Move lock acquisition up to script entrypoint level

Locking the part of the code that applies the migrations isn't enough:
the code that chooses which migrations to apply/rollback also needs to be locked,
otherwise concurrent processes will still try to apply the same migrations.

2 files changed, 21 insertions, 17 deletions

diff --git a/yoyo/backends.py b/yoyo/backends.py
index f6a3f36..6af931d 100644
--- a/yoyo/backends.py
+++ b/yoyo/backends.py
@@ -309,12 +309,11 @@ class DatabaseBackend(object):
         """
         if not migrations:
             return
-        with self.lock_migration_table():
-            for m in migrations:
-                try:
-                    self.apply_one(m, force=force)
-                except exceptions.BadMigration:
-                    continue
+        for m in migrations:
+            try:
+                self.apply_one(m, force=force)
+            except exceptions.BadMigration:
+                continue
 
     def run_post_apply(self, migrations, force=False):
         """
diff --git a/yoyo/scripts/migrate.py b/yoyo/scripts/migrate.py
index c18d02e..bb3117c 100755
--- a/yoyo/scripts/migrate.py
+++ b/yoyo/scripts/migrate.py
@@ -160,33 +160,38 @@ def get_migrations(args, backend):
 
 def apply(args, config):
     backend = get_backend(args, config)
-    migrations = get_migrations(args, backend)
-    backend.apply_migrations(migrations, args.force)
+    with backend.lock_migration_table():
+        migrations = get_migrations(args, backend)
+        backend.apply_migrations(migrations, args.force)
 
 
 def reapply(args, config):
     backend = get_backend(args, config)
-    migrations = get_migrations(args, backend)
-    backend.rollback_migrations(migrations, args.force)
-    backend.apply_migrations(migrations, args.force)
+    with backend.lock_migration_table():
+        migrations = get_migrations(args, backend)
+        backend.rollback_migrations(migrations, args.force)
+        backend.apply_migrations(migrations, args.force)
 
 
 def rollback(args, config):
     backend = get_backend(args, config)
-    migrations = get_migrations(args, backend)
-    backend.rollback_migrations(migrations, args.force)
+    with backend.lock_migration_table():
+        migrations = get_migrations(args, backend)
+        backend.rollback_migrations(migrations, args.force)
 
 
 def mark(args, config):
     backend = get_backend(args, config)
-    migrations = get_migrations(args, backend)
-    backend.mark_migrations(migrations)
+    with backend.lock_migration_table():
+        migrations = get_migrations(args, backend)
+        backend.mark_migrations(migrations)
 
 
 def unmark(args, config):
     backend = get_backend(args, config)
-    migrations = get_migrations(args, backend)
-    backend.unmark_migrations(migrations)
+    with backend.lock_migration_table():
+        migrations = get_migrations(args, backend)
+        backend.unmark_migrations(migrations)
 
 
 def prompt_migrations(backend, migrations, direction):