[pve-devel] [RFC manager 3/3] node console: lift root at pam restriction for commands

[Fabian Grünbichler]

instead, fallback to a plain login shell if the current user is not already
root. both current custom commands are effectively a root shell, so it's not
possible to allow them for regular users.

note that the non-login commands via xtermjs already had the fallback behaviour
(i.e., no check for $param->{cmd}) previous to this commit, it was just not
exposed via our web UI, since the corresponding button/wizard was only enabled
for root at pam.

Signed-off-by: Fabian Grünbichler <f.gruenbichler at proxmox.com>
---

Notes:
    RFC because for a nice UX we probably want to somehow display or inject the
    command that should be executed once the user is (effectively) root in the
    console, instead of just opening a login prompt without any indication what the
    user should do with it..
    
    some possible options/suggestions offered so far:
    - let the API return the command in case of fallback, let the UI display it
    -- probably would work best if upgrade is converted to an inline xtermjs
       console, since that supports copy+paste
    - pass FAKE_SHELL to login, point it at a shell wrapper that echos a note with
      the command and then executes the real shell
    - pass FAKE_SHELL to login, point it at a wrapper that runs the command (or the
      command with sudo, in case the logged in console user is not root) with the
      user's real shell
    - wrap/reimplement the login binary to support passing a command to the
      shell (meh)
    
    the first one has the smallest chance of weird side-effects, but it also is
    less convenient (especially compared to the last two)

 PVE/API2/Nodes.pm           | 16 +++-------------
 www/manager6/Utils.js       |  5 +++--
 www/manager6/node/Config.js |  2 +-
 3 files changed, 7 insertions(+), 16 deletions(-)

diff --git a/PVE/API2/Nodes.pm b/PVE/API2/Nodes.pm
index 649735115..2595a0e52 100644
--- a/PVE/API2/Nodes.pm
+++ b/PVE/API2/Nodes.pm
@@ -948,7 +948,7 @@ __PACKAGE__->register_method ({
 	    node => get_standard_option('pve-node'),
 	    cmd => {
 		type => 'string',
-		description => "Run specific command or default to login (requires 'root\@pam')",
+		description => "Run specific command or default to login (only honored for 'root\@pam')",
 		enum => [keys %$shell_cmd_map],
 		optional => 1,
 		default => 'login',
@@ -997,11 +997,6 @@ __PACKAGE__->register_method ({
 	my $rpcenv = PVE::RPCEnvironment::get();
 	my ($user, undef, $realm) = PVE::AccessControl::verify_username($rpcenv->get_user());
 
-
-	if (defined($param->{cmd}) && $param->{cmd} ne 'login' && $user ne 'root at pam') {
-	    raise_perm_exc('user != root at pam');
-	}
-
 	my $node = $param->{node};
 
 	my $authpath = "/nodes/$node";
@@ -1086,7 +1081,7 @@ __PACKAGE__->register_method ({
 	    node => get_standard_option('pve-node'),
 	    cmd => {
 		type => 'string',
-		description => "Run specific command or default to login (requires 'root\@pam')",
+		description => "Run specific command or default to login (only honored for 'root\@pam')",
 		enum => [keys %$shell_cmd_map],
 		optional => 1,
 		default => 'login',
@@ -1216,7 +1211,7 @@ __PACKAGE__->register_method ({
 	    proxy => get_standard_option('spice-proxy', { optional => 1 }),
 	    cmd => {
 		type => 'string',
-		description => "Run specific command or default to login (requires 'root\@pam')",
+		description => "Run specific command or default to login (only honored for 'root\@pam')",
 		enum => [keys %$shell_cmd_map],
 		optional => 1,
 		default => 'login',
@@ -1239,11 +1234,6 @@ __PACKAGE__->register_method ({
 
 	my ($user, undef, $realm) = PVE::AccessControl::verify_username($authuser);
 
-
-	if (defined($param->{cmd}) && $param->{cmd} ne 'login' && $user ne 'root at pam') {
-	    raise_perm_exc('user != root at pam');
-	}
-
 	my $node = $param->{node};
 	my $proxy = $param->{proxy};
 
diff --git a/www/manager6/Utils.js b/www/manager6/Utils.js
index a150e848f..c95873701 100644
--- a/www/manager6/Utils.js
+++ b/www/manager6/Utils.js
@@ -1701,7 +1701,8 @@ Ext.define('PVE.Utils', {
 
     showCephInstallOrMask: function(container, msg, nodename, callback) {
 	if (msg.match(/not (installed|initialized)/i)) {
-	    if (Proxmox.UserName === 'root at pam') {
+	    var caps = Ext.state.Manager.get('GuiCap');
+	    if (caps.nodes['Sys.Console'] && caps.dc['Sys.Modify']) {
 		container.el.mask();
 		if (!container.down('pveCephInstallWindow')) {
 		    var isInstalled = !!msg.match(/not initialized/i);
@@ -1718,7 +1719,7 @@ Ext.define('PVE.Utils', {
 		}
 	    } else {
 		container.mask(Ext.String.format(gettext('{0} not installed.') +
-		    ' ' + gettext('Log in as root to install.'), 'Ceph'), ['pve-static-mask']);
+		    ' ' + gettext('Requires "Sys.Console" and "Sys.Modify" to install.'), 'Ceph'), ['pve-static-mask']);
 	    }
 	    return true;
 	} else {
diff --git a/www/manager6/node/Config.js b/www/manager6/node/Config.js
index 6ed2172aa..a4d10ce0d 100644
--- a/www/manager6/node/Config.js
+++ b/www/manager6/node/Config.js
@@ -248,7 +248,7 @@ Ext.define('PVE.node.Config', {
 		    itemId: 'apt',
 		    upgradeBtn: {
 			xtype: 'pveConsoleButton',
-			disabled: Proxmox.UserName !== 'root at pam',
+			disabled: !caps.nodes['Sys.Console'],
 			text: gettext('Upgrade'),
 			consoleType: 'upgrade',
 			nodename: nodename,
-- 
2.39.2