build(packaging): ship plugin .so files in DEB / RPM / SUSE artefacts

The chassis turns proxysql into a loader; runtime features
(mysqlx, genai/MCP) ship as separate .so files. Until now the
pre-existing packaging only saw the proxysql binary, so a v4.0
package install lost the plugins entirely — the operator had to
manually drop the .so files in place.

Wire them through all three packaging flavours:

* docker/images/proxysql/deb-compliant
  - entrypoint.bash: copies the built .so files into pkgroot/plugins/
    when the appropriate build flag is set (PROXYSQL40 for mysqlx,
    PROXYSQLGENAI for genai), then patches a placeholder in the
    equivs control file with the matching `Files:` entries that
    install them under /usr/lib/proxysql/.
  - proxysql.ctl: adds the placeholder line.

* docker/images/proxysql/{rhel,suse}-compliant
  - entrypoint.bash: copies the .so files into proxysql-${VER}/usr/lib/
    proxysql/ before the source tarball is rolled, and passes
    `--define "with_plugins 1"` to rpmbuild when the flags are set.
  - proxysql.spec: gates the new `%dir /usr/lib/proxysql` +
    `/usr/lib/proxysql/*.so` block under `%if 0%{?with_plugins}` so
    v3.x release builds (where the directory is empty) don't fail
    the build with `RPM build errors: File not found by glob`.

* etc/proxysql.cnf: add a commented-out `plugins=(...)` example
  with absolute paths matching the install location. Operators have
  to opt in explicitly — auto-loading would silently change behaviour
  on a v3.x → v4.0 upgrade without giving them a chance to review.

Conditional on PROXYSQL40 / PROXYSQLGENAI throughout so the v3.x
release-package paths stay byte-identical to before this commit.

docker/images/proxysql/deb-compliant/ctl/proxysql.ctl

@@ -18,6 +18,7 @@ Files: proxysql /usr/bin/
  systemd/system/proxysql.service /lib/systemd/system/
  tools/proxysql_galera_checker.sh /usr/share/proxysql/tools/
  tools/proxysql_galera_writer.pl /usr/share/proxysql/tools/
+PKG_PLUGIN_FILES_PLACEHOLDER
 Description: High performance MySQL and PostgreSQL proxy
  ProxySQL is a fast, reliable MySQL and PostgreSQL proxy with advanced runtime configuration management (virtually no configuration change requires a restart). 
  .

docker/images/proxysql/deb-compliant/entrypoint/entrypoint.bash

@@ -90,6 +90,37 @@ cp ../src/proxysql ./
 cp -r ../etc ./etc
 cp -r ../tools ./tools
 cp -r ../systemd ./systemd
+
+# Plugin .so artefacts (v4.0+ chassis): the proxysql binary is the
+# loader; runtime features (mysqlx, genai/MCP) ship as separate .so
+# files installed to /usr/lib/proxysql/ and named in proxysql.cnf
+# `plugins=("...")` to be loaded.  Conditional on the same flags that
+# gated the build above so v3.x deb packaging stays unchanged.
+PLUGIN_FILES_LINES=""
+mkdir -p ./plugins
+if [[ "${PROXYSQL40:-}" == "1" || "${PROXYSQLGENAI:-}" == "1" ]]; then
+    if [[ -f ../plugins/mysqlx/ProxySQL_Mysqlx_Plugin.so ]]; then
+        cp ../plugins/mysqlx/ProxySQL_Mysqlx_Plugin.so ./plugins/
+        PLUGIN_FILES_LINES+=" plugins/ProxySQL_Mysqlx_Plugin.so /usr/lib/proxysql/\n"
+    fi
+fi
+if [[ "${PROXYSQLGENAI:-}" == "1" ]]; then
+    if [[ -f ../plugins/genai/ProxySQL_GenAI_Plugin.so ]]; then
+        cp ../plugins/genai/ProxySQL_GenAI_Plugin.so ./plugins/
+        PLUGIN_FILES_LINES+=" plugins/ProxySQL_GenAI_Plugin.so /usr/lib/proxysql/\n"
+    fi
+fi
+# Substitute the placeholder line in the ctl file.  If no plugins were
+# built (v3.x release builds), strip the placeholder line entirely.
+if [[ -n "${PLUGIN_FILES_LINES}" ]]; then
+    # awk so we don't have to escape the newline-laden RHS for sed.
+    awk -v repl="${PLUGIN_FILES_LINES%\\n}" '{
+        if ($0 == "PKG_PLUGIN_FILES_PLACEHOLDER") { gsub("\\\\n", "\n", repl); printf "%s", repl; }
+        else { print; }
+    }' ./proxysql.ctl > ./proxysql.ctl.new && mv ./proxysql.ctl.new ./proxysql.ctl
+else
+    sed -i '/^PKG_PLUGIN_FILES_PLACEHOLDER$/d' ./proxysql.ctl
+fi
 DEB_BUILD_OPTIONS=nostrip equivs-build proxysql.ctl
 cp ./proxysql_${CURVER}_${ARCH}.deb ../binaries/proxysql_${CURVER}-${PKG_RELEASE}_${ARCH}.deb
 # get SHA1 of the packaged executable

docker/images/proxysql/rhel-compliant/entrypoint/entrypoint.bash

@@ -81,13 +81,38 @@ cp -a etc/proxysql.cnf proxysql/etc/
 cp -a etc/logrotate.d proxysql/etc/
 mkdir -p proxysql/usr/share/proxysql/tools
 cp -a tools/proxysql_galera_checker.sh tools/proxysql_galera_writer.pl proxysql/usr/share/proxysql/tools
+
+# Plugin .so artefacts (v4.0+ chassis): proxysql becomes the loader;
+# runtime features (mysqlx, genai/MCP) ship as separate .so files
+# installed to /usr/lib/proxysql/ and named in proxysql.cnf
+# `plugins=("...")` to be loaded.  Conditional on the same flags that
+# gated the build above so v3.x rpm packaging stays unchanged.  The
+# proxysql.spec %files section already lists /usr/lib/proxysql/* so
+# anything dropped in this directory ends up packaged automatically.
+if [[ "${PROXYSQL40:-}" == "1" || "${PROXYSQLGENAI:-}" == "1" ]]; then
+    mkdir -p proxysql/usr/lib/proxysql
+    if [[ -f plugins/mysqlx/ProxySQL_Mysqlx_Plugin.so ]]; then
+        cp plugins/mysqlx/ProxySQL_Mysqlx_Plugin.so proxysql/usr/lib/proxysql/
+    fi
+fi
+if [[ "${PROXYSQLGENAI:-}" == "1" ]]; then
+    mkdir -p proxysql/usr/lib/proxysql
+    if [[ -f plugins/genai/ProxySQL_GenAI_Plugin.so ]]; then
+        cp plugins/genai/ProxySQL_GenAI_Plugin.so proxysql/usr/lib/proxysql/
+    fi
+fi
 mv proxysql "proxysql-${CURVER}"
 tar czvf "proxysql-${CURVER}.tar.gz" proxysql-${CURVER}
 mkdir -p /root/rpmbuild/{RPMS,SRPMS,BUILD,SOURCES,SPECS,tmp}
 chown -R root:root /root/rpmbuild/SPECS
 mv "/opt/proxysql/proxysql-${CURVER}.tar.gz" /root/rpmbuild/SOURCES
 # build package
-cd /root/rpmbuild && rpmbuild -ba SPECS/proxysql.spec --define "version ${CURVER}"
+RPMBUILD_DEFINES=( --define "version ${CURVER}" )
+if [[ "${PROXYSQL40:-}" == "1" || "${PROXYSQLGENAI:-}" == "1" ]]; then
+    # gates the %if 0%{?with_plugins} block in proxysql.spec %files
+    RPMBUILD_DEFINES+=( --define "with_plugins 1" )
+fi
+cd /root/rpmbuild && rpmbuild -ba SPECS/proxysql.spec "${RPMBUILD_DEFINES[@]}"
 cp "/root/rpmbuild/RPMS/${ARCH}/proxysql-${CURVER}-1.${ARCH}.rpm" "/opt/proxysql/binaries/proxysql-${CURVER}-1-${PKG_RELEASE}.${ARCH}.rpm"
 # get SHA1 of the packaged executable
 mkdir -p /opt/proxysql/pkgroot/tmp

docker/images/proxysql/rhel-compliant/rpmmacros/rpmbuild/SPECS/proxysql.spec

@@ -76,6 +76,15 @@ rm -rf %{buildroot}
 %{_sysconfdir}/systemd/system/%{name}-initial.service
 /usr/share/proxysql/tools/proxysql_galera_checker.sh
 /usr/share/proxysql/tools/proxysql_galera_writer.pl
+# Plugin .so artefacts for v4.0+ chassis builds (mysqlx, genai/MCP).
+# Gated on the `with_plugins` define passed by the rhel-compliant
+# entrypoint when PROXYSQL40=1 or PROXYSQLGENAI=1.  Without the gate
+# the wildcard match would fail on v3.x release builds where the
+# directory is empty and rpmbuild aborts on no-files-match.
+%if 0%{?with_plugins}
+%dir /usr/lib/proxysql
+/usr/lib/proxysql/*.so
+%endif
 %config(noreplace) %attr(750,%{name},%{name}) /var/run/%{name}/
 %config(noreplace) %attr(750,%{name},%{name}) /var/lib/%{name}/
 

docker/images/proxysql/suse-compliant/entrypoint/entrypoint.bash

@@ -84,10 +84,32 @@ cp -a systemd proxysql-${CURVER}/etc/
 cp -a etc/proxysql.cnf proxysql-${CURVER}/etc/
 cp -a etc/logrotate.d proxysql-${CURVER}/etc/
 cp -a tools/proxysql_galera_checker.sh tools/proxysql_galera_writer.pl proxysql-${CURVER}/usr/share/proxysql/tools
+
+# Plugin .so artefacts (v4.0+ chassis); see rhel-compliant entrypoint
+# for the full rationale.  Gated on the same build flags so v3.x
+# packaging is unchanged.
+if [[ "${PROXYSQL40:-}" == "1" || "${PROXYSQLGENAI:-}" == "1" ]]; then
+    mkdir -p proxysql-${CURVER}/usr/lib/proxysql
+    if [[ -f plugins/mysqlx/ProxySQL_Mysqlx_Plugin.so ]]; then
+        cp plugins/mysqlx/ProxySQL_Mysqlx_Plugin.so proxysql-${CURVER}/usr/lib/proxysql/
+    fi
+fi
+if [[ "${PROXYSQLGENAI:-}" == "1" ]]; then
+    mkdir -p proxysql-${CURVER}/usr/lib/proxysql
+    if [[ -f plugins/genai/ProxySQL_GenAI_Plugin.so ]]; then
+        cp plugins/genai/ProxySQL_GenAI_Plugin.so proxysql-${CURVER}/usr/lib/proxysql/
+    fi
+fi
+
 tar czvf "proxysql-${CURVER}.tar.gz" proxysql-${CURVER}
 mv "/opt/proxysql/proxysql-${CURVER}.tar.gz" "/root/rpmbuild/SOURCES"
 # build package
-rpmbuild -bb --define "version ${CURVER}" /root/rpmbuild/SPECS/proxysql.spec
+RPMBUILD_DEFINES=( --define "version ${CURVER}" )
+if [[ "${PROXYSQL40:-}" == "1" || "${PROXYSQLGENAI:-}" == "1" ]]; then
+    # gates the %if 0%{?with_plugins} block in proxysql.spec %files
+    RPMBUILD_DEFINES+=( --define "with_plugins 1" )
+fi
+rpmbuild -bb "${RPMBUILD_DEFINES[@]}" /root/rpmbuild/SPECS/proxysql.spec
 cp /root/rpmbuild/RPMS/${ARCH}/proxysql-${CURVER}-1.${ARCH}.rpm ./binaries/proxysql-${CURVER}-1-${PKG_RELEASE}.${ARCH}.rpm
 # get SHA1 of the packaged executable
 mkdir -p /opt/proxysql/pkgroot/tmp

docker/images/proxysql/suse-compliant/rpmmacros/rpmbuild/SPECS/proxysql.spec

@@ -76,6 +76,12 @@ rm -rf %{buildroot}
 %{_sysconfdir}/systemd/system/%{name}-initial.service
 /usr/share/proxysql/tools/proxysql_galera_checker.sh
 /usr/share/proxysql/tools/proxysql_galera_writer.pl
+# Plugin .so artefacts for v4.0+ chassis builds (mysqlx, genai/MCP).
+# See rhel-compliant proxysql.spec for the rationale on the gate.
+%if 0%{?with_plugins}
+%dir /usr/lib/proxysql
+/usr/lib/proxysql/*.so
+%endif
 %config(noreplace) %attr(750,%{name},%{name}) /var/run/%{name}/
 %config(noreplace) %attr(750,%{name},%{name}) /var/lib/%{name}/
 

etc/proxysql.cnf

@@ -34,6 +34,17 @@
 datadir="/var/lib/proxysql"
 errorlog="/var/lib/proxysql/proxysql.log"
 
+# Plugin chassis (v4.0+).  Uncomment to load runtime-loadable
+# extensions.  Each entry is the absolute path to a .so file shipped
+# under /usr/lib/proxysql/.  Plugins are loaded in declaration order
+# during startup; missing files cause the proxy to abort with an
+# explanatory message.
+#
+# plugins=(
+# 	"/usr/lib/proxysql/ProxySQL_Mysqlx_Plugin.so"
+# 	"/usr/lib/proxysql/ProxySQL_GenAI_Plugin.so"
+# )
+
 admin_variables=
 {
 	admin_credentials="admin:admin"