From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id 5E8DB6AF35 for ; Wed, 17 Feb 2021 16:01:47 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 5529D23D4F for ; Wed, 17 Feb 2021 16:01:47 +0100 (CET) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [212.186.127.180]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS id A0DD423D41 for ; Wed, 17 Feb 2021 16:01:46 +0100 (CET) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id 6DD70461DB for ; Wed, 17 Feb 2021 16:01:46 +0100 (CET) To: pve-devel@lists.proxmox.com References: <20210207141832.3283706-1-aderumier@odiso.com> From: Mira Limbeck Message-ID: <8c94a7d6-542b-8927-143d-7ad733748202@proxmox.com> Date: Wed, 17 Feb 2021 16:01:44 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <20210207141832.3283706-1-aderumier@odiso.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-SPAM-LEVEL: Spam detection results: 0 AWL 0.457 Adjusted score from AWL reputation of From: address KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment NICE_REPLY_A -0.001 Looks like a legit reply (A) RCVD_IN_DNSWL_MED -2.3 Sender listed at https://www.dnswl.org/, medium trust SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record URIBL_BLOCKED 0.001 ADMINISTRATOR NOTICE: The query to URIBL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block for more information. [qemuserver.pm, cloudinit.pm] Subject: Re: [pve-devel] [PATCH V2 qemu-server] fix #1739: cloudinit: add cisshdeletehostkeys option X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Feb 2021 15:01:47 -0000 Thank you for the patch. I tried to test this patch with both a CentOS 8 and Ubuntu 20.04 VM and it never worked right. I added another line for 'once|yes|on|true' where ssh_deletekeys is set to 'true' as that is missing in this patch. Then I tried it with CentOS 8 and cloud-init 19.4. In the beginning the keys were deleted and regenerated, but after a few tries no matter using either of 'once', 'yes', 'on' or 'true' did not change anything. Even with a new instance-id the keys were never deleted no regenerated. In Ubuntu 20.04 with cloud-init 20.4 it was the other way around, even rebooting without any changes to the cloud-init config (no instance-id change) and cisshdeletehostkeys set to 'no' the keys were regenerated every time. What did you use to test this patch (OS, cloud-init version, specific cloudimg)? Some additional comments inline On 2/7/21 3:18 PM, Alexandre Derumier wrote: > This define behaviour of ssh server keys generation on cloudinit > config change. > > different value: > > - once : only once at vmstart (default value) > - no|off|false : never generate ssh key > - yes|on|true: always generate ssh key > > When value is defined to 'once', the value is rewriten to 'no' > in vmconfig after vm start > > We need to change instance-id at each config change because > network configuration is only done once in pre-init local service, > and a lock is done on instance-id, and they are no way to change > that in cloudinit vm config. > > The ssh host keys are regenerated by ssh module, once by instance. > user could change that,and do only once, > but in this same ssh module, the user public keys are also deployed. > > Signed-off-by: Alexandre Derumier > --- > PVE/QemuServer.pm | 9 ++++++++- > PVE/QemuServer/Cloudinit.pm | 10 +++++++++- > 2 files changed, 17 insertions(+), 2 deletions(-) > > diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm > index f401baf..c899b35 100644 > --- a/PVE/QemuServer.pm > +++ b/PVE/QemuServer.pm > @@ -760,6 +760,13 @@ my $confdesc_cloudinit = { > format => 'urlencoded', > description => "cloud-init: Setup public SSH keys (one key per line, OpenSSH format).", > }, > + cisshdeletehostkeys => { > + optional => 1, > + type => 'string', > + enum => [qw(once yes no on off true false)], > + default_key => 1, > + description => "cloud-init: Regenerate host SSH keys on config change.", > + }, > }; As mentioned on the previous patch, I'm not sure if we want to add another cloud-init config to the global config namespace. We could reuse the option 'cicustom' for this. Perhaps @Thomas could chime in regarding this? > > # what about other qemu settings ? > @@ -4951,7 +4958,7 @@ sub vm_start_nolock { > $conf = PVE::QemuConfig->load_config($vmid); # update/reload > } > > - PVE::QemuServer::Cloudinit::generate_cloudinitconfig($conf, $vmid); > + PVE::QemuServer::Cloudinit::generate_cloudinitconfig($conf, $vmid, 1); > > my $defaults = load_defaults(); > > diff --git a/PVE/QemuServer/Cloudinit.pm b/PVE/QemuServer/Cloudinit.pm > index c464bf3..7b24f93 100644 > --- a/PVE/QemuServer/Cloudinit.pm > +++ b/PVE/QemuServer/Cloudinit.pm > @@ -135,6 +135,7 @@ sub cloudinit_userdata { > foreach my $k (@$keys) { > $content .= " - $k\n"; > } > + $content .= "ssh_deletekeys: false\n" if defined($conf->{cisshdeletehostkeys}) && $conf->{cisshdeletehostkeys} =~ m/^(off|no|false)/; This is missing the case for 'once', 'on', 'true' and 'yes' where ssh_deletekeys is set to 'true'. And there's an additional whitespace at the end of the line. > > } > $content .= "chpasswd:\n"; > $content .= " expire: False\n"; > @@ -554,9 +555,10 @@ my $cloudinit_methods = { > }; > > sub generate_cloudinitconfig { > - my ($conf, $vmid) = @_; > + my ($conf, $vmid, $vmstart) = @_; > > my $format = get_cloudinit_format($conf); > + my $generated = undef; > > PVE::QemuConfig->foreach_volume($conf, sub { > my ($ds, $drive) = @_; > @@ -569,7 +571,13 @@ sub generate_cloudinitconfig { > or die "missing cloudinit methods for format '$format'\n"; > > $generator->($conf, $vmid, $drive, $volname, $storeid); > + $generated = 1; > }); > + > + if ($vmstart && $generated && (!defined($conf->{cisshdeletehostkeys}) || $conf->{cisshdeletehostkeys} eq 'once')) { > + $conf->{cisshdeletehostkeys} = 'no'; > + PVE::QemuConfig->write_config($vmid, $conf); > + } This always sets 'cisshdeletehostkeys' to 'no' if it is not set at all in the config which changes the default. I'd rather not do that for all, but only if it is set explicitly to 'once'. So that would then be: if ($vmstart && $generated && defined($conf->{cisshdeletehostkeys}) && $conf->{cisshdeletehostkeys} eq 'once') > } > > sub dump_cloudinit_config {