Installation

Server platform

The following instructions refer to an Ubuntu 22.04 server and should be adapted with other package manager commands if a different distribution is chosen.

Notes on tools and versions

Python

CAT is written in Python. At the moment of this deployment Indico officially supports Python versions 3.9 - 3.11, so CAT is based on Python 3.11.

Redis

Redis is used as a communication database for all MEOW tasks. It can be installed in various ways. For simplicity, the official Ubuntu Redis packages are used in MEOW.

Supervisord

supervisord is used to manage the MEOW "service". It takes care of starting the MEOW processes and restart them if needed.

PDF tools

qpdf, pdftk and mupdf are used by MEOW to manipulate the PDFs for final proceedings.

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Installing System Packages

apt install dbus-broker systemd-container
apt install htop vim p7zip unzip zip git tig
apt install build-essential python3.11-venv python3.11-minimal
apt install qpdf pdftk mupdf-tools mupdf
apt install redis-server redis-tools

Enabling and starting the Redis Service

systemctl enable redis
systemctl start redis

Setup MEOW code

First, let's create the CAT user and access its working directory

useradd --comment 'CAT system user' --create-home --system --home-dir /opt/cat --shell /usr/bin/bash cat
su - cat

Downloading sources

git clone https://github.com/JACoW-org/MEOW.git

Setting Python Virtual Environment

python3 -m venv venv
. ./venv/bin/activate
./venv/bin/pip install --upgrade pip
./venv/bin/pip install -r requirements.txt

Creating PURR/MEOW Shared Authentication Key

To create a shared authentication key for requests from the PURR client to the MEOW server, you will need an API key. The following command creates an API key for the user purr on the indico installation at indico.jacow.org and stores it in Redis. You can create different keys for different PURR installations, Indico events or even for other software that would use MEOW's APIs.

./venv/bin/python -m meow auth -login purr@indico.jacow.org

The output will look like this:

purr indico.jacow.org <api_key>

Please take note of this <api_key>: it will be needed in the PURR connection to MEOW settings of the Indico event.

Other meow useful commands

List keys present in the DB:

./venv/bin/python3 -m meow auth -list

Check a key:

./venv/bin/python3 -m meow auth -check <api_key>
purr indico.jacow.org <timestamp>

Remove a key from the DB:

./venv/bin/python3 -m meow auth -logout <api_key>
1

Starting supervisord

./venv/bin/supervisord -n -c ./conf/supervisord.conf

Test that MEOW is up and running

curl http://127.0.0.1:8080/api/ping/<api_key>
{
  "method": "ping",
  "params": {
    "user": "purr",
    "host": "indico.jacow.org",
    "date": "2023-10-02T13:51:08.737960"
  }
}