Re: [pve-devel] [PATCH container] setup: template_fixup: remove bogus LXC_NAME line from /etc/hosts

[Stoiko Ivanov <s.ivanov@proxmox.com>]

I just realized that this has been reported in our bugzilla:
https://bugzilla.proxmox.com/show_bug.cgi?id=4515

can gladly resent with the fitting prefix, (and will add it in case this
needs more work and a v2) - but if it gets applied as is adding 
a reference to the bug would be appreciated!


On Fri,  9 Jun 2023 19:36:27 +0200
Stoiko Ivanov <s.ivanov@proxmox.com> wrote:

> Templates not built directly by us, but redistributed from
> images.linuxcontainer.org contain the following line in /etc/hosts:
> `127.0.1.1       LXC_NAME`
> 
> While it is mostly cosmetic - LXC_NAME, contains an underscore and is
> not a valid DNS name.
> 
> Simply drop it for newly created containers in template_fixup.
> 
> We ship Debian, Devuan ourselves, without this line - so no need for
> modification there.
> 
> Currently the nixos container-template (see [0]) also does not seem to
> contain the line.
> 
> Noticed the issue with a fresh fedora container, where systemd-resolved
> logs a warning upon boot.
> 
> [0] https://nixos.wiki/wiki/Proxmox_Linux_Container
> 
> Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
> ---
>  src/PVE/LXC/Setup/Alpine.pm    |  2 ++
>  src/PVE/LXC/Setup/ArchLinux.pm |  2 ++
>  src/PVE/LXC/Setup/Base.pm      | 11 +++++++++++
>  src/PVE/LXC/Setup/CentOS.pm    |  2 ++
>  src/PVE/LXC/Setup/Fedora.pm    |  2 ++
>  src/PVE/LXC/Setup/Gentoo.pm    |  2 ++
>  src/PVE/LXC/Setup/SUSE.pm      |  2 ++
>  7 files changed, 23 insertions(+)
> 
> diff --git a/src/PVE/LXC/Setup/Alpine.pm b/src/PVE/LXC/Setup/Alpine.pm
> index 87d72be..8672f3c 100644
> --- a/src/PVE/LXC/Setup/Alpine.pm
> +++ b/src/PVE/LXC/Setup/Alpine.pm
> @@ -40,6 +40,8 @@ sub template_fixup {
>      $self->ct_symlink('/etc/init.d/savecache', '/etc/runlevels/shutdown/savecache');
>  
>      $self->setup_securetty($conf);
> +
> +    $self->remove_lxc_name_from_etc_hosts();
>  }
>  
>  sub setup_init {
> diff --git a/src/PVE/LXC/Setup/ArchLinux.pm b/src/PVE/LXC/Setup/ArchLinux.pm
> index 60118ef..e379ea1 100644
> --- a/src/PVE/LXC/Setup/ArchLinux.pm
> +++ b/src/PVE/LXC/Setup/ArchLinux.pm
> @@ -40,6 +40,8 @@ sub template_fixup {
>  
>      # edit /etc/securetty (enable login on console)
>      $self->setup_securetty($conf);
> +
> +    $self->remove_lxc_name_from_etc_hosts();
>  }
>  
>  sub setup_init {
> diff --git a/src/PVE/LXC/Setup/Base.pm b/src/PVE/LXC/Setup/Base.pm
> index 5534397..2d14599 100644
> --- a/src/PVE/LXC/Setup/Base.pm
> +++ b/src/PVE/LXC/Setup/Base.pm
> @@ -841,4 +841,15 @@ sub remove_pve_sections {
>      return $data =~ s/^\h*\Q$head\E.*^\h*\Q$tail\E.*?$//rgms;
>  }
>  
> +# templates from images.linuxcontainers.org have a bogus LXC_NAME line in /etc/hosts
> +sub remove_lxc_name_from_etc_hosts {
> +    my ($self) = @_;
> +    my $hosts = $self->ct_file_get_contents('/etc/hosts');
> +    my @lines = grep { !/^127.0.1.1\s+LXC_NAME$/ } split(/\n/, $hosts);
> +
> +    $hosts = join("\n", @lines). "\n";
> +
> +    $self->ct_file_set_contents('/etc/hosts', $hosts);
> +}
> +
>  1;
> diff --git a/src/PVE/LXC/Setup/CentOS.pm b/src/PVE/LXC/Setup/CentOS.pm
> index 1d31cee..e603d6c 100644
> --- a/src/PVE/LXC/Setup/CentOS.pm
> +++ b/src/PVE/LXC/Setup/CentOS.pm
> @@ -119,6 +119,8 @@ sub template_fixup {
>  
>      # always call so root can login, if /etc/securetty doesn't exists it's a no-op
>      $self->setup_securetty($conf);
> +
> +    $self->remove_lxc_name_from_etc_hosts();
>  }
>  
>  sub setup_init {
> diff --git a/src/PVE/LXC/Setup/Fedora.pm b/src/PVE/LXC/Setup/Fedora.pm
> index 17ae7da..6e54a9e 100644
> --- a/src/PVE/LXC/Setup/Fedora.pm
> +++ b/src/PVE/LXC/Setup/Fedora.pm
> @@ -24,6 +24,8 @@ sub template_fixup {
>      my ($self, $conf) = @_;
>      $self->setup_securetty($conf);
>      $self->ct_unlink('/etc/systemd/system/getty@.service');
> +
> +    $self->remove_lxc_name_from_etc_hosts();
>  }
>  
>  sub setup_init {
> diff --git a/src/PVE/LXC/Setup/Gentoo.pm b/src/PVE/LXC/Setup/Gentoo.pm
> index 6dc8e9f..501db54 100644
> --- a/src/PVE/LXC/Setup/Gentoo.pm
> +++ b/src/PVE/LXC/Setup/Gentoo.pm
> @@ -35,6 +35,8 @@ sub devttydir {
>  sub template_fixup {
>      my ($self, $conf) = @_;
>      $self->setup_securetty($conf);
> +
> +    $self->remove_lxc_name_from_etc_hosts();
>  }
>  
>  sub setup_init {
> diff --git a/src/PVE/LXC/Setup/SUSE.pm b/src/PVE/LXC/Setup/SUSE.pm
> index 7863b50..3c5fc68 100644
> --- a/src/PVE/LXC/Setup/SUSE.pm
> +++ b/src/PVE/LXC/Setup/SUSE.pm
> @@ -52,6 +52,8 @@ sub template_fixup {
>      # temporary fix for systemd-firstboot
>      $self->ct_file_set_contents('/etc/locale.conf', "LANG=C.utf8") if !$self->ct_file_exists('/etc/locale.conf');
>      $self->ct_symlink('/usr/share/zoneinfo/UTC', '/etc/localtime') if !$self->ct_file_exists('/etc/localtime');
> +
> +    $self->remove_lxc_name_from_etc_hosts();
>  }
>  
>  sub setup_init {