How to backup Docker volumes for Kiwi TCMS

Posted by Alexander Todorov on Mon 30 July 2018 under customization

When you start Kiwi TCMS by running docker-compose up (see here) it will automatically create 2 volumes: kiwi_db_data and kiwi_uploads. This blog post will outline how to backup these docker volumes.

Note: in the instructions below kiwi_db is the container name and kiwi is the database name used inside the docker-compose.yml file!

MariaDB/MySQL database

To export all contents from the docker container execute the command:

docker exec -u 0 -i kiwi_db mysqldump kiwi > backup.sql

This will create a file named backup.sql in the current directory, outside of the running container!

You can restore the database contents by using the following command:

cat backup.sql | docker exec -u 0 -i kiwi_db mysql -v kiwi

Notes:

  1. The commands above using -u 0 are executed with root privileges inside the container. In this way you don't need to type-in the database password!
  2. Depending on your scenario you may want to remove the existing volume (docker-compose down && docker volume rm kiwi_db_data) before restoring the database!

Postgres database

To export all contents from the docker container execute the command:

docker exec -i kiwi_db pg_dump --dbname=kiwi -F c > backup.bak

This will create a file named backup.bak in the current directory, outside of the running container. This is a PostgreSQL custom database dump format which contains all data and schema definitions. That is a binary file which can be read with the pg_restore command!

To drop and restore the entire database execute:

docker exec -i kiwi_db psql -c "DROP DATABASE IF EXISTS kiwi;"
cat backup.bak | docker exec -i kiwi_db pg_restore --dbname=template1 -vcC

Multi-tenant database

The kiwitcms-tenant add-on and/or Kiwi TCMS Enterprise work only on Postgres! Each tenant (aka name-space) uses a separate database schema. The first schema name is public.

The backup and restore instructions shown above operate on all tenants together! If you want to [drop and] restore an individual tenant then use the commands:

docker exec -it kiwi_db psql --dbname=kiwi

kiwi=> DROP SCHEMA $tenant_name CASCADE;
....
DROP SCHEMA
kiwi=> CREATE SCHEMA $tenant_name;
CREATE SCHEMA
kiwi=>Ctrl+D

cat backup.bak | docker exec -i kiwi_db pg_restore --dbname=kiwi -v --schema $tenant_name

Backing up file uploads

Uploaded files can easily be backed up with:

docker exec -i kiwi_web /bin/tar -cP /Kiwi/uploads > uploads.tar

and then restored with:

cat uploads.tar | docker exec -i kiwi_web /bin/tar -x

You may also try the rsync command but be aware that it is not installed by default!

Note: the same approach may be used to backup /var/lib/mysql/ or /var/lib/pgsql/data from the kiwi_db container.

Backing up multi-tenant uploads

By default multi-tenant file uploads are stored under /Kiwi/uploads/tenant/$tenant_name. You can archive all contents with the same procedure above. If you wish to restore files per tenant you will have to upload the $tenant_name directory into the docker volume.

Alternatives

By default both docker volumes created for Kiwi TCMS use the local driver and are available under /var/lib/docker/volumes/<volume_name> on the host running your containers. You can try backing them up from there as well.

Another alternative is to use the docker-lvm-plugin and create these volumes as LVM2 block devices. Then use lvcreate -s command to create a snapshot volume. For more information see chapter 2.3.5. Snapshot Volumes from the LVM Administrator Guide for Red Hat Enterprise Linux 7.

Happy testing!