Merge lp:~mars/launchpad/check-db-revision-target into lp:launchpad

[Māris Fogels]

This branch adds a check to 'make run' that will abort server startup at the soonest possible point if the currently installed database schema does not match what your branch requires.

Hi,

This branch adds a new script and Makefile target for checking the current branch's required database schema. The Makefile target is a dependency of the 'make run' and 'make start' families. If the currently installed schema version does not match, then the script will exit with an error.

The idea is to save a few minutes of everyone's life by having the 'make run' process exit as soon as possible, rather than waiting for the app server to start and *then* watching it fail because a schema mismatch was not detected sooner.

This change was discussed with the LOSAs. They do not see a problem with me changing the 'run' and 'start' targets in this way, as they do not use them.

I manually tested the change by running 'make schema' in db-stable. It works. 'make check_schema' fails on the schema mismatch, as does 'make run'.

Maris

[Aaron Bentley (abentley)]

review: Approve

=== modified file 'Makefile'
--- Makefile	2010-04-08 19:19:13 +0000
+++ Makefile	2010-04-12 19:57:34 +0000
@@ -78,6 +78,9 @@
 check_config: build
 	bin/test -m canonical.config.tests -vvt test_config
 
+check_schema: build
+	${PY} utilities/check-db-revision.py
+
 # Clean before running the test suite, since the build might fail depending
 # what source changes happened. (e.g. apidoc depends on interfaces)
 check: clean build
@@ -210,17 +213,17 @@
 	# Handle merge proposal creations.
 	$(PY) cronscripts/mpcreationjobs.py
 
-run: inplace stop
+run: check_schema inplace stop
 	$(RM) thread*.request
 	bin/run -r librarian,google-webservice,memcached -i $(LPCONFIG)
 
-start-gdb: inplace stop support_files
+start-gdb: check_schema inplace stop support_files
 	$(RM) thread*.request
 	nohup gdb -x run.gdb --args bin/run -i $(LPCONFIG) \
 		-r librarian,google-webservice
 		> ${LPCONFIG}-nohup.out 2>&1 &
 
-run_all: inplace stop hosted_branches
+run_all: check_schema inplace stop hosted_branches
 	$(RM) thread*.request
 	bin/run -r librarian,buildsequencer,sftp,mailman,codebrowse,google-webservice,memcached \
 	    -i $(LPCONFIG)
@@ -234,7 +237,7 @@
 stop_codebrowse:
 	$(PY) sourcecode/launchpad-loggerhead/stop-loggerhead.py
 
-run_codehosting: inplace stop hosted_branches
+run_codehosting: check_schema inplace stop hosted_branches
 	$(RM) thread*.request
 	bin/run -r librarian,sftp,codebrowse -i $(LPCONFIG)
 
@@ -440,4 +443,4 @@
 	schema default launchpad.pot check_merge_ui pull scan sync_branches\
 	reload-apache hosted_branches check_db_merge check_mailman check_config\
 	jsbuild jsbuild_lazr clean_js buildonce_eggs \
-	sprite_css sprite_image css_combine compile
+	sprite_css sprite_image css_combine compile check_schema

=== added file 'utilities/check-db-revision.py'
--- utilities/check-db-revision.py	1970-01-01 00:00:00 +0000
+++ utilities/check-db-revision.py	2010-04-12 19:57:34 +0000
@@ -0,0 +1,22 @@
+#!/usr/bin/python2.5 -S
+# Copyright 2010 Canonical Ltd.  All rights reserved.
+
+"""
+Check that the database revision of the current branch matches the current
+database schema number.
+"""
+
+import _pythonpath
+import sys
+
+from canonical.database.revision import (
+    confirm_dbrevision_on_startup, InvalidDatabaseRevision)
+
+try:
+    confirm_dbrevision_on_startup()
+except InvalidDatabaseRevision, err:
+    print "Oops, we are trying to use an invalid database revision!"
+    print err
+    sys.exit(1)
+else:
+    sys.exit(0)