From: Filip Schauer <f.schauer@proxmox.com>
To: pve-devel@lists.proxmox.com
Subject: [pve-devel] [PATCH container v2 09/11] manage DHCP for containers with custom entrypoint
Date: Wed, 11 Jun 2025 16:49:01 +0200 [thread overview]
Message-ID: <20250611144903.200940-10-f.schauer@proxmox.com> (raw)
In-Reply-To: <20250611144903.200940-1-f.schauer@proxmox.com>
Containers that do not use the default `/sbin/init` entrypoint may lack
in‑container network management. A previous commit already handles
static IP addresses. Now this commit also handles DHCP. This is done
using a `dhclient` process for each network interface.
Signed-off-by: Filip Schauer <f.schauer@proxmox.com>
---
src/PVE/LXC.pm | 74 ++++++++++++++++++++++++++++++++++++++++---
src/PVE/LXC/Config.pm | 6 +++-
2 files changed, 74 insertions(+), 6 deletions(-)
diff --git a/src/PVE/LXC.pm b/src/PVE/LXC.pm
index 0131ac3..e91b53a 100644
--- a/src/PVE/LXC.pm
+++ b/src/PVE/LXC.pm
@@ -1004,6 +1004,8 @@ sub vm_stop_cleanup {
PVE::Storage::deactivate_volumes($storage_cfg, $vollist);
};
warn $@ if $@; # avoid errors - just warn
+
+ kill_dhclients($vmid, '*') if (PVE::LXC::Config->get_entrypoint($conf) ne "/sbin/init");
}
sub net_tap_plug : prototype($$) {
@@ -1189,6 +1191,34 @@ sub get_interfaces {
return $res;
}
+sub manage_dhclient {
+ my ($action, $vmid, $ipversion, $eth, $rootdir) = @_;
+
+ File::Path::make_path("/var/lib/lxc/$vmid/hook") if $action eq 'start';
+ my $pidfile = "/var/lib/lxc/$vmid/hook/dhclient$ipversion-$eth.pid";
+ my $leasefile = "/var/lib/lxc/$vmid/hook/dhclient$ipversion-$eth.leases";
+ my $scriptfile = '/usr/share/lxc/hooks/dhclient-script';
+ PVE::Tools::run_command([
+ 'lxc-attach', '-n', $vmid, '-s', 'NETWORK|UTSNAME', '--',
+ 'aa-exec', '-p', 'unconfined',
+ '/sbin/dhclient', $action eq 'start' ? '-1' : '-r', "-$ipversion",
+ '-pf', $pidfile, '-lf', $leasefile, '-e', "ROOTFS=$rootdir", '-sf', $scriptfile, $eth
+ ]);
+}
+
+sub kill_dhclients {
+ my ($vmid, $eth) = @_;
+
+ foreach my $pidfile (glob("/var/lib/lxc/$vmid/hook/dhclient*-$eth.pid")) {
+ my $pid = eval { file_get_contents($pidfile) };
+ if (!$@) {
+ chomp $pid;
+ kill 9, $pid if ($pid =~ m/^\d+$/);
+ unlink($pidfile);
+ }
+ }
+}
+
sub update_ipconfig {
my ($vmid, $conf, $opt, $eth, $newnet, $rootdir) = @_;
@@ -1223,11 +1253,21 @@ sub update_ipconfig {
# step 1: add new IP, if this fails we cancel
my $is_real_ip = ($newip && $newip !~ /^(?:auto|dhcp|manual)$/);
- if ($change_ip && $is_real_ip) {
- eval { &$ipcmd($family_opt, 'addr', 'add', $newip, 'dev', $eth); };
- if (my $err = $@) {
- warn $err;
- return;
+ if ($change_ip) {
+ if (PVE::LXC::Config->get_entrypoint($conf) ne "/sbin/init") {
+ if ($newip && $newip eq 'dhcp') {
+ manage_dhclient('start', $vmid, $ipversion, $eth, $rootdir);
+ } elsif ($oldip && $oldip eq 'dhcp') {
+ manage_dhclient('stop', $vmid, $ipversion, $eth, $rootdir);
+ }
+ }
+
+ if ($is_real_ip) {
+ eval { &$ipcmd($family_opt, 'addr', 'add', $newip, 'dev', $eth); };
+ if (my $err = $@) {
+ warn $err;
+ return;
+ }
}
}
@@ -2707,6 +2747,30 @@ sub vm_start {
}
PVE::GuestHelpers::exec_hookscript($conf, $vmid, 'post-start');
+ my @dhcpv4_interfaces = ();
+ my @dhcpv6_interfaces = ();
+ foreach my $k (sort keys %$conf) {
+ next if $k !~ m/^net(\d+)$/;
+ my $d = PVE::LXC::Config->parse_lxc_network($conf->{$k});
+ push @dhcpv4_interfaces, $d->{name} if $d->{ip} && $d->{ip} eq 'dhcp';
+ push @dhcpv6_interfaces, $d->{name} if $d->{ip6} && $d->{ip6} eq 'dhcp';
+ }
+
+ my $pid = PVE::LXC::find_lxc_pid($vmid);
+ my $rootdir = "/proc/$pid/root";
+
+ if (PVE::LXC::Config->get_entrypoint($conf) ne "/sbin/init") {
+ foreach my $eth (@dhcpv4_interfaces) {
+ eval { manage_dhclient('start', $vmid, 4, $eth, $rootdir) };
+ PVE::RESTEnvironment::log_warn("DHCP failed - $@") if $@;
+ }
+
+ foreach my $eth (@dhcpv6_interfaces) {
+ eval { manage_dhclient('stop', $vmid, 6, $eth, $rootdir) };
+ PVE::RESTEnvironment::log_warn("DHCP failed - $@") if $@;
+ }
+ }
+
return;
}
diff --git a/src/PVE/LXC/Config.pm b/src/PVE/LXC/Config.pm
index d7d8b6a..854e711 100644
--- a/src/PVE/LXC/Config.pm
+++ b/src/PVE/LXC/Config.pm
@@ -1490,9 +1490,13 @@ sub vmconfig_hotplug_pending {
$cgroup->change_cpu_shares(undef);
} elsif ($opt =~ m/^net(\d)$/) {
my $netid = $1;
+ my $net = PVE::LXC::Config->parse_lxc_network($conf->{$opt});
+ if (PVE::LXC::Config->get_entrypoint($conf) ne "/sbin/init") {
+ PVE::LXC::kill_dhclients($vmid, $net->{name});
+ }
+
PVE::Network::veth_delete("veth${vmid}i$netid");
if ($have_sdn) {
- my $net = PVE::LXC::Config->parse_lxc_network($conf->{$opt});
print "delete ips from $opt\n";
eval { PVE::Network::SDN::Vnets::del_ips_from_mac($net->{bridge}, $net->{hwaddr}, $conf->{hostname}) };
warn $@ if $@;
--
2.39.5
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next prev parent reply other threads:[~2025-06-11 14:49 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-11 14:48 [pve-devel] [PATCH container/manager/proxmox{, -perl-rs}/storage v2 00/11] support OCI images as container templates Filip Schauer
2025-06-11 14:48 ` [pve-devel] [PATCH proxmox v2 01/11] add proxmox-oci crate Filip Schauer
2025-06-24 12:42 ` Wolfgang Bumiller
2025-06-25 8:13 ` Wolfgang Bumiller
2025-06-11 14:48 ` [pve-devel] [PATCH proxmox-perl-rs v2 02/11] add Perl mapping for OCI container image parser/extractor Filip Schauer
2025-06-24 12:51 ` Wolfgang Bumiller
2025-06-25 7:59 ` Filip Schauer
2025-06-25 8:10 ` Wolfgang Bumiller
2025-06-11 14:48 ` [pve-devel] [PATCH container v2 03/11] config: whitelist lxc.init.cwd Filip Schauer
2025-06-25 9:00 ` [pve-devel] applied: " Wolfgang Bumiller
2025-06-11 14:48 ` [pve-devel] [PATCH container v2 04/11] add support for OCI images as container templates Filip Schauer
2025-06-11 14:48 ` [pve-devel] [PATCH container v2 05/11] config: add entrypoint parameter Filip Schauer
2025-06-11 14:48 ` [pve-devel] [PATCH container v2 06/11] configure static IP in LXC config for custom entrypoint Filip Schauer
2025-06-25 8:26 ` Wolfgang Bumiller
2025-06-25 8:30 ` Wolfgang Bumiller
2025-06-25 8:52 ` Stefan Hanreich
2025-06-11 14:48 ` [pve-devel] [PATCH container v2 07/11] setup: debian: create /etc/network path if missing Filip Schauer
2025-06-11 14:49 ` [pve-devel] [PATCH container v2 08/11] setup: recursively mkdir /etc/systemd/{network, system-preset} Filip Schauer
2025-06-11 14:49 ` Filip Schauer [this message]
2025-06-25 8:50 ` [pve-devel] [PATCH container v2 09/11] manage DHCP for containers with custom entrypoint Wolfgang Bumiller
2025-06-11 14:49 ` [pve-devel] [PATCH storage v2 10/11] allow .tar container templates Filip Schauer
2025-06-24 13:11 ` Wolfgang Bumiller
2025-06-11 14:49 ` [pve-devel] [PATCH manager v2 11/11] ui: storage upload: accept *.tar files as vztmpl Filip Schauer
2025-06-17 8:01 ` [pve-devel] [PATCH container/manager/proxmox{, -perl-rs}/storage v2 00/11] support OCI images as container templates Christoph Heiss
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