bitbake-layers: Add ability to update the reference of repositories

This creates a new layers setup with, or, modifies an existing layers
setup using, one or more repositories where the references are provided
by the user.

This is a very minimal implementation, no validation of any reference
is done and it is left to the user to provide a valid value.

(From OE-Core rev: e69444de713e1ec7959c71f9cdf965d3b5a1c6be)

Signed-off-by: Jermain Horsman <jermain.horsman@nedap.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/bblayers/setupwriters/oe-setup-layers.py

@@ -31,16 +31,69 @@ class OeSetupLayersWriter():
         with open(output, 'w') as f:
             json.dump(repos, f, sort_keys=True, indent=4)
 
+    def _read_repo_config(self, json_path):
+        with open(json_path) as f:
+            json_config = json.load(f)
+
+        supported_versions = ["1.0"]
+        if json_config["version"] not in supported_versions:
+            err = "File {} has version {}, which is not in supported versions: {}".format(json_path, json_config["version"], supported_versions)
+            logger.error(err)
+            raise Exception(err)
+
+        return json_config
+
+    def _modify_repo_config(self, json_config, args):
+        sources = json_config['sources']
+        for pair in args.custom_references:
+            try:
+                repo, rev = pair.split(':', maxsplit=1)
+            except ValueError:
+                err = "Invalid custom reference specified: '{}'. Provide one using 'REPOSITORY:REFERENCE'.".format(pair)
+                logger.error(err)
+                raise Exception(err)
+            if not repo in sources.keys():
+                err = "Repository {} does not exist in setup-layers config".format(repo)
+                logger.error(err)
+                raise Exception(err)
+
+            layer_remote = json_config['sources'][repo]['git-remote']
+            layer_remote['rev'] = rev
+            # Clear describe
+            layer_remote['describe'] = ''
+
     def do_write(self, parent, args):
         """ Writes out a python script and a json config that replicate the directory structure and revisions of the layers in a current build. """
-        if not os.path.exists(args.destdir):
-            os.makedirs(args.destdir)
-        repos = parent.make_repo_config(args.destdir)
-        json = {"version":"1.0","sources":repos}
-        if not repos:
-            raise Exception("Could not determine layer sources")
         output = args.output_prefix or "setup-layers"
-        output = os.path.join(os.path.abspath(args.destdir),output)
+        output = os.path.join(os.path.abspath(args.destdir), output)
+
+        if args.update:
+            # Modify existing layers setup
+            if args.custom_references is None:
+                err = "No custom reference specified. Please provide one using '--use-custom-reference REPOSITORY:REFERENCE'."
+                logger.error(err)
+                raise Exception(err)
+
+            json = self._read_repo_config(output + ".json")
+            if not 'sources' in json.keys():
+                err = "File {}.json does not contain valid layer sources.".format(output)
+                logger.error(err)
+                raise Exception(err)
+
+        else:
+            # Create new layers setup
+            if not os.path.exists(args.destdir):
+                os.makedirs(args.destdir)
+            repos = parent.make_repo_config(args.destdir)
+            json = {"version":"1.0","sources":repos}
+            if not repos:
+                err = "Could not determine layer sources"
+                logger.error(err)
+                raise Exception(err)
+
+        if args.custom_references is not None:
+            self._modify_repo_config(json, args)
+
         self._write_json(json, output + ".json")
         logger.info('Created {}.json'.format(output))
         if not args.json_only:
@@ -50,3 +103,15 @@ class OeSetupLayersWriter():
     def register_arguments(self, parser):
         parser.add_argument('--json-only', action='store_true',
             help='When using the oe-setup-layers writer, write only the layer configuruation in json format. Otherwise, also a copy of scripts/oe-setup-layers (from oe-core or poky) is provided, which is a self contained python script that fetches all the needed layers and sets them to correct revisions using the data from the json.')
+
+        parser.add_argument('--update', '-u',
+            action='store_true',
+            help=("Instead of writing a new json file, update an existing layer setup json file with custom references provided via the '--use-custom-reference' option."
+                  "\nThis will only update repositories for which a custom reference is specified, all other repositores will be left unchanged."))
+        parser.add_argument('--use-custom-reference', '-r',
+            action='append',
+            dest='custom_references',
+            metavar='REPOSITORY:REFERENCE',
+            help=("A pair consisting of a repository and a custom reference to use for it (by default the currently checked out commit id would be written out)."
+                  "\nThis value can be any reference that 'git checkout' would accept, and is not checked for validity."
+                  "\nThis option can be used multiple times."))