JavaScript RoadMap for OpenStack Newton

This post contains the current working draft of the OpenStack JavaScript roadmap. It’s a big list, and we need help to land it during the Newton cycle. Overall themes for this cycle are Consistency, Interoperability, and engaging with the JavaScript community at large, all topics which I’ve written about at length. Our end goal is to build the foundations of a JavaScript ecosystem, which permits the creation of entirely custom interfaces.

Note: We are not trying to replace Horizon, we are aiming to help those downstream who need something more than “Vanilla OpenStack”, and thus maintain their own code. The vast majority of modern UI and UX development happens in JavaScript, and there are many use cases that have not yet been met.

OpenStack Projects

These projects are part of the big tent, and will see significant development during the Newton Cycle.

ironic-webclient

The ironic-webclient will release its first version during the Newton cycle. We’re awfully close to having the basic set of features supported, and with some excellent feedback from the OpenStack UX team, will also have a sexy new user interface that’s currently in the review queue. Once this work is complete, we will begin extracting common components into a new project, named…

js-openstacklib

This new project will be incubated as a single, gate-tested JavaScript API client library for the OpenStack API’s. Its audience is software engineers who wish to build their own user interface using modern javascript tools. As we cannot predict downstream use cases, special care will be taken to ensure the project’s release artifacts can eventually support both browser and server based applications.

Philosophically, we will be taking a page from the python-openstackclient book, and avoid creating a new project for each of OpenStack’s services. We can make sure our release artifacts can be used piecemeal, however trying to maintain code consistency across multiple different projects is a hard lesson that others have already learned for us. Let’s not do that again.

Infrastructure Projects

These projects belong to OpenStack’s Infrastructure and/or QA team. They’re used to support the building of JavaScript projects in OpenStack.

js-generator-openstack

Yeoman is JavaScript’s equivalent of cookiecutter, providing a scaffolding engine which can rapidly set up, and maintain, new projects. Creating and maintaining a yeoman generator will be a critical part of engaging with the JavaScript community, and can drive adoption and consistency across OpenStack as well. Furthermore, it is sophisticated enough that it could also support many things that exist in today’s Python toolchain, such as dependency management, and common tooling maintenance.

Development of the yeoman generator will draw in lessons learned from OpenStack’s current UI Projects, including Fuel, StoryBoard, Ironic, Horizon, Refstack, and Health Dashboard, and attempt to converge on common practices across projects.

js-npm-publish-xstatic

This project aims to bridge the gap between our JavaScript projects, and Horizon’s measured migration to AngularJS. We don’t believe in duplicating work, so if it is feasible to publish our libraries in a way that Horizon may consume (via the existing xstatic toolchain), then we certainly should pursue that. The notable difference is that our own projects, such as js-openstacklib, don’t have to go through the repackaging step that our current xstatic packages do; thus, if it is possible for us to publish to npm and to xstatic/pypi at the same time, that would be best.

Xenial Build Nodes

As of two weeks ago, OpenStack’s Infrastructure is running a version of Node.js and npm more recent than what is available on Trusty LTS. Ultimately, we would like to converge this version on Node4 LTS, the release version maintained by the Node foundation. The easiest way to do this is to simply piggyback on Infra’s impending adoption of Xenial build nodes, though some work is required to ensure this transition goes smoothly.

Maintained Projects

The following projects are active and considered ‘complete’, though they will require continuous maintenance throughout the Newton cycle. I’ve included all the needed work that I am aware of, however if there’s something I’ve missed, please feel free to comment.

eslint-config-openstack

eslint has updated to version 2.x, and no more rule bugfixes are being landed in 1.x. eslint-config-openstack will follow in kind, updating itself to use eslint 2.x. We will releases this version as eslint-config-openstack v2.0.0, and continue to track the eslint version numbers from there. Downstream projects are encouraged to adopt this, as it is unlikely that automated dependency updates for JavaScript projects will land this cycle.

NPM Mirrors

We are currently synchronizing all npm packages to our AFS master disks, which should be the final step in getting functional npm mirrors. Some minor tweaking will be required to make them functional, and they will need to be maintained throughout the next cycle. Issues raised in the #openstack-infra channel will be promptly addressed.

This includes work on both the js-openstack-registry-hooks project and the js-afs-blob-store project, which are two custom components we use to drive our mirrors.

oslo_middleware.cors

CORS landed in mitaka, and we will continue to maintain it going forward. In the Newton cycle, we have the following new features planned:

  • Automatic allowed_origin detection from Keystone (zero-config).
  • More consistent use of set_defaults.
  • Configuration maintenance as projects deprecate X-* headers in accordance with RFC 6648.

Stretch Projects

These are projects which we know need to be done, however we simply do not have enough contributors.

Docs

Documentation is important. Usable documentation is even more important. The tricky bit is that OpenStack’s documentation is all python/sphinx based, and we have not yet investigated whether it’s possible to bridge the two languages. If you have time to explore this intersection, we’d be happy to hear your findings.


That concludes it for the Newton Cycle. As you can see, there’s a lot of work to do. Can you help?

JavaScript on the Trailing Edge

The public opinion of the JavaScript community is that it’s fast. We break things, we’re hungry for the latest features, and none of us want to return to the days of slow innovation that ended with the death of IE6. This really isn’t true; there are several core JavaScript projects, such as Angular, JQuery, and React, which have solid governance, and measured release cycles, that would mesh well with OpenStack. It just happens that those projects are surrounded by thousands of smaller ones, run by handfuls of engineers who are volunteering their time.

However, the JavaScript community offers many benefits, from layout frameworks to new user interface paradigms, and OpenStack could easily take advantage of all these. As I’ve pointed out, the user interface needs of a cloud platform vary by user, not by deployment, and it is high time that OpenStack catered to more than just the Operator mind set. There remain some obstacles to this, however they are easily solved:

Backwards Compatibility

The first challenge we face is backwards compatibility. We must balance the rapid adoption of new developments like ES6, with downstream LTS support commitments that can last several years. We must do all this, while also not losing ourselves in a morass of hacks, special cases, shortcuts, and workarounds. This requires common dependency management for all our JavaScript libraries, and we can easily draw on the lessons learned in OpenStack’s requirements project to lead the way.

Complacency

Furthermore, we face a social challenge, that of complacency. The counterargument I most frequently get is “Why not use Horizon”. As my previous post on composable cloud interfaces highlights, Horizon is too narrowly focused. While it does an admirable job at supporting the Operator use case, and provides many ways to extend itself, a brief survey I performed last year revealed that two thirds of downstream Horizon users either maintain full forks of horizon’s source, or are building entirely custom user interfaces. To me, this is stark evidence that horizon falls short of meeting the use cases of all of our OpenStack operators.

Funding

Lastly, we face the rather pedestrian challenge of funding. While I’ve come across broad support for a greater role of JavaScript in OpenStack’s UI development – to the level of squeefun bouncing in a hallway when I mentioned ES6 – it remains a fact of life that those corporate members with the most to gain by the strategic evolution of OpenStack are usually content to let ‘someone else’ do the work, while dedicating their own employees towards more immediate revenue sources.

 

It’s a Catch-22 situation: We cannot prove the viability of JavaScript thick-client UI’s without a functional alternative to horizon, but we cannot get to that alternative without engineers willing – and able – to contribute. Personally, I feel very privileged to be one of a very small number of fully dedicated upstream engineers. To the best of my knowledge, Elizabeth Elwell and I are the only two entirely dedicated towards strategically advancing User Interface development in OpenStack. We are making good progress, however we do not anticipate adoption in the next cycle.

With help, Newton will contain the last pieces we need.

Securely publishing to NPM, the OpenStack way

The following article has been making the rounds, claiming a new worm exploit against npm. First of all, this is not a new exploit, nor is it in any way unique to npm – pip, gem, rpm, and deb have the same issue. Many may not even consider this an exploit at all – it’s a known feature, provided by package repositories, that permit compiling platform-specific bytecode. This is useful if, for instance, your package depends on a c-level library.

The exploit works something like this:

  1. If you are easily authenticated against a package repository, and…
  2. …you install a package which compiles and runs someone else’s code, then…
  3. …an attacker can execute malicious code which can publish itself to your packages…
  4. …which will then subsequently infect anyone who fuzzily matches against your packages’ versions.

This is not news. Mitigation approaches exist. Here’s how we do it in OpenStack:

Step 1: Do not use privileged build environments

Every test, package, or other build command runs on a throwaway jenkins slave that only exists for that test, after which it is deleted. While during test setup the jenkins user begins with passwordless sudo, that privileged is almost always revoked before the tests are run. In short, even if malicious code is downloaded during npm install, it is never executed in an environment that permits a privilege escalation attack.

This approach doesn’t have to be restricted to our Cloud VM’s either. You can do this with docker images, vagrant boxes, you name it.

Step 2: Build an intermediary tarball with `npm pack`

`npm pack` builds a release tarball from a given package, in our case the current project at its release version tag. We do this on the above-mentioned throwaway slave, so that any scripts executed during the construction process cannot access any credentials. After construction, this tarball is uploaded to tarballs.openstack.org, from which anyone can retrieve it.

Step 3: Publish without scripts

OpenStack’s infrastructure contains one jenkins slave that possesses credentials necessary to publish artifacts. Its sole purpose in life is to download a release tarball, and to push that tarball to a package repository. In npm’s case, we execute  `npm publish <tarball> --ignore-scripts`, to ensure that none of the packages’ lifecycle events are accidentally executed, further isolating us from unexpected attacks.

Other security measures

In addition to the above publishing flow, we also have several policies in place intended to ensure that our packages are trustworthy.

    • Only one user owns our npm packages. This prevents other owners from accidentally compromising the package.
    • Only verified, gpg-signed git tags using registered keys will trigger our publish jobs. To easily enable this, add git-sign-tag=true to your global or local .npmrc (Of course, you’ll need to be able to sign a tag).
    • We strongly prefer using strict version matching in our packages, which also has the benefit of making our builds deterministic. The fastest way for you to accomplish this yourself is to commit your shrinkwrap file to version control.
    • We don’t just publish our code via npm; If you’d prefer using a git dependency, or a tarball link, that option is open to you.

JavaScript Dependency Management in OpenStack

A problem that I’ve been working on the last week has been JS dependency management – driven by npm and bower – inside of OpenStack. To be honest, this problem can be extended to JS dependency management in any application that wants to be packaged within a Linux distribution, as that is the ultimate bar that needs to be met. In this case, however, we’re just going to focus on OpenStack. And, to narrow things down even more, we’re only going to focus on front-end, bower-driven dependencies, used during runtime of the front-end.

To be clear: We are not talking about which tools to use. We are talking about making a javascript/html project’s source code both trustworthy enough for packagers, while providing access to the npm-driven toolchain preferred in this community.

Note: I anticipate updating this post to make more recommendations as I build out Ironic’s Webclient. Stay tuned.

Bower: Commit your dependencies

TL/DR: The ultimate recommendation to the OpenStack community is to use project-appropriate tools to resolve dependencies, but to ultimately commit them to source. For python, you might use something like bower.py. For NPM/Javascript projects, I personally recommend main-bower-files as demonstrated in this gulp file.

Requirement: Builds must be deterministic

Packagers’ customers are banks. Governments. Large corporations. Entities which need to ensure that the software they’re running can be signed and verified, and there are significant dollar values rolled up in SLA’s to ensure this. There’s lots of policies in place for this, some of which seem so draconic as to be beyond unreasonable. If you’re curious, I recommend reading up on PCI compliance. It all makes sense, once you realize that it’s possible to guess a password from the return speed of an error response.

In the world of packaging, this means that builds must be deterministic: If you run the build different times, the output must be exactly the same. If you can’t do that, you can’t md5 or sha1 sum the results for verification, and suddenly the packager is on the hook for the next big security breach.

Fact: Bower is not deterministic

Bower’s pretty neat. It is a registry, rather than a repository, so it only provides the address of where you can get a library, rather than providing the package itself. In the vast majority of cases, this means that bower will point you at a git repository, from which the command line client then extracts the tags as versions. This is pretty awesome, because it means that you can make github host your repository for you.

Yet…. git lets you go back in time and rewrite history. While awesome, this means that bower itself does not provide a deterministic way of resolving a dependency, and therefore cannot be used by packagers. Yes, you can cache bower and the git/svn repositories that it links to. In fact, I wrote a bower-mirror puppet module that will build a server for you that does just that. That does not solve the problem of git being non-deterministic though. As long as a library’s primary source is a git tag, you can’t trust it.

Solution: Use bower anyway

Wait, what? No, I’m serious. Fact is that bower is the de-facto dependency registry for front-end development. We should use it, because it’s an awesome tool. We should also ensure that our builds are deterministic, which means that bower should not be run as part of a build, and should only be used to assist in resolving and committing dependencies.

There is precedent: The NPM documentation itself recommends that you commit all your dependencies, a fact that came out during the SSL Debacle of 2014. Yet even without this recommendation from the JavaScript community itself, there is precedent in OpenStack via the oslo-incubator libraries. Since they are libraries in incubation, they are directly copied and committed into a target project, rather than using pip.

How do you do this? Well, that’s up to you. If you’re a mostly-python project that wants to use the bower registry but is allergic to node, then I’d suggest something like bower.py. If instead you’re using the NPM toolchain, something like the ‘update_dependencies’ target in this gulpfile should work for you.