Changes between Version 1 and Version 2 of ConfigPackageDev

Timestamp:

03/08/13 13:43:19 (12 years ago)

Author:

jdreed

Comment:

--

ConfigPackageDev

@@ -1 +1 @@
 See [http://debathena.mit.edu/config-package-dev/]
+
+
+A brief discussion of the debconf-hack feature:
+
+Primarily developed for zephyr-config to workaround the bug where you choose to use Hesiod (or have DEBIAN_FRONTEND=noninteractive), it pulls in an unconfigured Hesiod, tries to restart zhm, which can't contact any zephyr servers, and exits non-zero, so the postinst fails.
+
+{{{
+$ cat debathena-zephyr-config.debconf-hack 
+zephyr-clients  zephyr-clients/read_conf        boolean true
+zephyr-clients  zephyr-clients/need-servers     note    
+zephyr-clients  zephyr-clients/servers  string  z1.mit.edu z2.mit.edu
+}}}
+
+This snippet is added the the postinst, postrm
+
+{{{
+debconf_get () {
+    perl -MDebconf::Db -MDebconf::Question -e '
+        Debconf::Db->load(readonly => "true");
+        for $label (@ARGV) {
+            if ($q = Debconf::Question->get($label)) {
+                print $q->owners."\t".$q->name."\t".$q->type."\t".$q->value."\t".$q->flag("seen")."\n";
+            } else {
+                print "\t$label\t\t\tfalse\n";
+            }
+        }' -- "$@"
+}
+
+debconf_set () {
+    perl -MDebconf::Db -MDebconf::Template -MDebconf::Question -e '
+        Debconf::Db->load;
+        while (<>) {
+            chomp;
+            ($owners, $label, $type, $value, $seen) = split("\t");
+            @o{split(", ", $owners)} = ();
+            unless ($t = Debconf::Template->get($label)) {
+                next unless ($owners);
+                $t = Debconf::Template->new($label, $owners[0], $type);
+                $t->description("Dummy template");
+                $t->extended_description("This is a fake template used to pre-seed the debconf database. If you are seeing this, something is probably wrong.");
+            }
+            @to{split(", ", $t->owners)} = ();
+            map { $t->addowner($_) unless exists $to{$_}; } keys %o;
+            map { $t->removeowner($_) unless exists $o{$_}; } keys %to;
+            next unless ($q = Debconf::Question->get($label));
+            $q->value($value);
+            $q->flag("seen", $seen);
+            @qo{split(", ", $q->owners)} = ();
+            map { $q->addowner($_) unless exists $qo{$_}; } keys %o;
+            map { $q->removeowner($_) unless exists $o{$_}; } keys %qo;
+        }
+        Debconf::Db->save;'
+}
+}}}
+
+And then the postinst and postrm have:
+{{{
+if [ -f /var/cache/debathena-zephyr-config.debconf-save ]; then
+    debconf_set </var/cache/debathena-zephyr-config.debconf-save
+    rm -f /var/cache/debathena-zephyr-config.debconf-save
+fi
+}}}
+
+The preinst has:
+{{{
+if [ ! -f /var/cache/debathena-zephyr-config.debconf-save ]; then
+    debconf_get zephyr-clients/read_conf zephyr-clients/need-servers zephyr-clients/servers >/var/cache/debathena-zephyr-config.debconf-save
+    debconf_set <<EOF
+zephyr-clients  zephyr-clients/read_conf        boolean true    true
+zephyr-clients  zephyr-clients/need-servers     note            true
+zephyr-clients  zephyr-clients/servers  string  z1.mit.edu z2.mit.edu   true
+EOF
+fi
+}}}