[pve-devel] [PATCH v3 manager 1/3] api: ceph: add endpoint to fetch config keys

[Aaron Lauterer <a.lauterer@proxmox.com>]

This new endpoint allows to get the values of config keys that are
either set in the config db or the ceph.conf file.

Values that are set in the ceph.conf file have priority over values set
in the conifg db via 'ceph config set'.

Expects the --config-keys parameter as a semicolon separated list of
"<section>:<config key>" where the section is a section in the ceph.conf
or config db. For example: global:osd_pool_default_size

Signed-off-by: Aaron Lauterer <a.lauterer@proxmox.com>
---

changes since
v2:
* fixed small typo

v1:
* use kebab-case parameter names
* use kebab-case for the ceph config parameters, which also are returned
  that way
* improve how we parse and merge the config db and ceph.conf file. This
  way though, we dont warn if we cannot find a config key.
* renamed regex to make the distinctions clearer
* dropped 'format => string-list' as it didn't work when leaving out
  [;, ] from the regex. But we don't need both.

 PVE/API2/Ceph/Cfg.pm | 82 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 82 insertions(+)

diff --git a/PVE/API2/Ceph/Cfg.pm b/PVE/API2/Ceph/Cfg.pm
index 2225a1ac..f06c42f4 100644
--- a/PVE/API2/Ceph/Cfg.pm
+++ b/PVE/API2/Ceph/Cfg.pm
@@ -4,6 +4,7 @@ use strict;
 use warnings;
 
 use PVE::Ceph::Tools;
+use PVE::Cluster qw(cfs_read_file);
 use PVE::JSONSchema qw(get_standard_option);
 use PVE::RADOS;
 use PVE::Tools qw(file_get_contents);
@@ -36,6 +37,7 @@ __PACKAGE__->register_method ({
 	my $result = [
 	    { name => 'raw' },
 	    { name => 'db' },
+	    { name => 'value' },
 	];
 
 	return $result;
@@ -110,3 +112,83 @@ __PACKAGE__->register_method ({
 
 	return $res;
     }});
+
+
+my $SINGLE_CONFIGKEY_RE = qr/[0-9a-z\-_\.]+:[0-9a-zA-Z\-_]+/i;
+my $CONFIGKEYS_RE = qr/^(:?${SINGLE_CONFIGKEY_RE})(:?[;, ]${SINGLE_CONFIGKEY_RE})*$/;
+
+__PACKAGE__->register_method ({
+    name => 'value',
+    path => 'value',
+    method => 'GET',
+    proxyto => 'node',
+    protected => 1,
+    permissions => {
+	check => ['perm', '/', [ 'Sys.Audit' ]],
+    },
+    description => "Get configured values from either the config file or config DB.",
+    parameters => {
+	additionalProperties => 0,
+	properties => {
+	    node => get_standard_option('pve-node'),
+	    'config-keys' => {
+		type => "string",
+		typetext => "<section>:<config key>[;<section>:<config key>]",
+		pattern => $CONFIGKEYS_RE,
+		description => "List of <section>:<config key> items.",
+	    }
+	},
+    },
+    returns => {
+	type => 'object',
+	description => "Contains {section}->{key} children with the values",
+    },
+    code => sub {
+	my ($param) = @_;
+
+	PVE::Ceph::Tools::check_ceph_inited();
+
+	# Ceph treats '-' and '_' the same in parameter names, stick with '-'
+	my $normalize = sub {
+	    my $t = shift;
+	    $t =~ s/_/-/g;
+	    return $t;
+	};
+
+	my $requested_keys = {};
+	for my $pair (PVE::Tools::split_list($param->{'config-keys'})) {
+	    my ($section, $key) = split(":", $pair);
+	    $section = $normalize->($section);
+	    $key = $normalize->($key);
+
+	    $requested_keys->{$section}->{$key} = 1;
+	}
+
+	my $config = {};
+
+	my $rados = PVE::RADOS->new();
+	my $configdb = $rados->mon_command( { prefix => 'config dump', format => 'json' });
+	for my $s (@{$configdb}) {
+	    my ($section, $name, $value) = $s->@{'section', 'name', 'value'};
+	    my $n_section = $normalize->($section);
+	    my $n_name = $normalize->($name);
+
+	    $config->{$n_section}->{$n_name} = $value
+		if defined $requested_keys->{$n_section} && $n_name eq $n_name;
+	}
+
+	# read ceph.conf after config db as it has priority if settings are present in both
+	my $config_file = cfs_read_file('ceph.conf'); # cfs_read_file to get it parsed
+	for my $section (keys %{$config_file}) {
+	    my $n_section = $normalize->($section);
+	    next if !defined $requested_keys->{$n_section};
+
+	    for my $key (keys %{$config_file->{$section}}) {
+		my $n_key = $normalize->($key);
+		$config->{$n_section}->{$n_key} = $config_file->{$section}->{$key}
+		    if $requested_keys->{$n_section}->{$n_key};
+	    }
+	}
+
+	return $config;
+    }});
-- 
2.30.2