Good day everyone on the dev list,
We are adding an analysis tool to our application that uses the host's rootfs as one of its inputs.
Any help with troubleshooting, or specific known issues, or requests for more data would be appreciated.
TIA
tparchambault
ps: Regarding security - selinux is in Permissive mode. I do not know if seccomp filters are getting in the way or not; This is an out-ot-the-box RHEL9.0 base workstation install. In the FC34 prototype, I did need to allow certain syscalls via --system-call-filter in order to get a daemon within the container to run correctly but afaik that should have no bearing on the instantiation of the container.
==== On a RHEL9.0 host bash session ====
[toma@localhost ~]$ systemctl --version
systemd 250 (250-6.el9_0)
+PAM +AUDIT +SELINUX -APPARMOR +IMA +SMACK +SECCOMP +GCRYPT +GNUTLS +OPENSSL +ACL +BLKID +CURL +ELFUTILS -FIDO2 +IDN2 -IDN -IPTC +KMOD +LIBCRYPTSETUP +LIBFDISK +PCRE2 -PWQUALITY +P11KIT -QRENCODE +BZIP2 +LZ4 +XZ +ZLIB +ZSTD -BPF_FRAMEWORK +XKBCOMMON +UTMP +SYSVINIT default-hierarchy=unified
[toma@localhost ~]$ uname -a
Linux localhost.localdomain 5.14.0-70.17.1.el9_0.x86_64 #1 SMP PREEMPT Tue Jun 14 11:32:10 EDT 2022 x86_64 x86_64 x86_64 GNU/Linux
[toma@localhost ~]$
[toma@localhost ~]$ sudo time systemd-nspawn -D / -xb
^C^C^C^C^CCommand terminated by signal 15
40.81user 298.75system 6:29.72elapsed 87%CPU (0avgtext+0avgdata 8524maxresident)k
205032inputs+0outputs (0major+3287minor)pagefaults 0swaps
[toma@localhost ~]$
==== In another bash session on the same host ====
[toma@localhost ~]$ sudo machinectl list
[sudo] password for toma:
No machines.
[toma@localhost ~]$ sudo pkill nspawn
[toma@localhost ~]$
== In the original host bash session, w/increased logging and strace capture ==
[toma@localhost ~]$ sudo SYSTEMD_LOG_LEVEL=debug strace -o Development/nspawn.strace.rhel90.out systemd-nspawn -D / -xb
[sudo] password for toma:
Setting RLIMIT_CPU to infinity.
Setting RLIMIT_FSIZE to infinity.
Setting RLIMIT_DATA to infinity.
Setting RLIMIT_STACK to 8388608:infinity.
Setting RLIMIT_CORE to 0:infinity.
Setting RLIMIT_RSS to infinity.
Setting RLIMIT_NPROC to 14657.
Setting RLIMIT_NOFILE to 1024:524288.
Setting RLIMIT_MEMLOCK to 65536.
Setting RLIMIT_AS to infinity.
Setting RLIMIT_LOCKS to infinity.
Setting RLIMIT_SIGPENDING to 14657.
Setting RLIMIT_MSGQUEUE to 819200.
Setting RLIMIT_NICE to 0.
Setting RLIMIT_RTPRIO to 0.
Setting RLIMIT_RTTIME to infinity.
Found cgroup2 on /sys/fs/cgroup/, full unified hierarchy
Terminated
[toma@localhost ~]$
As with the first run, killed via pkill from the other terminal session.
Fwiw, on Fedora 34, the log debug output shows the instantiation of the
container after the "Found csgroup2..." line, with the container working as
documented eventually presenting the login prompt, i.e.
...
Setting RLIMIT_RTTIME to infinity.
Found cgroup2 on /sys/fs/cgroup/, full unified hierarchy
Spawning container fedora-1aabc34e0a52a82b on /.#machine.6e49b8aa974c6f37.
Press ^] three times within 1s to kill container.
Outer child is initializing.
Mounting / (MS_REC|MS_SLAVE "")...
...
[ OK ] Finished Update UTMP about System Runlevel Changes.
Fedora 34 (Workstation Edition)
Kernel 5.11.12-300.fc34.x86_64 on an x86_64 (console)
fedora-1aabc34e0a52a82b login:
We are adding an analysis tool to our application that uses the host's rootfs as one of its inputs.
As a proof of concept, we used systemd-nspawn on Fedora 34 to create an isolated container environment using the host's rootfs as the container's rootfs and things worked correctly and as expected. The host's rootfs is analyzed with tmp and results files generated within the container without persistent modifications affecting the host's rootfs. Since RHEL is our ultimate target platform, I've been trying to duplicate our work over RHEL9.0 without success with the container not being instantiated.
I've tried to boil down the duplication code to the simplest example, which is also an example in the man page $ sudo systemd-nspawn -xbD/. As with my prototyping, the container does not seem to be instantiated.Any help with troubleshooting, or specific known issues, or requests for more data would be appreciated.
TIA
tparchambault
ps: Regarding security - selinux is in Permissive mode. I do not know if seccomp filters are getting in the way or not; This is an out-ot-the-box RHEL9.0 base workstation install. In the FC34 prototype, I did need to allow certain syscalls via --system-call-filter in order to get a daemon within the container to run correctly but afaik that should have no bearing on the instantiation of the container.
==== On a RHEL9.0 host bash session ====
[toma@localhost ~]$ systemctl --version
systemd 250 (250-6.el9_0)
+PAM +AUDIT +SELINUX -APPARMOR +IMA +SMACK +SECCOMP +GCRYPT +GNUTLS +OPENSSL +ACL +BLKID +CURL +ELFUTILS -FIDO2 +IDN2 -IDN -IPTC +KMOD +LIBCRYPTSETUP +LIBFDISK +PCRE2 -PWQUALITY +P11KIT -QRENCODE +BZIP2 +LZ4 +XZ +ZLIB +ZSTD -BPF_FRAMEWORK +XKBCOMMON +UTMP +SYSVINIT default-hierarchy=unified
[toma@localhost ~]$ uname -a
Linux localhost.localdomain 5.14.0-70.17.1.el9_0.x86_64 #1 SMP PREEMPT Tue Jun 14 11:32:10 EDT 2022 x86_64 x86_64 x86_64 GNU/Linux
[toma@localhost ~]$
[toma@localhost ~]$ sudo time systemd-nspawn -D / -xb
^C^C^C^C^CCommand terminated by signal 15
40.81user 298.75system 6:29.72elapsed 87%CPU (0avgtext+0avgdata 8524maxresident)k
205032inputs+0outputs (0major+3287minor)pagefaults 0swaps
[toma@localhost ~]$
==== In another bash session on the same host ====
[toma@localhost ~]$ sudo machinectl list
[sudo] password for toma:
No machines.
[toma@localhost ~]$ sudo pkill nspawn
[toma@localhost ~]$
== In the original host bash session, w/increased logging and strace capture ==
[toma@localhost ~]$ sudo SYSTEMD_LOG_LEVEL=debug strace -o Development/nspawn.strace.rhel90.out systemd-nspawn -D / -xb
[sudo] password for toma:
Setting RLIMIT_CPU to infinity.
Setting RLIMIT_FSIZE to infinity.
Setting RLIMIT_DATA to infinity.
Setting RLIMIT_STACK to 8388608:infinity.
Setting RLIMIT_CORE to 0:infinity.
Setting RLIMIT_RSS to infinity.
Setting RLIMIT_NPROC to 14657.
Setting RLIMIT_NOFILE to 1024:524288.
Setting RLIMIT_MEMLOCK to 65536.
Setting RLIMIT_AS to infinity.
Setting RLIMIT_LOCKS to infinity.
Setting RLIMIT_SIGPENDING to 14657.
Setting RLIMIT_MSGQUEUE to 819200.
Setting RLIMIT_NICE to 0.
Setting RLIMIT_RTPRIO to 0.
Setting RLIMIT_RTTIME to infinity.
Found cgroup2 on /sys/fs/cgroup/, full unified hierarchy
Terminated
[toma@localhost ~]$
As with the first run, killed via pkill from the other terminal session.
Fwiw, on Fedora 34, the log debug output shows the instantiation of the
container after the "Found csgroup2..." line, with the container working as
documented eventually presenting the login prompt, i.e.
...
Setting RLIMIT_RTTIME to infinity.
Found cgroup2 on /sys/fs/cgroup/, full unified hierarchy
Spawning container fedora-1aabc34e0a52a82b on /.#machine.6e49b8aa974c6f37.
Press ^] three times within 1s to kill container.
Outer child is initializing.
Mounting / (MS_REC|MS_SLAVE "")...
...
[ OK ] Finished Update UTMP about System Runlevel Changes.
Fedora 34 (Workstation Edition)
Kernel 5.11.12-300.fc34.x86_64 on an x86_64 (console)
fedora-1aabc34e0a52a82b login:
