Re: Help with pasta usage

Re: Help with pasta usage

[Stefano Brivio]

Hi Ayon,

On Sat, 10 May 2025 21:26:29 -0230
Ayon T <sanroz.mozan13@gmail.com> wrote:

> Hi,
> 
> I've been using pasta as a network driver for rootless docker and I've been
> running into a couple of issues for a while now. I hope this is where I can
> find some help troubleshooting.
> 
> The issue is that when I use pasta as the network driver as opposed to
> slirp4netns, I'm unable to access the internet through rootless docker or
> use ping (or traceroute) through its containers. So if I run "docker pull
> <image-name>" I get a timeout error:
> 
> > Using default tag: latest  
> Error response from daemon: Get "https://registry-1.docker.io/v2/": dial
> tcp: lookup registry-1.docker.io on 10.0.2.3:53: read udp 169.254.2.1:58905
> ->10.0.2.3:53: i/o timeout  
> 
> I'm running pasta version 0.0~git20250217.a1e48a0-1 on Ubuntu 24.04.2 LTS
> with docker v27.3.1 build ce12230.

I suspect you might be hitting this:

  https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/2077158

...which is fixed on Ubuntu 24.10 and later versions. As a workaround,
I guess you can create the AppArmor profile for pasta manually, from:

  https://passt.top/passt/tree/contrib/apparmor/usr.bin.pasta

or set /proc/sys/kernel/unprivileged_userns_apparmor_policy to 0, see
also:

  https://github.com/kubevirt/kubevirt/issues/12333

Let me know if you still hit the issue.

-- 
Stefano

Re: Help with pasta usage

[Stefano Brivio]

On Mon, 12 May 2025 12:18:17 -0230
Ayon T <sanroz.mozan13@gmail.com> wrote:

> Hi,
> 
> Thanks for responding back to me. I was trying these solutions, when I
> realised that my /etc/apparmor.d/ directory already contains usr.bin.pasta.
> I believe this is because I downloaded the latest package from the
> launchpad.

...wait, so it's not 0.0~git20250217.a1e48a0-1 anymore? What version of
passt are you using now?

And what version of rootlesskit are you running? Does it contain this
fix:

  https://github.com/rootless-containers/rootlesskit/pull/458

it's not directly related to your issue, but it changes the behaviour
significantly.

I don't remember how you would pass pasta options through moby /
rootlesskit, but ideally you should try running pasta with --debug and
--log-file. Another important bit of information would be if container
connectivity works with an existing container (on 'docker run', not
'docker pull'), and, if it doesn't, whether pasta is running (check
with 'ps ax') while the container is running.

-- 
Stefano

Re: Help with pasta usage

[Stefano Brivio]

Hi Ayon,

On Tue, 20 May 2025 12:09:46 -0230
Ayon T <sanroz.mozan13@gmail.com> wrote:

> Hi,
> 
> I'm sorry for the delayed response. No, I am still using
> 0.0~git20250217.a1e48a0-1. I just meant that I had not used apt for
> installing passt.

...where did you take that package from, though? If it's something like
alvistack (https://github.com/alvistack/passt-top-passt/), there might
be other patches or modified / missing AppArmor profiles, and I can't
really look into that as well (I already maintain official packages, at
least for Debian).

> I had an upgrade planned to Ubuntu 24.10 and after that upgrade, my
> connections to port 53 are being refused when I'm using pasta, leaving me
> unable to use a DNS resolver. I'm not sure why this is. It works fine with
> the default network driver.
> 
> This is not the issue I contacted you with and that's why I'm trying to
> figure out why this is happening myself (albeit with little luck).

I would suggest to start passing the --pcap option to pasta, say:

  podman run --net=pasta:--pcap,/tmp/port53.pcap ...

and then have a look at the resulting packet capture (with Wireshark /
tshark, for example).

As we keep fixing bugs, and we fixed quite a lot of things with UDP
flows since February, an updated package, or even a build from source,
(git clone git://passt.top && cd passt && make && sudo make install)
might be worth a try.

It takes a few seconds to build / install, and can be removed cleanly
with 'sudo make uninstall'.

-- 
Stefano