TE-2583 Avoid redundant bok-choy DB setup steps

pavelib/database.py

@@ -91,14 +91,16 @@ def update_local_bokchoy_db_from_s3(options):
     fingerprint = fingerprint_bokchoy_db_files(MIGRATION_OUTPUT_FILES, ALL_DB_FILES)
     fingerprints_match = does_fingerprint_on_disk_match(fingerprint)
 
+    # Calculating the fingerprint already reset the DB, so we don't need to
+    # do it again (hence use_existing_db=True below)
     if fingerprints_match:
-        print ("DB cache files match the current migrations.")
-        reset_test_db(BOKCHOY_DB_FILES, update_cache_files=False)
+        print("DB cache files match the current migrations.")
+        reset_test_db(BOKCHOY_DB_FILES, update_cache_files=False, use_existing_db=True)
 
     elif is_fingerprint_in_bucket(fingerprint, CACHE_BUCKET_NAME):
-        print ("Found updated bokchoy db files at S3.")
+        print("Found updated bokchoy db files at S3.")
         refresh_bokchoy_db_cache_from_s3(fingerprint, CACHE_BUCKET_NAME, BOKCHOY_DB_FILES)
-        reset_test_db(BOKCHOY_DB_FILES, update_cache_files=False)
+        reset_test_db(BOKCHOY_DB_FILES, update_cache_files=False, use_existing_db=True)
 
     else:
         msg = "{} {} {}".format(
@@ -106,8 +108,8 @@ def update_local_bokchoy_db_from_s3(options):
             "Loading the bokchoy db files from disk",
             "and running migrations."
         )
-        print (msg)
-        reset_test_db(BOKCHOY_DB_FILES, update_cache_files=True)
+        print(msg)
+        reset_test_db(BOKCHOY_DB_FILES, update_cache_files=True, use_existing_db=True)
         # Check one last time to see if the fingerprint is present in
         # the s3 bucket. This could occur because the bokchoy job is
         # sharded and running the same task in parallel

pavelib/paver_tests/test_database.py

@@ -115,7 +115,7 @@ class TestPaverDatabaseTasks(MockS3Mixin, TestCase):
             self.assertFalse(_mock_get_file.called)
         calls = [
             call('{}/scripts/reset-test-db.sh --calculate_migrations'.format(Env.REPO_ROOT)),
-            call('{}/scripts/reset-test-db.sh'.format(Env.REPO_ROOT))
+            call('{}/scripts/reset-test-db.sh --use-existing-db'.format(Env.REPO_ROOT))
         ]
         _mock_sh.assert_has_calls(calls)
 
@@ -156,7 +156,7 @@ class TestPaverDatabaseTasks(MockS3Mixin, TestCase):
             )
         calls = [
             call('{}/scripts/reset-test-db.sh --calculate_migrations'.format(Env.REPO_ROOT)),
-            call('{}/scripts/reset-test-db.sh'.format(Env.REPO_ROOT))
+            call('{}/scripts/reset-test-db.sh --use-existing-db'.format(Env.REPO_ROOT))
         ]
         _mock_sh.assert_has_calls(calls)
 
@@ -184,7 +184,7 @@ class TestPaverDatabaseTasks(MockS3Mixin, TestCase):
         database.update_local_bokchoy_db_from_s3()  # pylint: disable=no-value-for-parameter
         calls = [
             call('{}/scripts/reset-test-db.sh --calculate_migrations'.format(Env.REPO_ROOT)),
-            call('{}/scripts/reset-test-db.sh --rebuild_cache'.format(Env.REPO_ROOT))
+            call('{}/scripts/reset-test-db.sh --rebuild_cache --use-existing-db'.format(Env.REPO_ROOT))
         ]
         _mock_sh.assert_has_calls(calls)
 

pavelib/utils/db_utils.py

@@ -30,7 +30,7 @@ def remove_files_from_folder(files, folder):
             continue
 
 
-def reset_test_db(db_cache_files, update_cache_files=True):
+def reset_test_db(db_cache_files, update_cache_files=True, use_existing_db=False):
     """
     Reset the bokchoy test db for a new test run
 
@@ -41,6 +41,8 @@ def reset_test_db(db_cache_files, update_cache_files=True):
     cmd = '{}/scripts/reset-test-db.sh'.format(Env.REPO_ROOT)
     if update_cache_files:
         cmd = '{} --rebuild_cache'.format(cmd)
+    if use_existing_db:
+        cmd = '{} --use-existing-db'.format(cmd)
     sh(cmd)
     verify_files_exist(db_cache_files)
 

scripts/reset-test-db.sh

@@ -46,6 +46,9 @@ for i in "$@"; do
         -c|--calculate_migrations)
             CALCULATE_MIGRATIONS=true
             ;;
+        -u|--use-existing-db)
+            USE_EXISTING_DB=true
+            ;;
     esac
 done
 
@@ -94,24 +97,28 @@ rebuild_cache_for_db() {
 }
 
 for db in "${database_order[@]}"; do
-    echo "CREATE DATABASE IF NOT EXISTS ${databases[$db]};" | mysql $MYSQL_HOST -u root
-
-    # Clear out the test database
-    #
-    # We are using the reset_db command which uses "DROP DATABASE" and
-    # "CREATE DATABASE" in case the tests are being run in an environment (e.g. devstack
-    # or a jenkins worker environment) that already ran tests on another commit that had
-    # different migrations that created, dropped, or altered tables.
-    echo "Issuing a reset_db command to the $db bok_choy MySQL database."
-    ./manage.py lms --settings $SETTINGS reset_db --traceback --router $db
-
-    # If there are cached database schemas/data, then load them.
-    # If they are missing, then we will want to build new cache files even if
-    # not explicitly directed to do so via arguments passed to this script.
-    if [[ ! -f $DB_CACHE_DIR/bok_choy_schema_$db.sql || ! -f $DB_CACHE_DIR/bok_choy_data_$db.json || ! -f $DB_CACHE_DIR/bok_choy_migrations_data_$db.sql ]]; then
-        REBUILD_CACHE=true
-    else
-        load_cache_into_db
+    if ! [[ $USE_EXISTING_DB ]]; then
+        echo "CREATE DATABASE IF NOT EXISTS ${databases[$db]};" | mysql $MYSQL_HOST -u root
+
+        # Clear out the test database
+        #
+        # We are using the reset_db command which uses "DROP DATABASE" and
+        # "CREATE DATABASE" in case the tests are being run in an environment (e.g. devstack
+        # or a jenkins worker environment) that already ran tests on another commit that had
+        # different migrations that created, dropped, or altered tables.
+        echo "Issuing a reset_db command to the $db bok_choy MySQL database."
+        ./manage.py lms --settings $SETTINGS reset_db --traceback --router $db
+    fi
+
+    if ! [[ $CALCULATE_MIGRATIONS ]]; then
+        # If there are cached database schemas/data, then load them.
+        # If they are missing, then we will want to build new cache files even if
+        # not explicitly directed to do so via arguments passed to this script.
+        if [[ ! -f $DB_CACHE_DIR/bok_choy_schema_$db.sql || ! -f $DB_CACHE_DIR/bok_choy_data_$db.json || ! -f $DB_CACHE_DIR/bok_choy_migrations_data_$db.sql ]]; then
+            REBUILD_CACHE=true
+        else
+            load_cache_into_db
+        fi
     fi
 done