Zuul Dashboard Javascript

zuul-web has an html, css and javascript component, zuul-dashboard, that is managed using Javascript toolchains. It is intended to be served by zuul-web directly from zuul/web/static in the simple case, or to be published to an alternate static web location, such as an Apache server.

The web dashboard is written in React and PatternFly and is managed by create-react-app and yarn which in turn both assume a functioning and recent nodejs installation.


The web dashboard source code and package.json are located in the web directory. All the yarn commands need to be executed from the web directory.

For the impatient who don’t want deal with javascript toolchains

tl;dr - You have to build stuff with javascript tools.

The best thing would be to get familiar with the tools, there are a lot of good features available. If you’re going to hack on the Javascript, you should get to know them.

If you don’t want to hack on Javascript and just want to run Zuul’s tests, tox has been set up to handle it for you.

If you do not have yarn installed, tox will use nodeenv to install node into the active python virtualenv, and then will install yarn into that virtualenv as well.

yarn dependency management

yarn manages the javascript dependencies. That means the first step is getting yarn installed.


The tools/install-js-tools.sh script will add apt or yum repositories and install nodejs and yarn from them. For RPM-based distros it needs to know which repo description file to download, so it calls out to tools/install-js-repos-rpm.sh.

Once yarn is installed, getting dependencies installed is:

yarn install

The yarn.lock file contains all of the specific versions that were installed before. Since this is an application it has been added to the repo.

To add new runtime dependencies:

yarn add awesome-package

To add new build-time dependencies:

yarn add -D awesome-package

To remove dependencies:

yarn remove terrible-package

Adding or removing packages will add the logical dependency to package.json and will record the version of the package and any of its dependencies that were installed into yarn.lock so that other users can simply run yarn install and get the same environment.

To update a dependency:

yarn add awesome-package

Dependencies are installed into the node_modules directory. Deleting that directory and re-running yarn install should always be safe.

Dealing with yarn.lock merge conflicts

Since yarn.lock is generated, it can create merge conflicts. Resolving them at the yarn.lock level is too hard, but yarn itself is deterministic. The best procedure for dealing with yarn.lock merge conflicts is to first resolve the conflicts, if any, in package.json. Then:

yarn install --force
git add yarn.lock

Which causes yarn to discard the yarn.lock file, recalculate the dependencies and write new content.

React Components and Styling

Each page is a React Component. For instance the status.html page code is web/src/pages/status.jsx. It is usually a good idea not to put too much markup in those page components and create different components for this instead. This way, the page component can deal with the logic like reloading data if needed or evaluating URL parameters and the child components can deal with the markup. Thus, you will find a lot of components in the web/src/containers directory that mainly deal with the markup.

Mapping of pages/urls to components can be found in the route list in web/src/routes.js.

The best way to get started is to check out the libraries that glue everything together. Those are React, react-router and Redux.

For the visual part we are using PatternFly. For a list of available PatternFly React components, take a look at the Components section in their documentation. If a single component is not enough, you could also take a look at the Demos sections which provides some more advanced examples incorporating multiple components and their interaction.

If you are unsure which component you should use for your purpose, you might want to check out the Usage and behaviour section in their design guidelines.

There is also a list of available icons including some recommendations on when to use which icon. In case you don’t find an appropriate icon there, you could check out the FontAwesome Free icons, as most of them are included in PatternFly. To find out if an icon is available, simply try to import it from the @patternfly/react-icons package.

For example if you want to use the address-book icon (which is not listed in the PatternFly icon list) you can import it via the following statement:

import { AddressBookIcon } from '@patternfly/react-icons'

Please note that the spelling of the icon name changes to CamelCase and is always extended by Icon.


Building the code can be done with:

yarn build

zuul-web has a static route defined which serves files from zuul/web/static. yarn build will put the build output files into the zuul/web/static directory so that zuul-web can serve them.

Development server that handles things like reloading and hot-updating of code can be started with:

yarn start

will build the code and launch the dev server on localhost:3000. Fake api response needs to be set in the web/public/api directory.

mkdir public/api/
for route in info status jobs builds; do
curl -o public/api/${route} https://zuul.openstack.org/api/${route}

To use an existing zuul api, uses the REACT_APP_ZUUL_API environment variable:

# Use openstack zuul's api:
yarn start:openstack

# Use software-factory multi-tenant zuul's api:
yarn start:multi

# Use a custom zuul:
REACT_APP_ZUUL_API="https://zuul.example.com/api/" yarn start

To run eslint tests locally:

yarn lint


The web application is a set of static files and is designed to be served by zuul-web from its static route. In order to make sure this works properly, the javascript build needs to be performed so that the javascript files are in the zuul/web/static directory. Because the javascript build outputs into the zuul/web/static directory, as long as yarn build has been done before pip install . or python setup.py sdist, all the files will be where they need to be. As long as yarn is installed, the installation of zuul will run yarn build appropriately.

By default, zuul-web provides a Progressive Web Application but does not run a Service Worker. For deployers who would like to enable one, set the environment variable REACT_APP_ENABLE_SERVICE_WORKER=true during installation.