Run mysqldump in Docker container

dumpmysql.sh

#!/usr/bin/env bash

cmdname=$(basename $0)

[[ -x "$(command -v docker)" ]] || { echo "This script requires docker to be installed" >&2; exit 1; }

usage () {
    cat <<END
Usage:
    $cmdname [OPTIONS] db [args to mysqldump]

    Dump database to local file SQL script.
    The dump will contain both schema and data. This can be overwritten by
    passing additional arguments to mysqldump, e.g. --no-create-info or --no-data
    For complete argument list visit: https://dev.mysql.com/doc/refman/8.0/en/mysqldump.html
    
    Parameters
        db        : The name of the database to dump.
    Options        
        -h        : Host. Defaults to env variable MYSQL_HOST.    
        -P        : Port. Defaults to env variable MYSQL_PORT.    
        -u        : Username. Defaults to env variable MYSQL_USERNAME.
        -p        : Password. Default to env varible MYSQL_PASSWORD.
        -o        : Output file (will be overwritten). Defaults to ./db.sql.
END
}

spin()
{
  spinner="/|\\-/|\\-"
  while :
  do
    for i in `seq 0 7`
    do
      echo -n "${spinner:$i:1}"
      echo -en "\010"
      sleep 0.1
    done
  done
}

declare user=${MYSQL_USERNAME}
declare pwd=${MYSQL_PASSWORD}
declare host=${MYSQL_HOST}
declare port=${MYSQL_PORT}

while getopts "h:P:u:p:o:" opt; do
    case $opt in
        h)
            host=${OPTARG}
            ;;    
        P)
            port=${OPTARG}
            ;;    
        u)
            user=${OPTARG}
            ;;
        p)
            pwd=${OPTARG}
            ;;
        o)
            outfile=${OPTARG}
            ;;       
        \?)
            exit 1
            ;;
    esac
done
shift $(( OPTIND -1))

[[ $1 ]] || { echo "missing db parameter" && usage; >&2 exit 1; }
[[ $user ]] || { echo "no user found" && usage; >&2 exit 1; }
[[ $pwd ]] || { echo "no password found" && usage; >&2 exit 1; }
[[ $host ]] || { echo "no host found" && usage; >&2 exit 1; }
[[ $port ]] || { echo "no port found" && usage; >&2 exit 1; }
declare db=$1
shift
dumpargs=$@
[[ $outfile ]] || outfile=${db}.sql

#TODO: check write permission on outfile

echo "Start dumping..."
# Start the Spinner:
spin &
# Make a note of its Process ID (PID):
SPIN_PID=$!
# Kill the spinner on any signal, including our own exit.
trap "kill -9 $SPIN_PID" `seq 0 15`

docker run --rm -it mariadb:10.4.2-bionic mysqldump \
    -h "$host" \
    -P "$port" \
    -u "$user" \
    -p"$pwd" \
    "$db" \
    $dumpargs > $outfile

#Check if success
if [[ $? -ne 0 ]]; then
    #error msg will be in tempfile
    cat "${outfile}" && rm "${outfile}"
    exit 1
fi

echo "Finished."
exit 0