Add Galera WSREP Provider

wodby / mariadb

MariaDB docker container image

https://wodby.com/stacks/mariadb

GNU General Public License v2.0

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Add Galera WSREP Provider #28

Closed tomalok closed 4 years ago

tomalok commented 4 years ago

download, patch, build, install, and strip Galera WSREP Provider
patches allow Galera to build on Alpine/musl for x86/x86_64 architectures (patches would need tweaks to support other arch's)
adds NPROC make variable (my builds were unstable with -j $(nproc))
set default ALPINE_VER to 3.11

csandanov commented 4 years ago

Thanks. A couple things:

how much does it increase the compressed image size? I guess not much but want to know beforehand (we could use a separate tag for Galera)
I think alpine upgrade should be a separate update, we still have 3.8 for 10.1 and 3.10 for the rest ( see ./circleci). Or is it important to have 3.11 for galera?

tomalok commented 4 years ago

The only additional artifact in the image is /usr/lib/libgalera_smm.so, which is 2,634,224 bytes, stripped. The Galera build process also produces a garbd (galera arbitrator) daemon to provide quorum for clusters with even number of nodes (and a man page for that daemon)... For Alpine, I bundled those in separate packages, as they have no dependencies on the library and didn't make sense to put in the wodby/mariadb image.
There is no requirement for Alpine 3.11, but personally, I like to keep as current as possible. I can roll back ALPINE_VER back in this PR if you like.

csandanov commented 4 years ago

Yes, could you please rollback the Alpine version, we will perform the update separately.

Also, it's not really clear how to use galera with this image, if you look up helm chart for galera, they have a specific binary that runs in the entrypoint and searching for other galera master instances in the network and connects them all together (is it garbd?). If we want people to run galera with this image we should document it in README.

tomalok commented 4 years ago

Okay, things for to do, off the top of my head yet...

[x] Roll back the Alpine version
[x] Make build of Galera optional
[ ] ~Per Galera Versions builds of 10.1, 10.2, and 10.3 should use Galera 25.3.28 (10.5.1 should use 26.4.4, but you're not tracking 10.5 yet)~
[x] Maybe include garbd? A search on https://hub.docker.com didn't turn up many hits, and only one is recent.
[x] Add WSREP_ configuration to the template
[x] Add some docs about how to start a cluster, and perhaps about garbd

I'm only seeing linux/amd64 OS/arch values for wodby/mariadb, so it should not be a blocker that the musl patches don't work (yet) for non-x86 arch.

tomalok commented 4 years ago

Ran into some complications building Galera with MariaDB versions prior to 10.4... Dropping that item off the to-do list.

tomalok commented 4 years ago

needed rsync and socat for Galera SST.
updated 10.4 my.cnf.tmpl to include Galera WSREP_* configs and enforce some other configs when WSREP_ON env var exists. (Is there a way with gotpl to specify that it exists and its value is ON?)
added WSREP_* vars to README.md

tomalok commented 4 years ago

The latest commit adds a runtime dependency for garbd, and fleshes out the rest of the Galera-related documentation in the README.

@csandanov - unless there's anything else you think needs tweaking, I think this PR is ready.

csandanov commented 4 years ago

Thank you, looks good. We'll have to add tests with wsrep enabled at some point.