Download audio of Mogra Twitch & Ustream streams

# The following should work on Debian Stretch, Ubuntu 18.04 and maybe Ubuntu 16.04

sudo apt-get update
sudo apt-get install python3 python3-venv ffmpeg
sudo useradd --home-dir /var/lib/mogra-dl --create-home --system --shell /sbin/nologin --user-group mogra-dl

sudo -u mogra-dl bash

python3 -m venv /var/lib/mogra-dl/.local/python-env
/var/lib/mogra-dl/.local/python-env/bin/pip3 install --upgrade --upgrade-strategy only-if-needed pip
/var/lib/mogra-dl/.local/python-env/bin/pip3 install --upgrade --upgrade-strategy only-if-needed setuptools
/var/lib/mogra-dl/.local/python-env/bin/pip3 install --upgrade --upgrade-strategy only-if-needed youtube-dl
/var/lib/mogra-dl/.local/python-env/bin/pip3 install --upgrade --upgrade-strategy only-if-needed streamlink
mkdir -p /var/lib/mogra-dl/twitch/{mogra,anisphere,anime_mogra,}
mkdir -p /var/lib/mogra-dl/ustream/{mogra1,}

echo '#!/bin/bash
while true; do
  datetime="$(TZ='Asia/Tokyo' date +"%Y-%m-%d_%H-%M-%S")"
  # download stream audio
  /var/lib/mogra-dl/.local/python-env/bin/youtube-dl -ci --quiet -o ${datetime}.m4a --extract-audio --audio-quality 0 --no-part https://twitch.tv/$1
  sleep 30
done
' > /var/lib/mogra-dl/twitch/dl.sh
chmod +x /var/lib/mogra-dl/twitch/dl.sh

echo '#!/bin/bash
for video in "*.mp4" ; do
  if [[ -f "$video" ]]; then
    # extract audio
    ffmpeg -i "$video" -vn -c:a copy "$(echo $video | sed 's/mp4/m4a/')"
    rm "$video"
  fi
done
while true; do
  datetime="$(TZ='Asia/Tokyo' date +"%Y-%m-%d_%H-%M-%S")"
  # download stream video
  /var/lib/mogra-dl/.local/python-env/bin/streamlink http://ustream.tv/channel/$1 best -o "${datetime}.mp4" -f
  if [[ -f "${datetime}.mp4" ]]; then
    # extract audio
    ffmpeg -i "${datetime}.mp4" -vn -c:a copy "${datetime}.m4a"
    rm "${datetime}.mp4"
  else
    sleep 30
  fi
done
' > /var/lib/mogra-dl/ustream/dl.sh
chmod +x /var/lib/mogra-dl/ustream/dl.sh

echo '#!/bin/bash
cd "$(pwd)"
for dir in /var/lib/mogra-dl/{twitch,ustream}/* ; do
  if [[ -d "$dir" ]]; then
    channel_name="$(basename $dir)"
    cd "$dir"
    ../dl.sh "$channel_name" &
    cd - > /dev/null
  fi
done
wait
' > /var/lib/mogra-dl/mogra-dl.sh
chmod +x /var/lib/mogra-dl/mogra-dl.sh

exit

sudo echo '# Update youtube-dl and streamlink daily, reporting to syslog
00 00 * * * mogra-dl       /var/lib/mogra-dl/.local/python-env/bin/pip3 install --upgrade --upgrade-strategy only-if-needed youtube-dl 2>&1 | /usr/bin/logger -t mogra-dl-update
02 00 * * * mogra-dl       /var/lib/mogra-dl/.local/python-env/bin/pip3 install --upgrade --upgrade-strategy only-if-needed streamlink 2>&1 | /usr/bin/logger -t mogra-dl-update
#
' > /etc/cron.d/mogra-dl-update

sudo echo '[Unit]
After=network.target

[Service]
WorkingDirectory=/var/lib/mogra-dl
ExecStart=/var/lib/mogra-dl/mogra-dl.sh
User=mogra-dl
Group=mogra-dl
Restart=always
StandardOutput=syslog
StandardError=syslog
SyslogIdentifier=mogra-dl

[Install]
WantedBy=multi-user.target
' > /etc/systemd/system/mogra-dl.service

sudo systemctl daemon-reload
sudo systemctl enable mogra-dl.service
sudo service mogra-dl start