NixOS is special and deviates in many places from a "standard" Linux system. In this case, /bin/sh does not exist on the actual filesystem, at least not before the initial activation - which creates a symlink at /bin/sh.
Thus try a bit harder to detect the architecture for NixOS containers by inspecting the init script, which contains a shebang-line with the full path to the system shell. This moves the architecture detection code to the end of the container creation lifecycle, so that it can be implemented as a plugin subroutine. Therefore this mechanism is now generic enough that it can be adapted to other container OS's in the future if needed. AFAICS `arch` is only used when writing the actual LXC config, so determining it later during creation does not change anything. Tested by creating a NixOS and a Debian container (to verify that nothing regressed) and checking if the warning "Architecure detection failed: [..]" no longer appears for the NixOS CT and if `arch` in the CT config is correct. Also tested restoring both containers from a local and a PBS backup, as well as migrating both container. Signed-off-by: Christoph Heiss <[email protected]> --- src/PVE/LXC/Create.pm | 76 ------------------------------------- src/PVE/LXC/Setup.pm | 64 +++++++++++++++++++++++++++++++ src/PVE/LXC/Setup/Base.pm | 8 ++++ src/PVE/LXC/Setup/NixOS.pm | 17 +++++++++ src/PVE/LXC/Setup/Plugin.pm | 5 +++ 5 files changed, 94 insertions(+), 76 deletions(-) diff --git a/src/PVE/LXC/Create.pm b/src/PVE/LXC/Create.pm index b2e3d00..adf917c 100644 --- a/src/PVE/LXC/Create.pm +++ b/src/PVE/LXC/Create.pm @@ -16,72 +16,6 @@ use PVE::VZDump::ConvertOVZ; use PVE::Tools; use POSIX; -sub detect_architecture { - my ($rootdir) = @_; - - # see https://en.wikipedia.org/wiki/Executable_and_Linkable_Format - - my $supported_elf_machine = { - 0x03 => 'i386', - 0x3e => 'amd64', - 0x28 => 'armhf', - 0xb7 => 'arm64', - 0xf3 => 'riscv', - }; - - my $elf_fn = '/bin/sh'; # '/bin/sh' is POSIX mandatory - my $detect_arch = sub { - # chroot avoids a problem where we check the binary of the host system - # if $elf_fn is an absolut symlink (e.g. $rootdir/bin/sh -> /bin/bash) - chroot($rootdir) or die "chroot '$rootdir' failed: $!\n"; - chdir('/') or die "failed to change to root directory\n"; - - open(my $fh, "<", $elf_fn) or die "open '$elf_fn' failed: $!\n"; - binmode($fh); - - my $length = read($fh, my $data, 20) or die "read failed: $!\n"; - - # 4 bytes ELF magic number and 1 byte ELF class, padding, machine - my ($magic, $class, undef, $machine) = unpack("A4CA12n", $data); - - die "'$elf_fn' does not resolve to an ELF!\n" - if (!defined($class) || !defined($magic) || $magic ne "\177ELF"); - - my $arch = $supported_elf_machine->{$machine}; - die "'$elf_fn' has unknown ELF machine '$machine'!\n" - if !defined($arch); - - if ($arch eq 'riscv') { - if ($class eq 1) { - $arch = 'riscv32'; - } elsif ($class eq 2) { - $arch = 'riscv64'; - } else { - die "'$elf_fn' has invalid class '$class'!\n"; - } - } - - return $arch; - }; - - my $arch = eval { PVE::Tools::run_fork_with_timeout(10, $detect_arch); }; - my $err = $@; - - if (!defined($arch) && !defined($err)) { - # on timeout - die "Architecture detection failed: timeout\n"; - } elsif ($err) { - # any other error - $arch = 'amd64'; - print "Architecture detection failed: $err\nFalling back to $arch.\n" . - "Use `pct set VMID --arch ARCH` to change.\n"; - } else { - print "Detected container architecture: $arch\n"; - } - - return $arch; -} - sub restore_archive { my ($storage_cfg, $archive, $rootdir, $conf, $no_unpack_error, $bwlimit) = @_; @@ -118,11 +52,6 @@ sub restore_proxmox_backup_archive { PVE::Storage::PBSPlugin::run_raw_client_cmd( $scfg, $storeid, $cmd, $param, userns_cmd => $userns_cmd); - - # if arch is set, we do not try to autodetect it - return if defined($conf->{arch}); - - $conf->{arch} = detect_architecture($rootdir); } sub restore_tar_archive { @@ -183,11 +112,6 @@ sub restore_tar_archive { my $err = $@; close($archive_fh) if defined $archive_fh; die $err if $err && !$no_unpack_error; - - # if arch is set, we do not try to autodetect it - return if defined($conf->{arch}); - - $conf->{arch} = detect_architecture($rootdir); } sub recover_config { diff --git a/src/PVE/LXC/Setup.pm b/src/PVE/LXC/Setup.pm index 891231f..4346c5e 100644 --- a/src/PVE/LXC/Setup.pm +++ b/src/PVE/LXC/Setup.pm @@ -131,6 +131,20 @@ sub new { $plugin->{rootgid} = $rootgid; } + # if arch is unset, we try to autodetect it + if (!defined($conf->{arch})) { + my $arch = eval { $self->protected_call(sub { $plugin->detect_architecture() }) }; + + if (!defined($arch)) { + $arch = 'amd64'; + print "Falling back to $arch.\nUse `pct set VMID --arch ARCH` to change.\n"; + } else { + print "Detected container architecture: $arch\n"; + } + + $conf->{arch} = $arch; + } + return $self; } @@ -346,4 +360,54 @@ sub get_ct_init_path { return $init; } +sub detect_architecture { + my ($elf_fn) = @_; + + # see https://en.wikipedia.org/wiki/Executable_and_Linkable_Format + + my $supported_elf_machine = { + 0x03 => 'i386', + 0x3e => 'amd64', + 0x28 => 'armhf', + 0xb7 => 'arm64', + 0xf3 => 'riscv', + }; + + my $detect_arch = sub { + open(my $fh, "<", $elf_fn) or die "open '$elf_fn' failed: $!\n"; + binmode($fh); + + my $length = read($fh, my $data, 20) or die "read failed: $!\n"; + + # 4 bytes ELF magic number and 1 byte ELF class, padding, machine + my ($magic, $class, undef, $machine) = unpack("A4CA12n", $data); + + die "'$elf_fn' does not resolve to an ELF!\n" + if (!defined($class) || !defined($magic) || $magic ne "\177ELF"); + + my $arch = $supported_elf_machine->{$machine}; + die "'$elf_fn' has unknown ELF machine '$machine'!\n" + if !defined($arch); + + if ($arch eq 'riscv') { + if ($class eq 1) { + $arch = 'riscv32'; + } elsif ($class eq 2) { + $arch = 'riscv64'; + } else { + die "'$elf_fn' has invalid class '$class'!\n"; + } + } + + return $arch; + }; + + my $arch = eval { PVE::Tools::run_fork_with_timeout(10, $detect_arch); }; + my $err = $@ // "timeout\n"; + + die "Architecture detection failed: $err" if !defined($arch); + + return $arch; +} + 1; diff --git a/src/PVE/LXC/Setup/Base.pm b/src/PVE/LXC/Setup/Base.pm index 547abdb..93c1d34 100644 --- a/src/PVE/LXC/Setup/Base.pm +++ b/src/PVE/LXC/Setup/Base.pm @@ -18,6 +18,7 @@ use PVE::INotify; use PVE::Tools; use PVE::Network; +use PVE::LXC::Setup; use PVE::LXC::Setup::Plugin; use base qw(PVE::LXC::Setup::Plugin); @@ -574,6 +575,13 @@ sub ssh_host_key_types_to_generate { }; } +sub detect_architecture { + my ($self) = @_; + + # '/bin/sh' is POSIX mandatory + return PVE::LXC::Setup::detect_architecture('/bin/sh'); +} + sub pre_start_hook { my ($self, $conf) = @_; diff --git a/src/PVE/LXC/Setup/NixOS.pm b/src/PVE/LXC/Setup/NixOS.pm index 845d2d5..4f7b93e 100644 --- a/src/PVE/LXC/Setup/NixOS.pm +++ b/src/PVE/LXC/Setup/NixOS.pm @@ -5,6 +5,7 @@ use warnings; use File::Path 'make_path'; +use PVE::LXC::Setup; use PVE::LXC::Setup::Base; use base qw(PVE::LXC::Setup::Base); @@ -37,4 +38,20 @@ sub setup_init { my ($self, $conf) = @_; } +sub detect_architecture { + my ($self) = @_; + + # /bin/sh only exists as a symlink after the initial system activaction on first boot. + # To detect the actual architecture of the system, examine the shebang line of the /sbin/init + # script, which has the full path to the system shell. + my $init_path = '/sbin/init'; + open(my $fh, '<', $init_path) or die "open '$init_path' failed: $!\n"; + + if (<$fh> =~ /^#! ?(\S*)/) { + return PVE::LXC::Setup::detect_architecture($1); + } + + die "Architecture detection failed: could not find a shell\n"; +} + 1; diff --git a/src/PVE/LXC/Setup/Plugin.pm b/src/PVE/LXC/Setup/Plugin.pm index 3d968e7..b9d9c2d 100644 --- a/src/PVE/LXC/Setup/Plugin.pm +++ b/src/PVE/LXC/Setup/Plugin.pm @@ -62,6 +62,11 @@ sub ssh_host_key_types_to_generate { croak "implement me in sub-class\n"; } +sub detect_architecture { + my ($self) = @_; + croak "implement me in sub-class\n"; +} + # hooks sub pre_start_hook { -- 2.39.2 _______________________________________________ pve-devel mailing list [email protected] https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
