Move k8s container cleanup to containerd service

This introduces k8s-container-cleanup script that will be called
when containerd.service is stopped. The script detects whether systemd
state is 'stopping' due to shutdown/reboot, then stops all running
containers before the service shuts down.

During shutdown/reboot, some containers are not receiving the
SIGTERM signal. This leads to unexpected behaviour such as
generating huge coredumps.

There is an upstream issue regarding this:
https://github.com/kubernetes/kubernetes/issues/107158
The problem seems to be systemd related but this commit
addresses the problem with a workaround.

This reverts commit f3c18b0f79.
The k8s-container-cleanup script is moved from kubelet.service
to containerd.service. The ExecStopPost that calls this script
is removed, and replaced with ExecStop in containerd.service
to call the script (in config-files repo).

The k8s-container-cleanup script requires containerd is running
in order to use crictl utility. The shutdown of kubelet and
containerd have unpredictable timing, so the cleanup must be done
in containerd.

Test Plan: On AIO-SX
PASS: Verify k8s-container-cleanup logs to daemon.log during 'stopping.
PASS: Manual change containerd/kubelet shutdown timing and verify.
k8s-container-cleanup running to completion before containerd stopped.
PASS: Reboot and verify k8s-container-cleanup running to completion.
PASS: Lock/unlock and verify k8s-container-cleanup running to completion.
PASS: Manually run spellintian tool against k8s-container-cleanup.sh.
PASS: Manually run shellcheck tool against k8s-container-cleanup.sh.
PASS: Zuul tox bashate tool against k8s-container-cleanup.sh.

Partial-Bug: 1964111
Change-Id: Ic8a9e257f861ae218a8520205eced3eaa580dd20
Signed-off-by: Jim Gauld <james.gauld@windriver.com>
This commit is contained in:
Jim Gauld 2022-03-23 16:51:14 -04:00
parent 89aadafae9
commit 169a0c0ee3
7 changed files with 58 additions and 24 deletions

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@ -12,6 +12,7 @@ Source0: containerd-v%{version}.tar.gz
Source1: runc-1.0.2.tar.gz
Source2: crictl-v1.21.0-linux-amd64.tar.gz
Source3: crictl.yaml
Source4: k8s-container-cleanup.sh
Patch1: 0001-customize-containerd-for-StarlingX.patch
Patch2: 0002-CRI-Reduce-clutter-of-log-entries-during-process-exe.patch
URL: https://www.starlingx.io
@ -43,6 +44,7 @@ Provides: containerd.io
%global _missing_build_ids_terminate_build 0
%define local_sbindir /usr/local/sbin
%define CONTAINERD_DIR ${HOME}/go/src/github.com/containerd/containerd
%define RUNC_DIR ${HOME}/go/src/github.com/opencontainers/runc
@ -94,6 +96,8 @@ install -d %{buildroot}%{_sysconfdir}
install -m 644 %{_sourcedir}/crictl.yaml %{buildroot}%{_sysconfdir}/crictl.yaml
install -d %{buildroot}%{_unitdir}
install -p -m 644 %{CONTAINERD_DIR}/containerd.service %{buildroot}%{_unitdir}/containerd.service
install -d %{buildroot}%{local_sbindir}
install -m 755 %{SOURCE4} %{buildroot}%{local_sbindir}/k8s-container-cleanup
# list files owned by the package here
%files
@ -108,3 +112,4 @@ install -p -m 644 %{CONTAINERD_DIR}/containerd.service %{buildroot}%{_unitdir}/c
%{_bindir}/crictl
%{_sysconfdir}/crictl.yaml
%{_unitdir}/containerd.service
%{local_sbindir}/k8s-container-cleanup

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@ -0,0 +1,53 @@
#!/bin/bash
# Copyright (c) 2022 Wind River Systems, Inc.
#
# SPDX-License-Identifier: Apache-2.0
#
# The script will run during containerd.service ExecStop.
# This script detects whether systemd state is 'stopping' due to
# shutdown/reboot, then will stop all running containers before the
# service shuts down.
#
# All running containers are stopped one container at a time.
# The internal implementation of 'crictl stop --timeout <n>'
# sends a SIGTERM to the container, and will use SIGKILL only
# if the timeout is reached.
#
NAME=$(basename "${0}")
# Log info message to /var/log/daemon.log
function LOG {
logger -p daemon.info -t "${NAME}($$): " "${@}"
}
# Log error message to /var/log/daemon.log
function ERROR {
logger -p daemon.error -t "${NAME}($$): " "${@}"
}
state=$(timeout 10 systemctl is-system-running)
RC=$?
LOG "System state is: ${state}, RC = ${RC}."
case $RC in
124)
# systemctl hung.
ERROR "systemctl timed out. System state unknown."
;;
[01])
# 0 - running; 1 - initializing, starting, degraded, maintenance, stopping
if [ "$state" = "stopping" ]; then
LOG "Stopping all containers."
# Use crictl to gracefully stop each container. If specified timeout is
# reached, it forcibly kills the container. There is no need to check
# return code since there is nothing more we can do, and crictl already
# logs to daemon.log.
crictl ps -q | xargs -r -I {} crictl stop --timeout 5 {}
LOG "Stopping all containers completed."
exit 0
fi
;;
esac
exit 0

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@ -13,7 +13,6 @@ ExecStartPre=-/usr/local/sbin/sanitize_kubelet_reserved_cpus.sh /etc/sysconfig/k
ExecStartPre=-/usr/bin/kubelet-cgroup-setup.sh
ExecStartPost=/bin/bash -c 'echo $MAINPID > /var/run/kubelet.pid;'
ExecStopPost=/bin/rm -f /var/run/kubelet.pid
ExecStopPost=-/usr/local/sbin/k8s-container-cleanup
Restart=always
StartLimitInterval=0
RestartSec=10

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@ -13,7 +13,6 @@ ExecStartPre=-/usr/local/sbin/sanitize_kubelet_reserved_cpus.sh /etc/sysconfig/k
ExecStartPre=-/usr/bin/kubelet-cgroup-setup.sh
ExecStartPost=/bin/bash -c 'echo $MAINPID > /var/run/kubelet.pid;'
ExecStopPost=/bin/rm -f /var/run/kubelet.pid
ExecStopPost=-/usr/local/sbin/k8s-container-cleanup
Restart=always
StartLimitInterval=0
RestartSec=10

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@ -13,7 +13,6 @@ ExecStartPre=-/usr/local/sbin/sanitize_kubelet_reserved_cpus.sh /etc/sysconfig/k
ExecStartPre=-/usr/bin/kubelet-cgroup-setup.sh
ExecStartPost=/bin/bash -c 'echo $MAINPID > /var/run/kubelet.pid;'
ExecStopPost=/bin/rm -f /var/run/kubelet.pid
ExecStopPost=-/usr/local/sbin/k8s-container-cleanup
Restart=always
StartLimitInterval=0
RestartSec=10

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@ -1,18 +0,0 @@
#!/bin/bash
# Copyright (c) 2022 Wind River Systems, Inc.
#
# SPDX-License-Identifier: Apache-2.0
#
# The script will run everytime after the kubelet service is stopped.
#
# It will detect any unfinished pod and will try to send them SIGTERM
# within 5s. If it times out, SIGKILL will be sent.
#
state=$(timeout 10 systemctl is-system-running)
if [ "$state" = "stopping" ]; then
crictl ps | cut -d ' ' -f 1 | tail -n +2 | xargs -I {} crictl stop --timeout 5 {}
fi
exit 0

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@ -43,7 +43,6 @@ Source4: upgrade_k8s_config.sh
Source5: sanitize_kubelet_reserved_cpus.sh
Source6: k8s-container-cleanup
Patch1: kubelet-service-remove-docker-dependency.patch
BuildArch: noarch
@ -106,7 +105,6 @@ install -m 700 %{SOURCE4} %{buildroot}/%{local_sbindir}/upgrade_k8s_config.sh
install -m 700 %{SOURCE5} %{buildroot}/%{local_sbindir}/sanitize_kubelet_reserved_cpus.sh
install -m 755 %{SOURCE6} %{buildroot}%{local_sbindir}/k8s-container-cleanup
# install service files
install -v -d -m 0755 %{buildroot}%{_unitdir}
install -v -m 0644 -t %{buildroot}%{_unitdir} contrib/init/systemd/kubelet.service
@ -127,7 +125,6 @@ install -v -p -m 0644 -t %{buildroot}/%{_sysconfdir}/systemd/system.conf.d %{SOU
# the following are execution scripts
%{local_sbindir}/upgrade_k8s_config.sh
%{local_sbindir}/sanitize_kubelet_reserved_cpus.sh
%{local_sbindir}/k8s-container-cleanup
# the following are symlinks
%{_bindir}/kubeadm