openrc/init.d/php-fpm.in.in: don't run eselect during sysinit.

OpenRC caches its dependency tree at boot time, before any non-boot
services have started. It does this by sourcing service scripts, which
means that running commands in global scope is dangerous because they
may not be available yet. In bug 910589 we witness this with a call to
eselect in the php-fpm service script, which in turn runs realpath,
and can fail:

  /usr/bin/eselect line 65 /dev/fd/63 No such file or directory
  /usr/share/eselect/libs/path-manipulations.bash: line 66 realpath :
  No such file or directory

Since there are no dependencies for the php-fpm service, and since no
other parts of the service script are cached at that time (source:
prayer), the error is harmless. This commit essentially hides it: we
now check if the RC_RUNLEVEL is "sysinit" and skip the PHP_SLOT
computation if it is.

Signed-off-by: Michael Orlitzky <mjo@gentoo.org>
Bug: https://bugs.gentoo.org/910589

1 files changed, 15 insertions, 3 deletions

diff --git a/openrc/init.d/php-fpm.in.in b/openrc/init.d/php-fpm.in.in
index 3e67e3c..79300b6 100644
--- a/openrc/init.d/php-fpm.in.in
+++ b/openrc/init.d/php-fpm.in.in
@@ -17,9 +17,21 @@
 #
 
 PHP_SLOT="${SVCNAME#php-fpm-}"
-if [ "${PHP_SLOT}" = "php-fpm" ] ; then
-    # Getting the saved slot allows for clean stops when upgrading to a new slot
-    # This will initially be empty on start and fall through to the default
+
+# OpenRC caches service dependencies at boot time (in the sysinit
+# runlevel), before any non-boot services are started. If we try to
+# run eselect then, it can fail, producing a scary error message (bug
+# 910589). For now, the error message is harmless, but we may be
+# relying on an implementation detail to make that claim: it's
+# important that no other parts of this script are cached when its
+# dependencies are. Nevertheless -- for now at least -- we can avoid
+# the error message by skipping the call to eselect in the sysinit
+# runlevel, because our (empty) depend() function does not use
+# PHP_SLOT in any way.
+if [ "${PHP_SLOT}" = "php-fpm" ] && [ "${RC_RUNLEVEL}" != "sysinit" ]; then
+    # Getting the saved slot allows for clean stops when upgrading to
+    # a new slot This will initially be empty on start and fall
+    # through to the default
     PHP_SLOT="$(service_get_value PHP_SLOT)"
     if [ -z "${PHP_SLOT}" ]; then
         PHP_SLOT="$(eselect php show fpm)"