Bash function(s) to download Youtube videos using Docker

docker.fn.sh

docker-toolbox() {
  DOCKER_VM=$(docker-machine ip default)
  DOCKER_HOST=tcp://${DOCKER_VM}:2376
  DOCKER_CERT_PATH=~/.docker/machine/machines/default
  DOCKER_TLS_VERIFY=1
  export DOCKER_VM DOCKER_HOST DOCKER_CERT_PATH DOCKER_TLS_VERIFY
  if [ ! "$1" = "-s" ]; then
    echo "Using Docker Host: ${DOCKER_HOST}"
  fi
}

USAGE.md

Add the bash functions to your profile, either directly in ~/.bash_profile or preferably by loading the snippets from ~/.bash_profile.d - for example add the following to your .bash_profile:

# Run snippets
for script in ~/.bash_profile.d/*.sh ; do
        if [ -r $script ] ; then
                . $script
        fi
done

Source your updated profile and you can then download source vids from Youtube as follows:

Download By default it outputs to ./video.mp4

youtube-dl https://www.youtube.com/watch?v=WPsu4OH9hsk

Download to specific file You can download to a specific location/filename

youtube-dl https://www.youtube.com/watch?v=WPsu4OH9hsk ~/brooklyn-gource.mp4

utils.fn.sh

# from - http://stackoverflow.com/a/7126780
dir_resolve()
{
  cd "$1" 2>/dev/null || return $?  # cd to desired directory; if fail, quell any error messages but return exit status
  echo "`pwd -P`" # output full, link-resolved path
}

youtube-dl.fn.sh

###
# Author: @johnmccabe
# Date: 16/1/16
#
# Bash function to download Youtube videos using jbergknoff/youtube-dl
# Docker image.
#
# Requires:
#   utils.fn.sh#dir_resolve
#   docker.fn.sh#docker-toolbox
###

youtube-dl(){
  video_url=$1
  output=$2

  if [ $# -eq 0 ]; then
    echo "usage: youtube-dl <video url> [<output file>]"
    return 0
  fi

  if [ -z "$output" ]; then
    output_dir="."
    abs_output_dir=$(pwd)
    output_file="video.mp4"
  else

    if [ -d "$output" ]; then
      echo "Supplied output file is a directory. Exiting..."
      return 1
    fi

    if [ -e "$output" ]; then
      echo "Supplied output file already exists. Exiting..."
      return 1
    fi

    output_dir=`dirname ${output}`

    # Prompt to create  output directory if not found
    if [ ! -d "${output_dir}" ] ; then
      read -p "Output directory does not exist. Do you want to create it? [yN]" -n 1 -r
      echo
      if [[ $REPLY =~ ^[Yy]$ ]]; then
        echo "creating dir [${output_dir}] ..."
        mkdir -p ${output_dir}
      else
        echo "exiting..."
        return 0
      fi
    fi

    # use utils#dir_resolve to get absolute path
    abs_output_dir=`dir_resolve ${output_dir}`
    output_file=`basename ${output}`

  fi

  # Try to setup docker environment variables
  docker-toolbox

  echo "Downloading ${video_url} to ${output_dir}/${output_file} ..."
  docker run -it --rm -v "${abs_output_dir}:/src" jbergknoff/youtube-dl \
    -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]' \
    -o /src/${output_file} \
    ${video_url}

  echo
  echo "Video downloaded to ${output_dir}/${output_file}"
}