Add mariadb backup as optional option for wsrep_sst_method

[eRadical]

mariabackup is an alternative to rsync that does not block the donor node

[mrlesmithjr]

@eRadical - I merged some PR's from @elcomtik which caused some conflicts with this PR. Do you mind rebasing to resolve these and we can get this PR merged as well?

[elcomtik]

@eRadical Did it worked? I use mariabackup when SST encryption is needed. What I found is that mariabackup needs to authenticate on the donor node, so I had to create a user for that. I don't see that you use any SST authentication.

You may see respective code at

ansible-mariadb-galera-cluster/defaults/main.yml

Lines 159 to 165 in 1e263fa

	mariadb_sst_user:
	- name: "{{ mariadb_sst_username }}"
	hosts:
	- "localhost"
	plugin: "unix_socket"
	password: "{{ mariadb_sst_password }}"
	priv: "*.*:RELOAD,PROCESS,LOCK TABLES,BINLOG MONITOR"

and

ansible-mariadb-galera-cluster/tasks/mysql_users.yml

Line 20 in 1e263fa

- "{{ galera_sst_tls_enabled | ternary( mariadb_mysql_users | union( mariadb_sst_user ), mariadb_mysql_users ) }}"

and in any galera config file, eg.

ansible-mariadb-galera-cluster/templates/etc/my.cnf.d/server.cnf.j2

Line 85 in 1e263fa

wsrep_sst_auth="{{ mariadb_sst_user }}:{{ mariadb_sst_password }}"

[eRadical]

Haven't had any time yesterday as i was distracted by other chores.
Today I'll spin up a cluster w/ the above to test.

Thanx @elcomtik for those. Will incorporate!

[eRadical]

You're right @elcomtik, it does need authentication.

I've changed the logic to create user & use mariabackup without tls.
The tls part is still there but can be enabled separately.

What do you both think about this form? cc @mrlesmithjr

[elcomtik]

This looks almost perfect, although it removed functionality to automatically use mariabackup if sst encryption is enabled.
I would like if variable galera_sst_method default would be conditional which will switch on mariabackup if SST TLS is used.

Something like this (I have not tested this code yet)

galera_sst_method = "mariadb_tls_files and mariadb_tls_files|length == 3 and galera_sst_tls_enabled | ternary( "mariabackup", "rsync" )"

This could be overridden by the user if needed

[eRadical]

In defaults/main.yml I would change galera_sst_method to galera_sst_default_method:

galera_sst_default_method: rsync

In vars/main.yaml I would add:

galera_sst_method: "{{ mariadb_tls_files and mariadb_tls_files|length == 3 and galera_sst_tls_enabled | ternary( "mariabackup", galera_sst_default_method ) }}"

Thoughts ? cc @mrlesmithjr

[eRadical]

Done as @elcomtik suggested!

@mrlesmithjr - this is ready to be merged!

I have some clusters to spin up! :)

[elcomtik]

Looks, good. Please look at my last comment about xtrabackup-v2

[elcomtik]

we should not list xtrabackup-v2, because install of respective packages is not handled yet

[eRadical]

Or we could just say it's unsupported by the role!

[elcomtik]

@eRadical I just found an issue with WSREP auth. It affects your PR, you should rebase it when my PR is merged.

[eRadical]

As soon as @mrlesmithjr can help us merge both of them!

[mrlesmithjr]

Merged #68

[eRadical]

rebased and added also a note that xtrabackup-v2 is not implemented by this role

[elcomtik]

Perfect job @eRadical. LGTM @mrlesmithjr

[mrlesmithjr]

Merged and thanks to you both as always!