moudi-oracle)

If node has been installed with nvm then it will be not be available systemwide. NVM has to be set up correctly before running and then $(which node) ... should be used to select the default node version as provided by NVM. All of this setup code including the invocation of oracle.js is best put into a run-moudi.sh script which can then be executed with cron:

#!/bin/bash

# NVM needs the ability to modify your current shell session's env vars,
# which is why it's a sourced function.
# See https://gist.github.com/simov/cdbebe2d65644279db1323042fcf7624

export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && . "$NVM_DIR/nvm.sh"  # This loads nvm

# uncomment the line below if you need a specific version of node
# other than the one specified as `default` alias in NVM (optional)
# nvm use 4 1> /dev/null

# run moudi with the node version selected by NVM
MOUDI_HOME=$HOME/moudi
$(which node) $MOUDI_HOME/oracle/src/js/oracle.js $MOUDI_HOME/config.json 2>&1

Configuration file format

{
	"mailconfig": {
		"host": "mail.yourhost.ch",
		"port": 465,
		"secure": true,
		"user": "***",
		"pass": "***",
		"from": "Moudi Oracle <***>"
	},
	"organizers" : [
		{ 
			"username" : "ff",
			"name"  : "Fred",
			"email" : "fred@feuerstein.ch"
		}, 
		{
			"username"    : "jd",
			"name"  : "John",
			"email" : "john@doe.com"
		}
	],
	"tramlines": [ 2, 3, 4,  5, 6, 7,  8, 9, 10,  11, 13, 14 ],
	"history" : [
		{
			"month" : "2020-01",
			"organizer" : "ff",
			"tramline" : 4
		}
	],
    "auth-tokens" : {
         "2020-01": "a862rP1k"
    }
}

Auth-tokens are generated when oracle creates history entry and sent to the organizer. It can be used to authorize modification of a history entry via web interface.

Web

The web site shows tram lines, restaurant candidates and history. At its core it uses the Overpass API of the Open Street Map Project to search for map features and to perform geospatial selection of restaurants.

Deployment

The web site implementation can be found in the web folder of the project. No build is necessary. The site can be be deployed by pulling the latest updates to a git repo on the deployment machine and by serving the web folder of the project as document root, e.g. with lighttpd.

To run cgi-scripts (e.g. to fetch the Moudi history), Python needs to be set up and the HTTP server must be configured to run Python files in cgi-bin.

The config.json file should be located outside the web directory.

Version

A git post-merge hook is used to write the current version along with the checkout time to a file version.txt, which is displayed by the web site if available.

.git/hooks/post-merge, .git/hooks/post-checkout

#!/bin/sh
# write version.txt file with commit ID and current time
git log -n 1 --date=format:"%Y-%m-%d %H:%M" --format=format:"rev.%h (deployed at %ad)" HEAD > web/version.txt

Libraries

Leaflet an open-source JavaScript library for mobile-friendly interactive maps
OsmToGeoJSON Converts OSM data into GeoJSON.

zaploink/moudi-oracle