Split CI build step.

.github/workflows/default.yml

@@ -130,6 +130,10 @@ jobs:
           cp docker-compose.sample.yml docker-compose.yml
           cp docker-compose.testing.yml docker-compose.override.yml
 
+      - name: Build Functional test image.
+        run: |
+          docker-compose build web
+
       - name: Run functional test suite.
         run: |
           chmod 777 tests/_output/

util/docker/mariadb/setup/mariadb.sh

@@ -13,7 +13,7 @@ apt-get update
 		echo "mariadb-server" mysql-server/root_password_again password 'unused'; \
 } | debconf-set-selections
 
-apt-get install -q -y --no-install-recommends mariadb-server mariadb-backup
+apt-get install -q -y --no-install-recommends mariadb-server mariadb-backup pwgen
 
 rm -rf /var/lib/mysql
 mkdir -p /var/lib/mysql /var/run/mysqld