rootless: slirp4netns doesn't start since v1.17.4+k3s1
AkihiroSuda opened this issue · comments
Version:
k3s-v1.17.4+k3s1 version v1.17.4+k3s1 (3eee8ac)
Reproducible on master ( 690a4ca ) as well.
K3s arguments:
--rootless
Describe the bug
slirp4netns doesn't start since v1.17.4+k3s1
Originally reported by @ShylajaDevadiga in #1487 (comment)
To Reproduce
$ k3s server --rootlessExpected behavior
The server should start up
Actual behavior
FATA[2020-04-29T15:00:45.809243936+09:00] failed to setup network &{binary:slirp4netns mtu:65520 ipnet:0xc00102b140 disableHostLoopback:true apiSocketPath: enableSandbox:false enableSeccomp:false}: waiting for ready fd (/home/suda/.rancher/k3s/data/6a3098e6644f5f0dbfe14e5efa99bb8fdf60d63cae89fdffd71b7de11a1f1430/bin/slirp4netns --mtu 65520 -r 3 --disable-host-loopback --cidr 10.41.0.0/16 53578 tap0): slirp4netns failed
FATA[2020-04-29T15:00:45.815057884+09:00] child diedparsing message from fd 3: EOF Additional context / logs
Ubuntu 20.04, slirp4netns v1.0.1.
v1.17.3+k3s1 and v1.17.2+k3s1 don't hit this issue, but fail with another error (F0429 14:59:58.559339 53465 kubelet.go:1380] Failed to start ContainerManager [open /proc/sys/vm/overcommit_memory: permission denied, open /proc/sys/kernel/panic: permission denied, open /proc/sys/kernel/panic_on_oops: permission denied])
v1.17.0+k3s1 and v1.16.7+k3s1 work as expected.
Interesting, ./bin/k3s server --rootless almost works (it fails with CNI binary path issue, but that's unrelated topic here), while ./dist/artifacts/k3s server --rootless does not.
@ibuildthecloud PTAL?
I found that slirp4netns is failing with "the option -r FD requires -c" error.
The error should not happen for slirp4netns >= v0.4.0: rootless-containers/slirp4netns@9115b34#diff-2045016cb90d1e65d71c2407a2570927L474
However, ./dist/artifacts/k3s seems bundled with very old and unstable version of slirp4netns (v0.3.0-alpha.2+dev).
Updating the bundled slirp4netns binary should fix the issue.
@ibuildthecloud @erikwilson Let me know how I can help updating the binary.
There are a couple PRs open against k3s-root to update slirp4netns; I'm not sure why they haven't been merged yet.
There are some issues building slirp4netns with buildroot due to some new package dependencies, so the PRs are insufficient in their current form. I would definitely like to fix this but it is a matter of getting a new build pipeline figured out.
A quick workaround is to just drop slirp4netns from the embedded archive, and require it as an external binary.
Needed for #1487
k3s-io/k3s-root#24 should solve the issue
@AkihiroSuda this should be fixed in master.
Thanks!