Agent doesn't build on docker container leading to possible glibc mismatch

[daniel-brenot]

When compiling firecracker and the other binaries, the agent is built on the host os. This is an issue as the GLIBC version on the host may not match the version in bullseye, the image used as the base for the vm image. Because of this, when I run the daemon on my machine pointing to the vm image i built on my machine, i get an error that the version of GLIBC is not new enough for the agent, causing the image to not boot.

I was able to make the issue go away by updating the debian version used in debootstrap, however this is temporary and will stop working when the GLIBC version on bullseye stops matching the version on my ubuntu version.

I think the best path forward is to use a debian container to build the agent. It should be the same base image as is used for the debootstrap so that the glibc version always matches between them.

I may make a pr for this.

[daniel-brenot]

So I did a bit more digging and it seems like the agent is supposably built in a docker container with the same version of glibc as the agent. I'm not sure what leads to this issue on my end, but what I do know is that replacing the "bullseye" with "bookworm" in the makefile for the image builder does seem to fix it.

I'm not sure the cause of this issue or what the correct path forward is. I'm on ubuntu LTS, which at the time of writing is version 24.04

[Kern--]

It's probably better to build with STATIC_AGENT=1 make so that the agent doesn't depend on glibc.

[daniel-brenot]

Good call, i'll swap out my replacement code with that. I would suggest adding that to the getting started as a way of resolving this issue as I think it's a bit of a gocha for newcommers

[pendo324]

Good call, i'll swap out my replacement code with that. I would suggest adding that to the getting started as a way of resolving this issue as I think it's a bit of a gocha for newcommers

Can you raise a PR to make the documentation clearer in this regard? I'd be happy to review/merge it