[NormB]

Summary
Add five community-contributed modules under modules-contrib/ that integrate OpenSIPS with NATS and JetStream. Like all contrib modules, they are excluded from the default make and make install targets and are built only when selected explicitly.

Details

Module	Purpose	Production C (approx. lines)
nats	Shared connection pool and libnats loader; the only module that talks to libnats	10,000 together with event_nats
event_nats	Event transport publishing to NATS subjects and JetStream	Counted with nats
cachedb_nats	cachedb backend on JetStream KV, for usrloc and b2b	14,900
cachedb_nats_fts	Optional full-text search add-on for cachedb_nats	3,400
nats_consumer	JetStream pull consumer with a shared-memory ring and request/reply	13,900

cachedb_nats, event_nats and nats_consumer bind to nats.so at runtime through load_nats_api. cachedb_nats_fts plugs into cachedb_nats.

The change is 314 files, 78,167 insertions and 8 deletions. Of those, 308 files and 77,857 lines are under modules-contrib/, 179 files and 27,754 lines of them the unit tests (each module's test/ suite).

Solution

The modules load libnats with dlopen and never link -lnats, so packages need it only as a build dependency. The libnats found at runtime must have the same major.minor as the build headers, or OpenSIPS refuses to start. If libnats is missing or too old at build time, each module is skipped without failing the build.

Dependencies

Dependency	Needed for	Minimum	Source
libnats (nats.c)	Building and running all five modules	3.14	nats.c v3.14.0; Debian trixie's libnats-dev 3.10.1 is too old
nats-server with JetStream	Running	2.10	nats-server releases
tls_mgm and a TLS-enabled libnats	tls:// URLs only	None	-DNATS_BUILD_WITH_TLS=ON

Build

LIBNATS_TLS=ON scripts/build/install_libnats.sh
make all
make modules-contrib modules="modules-contrib/nats modules-contrib/cachedb_nats modules-contrib/cachedb_nats_fts modules-contrib/event_nats modules-contrib/nats_consumer"

To load them, include both module trees in mpath and load nats.so before the others.

Test

Each module has a unit-test suite in modules-contrib/<module>/test/, run in the existing layout by unittests.yml (the CI legs now install libnats; a suite whose module was not built is skipped):

make test-nats test-event_nats test-nats_consumer test-cachedb_nats_fts test-cachedb_nats

The end-to-end checks are SIPssert scenarios kept with the modules' maintainer, on the nats-sets branch of NormB/sipssert-opensips-tests (sets nats, event_nats, cachedb_nats, nats_consumer; they need an image with the NATS modules).

Verification

Local checks ran on Debian 13: the unit suites with gcc 14 (with -D_FORTIFY_SOURCE=2) and clang 19 (-O3), against nats.c 3.15.0-beta, the SIPssert sets against an image with nats.c v3.14.0 (the pinned install_libnats.sh version) and nats-server 2.11.10.

Check	Result
Build of the 5 modules, -Werror, on current master	0 warnings
Unit suites (make test-<module>), gcc and clang	5 of 5 pass: 655, 181, 817, 131 and 1,197 assertions
A suite whose module is not built (no libnats)	Skipped, not failed
SIPssert sets (NormB/sipssert-opensips-tests, nats-sets)	13 of 13 scenarios pass

Compatibility
These are new contrib modules, with no changes to core or existing module code. Outside modules-contrib/, the branch adds Debian and RPM packaging entries and a libnats install script, installs libnats in unittests.yml, and makes Makefile.test skip a module suite whose module was not built.

Closing issues
None.