Backup Testing

Test backup functionality provided by OOM: oom/cronjob.yaml at master · onap/oom · GitHub

Container downloads mariadb image and runs some shell commands

initContainers: {{- include "common.readinessCheck.waitFor" . | nindent 12 }}
- name: mariadb-galera-backup-init
image: {{ include "repositoryGenerator.image.mariadb" . }}
imagePullPolicy: {{ .Values.global.pullPolicy | default .Values.pullPolicy }}
{{ include "common.containerSecurityContext" . | indent 14 | trim }}
command:
- /bin/bash
- -c
- |
remove_dir(){
dirToRemove=$1
rm -rf $dirToRemove
echo "Failed" > /backup/backup.log
echo "Backup failed!!!"
}

target_dir=/backup/backup-`date +%s`
mkdir -p $target_dir

mysqlhost={{ include "common.servicename" . }}.{{ include "common.namespace" . }}

mariabackup --backup --target-dir=$target_dir --user=root --password=$DB_PASS --host=$mysqlhost

ret_code=$?
if [ $ret_code -ne 0 ]; then
remove_dir $target_dir
exit 0
fi

echo "Starting Backup Preparation!!!"
mariabackup --prepare --target-dir=$target_dir
ret_code=$?
if [ $ret_code -ne 0 ]; then
remove_dir $target_dir
exit 0
fi
echo "Success" > /backup/backup.log
echo "Backup Successful!!!"

Testing

1. Check mariabackup version on localhost: mariabackup --version → mariabackup based on MariaDB server 10.3.25-MariaDB debian-linux-gnu (x86_64)
2. Start docker container using this version: docker run -it mariadb:10.3.25 bash
3. Check backup version in container:  mariabackup --version ->mariabackup based on MariaDB server 10.3.25-MariaDB debian-linux-gnu (x86_64)
4. Copy mariabackup command from the code above and replace variable with actual values: mariabackup --backup --target-dir=/tmp --user=root --password=root --host=host.docker.internal --port=3355 → 2021-05-19 11:55:10 0 [ERROR] InnoDB: File /var/lib/mysql/ib_logfile0: 'open' returned OS error 71. Cannot continue operation
   210519 11:55:10 [ERROR] mysqld got signal 6 ;
5. Try the same command locally: sudo mariabackup --backup --target-dir=/tmp --user=root --password=***** --host=localhost --port=3355 →[00] 2021-05-19 11:03:32 completed OK!
6. Create a new user on local mariadb server: create user backup identified by 'backup';
7. Grant all privileges to backup: GRANT ALL PRIVILEGES ON *.* TO 'backup'@'%'; FLUSH PRIVILEGES;
8. Re-try mariabackup from the container: mariabackup --backup --target-dir=/tmp --user=backup --password=backup --host=host.docker.internal --port=3355 → [ERROR] InnoDB: File /var/lib/mysql/ib_logfile0: 'open' returned OS error 71. Cannot continue operation
   210519 10:07:59 [ERROR] mysqld got signal 6 ;
9. Run the command locally: sudo mariabackup --backup --target-dir=/tmp --user=backup --password=backup --host=localhost --port=3355 → [00] 2021-05-19 11:10:27 completed OK!
10. Try using mysqldump in the container instead: mysqldump --all-databases --host=host.docker.internal --port=3355 --user=backup --password=backup → -- Dump completed on 2021-05-19 10:12:37
11. Try mysqldump locally: sudo mysqldump --all-databases --host=localhost --port=3355 --user=backup --password=backup → -- Dump completed on 2021-05-19 11:15:24
12. Try mysqldump in the container with the root user: mysqldump --all-databases --host=host.docker.internal --port=3355 --user=root --password=root → -- Dump completed on 2021-05-19 11:59:54
13. If we may the /var/lib/mysql directory from the localhost to the container, then mariabackup works in the container:  docker run -it -v /var/lib/mysql:/var/lib/mysql mariadb:10.3.25 bash → mariabackup --backup --target-dir=/tmp --user=root --password=root --host=host.docker.internal --port=3355 → [00] 2021-05-19 12:16:10 completed OK!

Conclusion

1. mariabackup does not work remotley  [MDEV-15075] unless the /var/lib/mysql directory from the database host can be mapped to the same directory in the container.
2. mysqldump is a more reliable option.