From: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Date: Thu, 19 Oct 2017 19:32:20 +0000 (-0400)
Subject: systemd: drop RefuseManualStart=true, disable kresd.service by default
X-Git-Tag: v1.99.1-alpha~2^2~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a0d93df69e27d5b1b4ca115a66a5fb970746fb3c;p=thirdparty%2Fknot-resolver.git

systemd: drop RefuseManualStart=true, disable kresd.service by default

I introduced RefuseManualStart=true last year when writing the initial
systemd unit file for kresd.  I did this because i didn't want to
start running the daemon if no one was going to talk to it.

I'm no longer convinced that this directive has a good justification.
While i think that there is no need to activate the service without
socket activation, i think preventing manual invocation is actively
harmful (admins will reflexively do "systemctl restart kresd" just
like they do "systemctl restart apache2" and it's jarring to have it
rejected).

A distributor who wants to (by default) delay kresd startup until it
is accessed can ship the preset file included here, but leave the
*.socket units enabled by default.
---

diff --git a/systemd/90-kresd.preset b/systemd/90-kresd.preset
new file mode 100644
index 000000000..ee9934054
--- /dev/null
+++ b/systemd/90-kresd.preset
@@ -0,0 +1,6 @@
+# kresd is fully socket-activated, so it does not need to be enabled
+# in the systemd sense (automatically started at boot).  The
+# associated sockets *are* enabled however, so the kresd service will
+# be started as soon as anything connects to one of the listening
+# sockets.
+disable kresd.service
diff --git a/systemd/README.md b/systemd/README.md
index 8ddbdc17d..daa414da2 100644
--- a/systemd/README.md
+++ b/systemd/README.md
@@ -6,6 +6,11 @@ by systemd (or any supervisor that provides equivalent file descriptor
 initialization via the interface supported by
 sd_listen_fds_with_names(3)).
 
+Distributors of systems using systemd may wish to place
+./90-kresd.preset in /lib/systemd/systemd-preset/90-kresd.preset if
+they want to delay daemon launch until it is accessed. (see
+systemd.preset(5)).
+
 When run in this configuration:
 
  * it will be run under a non-privileged user, which means it will not
diff --git a/systemd/kresd.service b/systemd/kresd.service
index 186126d00..202240136 100644
--- a/systemd/kresd.service
+++ b/systemd/kresd.service
@@ -1,8 +1,6 @@
 [Unit]
 Description=Knot DNS Resolver daemon
 Documentation=man:kresd(8)
-## This is a socket-activated service:
-RefuseManualStart=true
 
 [Service]
 Type=notify