1 files changed, 73 insertions, 0 deletions
diff --git a/migrations/002-missing-chunk-morphs.py b/migrations/002-missing-chunk-morphs.py
new file mode 100755
index 00000000..2c93804e
--- /dev/null
+++ b/migrations/002-missing-chunk-morphs.py
@@ -0,0 +1,73 @@
+#!/usr/bin/env python
+# Copyright (C) 2015  Codethink Limited
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; version 2 of the License.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+'''Migration to Baserock Definitions format version 2.
+
+In version 2, the processing of the 'morph:' field within stratum .morph files
+became more strict.  This migration checks whether definitions are valid
+according to version 2 of the format.
+
+'''
+
+
+import os
+import sys
+import warnings
+
+import migrations
+
+
+TO_VERSION = 2
+
+
+def check_missing_chunk_morphs(contents, filename):
+    assert contents['kind'] == 'stratum'
+
+    valid = True
+
+    for chunk_ref in contents.get('chunks', []):
+        if 'morph' in chunk_ref:
+            chunk_path = os.path.join('.', chunk_ref['morph'])
+            if not os.path.exists(chunk_path):
+                # There's no way we can really fix this, so
+                # just warn and say the migration failed.
+                warnings.warn(
+                    "%s points to non-existant file %s" %
+                    (contents['name'], chunk_ref['morph']))
+                valid = False
+
+    return valid
+
+
+try:
+    if migrations.check_definitions_version(TO_VERSION - 1):
+        safe_to_migrate = migrations.process_definitions(
+            kinds=['stratum'], validate_cb=check_missing_chunk_morphs)
+
+        if not safe_to_migrate:
+            sys.stderr.write(
+                "Migration failed due to one or more warnings.\n")
+            sys.exit(1)
+        else:
+            migrations.set_definitions_version(TO_VERSION)
+            sys.stdout.write("Migration completed successfully.\n")
+            sys.exit(0)
+    else:
+        sys.stdout.write("Nothing to do.\n")
+        sys.exit(0)
+except RuntimeError as e:
+    sys.stderr.write("Error: %s\n" % e.message)
+    sys.exit(1)