10343: Add comment about unwieldy ExecStart command.

diff --git a/services/dockercleaner/arvados-docker-cleaner.service b/services/dockercleaner/arvados-docker-cleaner.service
index 466e971fee4fb91714361ef90871bdf6f21b8e29..031058242a21179f15a0ef36ce9456f657811338 100644 (file)
--- a/services/dockercleaner/arvados-docker-cleaner.service
+++ b/services/dockercleaner/arvados-docker-cleaner.service
@@ -9,6 +9,10 @@ Type=simple
 Restart=always
 RestartSec=10s
 RestartPreventExitStatus=2
+#
+# This unwieldy ExecStart command detects at runtime whether
+# arvados-docker-cleaner is installed with the Python 3.3 Software
+# Collection, and if so, invokes it with the "scl" wrapper.
 ExecStart=/bin/sh -c 'if [ -e /opt/rh/python33/root/bin/arvados-docker-cleaner ]; then exec scl enable python33 arvados-docker-cleaner; else exec arvados-docker-cleaner; fi'
 
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