docker-duplicity-cron/start.sh

#! /bin/bash
set -euf

# If first arg is bash, we'll just execute directly
if [ $# -gt 0 ] && [ "$1" == "bash" ]; then
    exec "$@"
    exit 0
fi

# If no env variable set, get from command line
if [ "$OPT_ARGUMENTS" == "" ]; then
    export OPT_ARGUMENTS="$*"
fi

# If key id is provied add arg
if [ -n "$GPG_KEY_ID" ]; then
    export OPT_ARGUMENTS="$OPT_ARGUMENTS --encrypt-sign-key=\"$GPG_KEY_ID\""
fi

# If set to restore on start, restore if the data volume is empty
if [ "$RESTORE_ON_EMPTY_START" == "true" ] && [ -z "$(ls -A "$PATH_TO_BACKUP")" ]; then
    /cron-exec.sh /restore.sh
fi

# Unless explicitly skipping, take a backup on startup
if [ "$SKIP_ON_START" != "true" ]; then
    /cron-exec.sh /backup.sh
fi

if [ -n "$CRON_SCHEDULE" ]; then
    # Export the environment to a file so it can be loaded from cron
    env | sed 's/^\(.*\)=\(.*\)$/export \1="\2"/g' > /env.sh
    # Remove some vars we don't want to keep
    sed -i '/\(HOSTNAME\|affinity\|SHLVL\|PWD\)/d' /env.sh

    # Use bash for cron
    echo "SHELL=/bin/bash" > /crontab.conf

    # Schedule the backups
    echo "$CRON_SCHEDULE /cron-exec.sh /backup.sh" >> /crontab.conf
    echo "Backups scheduled as $CRON_SCHEDULE"

    if [ -n "$FULL_CRON_SCHEDULE" ]; then
        echo "$FULL_CRON_SCHEDULE /cron-exec.sh /backup.sh full" >> /crontab.conf
        echo "Full backup scheduled as $VERIFY_CRON_SCHEDULE"
    fi

    if [ -n "$VERIFY_CRON_SCHEDULE" ]; then
        echo "$VERIFY_CRON_SCHEDULE /cron-exec.sh /verify.sh" >> /crontab.conf
        echo "Verify scheduled as $VERIFY_CRON_SCHEDULE"
    fi

    # Add to crontab
    crontab /crontab.conf

    echo "Starting duplicity cron..."
    cron

    touch /cron.log /root/duplicity.log
    tail -f /cron.log /root/duplicity.log
fi