3 ms·

Is your Rust init private? What does it do?

tptacek 6y ago
Mostly just init stuff. We're transforming Docker containers (mostly) into standalone VMs, so it's doing all the scut work of taking a completely stripped-bare booted kernel and getting it to a state where you can run an arbitrary Linux program on it. I wouldn't want to take the thread off on a huge tangent, it's just funny that this was just recently super relevant to me (it would have been problematic if DNS-dependent Go programs depended on libc, because right now I can't assume there's a libc binary to be dynamically linked to). Bringing it back to Go and its (sometimes libc-dependent) DNS libraries: it is very annoying how fiddly it is to get a Go program to use an alternative DNS server.
- JoshTriplett 6y ago
  I'm currently in the process, right now, of writing a minimal init in Rust to do exactly the same thing. Is yours something you'd consider sharing? The sum total of what I want to do: bring up loopback, bring up the one and only Ethernet interface, set up its IP and basic routing, run another program, and do some basic log reporting.
  - tptacek 6y ago
    I hack on our init, but I didn't write it. So it's not my place to share it. And there's some us-specific stuff in it that wouldn't be super helpful to you. But you could definitely ask Jerome on our team; he's a super helpful guy, even if he's super quiet here (he's like the anti-me). One way or the other I'm sure we can help you get where you're going!
    - JoshTriplett 6y ago
      I reached out to Jerome. Thanks!
      - tptacek 6y ago
        Feel free to follow up with Kurt, me or Michael if you don't get a quick response; Jerome is in Montreal and he may be buried under a mountain of snow and brown gravy.
- alaties 6y ago
  Had a similar problem a couple years ago where I needed to use alternative DNS libraries to troubleshoot issues in a company's infrastructure. Golang's rules for what implementation to use are found here: https://golang.org/pkg/net/#hdr-Name_Resolution https://golang.org/pkg/net/#hdr-Name_Resolution A really solid alternative DNS client implementation can be found here: https://github.com/miekg/dns https://github.com/miekg/dns. Real easy to read and vet compared to a few other libraries I ran into when working on this problem.
- vidarh 6y ago
  If you can can control which DNS servers it talks to, implementing the DNS spec directly is a pretty trivial exercise to get full control. (If you can't, the main complexity is dealing with implementation quirks)

Mostly just init stuff. We're transforming Docker containers (mostly) into standalone VMs, so it's doing all the scut work of taking a completely stripped-bare booted kernel and getting it to a state where you can run an arbitrary Linux program on it. I wouldn't want to take the thread off on a huge tangent, it's just funny that this was just recently super relevant to me (it would have been problematic if DNS-dependent Go programs depended on libc, because right now I can't assume there's a libc binary to be dynamically linked to). Bringing it back to Go and its (sometimes libc-dependent) DNS libraries: it is very annoying how fiddly it is to get a Go program to use an alternative DNS server.

JoshTriplett 6y ago
I'm currently in the process, right now, of writing a minimal init in Rust to do exactly the same thing. Is yours something you'd consider sharing? The sum total of what I want to do: bring up loopback, bring up the one and only Ethernet interface, set up its IP and basic routing, run another program, and do some basic log reporting.
- tptacek 6y ago
  I hack on our init, but I didn't write it. So it's not my place to share it. And there's some us-specific stuff in it that wouldn't be super helpful to you. But you could definitely ask Jerome on our team; he's a super helpful guy, even if he's super quiet here (he's like the anti-me). One way or the other I'm sure we can help you get where you're going!
  - JoshTriplett 6y ago
    I reached out to Jerome. Thanks!
    - tptacek 6y ago
      Feel free to follow up with Kurt, me or Michael if you don't get a quick response; Jerome is in Montreal and he may be buried under a mountain of snow and brown gravy.
alaties 6y ago
Had a similar problem a couple years ago where I needed to use alternative DNS libraries to troubleshoot issues in a company's infrastructure. Golang's rules for what implementation to use are found here: https://golang.org/pkg/net/#hdr-Name_Resolution https://golang.org/pkg/net/#hdr-Name_Resolution A really solid alternative DNS client implementation can be found here: https://github.com/miekg/dns https://github.com/miekg/dns. Real easy to read and vet compared to a few other libraries I ran into when working on this problem.
vidarh 6y ago
If you can can control which DNS servers it talks to, implementing the DNS spec directly is a pretty trivial exercise to get full control. (If you can't, the main complexity is dealing with implementation quirks)