PYTHON_PATH=$(which python)
PSQL_PATH=$(which psql)

MYSQL_SCRIPT='mysql2file.py'
MYSQL_SERVER=
MYSQL_PORT=3306
MYSQL_DATABASE=
MYSQL_USER=
MYSQL_PASSWORD=

TODAY=$(date '+%Y%m%d')
DUMP_FILENAME="errors_${TODAY}.csv"
DUMP_FILEPREFIX="errors_${TODAY}-"
DUMP_SPLITFACTOR=6							# 3 XL nodes
DUMP_S3BUCKET=archivedlogs

REDSHIFT_ENDPOINT=fqdn
REDSHIFT_USER=user
REDSHIFT_DATABASE=reports
REDSDHIFT_PORT=1234
REDSHIFT_TABLE=errors

AWS_ACCESS_KEY_ID=asdf
AWS_SECRET_ACCESS=xcvb

MAINTENANCE_DAY=6							# Perform VACUUM and ANALYZE on Saturday

LOG_PATH="/home/${USER}/redshift_import-${TODAY}.log"

MYSQL_MINRANGE=$(date --date='2 days ago' '+%Y-%m-%d')
MYSQL_MAXRANGE=$(date --date='1 day ago' '+%Y-%m-%d')
MYSQL_COMMAND="
SELECT
  columns
FROM errors WHERE
WHERE time BETWEEN '${MYSQL_MINRANGE}' AND '${MYSQL_MAXRANGE}';
"

# Dump MySQL resultset to file
echo "Starting MySQL dump to ${DUMP_FILENAME}"
${PYTHON_PATH} ${MYSQL_SCRIPT} ${MYSQL_SERVER} ${MYSQL_PORT} ${MYSQL_USER} ${MYSQL_PASSWORD} ${MYSQL_DATABASE} ${DUMP_FILENAME} ${MYSQL_COMMAND}

# Split by end of line, not by file size
echo "Splitting dump into ${DUMP_SPLITFACTOR} files"
split -n l/${DUMP_SPLITFACTOR} ${DUMP_FILENAME} ${DUMP_FILEPREFIX}
# Compress in preparation for Redshift COPY
echo "Compressing MySQL dump files (gzip)"
gzip ${DUMP_FILEPREFIX}*

# Upload import files to S3
echo "Uploading dump files to S3 bucket ${DUMP_S3BUCKET}"
s3cmd put --reduced-redundancy ${DUMP_FILEPREFIX}* s3://${DUMP_S3BUCKET}/

# Issue COPY command to Redshift cluster
REDSHIFT_COMMAND="
COPY ${REDSHIFT_TABLE} FROM 's3://${DUMP_S3BUCKET}/${DUMP_FILEPREFIX}'
  CREDENTIALS 'aws_access_key_id=${AWS_ACCESS_KEY_ID};aws_secret_access_key=${AWS_SECRET_ACCESS}'
  GZIP
  CSV
  DELIMITER ','
  NULL AS '\N';
"

REDSHIFT_QUERY="${PSQL_PATH} -h ${REDSHIFT_ENDPOINT} -U ${REDSHIFT_USER} -d ${REDSHIFT_DATABASE} -p ${REDSHIFT_PORT}"

echo "Loading dump files from S3 into Redshift table ${REDSHIFT_TABLE}"
${REDSHIFT_QUERY} -f ${REDSHIFT_COMMAND} > ${LOG_PATH} 2>&1

if [ -f ${LOG_PATH} ] ; then
	echo -e "Import failed when loading to Redshift\n"
	cat ${LOG_PATH}
	s3cmd put --reduced-redundancy ${LOG_PATH}* s3://${DUMP_S3BUCKET}/
	exit 1
fi

# VACUUM and ANALYZE if we're in a maintenance window
if [ ${MAINTENANCE_DAY} -eq $(date '+%u') ] ; then
	REDSHIFT_COMMAND="VACUUM SORT ONLY ${REDSHIFT_TABLE};"
	echo "Vacuuming (resorting) data"
	${REDSHIFT_QUERY} -f ${REDSHIFT_COMMAND} > ${LOG_PATH} 2>&1

	REDSHIFT_COMMAND="ANALYZE ${REDSHIFT_TABLE};"
	echo "Analzying (regenerating statistics) of table"
	${REDSHIFT_QUERY} -f ${REDSHIFT_COMMAND} > ${LOG_PATH} 2>&1
fi

echo "Import complete!"