use ucf for gitlab-shell config

debian/conf/gitlab-debian.conf

@@ -8,6 +8,8 @@ gitlab_yml_private=/var/lib/gitlab/gitlab.yml
 gitlab_yml=/etc/gitlab/gitlab.yml
 gitlab_debian_conf_private=/var/lib/gitlab/gitlab-debian.conf
 gitlab_debian_conf=/etc/gitlab/gitlab-debian.conf
+gitlab_shell_config_private=/var/lib/gitlab-shell-config.yml
+gitlab_shell_config=/etc/gitlab-shell/config.yml
 gitlab_nginx_log=/var/log/gitlab
 gitlab_ssl_path=/etc/gitlab/ssl
 gitlab_shell_root=/usr/share/gitlab-shell

debian/postinst

@@ -103,7 +103,12 @@ EOF
           echo "Updating gitlab_url in gitlab-shell configuration..."
           sed -i \
 	  "s/gitlab_url: http*:\/\/.*/gitlab_url: ${gl_proto}:\/\/${GITLAB_HOST}/"\
-	  ${gitlab_shell_root}/config.yml
+	  ${gitlab_shell_config_private}
+
+          # Manage gitlab-shell's config.yml via ucf
+	  echo "Registering ${gitlab_shell_config} via ucf"
+	  ucf --debconf-ok --three-way ${gitlab_shell_config_private} ${gitlab_shell_config}
+	  ucfr gitlab ${gitlab_shell_config}
 	fi
         mkdir -p /etc/gitlab/ssl
         if [ -f "${nginx_ssl_conf_example_gz}" ]; then