zabbix: add full variants, add-on support for others, and update packaging

[danielfdickinson]

📦 Package Details

Maintainer: @danielfdickinson

Description:

1. Update the db dependencies on php8 modules. They can be 'select'
   because of the php8 dependency (and the php8 dependency is required
   prevent the various php8 module selects from causing a recursive
   dependency issues for Kconfig).
2. Rather than having a database selection for SQLITE which prevents
   the server or frontend from building, we add a 'core'
   variant for the proxy which uses sqlite3, and have the database
   Kconfig affect only the server and frontend.
3. In preparation for adding full variants with more features, we reduce
   the number of packages and variants by making SSL library selection a
   Kconfig choice instead of variants.
   This is a breaking change as -openssl and -gnutls packages will
   no longer exist.
   We choose GnuTLS as the default SSL/TLS provider as it tends to be
   smaller, and we choose the core and core-db variants as the
   default variants, again for size.
4. Adds a full variant of the agentd, server, and proxy which enables
   cURL, LDAP, and Net-SNMP support. It uses OpenSSL for this variant
   as LDAP and the SSL variant of Net-SNMP already pull it in. We also
   allow other variants to be self-compiled with the their selection of
   those features, for users with unusual requirements.

This approach keeps the number packages reasonable (< 20). With a different set of choices in the patch series at https://gitlab.com/dfd-web/firmware/openwrt-mirrors/packages/-/tree/pr-add-zabbix-variants-and-capabilities?ref_type=heads the number packages exploded to almost 40. In that series I not only kept the different SSL variants, but made database selection variants instead of a Kconfig options.

Even without that, if we do not make SSL a configuration option, we end up with upwards of 30 packages.

I believe this patch series provides the right balance between features and OpenWrt project resources.

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🧪 Run Testing Details

• OpenWrt Version: SNAPSHOT r33092-98e7ed1462
• OpenWrt Target/Subtarget: bcm27xx/bcm2712
• OpenWrt Device: Raspberry Pi 5 Model B Rev 1.0

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✅ Formalities

• I have reviewed the CONTRIBUTING.md file for detailed contributing guidelines.

[danielfdickinson]

Will also address #15419 and replaces #27716 .

[danielfdickinson]

@mhei @hnyman @systemcrash @GeorgeSapkin This is a significant change to the Zabbix package that gains users many features. Any comments, concerns, or approvals?

[systemcrash]

sqlite3 ftw :)

[danielfdickinson]

Currently testing. Also, would there be objections to merging all but the php8 dependency commit into one?

EDIT: Fixing foreach now.
EDIT 2: I merged all but the php8 dependency into a single commit. I have kept a copy of the unmerged version in a separate branch, so can bring it back if this is not wanted.

[GeorgeSapkin]

Maybe new variants should provide old ones, e.g. zabbix-proxy-core should provide zabbix-proxy-nossl. Or what is the intended migration path from old names to new ones?

[danielfdickinson]

Maybe new variants should provide old ones, e.g. zabbix-proxy-core should provide zabbix-proxy-nossl. Or what is the intended migration path from old names to new ones?

Already did something like this:

https://github.com/openwrt/packages/pull/28585/changes#diff-07c64987bed9bf3c8e2c4b4fd474104686096b489bf33bed2a0f23c9347108ddR337

  PROVIDES += zabbix-proxy-nossl

for all packages.

In case of the ssl variants I have a PROVIDES zabbix-proxy-ssl but not zabbix-proxy-openssl / zabbix-proxy-gnutls for two reasons:

1. DEFAULT_VARIANT cannot be set separately for different PROVIDES for a package, so it becomes non-deterministic what is the default provider for e.g. zabbix-proxy if one has e.g. a DEFAULT_VARIANT:=1 on both zabbix-proxy-core-ssl and zabbix-proxy-core.
2. zabbix-proxy-ssl being openssl or gnutls depends on the configuration choice made by the user or buildbot at compile time. As noted I consider this a breaking change, and I think it is better the user is made aware of the change.