[pve-devel] [PATCH v4 pve-storage 05/16] cephconfig: align our parser more with Ceph's parser

[Max Carrara <m.carrara@proxmox.com>]

 1. Comments, irrespective of whether they start with '#' or ';' are
    now treated the same. Otherwise, sections and key-value pairs with
    a trailing comment starting with ';' are still parsed. Consider
    this example:

      [some.section] # inline comment after section
      foo = bar ; inline comment after value

     The '[some.section]' section in the example above would otherwise
     not be parsed at all, while in the key-value definition 'foo'
     parses as the key, which is correct, but 'bar ; inline comment
     after value' parses as value, which is incorrect according to
     Ceph's grammar [0][1].

 2. Sections may now contain any character, including whitespace, but
    not '\n' or a comment literal '#' or ';'. The case for comment
    literals is handled in 1. above.

 3. Instead of treating '-', '_' and ' ' as the same, only '_' and ' '
    are treated the same, like in Ceph's parser [2].

 4. Although not crucial for Ceph, our parser now also supports empty
    sections. When a section header is successfully parsed, it gets
    added to the configuration hash and the parser continues operating
    on the next line.

[0]: https://git.proxmox.com/?p=ceph.git;a=blob;f=ceph/src/common/ConfUtils.cc;h=2f78fd02bf9e27467275752e6f3bca0c5e3946ce;hb=refs/heads/master#l178
[1]: https://git.proxmox.com/?p=ceph.git;a=blob;f=ceph/src/common/ConfUtils.cc;h=2f78fd02bf9e27467275752e6f3bca0c5e3946ce;hb=refs/heads/master#l194
[2]: https://git.proxmox.com/?p=ceph.git;a=blob;f=ceph/src/common/ConfUtils.cc;h=2f78fd02bf9e27467275752e6f3bca0c5e3946ce;hb=refs/heads/master#l294

Signed-off-by: Max Carrara <m.carrara@proxmox.com>
---
Changes v1 --> v2:
  * new
Changes v2 --> v3:
  * support comment literals (4.)
Changes v3 --> v4:
  * support empty sections
  * fix and move support for comment literals to separate patch

 src/PVE/CephConfig.pm | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/src/PVE/CephConfig.pm b/src/PVE/CephConfig.pm
index 6b10d46..74a92eb 100644
--- a/src/PVE/CephConfig.pm
+++ b/src/PVE/CephConfig.pm
@@ -10,6 +10,8 @@ cfs_register_file('ceph.conf',
 		  \&parse_ceph_config,
 		  \&write_ceph_config);
 
+# For more details on how Ceph's config parser works, see:
+# https://git.proxmox.com/?p=ceph.git;a=blob;f=ceph/src/common/ConfUtils.cc;h=2f78fd02bf9e27467275752e6f3bca0c5e3946ce;hb=refs/heads/master
 sub parse_ceph_config {
     my ($filename, $raw) = @_;
 
@@ -20,14 +22,18 @@ sub parse_ceph_config {
 
     my $section;
 
-    foreach my $line (@lines) {
-	$line =~ s/#.*$//;
+    for my $line (@lines) {
+	$line =~ s/(?<!\\)(#|;).*$//;
 	$line =~ s/^\s+//;
-	$line =~ s/^;.*$//;
 	$line =~ s/\s+$//;
 	next if !$line;
 
-	$section = $1 if $line =~ m/^\[(\S+)\]$/;
+	if ($line =~ m/^\[(.+)\]$/) {
+	    $section = $1;
+	    $cfg->{$section} = {} if !exists($cfg->{$section});
+	    next;
+	}
+
 	if (!$section) {
 	    warn "no section - skip: $line\n";
 	    next;
@@ -35,11 +41,12 @@ sub parse_ceph_config {
 
 	if ($line =~ m/^(.*?\S)\s*=\s*(\S.*)$/) {
 	    my ($key, $val) = ($1, $2);
-	    # ceph treats ' ', '_' and '-' in keys the same, so lets do too
-	    $key =~ s/[-\ ]/_/g;
+	    # ceph treats ' ' and '_' in keys the same, so lets do too
+	    $key =~ s/ /_/g;
 	    $cfg->{$section}->{$key} = $val;
-	}
 
+	    next;
+	}
     }
 
     return $cfg;
-- 
2.39.2