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Bug 1893362: Ensure tail processes exit with parent #859

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merged 1 commit into from Nov 4, 2020
Merged

Bug 1893362: Ensure tail processes exit with parent #859

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8 changes: 7 additions & 1 deletion bindata/network/openshift-sdn/sdn-ovs.yaml
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Expand Up @@ -62,8 +62,14 @@ spec:
if [[ ! -S /run/openvswitch/db.sock ]]; then
systemctl_restart ovsdb-server
fi
# We need to explicitly exit on SIGTERM, see https://github.com/openshift/cluster-dns-operator/issues/65
function quit {
exit 0
}
trap quit SIGTERM
# Don't need to worry about restoring flows; this can only change if we've rebooted
exec tail -F /host/var/log/openvswitch/ovs-vswitchd.log /host/var/log/openvswitch/ovsdb-server.log
tail --pid=$BASHPID -F /host/var/log/openvswitch/ovs-vswitchd.log /host/var/log/openvswitch/ovsdb-server.log &
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Question: why does exec tail ... not exit when it gets a SIGTERM? Shouldn't that always exit? Bash is gone...

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By default in Linux (possibly Unix in general) pid 1 has SIGTERM set to ignore by default... For basically bad reasons this is still the default with pid namespaces; it clearly would have been better to change it but we can't now.

https://vagga.readthedocs.io/en/latest/pid1mode.html
https://hynek.me/articles/docker-signals/
etc.

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OHHHHHHHH. Wow.

wait
else

echo "openvswitch is running in container"
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9 changes: 8 additions & 1 deletion bindata/network/ovn-kubernetes/006-ovs-node.yaml
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Expand Up @@ -75,12 +75,19 @@ spec:
if [[ ! -S /run/openvswitch/db.sock ]]; then
systemctl_restart ovsdb-server
fi
# We need to explicitly exit on SIGTERM, see https://github.com/openshift/cluster-dns-operator/issues/65
function quit {
exit 0
}
trap quit SIGTERM
# Don't need to worry about restoring flows; this can only change if we've rebooted
exec tail -F /host/var/log/openvswitch/ovs-vswitchd.log /host/var/log/openvswitch/ovsdb-server.log
tail --pid=$BASHPID -F /host/var/log/openvswitch/ovs-vswitchd.log /host/var/log/openvswitch/ovsdb-server.log &
wait
else
echo "$(date -Iseconds) - starting ovs-daemons"
chown -R openvswitch:openvswitch /run/openvswitch
chown -R openvswitch:openvswitch /etc/openvswitch
# We need to explicitly exit on SIGTERM, see https://github.com/openshift/cluster-dns-operator/issues/65
function quit {
# Don't allow ovs-vswitchd to clear datapath flows on exit
kill -9 $(cat /var/run/openvswitch/ovs-vswitchd.pid 2>/dev/null) 2>/dev/null || true
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