Include MySQL client (mysql / mysqldump) in serversideup/php, or opt-in via ENV / extra tag

[MurzNN]

👉 Describe the problem

PHP apps (Drupal, Laravel, WordPress) need the MySQL/MariaDB CLI (mysql, mysqldump) in the container — not only pdo_mysql / mysqli. Drush (sql:cli, sql:dump), Artisan, and WP-CLI all shell out to those binaries.

The stock image does not include them. On Kubernetes we currently start as root and install at runtime:

apk add mysql-client

That adds startup latency, depends on package repos at every pod start, and breaks the unprivileged default.

👥 Problem evidence & reach

Anyone running Drush, Laravel dump/restore, or WP-CLI against MySQL hits this. Existing workarounds are custom Dockerfiles (default-mysql-client on Debian, mysql-client on Alpine) or CI apk add. Helm/K8s users who pull the Hub image directly cannot easily do that.

🏆 How to solve this problem

Any of these would work (prefer 1 or 2 if default size is a concern):

1. ENV opt-in (e.g. INSTALL_MYSQL_CLIENT=true): entrypoint installs the distro client once at start, then continues as www-data. Avoids a custom Dockerfile; still needs network/repos unless cached.
2. Separate tag with the client bundled, e.g. 8.4-fpm-nginx-mysql / 8.4-cli-mysql (or a -tools variant). Same unprivileged image, no runtime apk/apt.
3. Include in all tags if the size hit is acceptable.

Package names

• Debian: default-mysql-client (mysql-client has no candidate on current Debian)
• Alpine: mysql-client (pulls mariadb-client)

Estimated image size

Rough, from current distro packages (uncompressed in the image; compressed Hub layers are smaller):

• Alpine mariadb-client: ~25–30 MB installed (~7 MB package download)
• Debian default-mysql-client → mariadb-client: ~15–40 MB installed (metapackage itself is tiny; the client is the cost)

A dedicated Alpine “mysql-client only” image is ~18 MB compressed; added to serversideup/php expect on the order of ~10–20 MB extra compressed per tag, more on Debian if the full client (not -core) is used.

🥰 Describe the "impact" on users?

Drush/Artisan/WP-CLI DB commands work without a custom Dockerfile or root postStart install. Users who do not need the CLI keep a small default image (ENV or extra tag). Unprivileged user stays the default for bundled tags.

💯 How do we validate the problem is solved?

On Debian and Alpine, as www-data, without a custom image (bundled tag or ENV enabled):

1. mysql --version and mysqldump --version succeed.
2. mysql -h … -e 'SELECT 1' and a mysqldump against a test DB work.
3. Optional: drush sql:dump or equivalent Artisan/WP-CLI command.
4. Default tags without ENV stay unchanged in size and still run unprivileged.