Adds the ability to run operations/session changes with a dry-run option

onegov/core/cli.py

@@ -31,14 +31,16 @@ def cli(ctx, config, namespace):
 
 
 @cli.command()
+@click.option('--dry-run', default=False, is_flag=True,
+              help="Do not write any changes into the database.")
 @click.pass_context
-def upgrade(ctx):
+def upgrade(ctx, dry_run):
     """ Upgrades all application instances of the given namespace(s). """
 
     ctx = ctx.obj
 
     update_path = '/' + uuid4().hex
-    upgrade_runner = UpgradeRunner(get_tasks())
+    upgrade_runner = UpgradeRunner(get_tasks(), commit=not dry_run)
 
     for appcfg in ctx['config'].applications:
 
@@ -59,7 +61,8 @@ def get_upgrade_runner():
 
         @UpdateApplication.view(model=UpgradeRunner)
         def run_upgrade(self, request):
-            print("Running upgrade for {}".format(request.app.application_id))
+            title = "Running upgrade for {}".format(request.app.application_id)
+            print(click.style(title, underline=True))
             self.run_upgrade(request)
 
         config.commit()
@@ -74,7 +77,8 @@ def run_upgrade(self, request):
                 {
                     'path': appcfg.path,
                     'application': UpdateApplication,
-                    'namespace': appcfg.namespace
+                    'namespace': appcfg.namespace,
+                    'configuration': appcfg.configuration
                 }
             ]
         }), configure_morepath=False)

onegov/core/upgrade.py

@@ -1,7 +1,14 @@
+# -*- coding: utf-8 -*-
+
+import click
 import importlib
 import networkx as nx
 import pkg_resources
+import transaction
 
+from alembic.migration import MigrationContext
+from alembic.operations import Operations
+from onegov.core.utils import Bunch
 from inspect import getmembers, isfunction, ismethod
 
 
@@ -32,8 +39,8 @@ def get_upgrade_modules():
     for distribution, entry_map in get_distributions_with_entry_map('onegov'):
         if 'upgrade' in entry_map:
             yield (
-                distribution.name,
-                importlib.import_module(entry_map['upgrade'])
+                distribution.project_name,
+                importlib.import_module(entry_map['upgrade'].module_name)
             )
 
 
@@ -161,9 +168,44 @@ def get_tasks(upgrade_modules=None):
 class UpgradeRunner(object):
     """ Runs all tasks of a :class:`UpgradeTasksRegistry`. """
 
-    def __init__(self, tasks):
+    def __init__(self, tasks, commit=True):
         self.tasks = tasks
+        self.commit = commit
 
     def run_upgrade(self, request):
+
         for task_id, task in self.tasks:
-            task(request)
+
+            session = request.app.session()
+            connection = session.bind.connect()
+
+            context = Bunch(
+                request=request,
+                app=request.app,
+                session=session,
+                operations=Operations(MigrationContext.configure(connection))
+            )
+
+            operations_transaction = connection.begin()
+            session_savepoint = transaction.savepoint()
+
+            try:
+                task(context)
+                session.flush()
+
+                print(click.style('✓', fg='green'), task.task_name)
+
+            except:
+                operations_transaction.rollback()
+                session_savepoint.rollback()
+
+                print(click.style('✗', fg='red'), task.task_name)
+
+                raise
+            else:
+                if self.commit:
+                    operations_transaction.commit()
+                    transaction.commit()
+                else:
+                    operations_transaction.rollback()
+                    transaction.abort()

setup.py

@@ -10,6 +10,7 @@
 version = '0.3.9'
 
 dependencies = {
+    'alembic',
     'bleach',
     'cached_property',
     'chameleon',