Re: [pve-devel] [PATCH cluster v10 4/5] datacenter.cfg: add tag rights control to the datacenter config

["Fabian Grünbichler" <f.gruenbichler@proxmox.com>]

On November 15, 2022 2:02 pm, Dominik Csapak wrote:
> by adding a 'user-tag-privileges' and 'admin-tags' option.
> The first sets the policy by which "normal" users (with
> 'VM.Config.Options' on the respective guest) can create/delete tags
> and the second is a list of tags only settable by 'admins'
> ('Sys.Modify' on '/')
> 
> also add a helper 'get_allowed_tags' that returns the allowed (existing)
> tags, the privileged tags, and if a user can enter 'freeform' tags.
> 
> Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
> ---
> changes from v9:
> * get_allowed_tags now takes a bool + closure for checking the tag
>   access, prevents cyclic dependency between cluster and access-control
> * use 'for' instead of 'map'
> * fix indentation
>  data/PVE/DataCenterConfig.pm | 105 +++++++++++++++++++++++++++++++++++
>  1 file changed, 105 insertions(+)
> 
> diff --git a/data/PVE/DataCenterConfig.pm b/data/PVE/DataCenterConfig.pm
> index 532e5e5..f7f90e9 100644
> --- a/data/PVE/DataCenterConfig.pm
> +++ b/data/PVE/DataCenterConfig.pm
> @@ -154,6 +154,32 @@ my $tag_style_format = {
>      },
>  };
>  
> +my $user_tag_privs_format = {
> +    'user-allow' => {
> +	optional => 1,
> +	type => 'string',
> +	enum => ['none', 'list', 'existing', 'free'],
> +	default => 'free',
> +	description => "Controls tag usage for users without `Sys.Modify` on `/` bey either "

by

> +	    ."allowing `none`, a `list`, already `existing` or anything (`free`).",
> +	verbose_description => "Controls which tags can be set or deleted on resources an user "

"a" user

> +	    ."controls (such as guests). Users iwth the `Sys.Modify` privilege on `/` are always "

with

> +	    ." unrestricted. "
> +	    ."'none' means no tags are modifiable. "
> +	    ."'list' allows tags from the given list. "
> +	    ."'existing' means only already existing tags of resources able to access or from the"
> +	    ."given list. "

this is hard to parse, maybe reword?

> +	    ."'free' means users can assign any tags."

this one is worded differently than the rest (maybe):

'none' no tags are modifiable.
'list' tags from 'user-allow-list' are modifiable.
'existing' like list, but already existing tags of resource are also modifiable.
'free' no tag restrictions.

> +    },
> +    'user-allow-list' => {
> +	optional => 1,
> +	type => 'string',
> +	pattern => "${PVE::JSONSchema::PVE_TAG_RE}(?:\;${PVE::JSONSchema::PVE_TAG_RE})*",
> +	typetext => "<tag>[;<tag>...]",
> +	description => "List of tags users are allowed to set and delete (semicolon separated).",

maybe add "for 'user-allow' values 'list' or 'existing'"?

> +    },
> +};
> +
>  my $datacenter_schema = {
>      type => "object",
>      additionalProperties => 0,
> @@ -285,12 +311,66 @@ my $datacenter_schema = {
>  	    description => "Tag style options.",
>  	    format => $tag_style_format,
>  	},
> +	'user-tag-access' => {
> +	    optional => 1,
> +	    type => 'string',
> +	    description => "Privilege options for user settable tags",

user-settable

> +	    format => $user_tag_privs_format,
> +	},
> +	'privileged-tags' => {
> +	    optional => 1,
> +	    type => 'string',
> +	    description => "A list of tags that require a `Sys.Modify` on '/') to set and delete. "
> +		."Tags set here that are also in 'user-tag-access' also require `Sys.Modify`.",
> +	    pattern => "(?:${PVE::JSONSchema::PVE_TAG_RE};)*${PVE::JSONSchema::PVE_TAG_RE}",
> +	    typetext => "<tag>[;<tag>...]",

stray 'a' and ')' in first sentence.

I am not sure the second sentence is necessary, or rather, wouldn't it be better
to make the two lists mutually exclusive? e.g., by removing privileged tags from
the other list?

> +	},
>      },
>  };
>  
>  # make schema accessible from outside (for documentation)
>  sub get_datacenter_schema { return $datacenter_schema };
>  
> +# in scalar context, returns the list of allowed tags that exist
> +# in list context, returns a tuple of allowed tags, privileged tags, and if freeform is enabled
> +#

meh, this is a bit ugly, but okay

> +# first parameter is a bool if the user is 'privileged' (normally Sys.Modify on /)
> +# second parameter is a closure which takes the vmid. should check if the user can see the vm tags
> +sub get_allowed_tags {
> +    my ($privileged_user, $can_see_vm_tags) = @_;

couldn't this live somewhere else instead of having this weird interface? e.g.,
guest-common? it's not needed at all for parsing or writing the config, which is
what lives here in this module/repo/package..

the other priv related helper for this already lives there as well..

> +
> +    my $dc = PVE::Cluster::cfs_read_file('datacenter.cfg');
> +
> +    my $allowed_tags = {};
> +    my $privileged_tags = {};
> +    if (my $tags = $dc->{'privileged-tags'}) {
> +	$privileged_tags->{$_} = 1 for $tags->@*;
> +    }
> +    my $user_tag_privs = $dc->{'user-tag-access'} // {};
> +    my $user_allow = $user_tag_privs->{'user-allow'} // 'free';
> +    my $freeform = $user_allow eq 'free';
> +
> +    if ($user_allow ne 'none' || $privileged_user) {
> +	$allowed_tags->{$_} = 1 for ($user_tag_privs->{'user-allow-list'} //
[])->@*;
> +    }
> +
> +    if ($user_allow eq 'free' || $user_allow eq 'existing' || $privileged_user) {
> +	my $props = PVE::Cluster::get_guest_config_properties(['tags']);
> +	for my $vmid (keys $props->%*) {
> +	    next if !$privileged_user && !$can_see_vm_tags->($vmid);
> +	    $allowed_tags->{$_} = 1 for PVE::Tools::split_list($props->{$vmid}->{tags});
> +	}
> +    }
> +
> +    if ($privileged_user) {
> +	$allowed_tags->{$_} = 1 for keys $privileged_tags->%*;
> +    } else {
> +	delete $allowed_tags->{$_} for keys $privileged_tags->%*;
> +    }
> +
> +    return wantarray ? ($allowed_tags, $privileged_tags, $freeform) : $allowed_tags;
> +}
> +
>  sub parse_datacenter_config {
>      my ($filename, $raw) = @_;
>  
> @@ -333,6 +413,19 @@ sub parse_datacenter_config {
>  	$res->{'tag-style'} = parse_property_string($tag_style_format, $tag_style);
>      }
>  
> +    if (my $user_tag_privs = $res->{'user-tag-access'}) {
> +	$res->{'user-tag-access'} =
> +	    parse_property_string($user_tag_privs_format, $user_tag_privs);
> +
> +	if (my $user_tags = $res->{'user-tag-access'}->{'user-allow-list'}) {
> +	    $res->{'user-tag-access'}->{'user-allow-list'} = [split(';',
$user_tags)];

could (warn and?) filter out privileged tags here)

> +	}
> +    }
> +
> +    if (my $admin_tags = $res->{'privileged-tags'}) {
> +	$res->{'privileged-tags'} = [split(';', $admin_tags)];
> +    }
> +
>      # for backwards compatibility only, new migration property has precedence
>      if (defined($res->{migration_unsecure})) {
>  	if (defined($res->{migration}->{type})) {
> @@ -396,6 +489,18 @@ sub write_datacenter_config {
>  	$cfg->{'tag-style'} = PVE::JSONSchema::print_property_string($tag_style, $tag_style_format);
>      }
>  
> +    if (ref(my $user_tag_privs = $cfg->{'user-tag-access'})) {
> +	if (my $user_tags = $user_tag_privs->{'user-allow-list'}) {
> +	    $user_tag_privs->{'user-allow-list'} = join(';', sort $user_tags->@*);

same here

> +	}
> +	$cfg->{'user-tag-access'} =
> +	    PVE::JSONSchema::print_property_string($user_tag_privs, $user_tag_privs_format);
> +    }
> +
> +    if (ref(my $admin_tags = $cfg->{'privileged-tags'})) {
> +	$cfg->{'privileged-tags'} = join(';', sort $admin_tags->@*);
> +    }
> +
>      my $comment = '';
>      # add description as comment to top of file
>      my $description = $cfg->{description} || '';
> -- 
> 2.30.2
> 
> 
> 
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