Update mysql image in WordPress Docker setup to work on arm architectures

[justinahinon]

When following the steps in ​https://github.com/WordPress/wordpress-develop/blob/master/README.md to set up a WordPress Core development environment, you'll run into an error at this step: npm run env:start when the script is pulling the mysql image.

ERROR: no matching manifest for linux/arm64/v8 in the manifest list entries

This is due to mysql not supporting yet arm architectures (per ​https://github.com/docker-library/mysql/issues/318#issuecomment-339460074).

This PR allows pulling MySQL image on arm architectures while

Fixes https://core.trac.wordpress.org/ticket/52591

[desrosj]

I was working through this with @afragen over the weekend as well. It's likely that this will be fixed upstream, so I'm hesitant to make this temporary change.

For the time being, you can easily work around this with two approaches.

1. Create a docker-compose-override.yml file and define the mysql container with the platform specified.
2. Use mariadb instead of mysql. You can do this by changing the .env file LOCAL_DB_TYPE and LOCAL_DB_VERSION variables locally to mariadb and latest or by exporting those variables using command line before running npm run env:start.

I am writing a Build/Test Tools post for the Make Core blog detailing several tooling updates and I will include a small section detailing this and other small M1 issues that have been discovered.

[netweb]

Happy to test this, will test on M1 & Intel

As far as I'm aware right now MySQL haven't published an ARM64 build of MySQL 5.x, only 8.x

[netweb]

Replying to desrosj:

... It's likely that this will be fixed upstream, so I'm hesitant to make this temporary change.

For the time being, you can easily work around this with two approaches.

I agree, hard-coding platform: linux/x86_64 would break the other work-around, as MariaDB would then try to pull in the x86_64 version rather than the MAc M1 native linux/arm64 package, the other downside is that linux/x86_64 would be running through QEMU emulation and Rosetta 2, thus with degraded performance.

Another issues is that ​https://hub.docker.com/_/mysql is maintained by the Docker team, and not Oracle, the Docker team have yet to publish any linux/arm64 images on Docker Hub

The Docker Hub account ​https://hub.docker.com/r/mysql is a fork of the above by the Oracle team, and it does publish linux/arm64 images for MySQL v8

Going to close this ticket as the workarounds documented should be sufficient and has no further unintended consequences for those who are not using the ARM64 platform

Aside: Updating the docs in the .env file to document said workaround would be nice to see #goodfirstbug https://core.trac.wordpress.org/browser/trunk/.env