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Comment by mikepurvis | Hacker News Reader

Nonetheless, Bazel is very much set up for Google's mentality of building giant static binaries from head and shipping them off to a server somewhere, where they'll be replaced in two weeks with the next release, and then never thought of again. There's some software out here in the world that works like that, but most of it doesn't.

In any case, CMake is _also_ a dependency management system, but works with libraries in the way that they are shipped on a typical Linux distribution. It lets you find common stuff easily, and has multiple extension points in terms of adding support for new libraries. CMake itself can ship your find module, the library you're linking against can ship it, or you can ship it yourself.

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Trend wise, applications are expanding more and more into controlling its whole life-cycle from binary to deployment. Repeatable build Containers VM Unikernels Standardized libraries

There are other means to share build artifacts or code across language boundary, not necessarily through availability from OS distros. For example, Docker registry solves this issue with container images and overlay FS.

I think one way or another, Google's model has been proven to work for large-scale (probably the largest C++ code base on earth) c++ code base. In that I have my full confidence of adopting Google's proven approach.

disclaimer: Work at google, but not the c++ team

> Trend wise, applications are expanding more and more into controlling its whole life-cycle from binary to deployment. Repeatable build Containers VM Unikernels Standardized libraries

Maybe in the cloud, however that's only a portion of where you see C++ deployed. For embedded systems(where C & Rust are the only other options) I don't see it going this way anytime soon.

Repeatable builds are pretty universally desirable, why wouldn't you want it for embedded systems?

It seems pretty important for security, etc..

Note: Rust and cargo.lock files another example of things going in this direction.

Aren't embedded systems already there? What is a firmware blob if not a monolithic static build artifact? Bazel is perfect for this. I recently taught it how to build boot images for Xilinx FPGAs including a bitstream, first stage bootloader, kernel, and initial ramdisk, all hermetically built and bottled up into a boot.bin. I can reproduce my firmware from source control and get out the same bits. How neat is that?

Speaking of which, any possibility of open sourcing this? We are looking to get into FPGAs and would rather not reinvent a bicycle.

Yes.

It's a little complicated as I did it for a personal project, but I'm also pulling it into Google for my 20% project. It is by FAR easier/faster for me to release under Google's copyright, but there's a bit of "paperwork" I need to go through to get it staged and approved for the Google GitHub.

Since it seems there's interest I'll take a stab at that on Monday. It usually takes a week or two, but no promises. I don't anticipate any blocking issues, though, as the bazel bits don't expose anything about Google.

One caveat -- as released it won't quite be bitwise hermetic, as it depends on an external Xilinx toolchain, and Xilinx does non-hermetic things to their bits that are awkward to work around (you can, but my code to do that is a much less mature shell script full of dd and cat commands to rip apart bitstreams and glue them back together -- I've since found open source tooling for accomplishing the same task, but haven't adopted it yet).

Drop me an email (addr in profile) and I'll tell you when it's up.

> where C & Rust are the only other options

Java, Ada, Pascal, Basic also happen to be viable options, with compiler vendors still doing quite well.

> Trend wise, applications are expanding more and more into controlling its whole life-cycle from binary to deployment. Repeatable build Containers VM Unikernels Standardized libraries

Isn't this the reason behind the equifax breach? From what I understand (not a java dev) Apache struts is deployed along side the application, so the patch couldn't be applied until someone manually updated the dependencies and deployed a new version of the app.

If this was a "traditional" shared library on a distro then it would have been patched by the system administrators.

When you bundle dependencies via any method you are also bundling the exploits.

traditional shared libraries never have good enough interfaces to not break stuff. So tradtitionally, the shared library isn't updated anyway until the app is fixed and deployed for the new version of the shared lib.

Bundled dependencies are easy to handle from a security perspective.

Build stamping tells you what CLs are contained (or just go by monotonically incrementing number if it's bundled deps). Someone commits the CL that fixes the dependency. In any sane bundled system, this increments that number. You say that any binary in prod must be something past that CL (which can be verified using the build stamping). Done.

If it's running, it's fixed. Modify to have whatever grace period you want. The same works for shared dependencies, of course.

In practice, both shared dependencies and static dependencies have tradeoffs, but security is not one of them. Both can be and should be easy to make secure in the sense of "make sure it contains the fix".

Both may require app redeployment in practice, and expecting them not to is not a good strategy right now (for most programming languages)

> traditional shared libraries never have good enough interfaces to not break stuff. So tradtitionally, the shared library isn't updated anyway until the app is fixed and deployed for the new version of the shared lib.

I agree and disagree. Traditionally a lot of shared libraries are in the OS and quite good at not breaking things, you can run windows update or apt-get upgrade and apps shouldn't break. Breakages generally happen in higher level libraries, but that is a cultural issue more than a technical one. If more care is put into the interface and managing breaking changes then it is doable. But regardless of how libraries are being deployed "move fast and break things" is not an attitude I want from the developers of them.

Most language specific package managers I've used do a terrible job of telling developers which packages are obsolete and no longer supported or of what the ramifications for updating a package is. Most libraries in these repositories don't even support previous versions.

> Bundled dependencies are easy to handle from a security perspective.

But not from a user or corporate perspective. I shudder to think at how many old and unpatched libraries are currently in use in the corporate world where the have an attitude of "deploy, then don't touch until we request a feature". It's an uphill battle to even upgrade when there are no compatibility issues, if they need development time to update then they're likely to stick to an old version forever.

Users are unlikely to upgrade as well for various reasons, so if a shared library is bundled with an app it is unlikely to be patched.

However large and robust the deployment may be, it's still a narrow use case/environment compared. It may be very well outside the norm of C++ use cases, frankly. A lotta people make Windows apps still.

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