[pmg-devel] [PATCH pmg-api 2/2] update KAM.cf in pmg-daily

[Stoiko Ivanov <s.ivanov@proxmox.com>]

KAM.cf provides additional rules for SpamAssassin and is shipped with
proxmox-spamassassin. Since the rules get updated regularly, they should
get updated on a running installation along with the rules provided
by SpamAssassin directly.

The patch adds the functionalilty for downloading KAM.cf to pmg-daily, which
gets run (daily) by `pmg-daily.timer`

LWP::UserAgent's mirror method is used since it adds a 'If-Modified-Since'
header to the request, based on the provided localfile, sets the mtime
to the Last-Modified date and replaces the file only if the download was
successful.

I chose '/var/lib/pmg/spamassassin-extra' for keeping the updated version
to mirror '/usr/share/spamassassin-extra'

Tested the updated template:
* pmg-smtp-filter/SpamAssassin runs if either file is not present
* the file in /var/lib/pmg/spamassassin-extra takes precedence over the
  one shipped in '/usr/share/spamassassin-extra' (tested by locally modifying
  a rule-score)

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
---
 debian/dirs               |  1 +
 src/bin/pmg-daily         | 29 ++++++++++++++++++++++++++++-
 src/templates/local.cf.in |  2 ++
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/debian/dirs b/debian/dirs
index f7ac2e7..55393a8 100644
--- a/debian/dirs
+++ b/debian/dirs
@@ -2,3 +2,4 @@
 /etc/pmg/dkim
 /var/lib/pmg
 /var/lib/pmg/backup
+/var/lib/pmg/spamassassin-extra
diff --git a/src/bin/pmg-daily b/src/bin/pmg-daily
index 32ccb95..011ec25 100755
--- a/src/bin/pmg-daily
+++ b/src/bin/pmg-daily
@@ -19,6 +19,26 @@ use PMG::DBTools;
 use PMG::API2::Subscription;
 use PMG::API2::APT;
 
+# returns 1 if there was a newer version, 0 if not
+sub update_KAM {
+
+    my $kam_url = 'https://mcgrail.com/downloads/KAM.cf';
+    my $kam_local = '/var/lib/pmg/spamassassin-extra/KAM.cf';
+    my $ua = PMG::Utils::lwp_user_agent();
+    $ua->timeout(10);
+    $ua->max_size(1024*1024);
+
+    my $response;
+    eval { $response = $ua->mirror($kam_url, $kam_local); };
+    die "updating KAM.cf failed: $@\n" if $@;
+
+    return 1 if $response->is_success;
+    return 0 if $response->code == 304;
+
+    my $err = sprintf("unexpected response: %s - %s", $response->code(), $response->message());
+    die "fetching KAM.cf - $err\n";
+}
+
 $SIG{'__WARN__'} = sub {
     my $err = $@;
     my $t = $_[0];
@@ -72,13 +92,20 @@ if (my $http_proxy = $cfg->get('admin', 'http_proxy')) {
     $ENV{http_proxy} = $http_proxy;
 }
 
+my $restart_filter = 0;
 # update spamassassin rules
 if (system('sa-update') == 0) {
     # if the exit code is 0, new updates were downloaded
     # then restart the pmg-smtp-filter to load the new rules
-    PMG::Utils::service_cmd('pmg-smtp-filter', 'restart');
+    $restart_filter = 1;
+}
+
+if (update_KAM()) {
+    $restart_filter = 1;
 }
 
+PMG::Utils::service_cmd('pmg-smtp-filter', 'restart') if $restart_filter;
+
 # run bayes database maintainance
 system('sa-learn --force-expire >/dev/null 2>&1');
 
diff --git a/src/templates/local.cf.in b/src/templates/local.cf.in
index 899f970..1a64c78 100644
--- a/src/templates/local.cf.in
+++ b/src/templates/local.cf.in
@@ -27,3 +27,5 @@ score ANY_BOUNCE_MESSAGE [% pmg.spam.bounce_score %]
 
 include /usr/share/spamassassin-extra/KAM.cf
 
+include /var/lib/pmg/spamassassin-extra/KAM.cf
+
-- 
2.20.1