msggen: Start making the msggen library a standalone tool

There are quite some things we want to generate from the schema
definitions, both inside and outside of CLN itself. By bundling the
schemas into the library we can make use of the tooling without
running in the CLN source tree. This is in part used to generate some
of the interfaces in Greenlight.

Changelog-None

Makefile

@@ -356,6 +356,7 @@ include connectd/Makefile
 include lightningd/Makefile
 include cli/Makefile
 include doc/Makefile
+include contrib/msggen/Makefile
 include devtools/Makefile
 include tools/Makefile
 include plugins/Makefile
@@ -368,8 +369,8 @@ ifneq ($(RUST),0)
 	include cln-rpc/Makefile
 	include cln-grpc/Makefile
 
-$(MSGGEN_GENALL)&: doc/schemas/*.request.json doc/schemas/*.schema.json
-	PYTHONPATH=contrib/msggen $(PYTHON) contrib/msggen/msggen/__main__.py
+$(MSGGEN_GENALL)&: contrib/msggen/msggen/schema.json
+	PYTHONPATH=contrib/msggen $(PYTHON) contrib/msggen/msggen/__main__.py generate
 
 # The compiler assumes that the proto files are in the same
 # directory structure as the generated files will be. Since we

contrib/msggen/.gitignore

@@ -0,0 +1 @@
+contrib/msggen/dist/

contrib/msggen/Makefile

@@ -0,0 +1,4 @@
+#! /usr/bin/make
+
+contrib/msggen/msggen/schema.json: ${SCHEMAS}
+	PYTHONPATH=contrib/msggen ${PYTHON} contrib/msggen/msggen/__main__.py bundle doc/schemas

contrib/msggen/msggen/__main__.py

@@ -6,7 +6,7 @@
 from msggen.gen.grpc2py import Grpc2PyGenerator
 from msggen.gen.rust import RustGenerator
 from msggen.gen.generator import GeneratorChain
-from msggen.utils import load_jsonrpc_service
+from msggen.utils import load_jsonrpc_service, combine_schemas
 import logging
 from msggen.patch import VersionAnnotationPatch, OptionalPatch, OverridePatch
 from msggen.checks import VersioningCheck
@@ -62,11 +62,9 @@ def write_msggen_meta(meta):
     os.rename(f'.msggen.json.tmp.{pid}', '.msggen.json')
 
 
-def run(rootdir: Path):
-    schemadir = rootdir / "doc" / "schemas"
+def run():
     meta = load_msggen_meta()
     service = load_jsonrpc_service(
-        schema_dir=schemadir,
     )
 
     p = VersionAnnotationPatch(meta=meta)
@@ -91,14 +89,25 @@ def run(rootdir: Path):
     write_msggen_meta(meta)
 
 
-if __name__ == "__main__":
+def main():
     parser = argparse.ArgumentParser()
-    parser.add_argument(
-        '--rootdir',
-        dest='rootdir',
-        default='.'
-    )
+    subcmds = parser.add_subparsers(required=True, dest='command')
+    bundle = subcmds.add_parser("bundle", help="bundle schemas into package")
+    bundle.add_argument('schema_dir', action='store')
+
+    subcmds.add_parser("generate", help="generate all files")
     args = parser.parse_args()
-    run(
-        rootdir=Path(args.rootdir)
-    )
+
+    if args.command == 'generate':
+        run()
+    elif args.command == 'bundle':
+        dest = Path(__file__).parent / 'schema.json'
+        src = Path(__file__).parent / '..' / '..' / '..' / 'doc' / 'schemas'
+
+        print(f"Combining schemas from {src.resolve()} into {dest.resolve()}")
+        schema = combine_schemas(src, dest)
+        print(f"Created {dest} from {len(schema)} files")
+
+
+if __name__ == "__main__":
+    main()